Glocalized Solutions for Sustainability in Manufacturing

Glocalized Solutions for Sustainability in Manufacturing

Jürgen Hesselbach • Christoph Herrmann Editors

Glocalized Solutions for Sustainability in Manufacturing Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011

Editors Prof. Dr.-Ing. Dr. h.c. Jürgen Hesselbach Technische Universität Braunschweig Institut für Werkzeugmaschinen und Fertigungstechnik (IWF) Langer Kamp 19B 38106 Braunschweig Germany

PD Dr.-Ing. Christoph Herrmann Technische Universität Braunschweig Institut für Werkzeugmaschinen und Fertigungstechnik (IWF) Langer Kamp 19B 38106 Braunschweig Germany

ISBN 978-3-642-19691-1 e-ISBN 978-3-642-19692-8 DOI 10.1007/978-3-642-19692-8 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2011924877 © Springer-Verlag Berlin Heidelberg 2011 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: eStudio Calamar S.L. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface „[Sein] Kampf um Klarheit und Übersicht hat ungemein dazu beigetragen, die Probleme, Methoden und Resultate der Wissenschaft in vielen Köpfen lebendig werden zu lassen.“1 1

“[His] struggle for clarity and a comprehensive view has contributed immensely to bring the problems, methods and results of science into life.” Albert Einstein on the 70th birthday of Arnold Berliner. Die Naturwissenschaften (The Science of Nature),Vol.20/51, Springer, Berlin (1932).

Globalization, rapid developments in information technology, fast process- and product innovations, changing market requirements (e.g. environmental policies, increasing energy- and raw material costs) as well as global challenges, as the growing world population and the intensive use of limited resources, determine the surrounding conditions of producing companies in the 21st century. The comprehension for the resulting complex structures of social, political, economic, technical, ecological and organizational coherences increases with growing insights gained from natural sciences and technology. “Sustainable development” describes a way of how the needs of today’s generations can be satisfied without interfering with the possibilities of future generations. In order to follow this path, “ecological” change processes have to take place in society and economy. “Sustainable economies” require innovative products and processes and a life-cycle-oriented way of thinking and acting or rather a way of thinking and acting in terms of systems, i.e. in value chains and -networks embedded in the natural environment. Only by this means the shifting of problems can be avoided and integrated solutions can be created. This way of thinking and acting does not end with the customer, but proceeds up to the disposal of products and handling of materials and products and/or product parts in life cycles. Decisions on the planning and design of products and processes also have to be made in an integrated manner. This means that technical, economic and ecological aspects have to be integrated into one approach. This should be accomplished under a ”cradle-to-cradle” view – from the raw materials extraction up to end-of-life. This view should take into account not only the manufactured products but also the equipment and auxiliary materials which are necessary for production (e.g. machine tools, cooling lubricants). For this year’s conference we chose the theme “Glocalized Solutions for Sustainability in Manufacturing”. The term “glocalization” is a combination of the words “globalization” and “localization”. It was invented to describe a product or service design developed and distributed globally and also adapted specifically to each locality or culture it is marketed in. However, “Glocalized Solutions for Sustainability in Manufacturing“ do not only involve products or services that are changed for a local market by simple substitution or the omitting of functions. We want to address products and services that ensure a high standard of living everywhere. Resources required for manufacturing and use of such products are limited and not evenly distributed in the world. Locally available resources, local capabilities as well as local constraints have to be drivers for product- and process innovations. Thus, “Best of Local” is a starting point for glocalized solutions. This means for example that the availability of fuels based on biomass is a starting point for engine development in Brazil, whereas solar energy is going to be the most important energy source for future electric vehicles in countries of the earth’s sun belt (up to 35 degrees north and south of the equator). While water-based cooling lubricants are developed in Germany, technical animal fats and used edible fats are the basis for the production of cooling lubricants in Spain. Dandelion is used for the production of rubber; thus, car tires develop from renewable resources. The crushed hard shells of fruit stones (e.g. cherry stones) serve as filling material for polymers or are used as technical abrasives for the cleaning of surfaces. Locally accumulating waste streams are locally processed into new products. Thus, old PET bottles are not only recycled into world cup soccer shirts, but also into laptop bags. However, the use of resources is always linked to the environmental impact over all stages of a product life cycle from material extraction, transport and manufacturing to usage and to the end-of-life. Even if a local scope for design is always linked to global impacts, it has the potential to reduce the impact to an ecologically compatible minimum. Future glocalized engineering solutions will have the potential to address global challenges by providing products, services and processes that take into account local capabilities and constraints to achieve an economically, socially and environmentally sustainable society in a global perspective. The CIRP International Conference on Life Cycle Engineering is a platform for this wide and complex field. It will require the efforts of all of us to bring the problems, methods and results of Life Cycle Engineering into life.

Jürgen Hesselbach

Christoph Herrmann

Table of Contents

Preface .....................................................................................................................................................................................................

v

a

Organization ............................................................................................................................................................................................ a

xiii

Keynotes Electricity Metering and Monitoring in Manufacturing Systems ........................................................................................................ S. Kara, G. Bogdanski, W. Li

1

Implementing life Cycle Engineering efficiently into Automotive Endustry Processes ................................................................... S. Krinke

11

Leveraging Manufacturing for a Sustainable Future ........................................................................................................................... D. Dornfeld

17

Sustainability Engineering by Product-Service Systems .................................................................................................................... G. Seliger

22

Solvis Zero-Emission Factory - The 'Solvis way' - Structure and Subject ......................................................................................... H. Jäger

29

Manufacturing and the Science of Sustainability ................................................................................................................................ T. G. Gutowski

32

Indian Solar Thermal Technology – Technology to Protect Environment and Ecology .................................................................. D. Gadhia

40

a

Automotive Life Cycle Engineering Assessment of Energy and Resource Consumption of Processes and Process Chains within the Automotive Sector ............. R. Schlosser, F. Klocke, B. Döbbeler, B. Riemer, K. Hameyer, T. Herold, W. Zimmermann, O. Nuding, B. A. Schindler, M. Niemczyk

45

Assessment of Alternative Propulsion Systems for Vehicles ............................................................................................................ C. Herrmann, K. S. Sangwan, M. Mennenga, P. Halubek, P. Egede

51

Concept and Development of Intelligent Production Control to enable Versatile Production in the Automotive Factories of the Future ................................................................................................................................................................................................. S. U. H. Minhas, C. Lehmann, U. Berger

57

Resource Efficiency – what are the Objectives? .................................................................................................................................. M. Gernuks

63

Comparative Life Cycle Assessment of Remanufacturing and New Manufacturing of a Manual Transmission .......................... J. Warsen, M. Laumer, W. Momberg

67

a

Automotive Life Cycle Engineering - Recycling Coordination of Design-for-Recycling Activities in Decentralized Product Design Processes in the Automotive Industry ....... K. Schmidt, T. Volling, T. S. Spengler

73

A Strategic Framework for the Design of Recycling Networks for Lithium-Ion Batteries from Electric Vehicles ......................... C. Hoyer, K. Kieckhäfer, T. S. Spengler

79

Recovery of Active Materials from Spent Lithium-Ion Electrodes and Electrode Production Rejects ........................................... C. Hanisch, W. Haselrieder, A. Kwade

85

New Technologies for Remanufacturing of Automotive Systems Communicating via CAN Bus ................................................... R. Steinhilper, S. Freiberger, M. Albrecht, J. Käufl, E. Binder, C. Brückner

90

LCM applied to Auto Shredder Residue (ASR) ..................................................................................................................................... L. Morselli, A. Santini, F. Passarini, I. Vassura, L. Ciacci

96

viii

Table of Contents

Life Cycle Design - Methods and Tools Eco-Innovation by Integrating Biomimetic with TRIZ Ideality and Evolution Rules ......................................................................... J. L. Chen, Y.-C. Yang

101

Reasoning New Eco-Products by Integrating TRIZ with CBR and Simple LCA Methods ................................................................ C. J. Yang , J. L. Chen

107

Proposal of an Integrated Eco-Design Framework of Products and Processes ............................................................................... S. Kondoh, N. Mishima

113

Development of CAD System for Life Cycle Scenario-Based Product Design ................................................................................. E. Kunii, S. Fukushige, Y. Umeda

118

Environmental Impact Assessment Model for Wireless Sensor Networks ....................................................................................... J. Bonvoisin, A. Lelah, F. Mathieux, D. Brissaud

124

Considering the Social Dimension in Environmental Design ............................................................................................................. B. Dreux-Gerphagnon, N. Haoues

130

Proposal of an Ecodesign Maturity Model: supporting Companies to improve Environmental Sustainability ............................. D. C. A. Pigosso, H. Rozenfeld

136

Environmental and Operational Analysis of Ecodesign Methods Based on QFD and FMEA ......................................................... F. N. Puglieri, A. R. Ometto

142

Synergico: a new “Design for Energy Efficiency” Method enhancing the Design of more environmentally friendly Electr(on)ic Equipments ......................................................................................................................................................................... L. Domingo, D. Evrard, F. Mathieux, G. Moenne-Loccoz

148

Improving Product Design based on Energy Considerations ............................................................................................................ Y. Seow, S. Rahimifard

154

Eco-Design Tool to support the Use of Renewable Polymers within Packaging Applications ....................................................... J. Colwill, S. Rahimifard, A. Clegg

160

A

Life Cycle Design - Selected Applications State-of-the-art Ecodesign on the Electronics Shop Shelves? A Quantitative Analysis of Developments in Ecodesign of TV Sets ........................................................................................................................................................................................................... C. Boks, R. Wever, A. Stevels

167

Simultaneous Application of Design for Sustainable Behavior and Linked Benefit Strategies in Practice .................................. J. Schmalz, C. Boks

173

Strategic Evaluation of Manufacturing Technologies ......................................................................................................................... G. Reinhart, S. Schindler, P. Krebs

179

Consideration of the Precautionary Principle – the Responsible Development of Nano Technologies ........................................ M. Weil

185

Proposal of a Design Support Method for Sustainability Scenarios 1st Report: Designing Forecasting Scenarios ................... H. Wada, Y. Kishita, Y. Mizuno, M. Hirosaki, S. Fukushige, Y. Umeda

189

a

Sustainability in Manufacturing Evaluating Trade-Offs Between Sustainability, Performance, and Cost of Green Machining Technologies ................................. M. Helu, J. Rühl, D. Dornfeld, P. Werner, G. Lanza

195

Sustainable Production by Integrating Business Models of Manufacturing and Recycling Industries ......................................... C. Jonsson, J. Felix , A. Sundelin , B. Johansson

201

Life Cycle Engineering – Integration of New Products on Existing Production Systems in Automotive Industry ....................... W. Walla, J. Kiefer

207

Managing Sustainability in Product Design and Manufacturing ........................................................................................................ K. Ioannou, A. Veshagh

213

A System for Resource Efficient Process Planning for Wire EDM ..................................................................................................... S. Dhanik, P. Xirouchakis, R. Perez

219

Increased Trustability of Reliability Prognoses for Machine Tools ................................................................................................... G. Lanza, P. Werner, D. Appel, B. Behmann

225

Table of Contents

ix

Hidden Aspects of Industrial Packaging - The Driving Forces behind Packaging Selection Processes at Industrial Packaging Suppliers .................................................................................................................................................................................................. S. S. Casell

229

Applying Functionally Graded Materials by Laser Cladding: a cost-effective way to improve the Lifetime of Die-Casting Dies ........................................................................................................................................................................................................... S. Müller, H. Pries, K. Dilger, S. Ocylok, A. Weisheit, I. Kelbassa

235

A Total Life-Cycle Approach towards Developing Product Metrics for Sustainable Manufacturing .............................................. A. Gupta, A. D. Jayal, M. Chimienti, I. S. Jawahir

240

Carbon Footprint Analysis for Energy Improvement in Flour Milling Production ........................................................................... C. W. P. Shi, F. Rugrungruang, Z. Yeo, B. Song

246

a

Sustainability in Manufacturing - Energy Efficiency in Machine Tools Modelling Machine Tools for Self-Optimisation of Energy Consumption ......................................................................................... R. Schmitt, J. L. Bittencourt, R. Bonefeld

253

Energy-Efficient Machine Tools through Simulation in the Design Process .................................................................................... C. Eisele, S. Schrems, E. Abele

258

Energy Consumption Characterization and Reduction Strategies for Milling Machine Tool Use ................................................... N. Diaz, E. Redelsheimer, D. Dornfeld

263

An Investigation into Fixed Energy Consumption of Machine Tools ................................................................................................. W. Li, A. Zein, S. Kara, C. Herrmann

268

Energy Efficiency Measures for the Design and Operation of Machine Tools: An Axiomatic Approach ...................................... A. Zein, W. Li, C. Herrmann, S. Kara

274

Analyzing Energy Consumption of Machine Tool Spindle Units and Identification of Potential for Improvements of Efficiency ................................................................................................................................................................................................. E. Abele, T. Sielaff, A. Schiffler, S. Rothenbücher

280

a

Sustainability in Manufacturing - Energy Efficiency in Process Chains Energy Consumption as One Possible Exclusion Criterion for the Reuse of Old Equipment in New Production Lines ............. L. Weyand, H. Bley, M. Swat, K. Trapp, D. Bähre

287

Optimizing Energy Costs by Intelligent Production Scheduling ........................................................................................................ A. Pechmann, I. Schöler

293

Methodology for an Energy and Resource Efficient Process Chain Design ..................................................................................... S. Schrems, C. Eisele, E. Abele

299

A New Shop Scheduling Approach in Support of Sustainable Manufacturing ................................................................................. K. Fang, N. Uhan, F. Zhao, J. W. Sutherland

305

Comparison of the Resource Efficiency of Alternative Process Chains for Surface Hardening .................................................... G. Reinhart, S. Reinhardt, T. Föckerer, M. F. Zäh

311

Synergies from Process and Energy Oriented Process Chain Simulation – A Case Study from the Aluminium Die Casting Industry .................................................................................................................................................................................................... C. Herrmann, T. Heinemann, S. Thiede

317

a

Sustainability in Manufacturing - Methods and Tools for Energy Efficiency Context-Aware Analysis Approach to Enhance Industrial Smart Metering ....................................................................................... C. Herrmann, S.-H. Suh, G. Bogdanski, A. Zein, J.-M. Cha, J. Um, S. Jeong, A. Guzman

323

Exergy Efficiency Definitions for Manufacturing Processes .............................................................................................................. Renaldi, K. Kellens, W. Dewulf, J. R. Duflou

329

State of Research and an innovative Approach for simulating Energy Flows of Manufacturing Systems .................................... S. Thiede, C. Herrmann, S. Kara

335

Modular Modeling of Energy Consumption for Monitoring and Control ........................................................................................... A. Verl, E. Abele, U. Heisel, A. Dietmair, P. Eberspächer, R. Rahäuser, S. Schrems, S. Braun

341

Architecture for Multilevel Monitoring and Control of Energy Consumption .................................................................................. A. Verl, E. Westkämper, E. Abele, A. Dietmair, J. Schlechtendahl, J. Friedrich, H. Haag, S. Schrems

347

x

Table of Contents

Sustainability in Manufacturing - Selected Applications Green Performance Map – An Industrial Tool for Enhancing Environmental Improvements within a Production System ......... K. Romvall, M. Kurdve, M. Bellgran, J. Wictorsson

353

Analysis and Quantification of Improvement in Green Manufacturing Process of Silicon Nitride Products ................................ N. Mishima, S. Kondoh, H. Hyuga, Y. Zhou, K. Hirao

359

Evaluation of the Environmental Impact of different Lubrorefrigeration Conditions in Milling of γ-TiAl Alloy ............................. G. Rotella, P. C. Priarone, S. Rizzuti, L. Settineri

365

Quantitative and Qualitative Benefits of Green Manufacturing: an Empirical Study of Indian Small and Medium Enterprises .. K. S. Sangwan

371

Preliminary Environmental Assessment of Electrical Discharge Machining .................................................................................... K. Kellens, Renaldi, W. Dewulf, J. R. Duflou

377

Development of an Interpretive Structural Model of Obstacles to Environmentally Conscious Technology adoption in Indian Industry .................................................................................................................................................................................................... V. K. Mittal, K. S. Sangwan

383

Identifying Carbon Footprint Reduction Opportunities through Energy Measurements in Sheet Metal Part Manufacturing ...... C. W. P. Shi, F. Rugrungruang, Z. Yeo, K. H. K. Gwee, R. Ng, B. Song

389

Sustainable Production Research - a Proposed Method to design the Sustainability Measures ................................................... M. K. Wedel, B. Johansson, A. Dagman, J. Stahre

395

Green Production of CFRP Parts by Application of Inductive Heating .............................................................................................. M. Frauenhofer, S. Kreling, H. Kunz, K. Dilger

401

Saving Potential of Water for Foundry Sand Using Treated Coolant Water ...................................................................................... J. O. Gomes, V. E. O. Gomes, J. F. de Souza, E. Y. Kawachi

407

a

End of Life Management - Reuse and Remanufacturing Modular Grouping Exploration to design Remanufacturable Products ............................................................................................ N. Tchertchian, D. Millet, O. Pialot

413

Development of Part Agents for the Promotion of Reuse of Parts through Experiment and Simulation ...................................... H. Hiraoka, K. Ito, K. Nishida, K. Horii, Y. Shigeji

419

Systematic Categorization of Reuse and Identification of Issues in Reuse Management in the Closed Loop Manufacturing ... T. Sakai, S. Takata

425

Approach for Integration of Sustainability Aspects into Innovation Processes ............................................................................... S. Severengiz, P. Gausemeier, G. Seliger, F. A. Pereira

431

Remanufacturing Engineering Literature Overview and Future Research Needs ............................................................................ Q. Ke, H.-C. Zhang, G. Liu, B. Li

437

a

End of Life Management - Selected Applications Effects of Lateral Transshipments in Multi-Echelon Closed-Loop Supply Chains ........................................................................... K. Tracht, M. Mederer, D. Schneider

443

Development of an Interpretive Structural Model of Barriers to Reverse Logistics Implementation in Indian Industry .............. A. Jindal, K. S. Sangwan

448

Recycling of LCD Screens in Europe - State of the Art and Challenges ........................................................................................... S. Salhofer, M. Spitzbart, K. Maurer

454

End of Life Strategies in the Aviation Industry .................................................................................................................................... J. Feldhusen, J. Pollmanns, J. E. Heller

459

Contribution of Recycling Processes to Sustainable Resource Management ................................................................................. A. Pehlken, K.-D. Thoben

465

Business Issues in Remanufacturing: Two Brazilian Cases in the Automotive Industry ................................................................ O. T. Oiko, A. P. B. Barquet, A. R. Ometto

470

A Systematic Investigation for Reducing Shredder Residue for Complex Automotive Seat Subassemblies ............................... S. Barakat, J. Urbanic

476

Eco Quality Polymers-EQP ..................................................................................................................................................................... C. Luttropp, E. Strömberg

482

Table of Contents

xi

Intelligent Products to Support Closed-Loop Reverse Logistics ....................................................................................................... K. A. Hribernik, M. von Stietencron, C. Hans, K.-D. Thoben

486

The Prospects of Managing WEEE in Indonesia .................................................................................................................................. J. Hanafi, H. J. Kristina, E. Jobiliong, A. Christiani, A. V. Halim, D. Santoso, E. Melini

492

Medical Electrical Equipment - Good Refurbishment Practice at Siemens AG Healthcare ............................................................. M. Plumeyer, M. Braun

497

a

Information and Knowledge Management Sustainable Product Lifecycle Management: A Lifecycle based Conception of Monitoring a Sustainable Product Development ............................................................................................................................................................................................ M. Eigner, M. von Hauff, P. D. Schäfer

501

Semantic Web Based Dynamic Energy Analysis and Forecasts in Manufacturing Engineering .................................................... K. Wenzel, J. Riegel, A. Schlegel, M. Putz

507

Energy Data Acquisition and Utilization for Energy-Oriented Product Data Management .............................................................. T. Reichel, G. Rünger, D. Steger, U. Frieß, M. Wabner

513

Integrating Energy-Saving Process Chains and Product Data Models ............................................................................................. G. Rünger, A. Schubert, S. Goller, B. Krellner, D. Steger

519

Challenges in Data Management in Product Life Cycle Engineering ................................................................................................. T. Fasoli, S. Terzi, E. Jantunen, J. Kortelainen, J Sääski, T. Salonen

525

Business Game for Total Life Cycle Management ............................................................................................................................... S. Böhme, T. Heinemann, C. Herrmann, M. Mennenga, R. Nohr, J. Othmer

531

Requirements Management – a Premise for adequate Life Cycle Design ......................................................................................... S. Klute, C. Kolbe, R. Refflinghaus

537

Towards a Methodology for Analyzing Sustainability Standards using the Zachman Framework ................................................ S. Rachuri, P. Sarkar, A. Narayanan, J. H. Lee, P. Witherell

543

Sustainability through Next Generation PLM in Telecommunications Industry ............................................................................... J. Golovatchev, O. Budde

549

Challenges of an Efficient Data Management for Sustainable Product Design ................................................................................ T. Leitner, M. Stachura, A. Schiffleitner, N. Stein

554

Product and Policy Life Cycle Inventories with Market Driven Demand: An Engine Selection Case Study .................................. H. Grimes-Casey, C. Girata, K. Whitefoot, G. A. Keloeian, J. J. Winebrake, S. J. Skerlos

558

A Case-Study: Finding References to Product Development Knowledge from Analysis of Face-to-Face Meetings ................... B. Piorkowski, J. Gao, R. Evans

564

a

Life Cycle Assessment - Methods and Tools CAD-Integrated LCA Tool: Comparison with dedicated LCA Software and Guidelines for the Improvement ............................... A. Morbidoni, C. Favi, M. Germani

569

Comparison of two LCA Methodologies in the Machine-Tools Environmental Performance Improvement Process ................... M. Azevedo, M. Oliveira, J. P. Pereira, A. Reis

575

Developing Impact Assessment Methods: an Approach for addressing inherent Problems .......................................................... M. Toxopeus, V. Kickert, E. Lutters

581

Developing a Conceptual Framework for UT based LCA .................................................................................................................... J.-M. Cha, S.-H. Suh

587

Towards the Integration of Local and Global Environmental Assessment Methods: Application to Computer System Power Management ............................................................................................................................................................................................ V. Moreau, N. Gondran, V. Laforest Cradle to Cradle and LCA – is there a Conflict? .................................................................................................................................. A. Bjørn, M. Z. Hauschild

593 599

xii

Table of Contents

Life Cycle Assessment - Selected Applications Environmental Assessment of Printed Circuit Boards from Biobased Materials ............................................................................. Y. Deng, K. Van Acker, W. Dewulf, J. R. Duflou Application of Life Cycle Engineering for the Comparison of Biodegradable Polymers Injection Moulding Performance ............................................................................................................................................................................................ D. Almeida, P. Peças, I. Ribeiro, P. Teixeira, E. Henriques

605

611

Using Ecological Assessment during the Conceptual Design Phase of Chemical Processes – a Case Study ............................ L. Grundemann, J. C. Kuschnerow, T. Brinkmann, S. Scholl

617

Environmental Footprint of Single-Use Surgical Instruments in Comparison with Multi-Use Surgical Instruments .................. J. Schulz, J. Pschorn, S. Kara, C. Herrmann, S. Ibbotson, T. Dettmer, T. Luger

623

Comparative Carbon Footprint Assessment of Door made from Recycled Wood Waste versus Virgin Hardwood: Case Study of a Singapore Wood Waste Recycling Plant ....................................................................................................................................... R. Ng, C. W. P. Shi, J. S. C. Low, H. M. Lee, B. Song

629

a

Life Cycle Costing A Target Costing-Based Approach for Design to Energy Efficiency ................................................................................................. A. Bierer, U. Götze

635

Life Cycle Costing Assessment with both Internal and External Costs Estimation ......................................................................... S. Martinez, M. Hassanzadeh, Y. Bouzidi, N. Antheaume

641

Environmental and Economic Evaluation of Solar Thermal Panels using Exergy and Dimensional Analysis ............................. G. Medyna, E. Coatanea, D. Millet

647

Implications of Material Flow Cost Accounting for Life Cycle Engineering ...................................................................................... T. Viere, M. Prox, A. Möller, M. Schmidt

652

a

Life Cycle Costing - Modelling Aircraft Engine Component Deterioration and Life Cycle Cost Estimation ...................................................................................... Y. Zhao, A. Harrison, R. Roy, J. Mehnen

657

Life Cycle Cost Estimation using a Modeling Tool for the Design of Control Systems ................................................................... H. Komoto, T. Tomiyama

663

Assessing the Value of Sub-System Technologies including Life Cycle Alternatives .................................................................... A. Bertoni, O. Isaksson, M. Bertoni, T. Larsson

669

Costing for Avionic Through-Life Availability ...................................................................................................................................... L. Newnes, A. Mileham, G. Rees, P. Green

675

Eco Global Evaluation: Cross Benefits of Economic and Ecological Evaluation ............................................................................. N. Perry, A. Bernard, M. Bosch-Mauchand, J. LeDuigou, Y. Xu

681

A Index of Authors ......................................................................................................................................................................................

687

Organization

CHAIRMEN Prof. J. Hesselbach PD Dr.-Ing. Christoph Herrmann ORGANIZING COMMITTEE Chief Organizers Dipl.-Wirtsch.-Ing. Mark Mennenga Dipl.-Wirtsch.-Ing. Tim Heinemann Organizing Committee Hannah Jule Schäfer, M.A.

Dipl.-Wirtsch.-Ing. Katrin Kuntzky

Dipl.-Ing. (FH) Stefan Andrew

Dr.-Ing. Tobias Luger

Dr.-Ing. Ralf Bock

Dipl.-Chem. Gerlind Öhlschläger

Dipl.-Ing. Gerrit Bogdanski

Anne-Marie Schlake, M.A.

Dr.-Ing. Tina Dettmer

Dipl.-Wirtsch.-Ing. Tim Spiering

Dipl.-Wirtsch.-Ing. Patricia Egede

Dipl.-Wirtsch.-Ing. Julian Stehr

Dipl.-Wirtsch.-Ing. Philipp Halubek

Dipl.-Wirtsch.-Ing. Sebastian Thiede

Dipl.-Ing. Mohamad Jamal Kayasa

Dipl.-Wirtsch.-Ing. Marius Winter

Dipl.-Ing. Michael Krause

Dipl.-Wirtsch.-Ing. André Zein

INTERNATIONAL SCIENTIFIC COMMITTEE Prof. L. Alting / DK

Prof. N. Nasr / US

Porf. C. Boks / NO

Prof. A. Nee / SG

Prof. B. Bras / US

Prof. R. Neugebauer / DE

Prof. D. Brissaud / FR

Prof. A. Ometto / BR

Prof. J. L. Chen / TW

Prof. S. Salhofer / AT

Prof. W. Dewulf / BE

Prof. K. S. Sangwan / IN

Prof. D. Dornfeld / US

Prof. G. Seliger / DE

Prof. J. Duflou / BE

Prof. W. Sihn / AT

Prof. T. Gutowski / US

Prof. S. Skerlos / US

Prof. M. Hauschild / DK

Prof. T. Spengler / DE

Prof. H. Kaebernick / AU

Prof. S. H. Suh / KR

Prof. S. Kara / AU

Prof. J. Sutherland / US

Prof. F. Kimura / JP

Prof. S. Takata / JP

Prof. W. Knight / US

Prof. S. Tichkiewitch / FR

Prof. T. Lien / NO

Prof. T. Tomiyama / NL

Dr. C. Luttropp / SW

Prof. Y. Umeda / JP

Prof. H. Meier / DE

Prof. E. Westkämper / DE

Prof. L. Morselli / I

Prof. H. Zhang / US

Electricity Metering and Monitoring in Manufacturing Systems S. Kara

1, 2

, G. Bogdanski

1, 3

, W. Li

1, 2

1

Joint German-Australian Research Group in Sustainable Manufacturing and Life Cycle Management

2

Life Cycle Engineering & Management Research Group, School of Mechanical & Manufacturing Engineering, The University of New South Wales, Australia

3

Institute of Machine Tools and Production Technology (IWF), Product- and Life-Cycle-Management Research Group, Technische Universität Braunschweig, Germany

Abstract Traditionally, electricity costs in manufacturing have been considered as an overhead cost. In the last decade, the manufacturing industry has witnessed a dramatic increase in electricity costs, which can no longer be treated as an overhead, but a valuable resource to be managed strategically. However, this can only be achieved by strategically gathering electricity consumption data by metering and monitoring. This keynote paper presents the latest developments and challenges in electricity metering and monitoring systems and standards in the context of manufacturing systems. An industry case is presented to emphasise the challenges and the possible solutions to address them. Keywords: Manufacturing Systems; Energy Efficiency; Metering and Monitoring

1

INTRODUCTION

Global warming and its disastrous environmental and economic effects are considered as one of the major challenges that today’s and future generations have to face during the 21 century. One of the main attribute of this challenge is due to the environmental impact e.g. Green House Gas (GWP) emission, caused during the generation of electricity from fossil fuels [1]. Therefore, one of the possible ways to reduce GWP emission is to reduce the electricity consumption, which is also enforced by national and international initiatives, e.g. Kyoto agreement. In addition, industry has a high interest in reducing the energy consumption, because energy has become a major cost driver, especially for high technology industries with their energy intensive manufacturing processes. Energy cost has long been treated as a necessary overhead cost for creating value-added products. However, more and more industrial companies are consciously shifting towards treating energy as a valuable resource, which needs to be planned and managed as a variable input for their plant. A necessary prerequisite for such energy-conscious behaviour is to be able to systematically measure energy consumption in a manufacturing plant. One of the challenges plant managers facing today is to gain transparency inside complex energy distribution networks of their manufacturing plants. A fundamental prerequisite for achieving this transparency is primarily to meter the consumed energy and its related characteristics in time. In order to gain full awareness, the metered physical values need to be monitored, interpreted and visualized in plant management systems. Electrical energy is in high favour of industry because it can easily be converted into many lower energy forms such as heat, light, compressed air, mechanical torque and many others. Consumption of electrical energy, in comparison to other energy forms, can be measured easily and precisely. Therefore, other energy forms are usually converted by sensors and transducers into electrical signals which themselves can be picked up by standard procedures of electrical signal metering techniques. In this paper the evolution and the latest development in electricity

metering and monitoring technologies are first introduced. A rapid development in measurement instruments requires up-to-date standards in order to compare and select appropriate device. After giving an overview about the most relevant international and national standards, the potentials of electricity metering and monitoring in manufacturing plants are illustrated and technical requirements for metering and monitoring systems are presented. The most important aspects that need to be considered when designing metering strategies are highlighted with a case study from an Australian manufacturing company. 2

EVOLUTION OF MONITORING

ELECTRICITY

MEASUREMENT

AND

Since the introduction of electricity distribution grids, there has been a demand for devices to measure the energy consumption in order to assist suppliers for distributing, pricing and monitoring their service. As early as during the 1880s, companies were authorized to sell electricity. One of the first patents for an electricity meter had been taken out by Pulvermacher in 1868 for an electrolytic meter [2]. Besides the electrolytic meters, there were other early inventions for measuring electricity, for instance thermal meters, clock meters and motor meters. In 1884 the Aron Meter Co. started selling the first meters of the true dynamometer type electricity meter patented by Hermann Aron. They were considered to have the highest degree of accuracy of the available meters at that time. As one form of the motor meters, the induction meter (Ferraris disc meter), had emerged to meet the needs of the emerging multiphase generation and transmission of electric power for high precision Alternating Current (AC) meters. The induction meter is still in general use today but is reaching its limits of accuracy and lacking ability to communicate its metering values. Recent developments try to meet the demands of the evolving smart grid technology calling for multi-value measurement and bi-directional communication ability [3]. The advances in semiconductor technology have led to the technological overrun of bulky electromechanical meters by smaller dimensioned, solely electronic metering devices by the early 1990s. By removing all complex

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_1, © Springer-Verlag Berlin Heidelberg 2011

1

2

Keynotes

analogue/digital converter circuitry for the basic measurements such as current and voltage



multiplier for the instantaneous measurement values



time to frequency converters for voltage and current [6].

The overall structure of measuring elements of electronic meters is basically the same. However, the applied measurement techniques are, in contrast to electromechanical metering systems, very different. The multiplication of voltage and current for example can be done by a hall multiplier, a time division multiplier or digital multiplier [5-6]. Providing at least the same functionality as hybrid meters the electronic meters aim at offering extended information to the user. This is done through digital signal processing by means of microprocessors or customized integrated circuits. The digital circuitry can perform time accurate calculation of active, reactive, apparent energy and power factor as well as frequency and harmonic distortion metering with many mathematical functionalities such as averaging, min/max detection, integration and accumulation [4, 6]. All performed metering is provided to serve for billing and controlling of the supplied and used electrical energy. The application of different measurement principles and individually designed integrated circuitry in metering devices calls for national and international standards to allow users to verify their metered value in accordance to approved limitations. As an example for international standards, the IEC 62053 and the ANSI C12.20 mandates the accuracy of static watt-hour meters and have defined four different classes: class 2, class 1, class 0.5 and class 0.2 (e.g. class 0.5 requires a repeatable meter precision of 0.5% of nominal current and voltage) [7-8]. The revised German VDE 0410 had even clustered these classes into utility measurement ranging from class 1 to class 5 and into precision measurement ranging from class 0.1 to class 0.5 for directly indicating metering devices with a scale. The VDE 0410 has been overworked in the IEC 60051, within a much more comprehensive international standard for direct acting analogue electrical measuring instruments [9-10]. The electrical meters measurement chain is subject to an error of the measurement chain, expressed in the accuracy G, indicated by the class and enabling the user to calculate the limitations of maximum and minimum deviation ∆x inside a given metering measurement range xmax-min of the instrument

∆x = G xmax-min / 100%.

(1)

Current digital electricity meters available on the market already claim to some extent, to meet the accuracy limitation of 0.1% or

PURPOSE OF ELECTRICITY MONITORING IN INDUSTRY

MEASUREMENT

AND

Electricity metering and monitoring in industrial applications address a wide range of applications, which can be divided into three broad levels of application: 

Factory Level



Department Level



Unit Process Level.

In general, from the customer perspective, metering and monitoring of electricity in industry applications is done to gain transparency into electricity billing, internal electricity distribution and energy controlling. Each of the three stated levels above contains its own set of technical requirements concerning the metering equipment and the attached monitoring system. They also have their own associated potential benefits and degree of transparency requirement from the application of electricity metering and monitoring. Figure 1 shows a factory from an electricity consumer perspective with all its organisational sub-consumers within the three levels. Transparency gains through electricity metering and monitoring

Organizational level structure

• energy billing • energy contract •…

Factory

• energy accounting • identify hot-spots • transparency of energy flow within the factory • …

• energy modelling • process simulation • machine efficiency redesign • ...

Factory



3

Department 1

Machine 1

…

Department n

SubDepartment 1.1

...

SubDepartment n.1

SubDepartment 1.m

…

SubDepartment n.m

…

Machine i

Periphery System 1

…

Department

For simple kilowatt-hour metering the electromechanical meters such as Ferraris disc meters, are still considered to be the most economical solution because of its extremely long life and durability [5-6]. The metering industry has been trying to lengthen the technology life of the predominant electromechanical technology by using hybrid solutions, e.g. adding electronics to the present devices, to fulfil additional functions like maximum demand calculations as demanded by today’s suppliers to price industry and medium to large sized commercial electricity customers [6]. With the help of add-on electronics, hybrid meters can provide their users various other functions such as multi-rate registers, seasonal registers, historical value registers, maximum demand, and consumptions threshold definition. The inevitable next step in the evolution of electricity meters is the electronic meters. In contrast to electromechanical meters different principles are used to measure the basic values of electricity, from which all other values of interest are usually derived by means of electronic calculation. Basic elements for each power phase are:

lower, causing buyers to be confused because there is no existing international standard of 0.1% accuracy which a manufacturer could claim compliance to [11]. Therefore, standards need to keep up the pace of technological innovation in order to ensure that metering equipment buyers are able to compare and benchmark claimed accuracy by providing manufacturers a specified set of tests over the whole range of operation conditions of load current, power factor, temperature and harmonic distortion.

Unit Process

moving mechanical parts, the electronic meters are able to house multi-sensors within highly integrated circuits [4].

Periphery System j

Figure 1: Three levels of a factory as a consumer of electricity. The most important fact that needs to be stated is that the organisational structure rarely complies with the technical electricity distribution network, which brings additional challenges during department level electricity metering and monitoring which will be discussed later. What all three levels have in common in relation to metering electricity is the basic measurement values that all other specific information can be mathematically driven from: voltage and current with respect to time. For instance, in a general 3 phase system, the total active power PW tot can be calculated as:

PW tot = PW1 + PW2 + PW3

(2)

= U1N eff I1 eff cos φ1 + U2N eff I2 eff cos φ2 + U3N eff I3 eff cos φ3.

(3)

Keynotes

3

Where φn is the phase angle between the current In and the voltage Un of the n-th phase. In 2-phase-systems it is theoretically possible to meter only two lines because one line can be seen as the neutral. Nevertheless, it is often seen that 3-phase-systems are also equipped with three separate power meters to monitor three phases and to ensure a higher accuracy of the metering result, especially at low powers and high phase angles [12]. The accuracy of a measurement is therefore always directly related to the accuracy of the current and voltage measurement error and needs to be calculated accordingly. (a)

I1

(b)

K

L

k

l

U

V

u

v

I2

Figure 2: Current (a) and voltage (b) transformer circuits [12]. Usually a galvanic isolation, as depicted in Figure 2, is used in the current and voltage meters to prevent them from accidental overload from harming the sensitive metering equipment. The most widespread application to realize a galvanic isolation is a simple current and voltage transformer which is going into saturation if an overload is applied on the primary windings. The secondary windings are short circuited by the current meter. The transformation rate is generally dimensioned to conduct 1 or 5 A (current meter) and 100 V (voltage meter) on the secondary windings. The transformers are also regarded as part of the measuring chain and are also adding their own error in terms of accuracy limitation to the total measurement system. The IEC 60044-1 is dealing with the technical requirements of current transformers for instruments as well as their indicated accuracy classes [13]. Assuming a normal distribution of the measurement errors of the components, the total measurement systems accuracy Gtot is calculated as considering the accuracy levels of the transformer Gtrans and of the instrument Ginst:

Gtot = ( Gtrans2 + Ginst2 )1/2.

(4)

The error of a current transformer is actually consisting of a basic error, which can be very low in a good technically designed transformer, and an angular error, which is highly dependent on the applied apparent current burden [12]. The following section will

present a more specific view on the potential gains from metering and monitoring applications on the three organizational levels. Recent publications show, that the industrialized countries are facing a multidimensional pressure from the economical, ecological as well as legislative side to shift their field of actions more towards energy and resource efficient processes and structures within their company, their products and their services to stay competitive in the global market environment. 3.1

Factory Level

The electricity metering and monitoring on factory level is done on the interface between the electricity supplier and the consumer (factory inlet). Electricity is an energy resource that is demanded by the manufacturing industry ever since the light bulb was invented and the establishment of the electricity industry in the late nineteenth century. With the rising demand, quality and the continuity of the supply have become a serious concern [14]. As a result, today’s electricity grid and the supply of electric voltage are standardized within different regulations. For instance in Europe, the EN 50160 written by the European Electrotechnical Standards Body CENELEC is used [15]. The EN 50160 address the electric voltage as a good and the quality has to be ensured in the provision to the customer. Otherwise the customer would be able to claim a better product quality from the supplier. Electricity is a very unique product, being produced, delivered and used at the same instant of time [14]. Due to a high level of dependence on electric voltage supply, the industry and the public have to be sure that they can operate their electrical equipment without incurring additional capital expenditures due to a lack of quality in the electricity supply from the low (LV) and the medium voltage (MV) grids. The voltage quality can be imagined as the usability of electrical energy without interruptions. The subject of voltage quality is becoming more and more important in highly developed countries, because of the increased use of applications, which are very sensitive to disturbances of the voltage amplitude or of the voltage wave shape [16]. In order to check the quality of the electrical voltage supplied to the customer according to the given characteristics of the EN 50160, metering equipment suitable for that task needs to be deployed. Table 1 lists an extract of specifications from EN 50160 that brings in another important aspect of modern digital electricity meters – the resolution in time [4]. A high resolution of metering data can be ensured by a high sampling rate of the analogue-digital circuitry and a short settling time of any analogue components like the current and the voltage transformers and the amplification circuits.

Acceptable limits

Measurement Monitoring period interval

Grid Frequency

49.5 Hz to 50.5 Hz, 47 Hz to 52 Hz

10 s

1 week

Slow Voltage Changes

230 V ±10%

10 min

1 week

Voltage Sags or Dips (≤ 1 min)

10 to 1000 times per year (under 85% of nominal)

10 ms

1 year

Short Interruptions (≤ 3 min)

10 to 100 times per year (under 1% of nominal)

10 ms

1 year

Accidental, long interruptions (> 3 min)

10 to 50 times per year (under 1% of nominal)

10 ms

1 year

Temporary Overvoltages (line to ground)

Mostly < 1.5 kV

10 ms

-

Transient Overvoltages (line to ground)

Mostly < 6 kV

-

-

Voltage Unbalance

Mostly 2%, but occasionally 3%

10 min

1 week

Harmonic Voltages

8% total harmonic distortion (THD)

10 min

1 week

Supply voltage phenomenon

Table 1: Summary of electricity specifications from EN 50160 and related measurement intervals from Shtargot [4].

4

Keynotes

On the factory level, several aspects of the electric energy are essential to be metered in order to gain the certain state of transparency of the factory’s energy consumption from a holistic perspective [17-18]. Table 2 lists a summary of possible cost factors based on the electricity consumption on the factory level and possible potential benefits that can be achieved by gaining a certain level of transparency through metering key values such as listed in Table 1. By using a simple initial monitoring and controlling of consumption the electricity consumer will be able to address the problems on time and not retrospectively after receiving the bill. Electricity metering and monitoring on the factory level enables the consumer to check the quality characteristics of the supplied product and enables him to gain an important amount of transparency for time dependent controlling of energy consumption. Factory level: Cost factors

Total energy consumed, peak power demand, power factor limitation, THD feedback

Potential benefits enabled through electricity metering

Adaption of the electricity supply contract; preventing of peak charges through rescheduling of processes or events

Table 2: Cost factors and potential benefits through electricity metering and monitoring on factory level. 3.2

Department level

The department level structure usually consists of n departments which can show the functional units of the factory. Table 3 shows the major cost factors concerning electricity and related potential benefits through electricity metering and monitoring on department level. Department level: Cost factors

Specific energy consumed, peak power demand, power factor limitation

Potential benefits enabled through electricity metering

Energy intensive process scheduling; ability to deploy and track continuous improvement measures; department based energy saving targeting and benchmarking; simulative improvement of energy costing; effective utilization of secondary energy carriers produced by electricity; quantify energy savings

Table 3:

Cost factors and potential benefits through electricity metering and monitoring on department level.

The contents of Table 3 comply very much with the goals of smart metering and energy accounting, known from private households. The main goal is to try shortening the informational feedback time from the consumption of energy to the moment of billing [19]. For industry the simple monitoring is already a big leap forward to raise the corporate awareness and to motivate each individual to minimize their own share of energy consumption and their related costs. This will also lead to putting some effort into reducing their individual energy consumption without just shifting consumption from one individual consumer to the other. It has been shown that an extended holistic process and system understanding is beneficial in order to increase energy and resource efficiency measures in manufacturing sites. This is due to the fact that many sub-systems are interlinked and have indirect or direct coupled energy consumption, which are not obvious at first

sight and can cause a problem shift if efficiency measures are only applied from a narrow point of view [20]. Several researchers have already stated the basic need for reliable energy consumption data for a successful development towards more energy efficient processes and factories e.g. by use of software tools (energy aware process chain simulation, LCI of manufacturing process chains, evaluation of machine tool configuration) [21-24]. Some even put a special focus on the energy aware upper level planning and control of production, which can be defined as an interface between all three levels of a factory [25-26]. Some researchers have even tried to break down the assessed energy of the whole factory in order to allocate it to one product manufactured at the site, stating that a more efficient monitoring and control of energy used in infrastructure and technical services can help to optimise the plant level activities [27]. When planning and ultimately deploying an electricity metering and monitoring concept in a factory, it quickly becomes obvious that the electrical distribution network structure inside a factory highly varies from a simple organisational structure. This makes setting-up of a consistent metering network with proper upper level monitoring quite challenging. Especially, when the department structures are being monitored with the purpose of energy accounting based on organizational structures, the complexity of the deployed metering strategy increases dramatically. 3.3

Unit process level

Unit process level of electricity metering and monitoring is considered as the lowest hierarchical type of metering point selection. Meters are directly attached to single machines or machine components (e.g. auxiliary pumps, ventilation systems) and peripheral units such as decentralized coolant treatment or decentralized compressed air production systems. On this lowest level the most detail of electrical energy consumption can be obtained [17]. Direct monitoring of single machines may be required for energy optimized production planning around highly energy intensive processes or to conduct a deeper understanding of the energy flow distribution onto sub-components of production machines or to better understand the energetic coupling of in-line production processes [24, 28-30]. Table 4 shows the major cost factors concerning electricity and related potential benefits through electricity metering and monitoring on unit process level. Unit process level: Cost factors

Specific Energy Consumption (SEC), peak power demand, power factor limitation, THD feedback

Potential benefits enabled through electricity metering

Supplementing unit process values to machine LCI databases; energy forecasting in production design, process planning and control; energy labelling of machine tools and products; specific quantification of single efficiency measures; evaluation of technical improvements; condition monitoring as a prophylactic measure in energy and resource sufficiency

Table 4: Cost factors and potential benefits through electricity metering and monitoring on unit process level. Other publications utilized electricity metering and monitoring on unit process level by using energy and time studies to assess the specific environmental and economic impact of particular production processes which can then be used to build Life Cycle Inventory (LCI) databases [31-32].

Keynotes

5

In addition to impact assessment and efficiency improvements as planning tools, electricity metering and monitoring can also be used for condition monitoring and diagnostics of machines and processes. This enables to prevent energy and resource losses ahead of time such as tool changes, planning of maintenance cycles as well as early detection of tool wear. The international standard such as ISO 13374-1, are helping users to implement such established measures [33]. Others have also demonstrated additional benefit by combining electricity metering and monitoring data with machine control data (e.g. from programmable logic controllers) to gain beneficial additional transparency into process specific environmental impact assessment [34-35]. 4

GUIDELINE FOR ELECTRICTY MONITORING IN MANUFACTURING

METERING

AND

Rohdin and Thollander have listed in detail the barriers that especially non-energy intensive manufacturing companies are confronted with, when being faced by a decision to actually go for energy efficiency assessments and measures [36]. The study indicated that responsible staff often fears the interruption of production processes, the lack of insufficient sub-metering in the company structure to quantify and assess implemented efficiency measures and some even face a lack of technical skill to put metering and monitoring into action. Occupational Health and Safety is also critical in use and selection of measurement instruments. The IEC 61010-1 declares the general safety requirements for electrical test and measurement equipment for electrical industrial process control and laboratory equipment [37]. For easier recognition of suitable devices, the standard defines four categories (CAT I, II, III and IV) indicating the specified area of usage for the specific instrument (ranging from measurement in circuits not directly connected to the network up to measurement on overvoltage protection devices). To ensure a true comparability of measurement instruments brought into the market in the European Union, the European Parliament has issued the directive 2004/22/EC, also known as the MID [38]. The MID and related European and international standards like the IEC 60359 ensure a proper indication of performance criteria, basic functional requirements, which are a common way to indicate measurement ranges and limitations of uncertainties of measurement as well as indication of calibration results [39]. Various metering instruments and monitoring solutions are available on the market, which are able to fulfil the requested task of the user. Therefore, the challenge of the user is to define the task. Although, researchers like Schleich have already identified that a lack of information about energy consumption patterns has been found to be a barrier for energy efficiency, which can be overcome by installing metering devices and implementing energy management systems [40]; the biggest difficulty is in fact to define and execute the corresponding metering strategy. Designing a metering strategy incorporates the definition of a metering task, the goal which also describes the characteristics of the resulting measurement in terms of accuracy and resolution. A metering strategy also implies an estimation of the expected value to be metered in order to dimension the metering equipment accordingly. An over or under dimensioned metering system can result in a low accuracy and high variance of the metered value or even an overload situations with fatal errors. Only a few publications are seen in the community of manufacturing engineering that actually address how electricity metering of single devices is actually performed and which measurement instruments are recommended to be used [41].

In the following sections of the paper a guideline for electrical energy metering and monitoring will be presented. Technical and economical challenges will be addressed and specific ranges of technical specifications suitable for the three defined levels of application will be suggested. The decision of selecting suitable measurement instruments always depends on the minimum requirements due to the defined task and the economic aspect as a limiting factor for the upper range of requirements. Technical challenges: Electricity metering instruments are designed to cover a lot of measurement purposes. Some have been developed for highly accurate and real time monitoring like oscilloscopes and others have been designed to suit a variety of tasks such as multi-meters for network quality analysis. Each one of the instruments has different technical specifications that the user has to be aware of before making the purchasing decision. Against each task required, individual set of technical specifications need to be clarified by formulating a measurement strategy while giving certain ranges of specifications of the informational degree. Economical challenges: Selecting the most cost-effective metering solution requires a clear vision of the required outcome. More available options and features are always more expensive and are a quick step towards over-dimensioning. The economical challenges of each level provide some considerations that inevitably come with designing a measurement strategy and implementing electricity metering and monitoring. Factory Level: Selecting the right accuracy class is essential to be able to control electricity billing. Technical challenges: Factory level metering is done on or near the interface between the electricity supplier and the customer. The installed meters from the supplier in industry applications are usually electronic meters that do not simply meter the energy consumption in kilowatt-hours but additionally use certain register intervals in which the specific amount of energy is accumulated. For instance, the register interval in Germany is fixed to 15 minutes, which means the resulting accumulated 15 minute energy is used to charge peak loads in individual electricity supply contracts for industry consumers. The register values from the electronic meters are collected by the supplier by using remote instrument reading. The MID as well as the IEC 62053 enable the customer to select appropriate metering instruments to meter with a higher accuracy and in higher temporal resolution. As a result, breaking down the 15 minute standard register interval from the supplier to 30 second intervals can be used to gain transparency into how 15 minute peak charges occur and be a first step towards evaluation of whether load management could be used to lower the charges. Economical challenges: The investment for metering equipment on this level is considered low since only a few meters (at least one at each medium voltage transformer inlet) are needed. The resulting data volume is considered negligible. Despite this, the selection of the metering instrument is not a simple task. Scientific discussions from the early nineties up until now have stated that higher levels of sophistication in electricity metering will be essential to prepare the suppliers and customers for the inevitable utilization of the smart grid [42-43]. It should be kept in mind that the consumed amount of kilowatt-hours is not the only number that is of interest for the electricity suppliers. There are other parameters such as current, voltage, apparent power and their specific behaviour in time that demands costly improvements and maintenance actions in the distribution networks. Therefore, it might be in the interest of the customer to know in advance about these parameters in order to have transparency into energy billing. The selection of a metering device with the capability to meter active power, apparent power, power factor and the total harmonic

6

Keynotes

distortion as a quality parameter with a temporal resolution of 30 seconds up to 15 minutes with accuracies complying with the standards described earlier (as well as with the local requirements of the state legislations) is highly recommended as a quality parameter. The amount of data collected from one metering device in standard office applications will result in a data volume ranging from 280 megabytes to 8.2 gigabytes per year (depending on the selected resolution). Department level: Metering on department level is done to gain a better transparency of the energy flows inside the organisational and the technical distribution network of the factory. A certain degree of transparency enables organisational and technical energy efficiency measures. The metering strategy and the related challenges in the selection of metering equipment on department level are highly dependent on the consumption behaviour of the single substructures. This paper draws a distinction between highly dynamic behaviour, low dynamic behaviour and near static behaviour as addressed in Table 5. Highly dynamic energy consumption behaviour can be found in assembly or production departments or single lines with several inline processes and machines that perform highly variable processes. As a result, energy demand from the grid is highly variable as well. Low dynamic consumption behaviour can be found in technical building services and are represented by processes like compressed air production, technical air ventilation or facility heating. Near static consumption behaviour can be found in office complexes or in server rooms. These substructures show distinct periodic cycles over days or weeks while being not very prone to sudden changes or peak demands.

Department

Technical challenge: Table 5 presents recommendations for metering specifications for different metering strategies on department level related to the dynamic consumption behaviour of the regarded department. The recommended temporal resolution of the output data of the electronic metering devices are linked with the dynamic behaviour. A high dynamic behaviour needs high resolutions of the metering output data in order to achieve certain transparency and a satisfactory understanding of the consumption behaviour of the department. Behaviour

Resolution

Parameters

Highly dynamic

1 s – 1 min

Wh, VAh, PF

Low dynamic

30 s – 5 min

Wh, VAh, PF

Near static

1 min – 30 min

for high dynamic metering tasks, would result in a yearly data volume of 256 gigabyte (raw data) if three parameters (active power, apparent power and power factor) are logged continuously. Each sub meter added to the metering and monitoring structure adds its part of the data volume share that needs to be handled by the data processing system. The measurement instruments itself will also play a considerable role in the economical challenge. Measurement instruments with high accuracy classes and capabilities to meter THD and PF characteristics are usually too expensive to be distributed on department level metering applications. However, more and more, ultra low cost power quality meters and energy management systems with class A IEC 610004-30 compliance are emerging which will make electricity measurement possible on this level in the near future [44]. In fact, electricity metering and monitoring on department level can actually pay off very quickly as shown in a case study by Stephenson and Paun. The authors demonstrated how a small manufacturer was able to shift and reschedule some of his manufacturing machines to avoid peak charges, and power factor charges by soft starting controls for machine start-ups on Mondays and deferring electrical consumption on activities like energy intensive drying processes or chilled water production by less than two hours without affecting production requirements [45]. Unit process level: On unit process level the single process, machine, or component is being metered and monitored. As mentioned above, it might be needed to do unit process metering in applications considered as department level metering and monitoring, but the actual unit process metering is mostly considered to be research related or only short term metering rather than continuous. In the scientific community unit process metering and monitoring are often found throughout many case studies. Solding et al. have used metering data of unit processes to accumulate the fundamental data basis for energy aware production simulation in various degrees of detail [46]. Considering consumption profiles from products Elias et al. have shown the importance of electricity metering in order to evaluate the user behaviour’s influence on the product’s electric energy consumption [47]. Whereas Dietmair et al. have used electricity metering and monitoring on unit process level to analyse and evaluate machine tool design strategies to foster energy efficiency [48]. Li et al developed an empirical approach to model and predict unit process energy consumption for material removal processes [49].

Wh, PF Behaviour

Economical challenge: The department level metering has probably the highest variety of possible economic impacts that tend to be very case specific. However, general propositions can still be made to address the challenges. Metering on department level is often used to do energy accounting for a fixed sub structure, which can be an organisational structure (department), a production line for a specific product or a storage area. Each one of these clusters of defined sub consumers is drawing electricity from the internal distribution network. Since organisational structures and technical structures are mostly not same due to the building design, the consumer clusters might not be situated in the same branch of the distribution network, which will result in a high number of submeters. These meters can also be used for determining the unit process energy consumption pattern on individual processes. Complex structures of metering systems on this level requires a well structured communication and data computation system to handle the monitoring of the complex metering output data. Single meters with a data output resolution of 1 second, as recommended

Unit process

Table 5: Department level metering specifications.

Highly dynamic Low dynamic

Resolution

Parameters

10 ms – 1 min

Wh, VAh, PF, THD

1 s – 5 min

Wh, VAh, PF, THD

Table 6: Unit process level metering specifications. In all these electricity metering and monitoring applications, the accuracy is not of primary importance since no monetary value is calculated from the metered values. Moreover it is the qualitative importance of the metered values directly related to the high temporal resolution which enables an understanding into the process. Technical challenge: As in department level, the unit process metering specifications are closely related to the dynamics of the unit process’ electrical energy consumption behaviour. Highly dynamic behaviour is likely to be seen in high speed machining processes or robotic applications, whereas low dynamic processes can be seen in thermal or galvanic processes. As Table 6 shows,

Keynotes

7

the recommended temporal resolution can go down to 10 milliseconds for highly dynamic processes. On unit process level, the source of the harmonic distortion and low power factor can also be found and compensated by making use of continuous unit process metering as an input for closed loop controls. Economical challenge: The investment for metering equipment on this level is estimated to be high, because only the highly sophisticated metering systems are able to provide such high temporal resolutions and are able to handle the high data output volume from the single metering equipment. This high data volume enables real time monitoring, but at the same time makes logging applications very data intensive. Especially on unit process level, the harmonic distortion charge of the suppliers can be addressed, as the countermeasures can be applied directly at the source. Total harmonic distortion (THD) is an electrical noise feedback caused by electrical inverters and phase controlled modulators. THD does not only lower the quality of the distribution network, but also severely impacts local machines and sensitive devices. The following section of this paper addresses difficulties in selecting the right measurement equipment for a given task. 5

REVIEW OF AVAILABLE ENERGY METERING DEVICES

In the previous chapter it has been shown that within each electricity measurement task, whether to enable energy efficiency measures or to do energy accounting within organisational structures, it is always a challenge to formulate the right measurement strategy and to select the right measurement instruments for the task of metering. This section gives a brief overview of some typically metering devices found in the market as well as explaining some basic distinguishing features that must be considered in industrial and research applications. Table 7 presents a selection of most commonly used electricity metering instruments from industrial and research applications. The aim is neither to provide a complete list nor to rate the instruments in any way. The selection is just a very limited selection of some important features that distinguish the single instruments. The instrument features range from installation, which describe whether the device can be mounted in a fixed location or if it can be used in mobile applications. Mobile applications are usually found in short time measurement for quick energy assessments on factory or unit process level or in special research applications. Fixed types Measurement instrument:

Installation

of devices can be found in the long time measurement applications available on all levels. Such devices can be built-in directly into control or distribution cabinets. As the evolution of electricity metering devices has allowed user to obtain not only single measurands meters (Ferraris disc meter) but also multi measurands meters, a broad selection of possible measurands becomes available and allows more integrated applications. This enables for example single devices at factory level to provide users the information about active energy consumption for energy controlling as well as reactive energy and total harmonic distortion values for quality monitoring at the same time. The amounts of measurands that can be read from the single devices are defined by the complexity of the electronic meters and often manifest itself in the purchasing price. Table 5 and Table 6 show certain ranges of recommended resolutions of the metering points needed to perform metering applications. The output resolution presented in Table 7 should match these required resolutions in order to be well dimensioned for the metering task. The degree of output resolution is directly proportional the purchasing price of the instruments. Data loggers with resolutions of higher than a metering point per second can exceed 5000 EUR. A high output data resolution is not always a sign of quality. It is rather an indication of the possible types of information that can be gained from the metering data through analysis. As discussed earlier, a high degree of metering data resolution can quickly result into high additional costs for handling of the large amounts of resulting data if centralized monitoring is used. Selecting the right degree of detail is an essential part of the right dimensioning of a metering strategy. In large metering networks, commonly found in department level metering and monitoring, the communications interface plays a very important role as well. Metering and monitoring applications have to be able to use the same communication interface. Real-time monitoring and control applications often use industrial bus interfaces like Profibus or in near real-time applications interfaces like Ethernet. Simple applications such as monitoring for energy accounting do not rely on real-time data and are usually working with bus systems based on RS485 or even impulse signal recognition. The communication interface matching is very important when designing cost-effective metering strategies. Multi interface applications can easily lead to complex and costly software and hardware conflicts. If a holistic department level

Measurands*

Brand, series/type

Output resolution*

Communication interface*

IME, NEMO 96

Fixed type

V, A, W, VA, PF, THD

60 s

RS485, Impulse

Siemens, SIMEAS

Fixed type

V, A, W, VAR, VA, PF, THD

< 1s

Profibus, RS485

Schneider, Electrics, PM

Fixed type

V, A, W, VA, PF, THD

60 s

RS485, Impulse

Simpson, GIMA1000

Fixed type

V, A, W, VAR, VA, PF

1s

RS485, Impulse

Yokogawa,

Fixed type

V, A, W, VAR, VA, PF

<1 s

Ethernet, RS485, Pulse

AccuEnergy, Acuvim

Fixed type

V, A, W, VAR, VA, PF, THD

<1 s

Ethernet, Profibus, RS485, Impulse

Janitza Electronics, UMG 604

Fixed type

V, A, W, VAR, VA, PF, THD

<1 s

Ethernet, Profibus, Impulse

Chauvin Arnoux, C.A.8335

Mobile type

V, A, W, VAR, VA, PF, THD

1s

USB

Fluke, 434

Mobile type

V, A, W, VAR, VA, PF, THD

0.5 s

Voltech, PM3000

Mobile type

V, A, W, VAR, VA, PF, THD

<10 ms

Load Controls, PPC

Mobile type

W

National Instruments, cDAQ*

Mobile type

V, A

15 ms <1 s

USB RS232, IEEE488 Analogue 0-10 volts or 4-20 milliampere USB

*the listed features are retrieved from the datasheets of the devices and are due to change in future instrument revisions

Table 7: Selection of often found electricity measurement instruments with a selection of important distinguishing features.

8

Keynotes

6

REVIEW OF SELECTED ELECTRICITY METERING AND MONITORING SYSTEMS FOR RESEARCH PURPOSES

In this section, a special emphasis will be given to electricity metering and monitoring systems for research related purposes. As stated before, research applications most often utilize mobile systems in order to redeploy them easier. The last five instruments listed in Table 7 are mobile metering devices with different features, individual advantages and weaknesses. The two devices from Fluke and Chauvin Arnoux are highly sophisticated industrial multi-measurands instruments that are capable to log measurement values in high temporal resolution of up to 0.5 and 0.1 seconds respectively. Plug and play features allow users to perform highly mobile measurement strategies as found in quick energy assessments or simple before-and-after measurements to evaluate energy efficiency measures. Other instruments like from Voltech and Load Controls are very likely to be used in detail energy system analyses. Very high metering data resolutions in the range of hundredth of a second allow analysing transients, inrush currents and other short term electrical events. The specific characteristic of these two devices is that they need additional external digital analogue converters with high sampling rates for logging purposes of the analogue data output interface, which is additionally affecting the accuracy of the logged metering values. The last item on the list from National Instruments is a typical laboratory solution for research tasks, with an open programming platform to create individual metering algorithms. The individual algorithms and the specifications of the individual input modules define the amount of calculated measurands and their accuracy. Since such an open platform is not sufficient for energy accounting or related purposes on factory or department level, this mobile device is solely meant for research applications with a high degree of individuality and freedom. 7

INDUSTRY CASE: ONGOING CHALLENGES OF DEPLOYING A METERING AND MONITORING STRATEGY IN AN AUSTRALIAN MANUFACTURER

The presented case is derived from the analysis of a bio-medical products manufacturing company in Australia. The increasing energy bill due to both business growth and rising energy cost has been considered as one of the main issues in this company. This not only impacts the environmental performance of this company but also affects its business strategy. Reducing energy consumption would benefit the company both economically and ecologically. The main aim was to identify the areas of improvement as well as implementing energy accounting for individual functional units, processes and ultimately for the individual products. Thus, the company has decided to implement an energy management system. The first step taken is to establish a metering and monitoring system in order to achieve transparency into its energy consumption. The company initially aims to monitor the energy consumption behaviour from top factory level down to sub-department levels. Multiple energy meters were thus allocated throughout the distribution network. The factory plant is powered by an 11 kV electrical connection from the energy supplier. The voltage is decreased to 400 V three-phases by 3 transformers, which powers

3 main switch boards and then splits into different distribution boards. The energy meters attached at the three main transformers is to be able to perform parallel metering on the factory, which aims to check the accuracy of the electricity bill from the supplier. The metering devices at the distribution boards and circuit breakers were then assigned to individual department or sub-departments. A Supervisory Control and Data Acquisition system (SCADA) here allows the real time management of energy consumption. The system also allows the user to configure analysis and reports to show the previous and current energy consumptions. By performing the analysis of the demand for each department or area, management can determine the Key Performance Indicator (KPI) and apply procedures to minimise demand, which leads to energy savings and lower energy bill. The output from the power meter devices were collected with the SCADA server via RS485 communication, which requires gateways to access them to the factory Ethernet communication network. However, the deployed energy metering and monitoring system failed to provide reliable information of energy consumption of the plant. The aggregation of energy consumption measured at three main transformers did not agree with the electricity bill. The gap between measured value and billed amount far exceeded the errors due to the measurement. Assuming that the energy supplier measured the real amount of energy consumption and billed correctly, the failure to obtain similar total energy consumption reading internally may possibly due to the selection of power meters. As the energy supplier charges not only the total work load but also peak power, low power factor and THD, the current meters did not cope with the range of all the energy billing categories. The following Figure 3 shows the energy consumption profile of the factory over a year per period.

Main Transformers Plant Room

Energy [kWh]

metering strategy is to be deployed, a high amount of time has to be invested for investigating the possible existing communications infrastructure and resulting requirements for the new data communication system.

Administration Bottle Filling

Jan

Feb Mar Apr May Jun

Jul

Aug Sep Oct Nov Dec

Figure 3: Break-down of energy consumption profile over a year. The reading of the power meters at the distribution boards and circuit breakers experienced inconsistency throughout the period. For example, the recorded data for one department gave zero energy consumption for the whole year, where the plant actually runs 24/7. Another example is that some unusual spike was recorded for Administration department as shown in Figure 3, which even exceeded the total energy consumption of the main transformers. The possible reason for this failure is mainly due to the connection problem within the communication system between power meters and SCADA server. Furthermore, the layout of distribution network did not agree with the organizational structure as shown in Figure 4. In order to implement energy accounting for each organizational department, the energy monitoring system requires new metering points in the distribution network. As a result a new energy monitoring system

Keynotes

9

has been implemented, which resulted in changing some of the existing devices and installing new ones in order to extend the monitoring and measuring to individual processes. A considerable cost is thus caused to improve the energy metering and monitoring system.

Organizational Structure

Machine 1

…

…

SubDepartment

SubDepartment

SubDepartment

…

SubDepartment

SubDepartment

SubDepartment

SubDepartment

Periphery System 1

…

After these changes, company’s external reading and energy bill have started to agree with the internal measurements. Currently the company, in collaboration with the authors, has been developing a new energy oriented factory planning system in order to link the material flow to the energy flow within the factory. Currently the company’s energy bill exceeds $1M a year. Despite the initial investment with the introduction of the new system, company is expected to reduce its energy bill by about 30% as well as reducing its carbon foot-print substantially. SUMMARY AND OUTLOOK

Today’s manufacturing companies are facing a more stringent cost pressure than ever before due to rising energy and resource costs and the associated environmental impact. Manufacturing companies have come to realisation the importance of electrical energy metering and monitoring as a foundation to work out energy efficiency improvement potentials. This key note paper presented a short review of the evolution and the latest developments in electricity metering monitoring systems. A special emphasis is given the challenges of the designing of metering strategies in order to properly dimension metering instruments for a given task. In addition, the paper addressed the critical aspects of data communication and the compatibility of interfaces in relation to different application areas. An exemplary list of metering devices was presented to demonstrate how the features of the different measurement instruments can be matched for certain measurement tasks on different application levels. In order to emphasise the importance of a well designed metering strategy and selection of the right metering and monitoring equipments, a case study from a manufacturing company was presented. 9 [1]

Schwendtner, M.F. (1996): Digital measurement system for electricity meters, in Metering and Tariffs for Energy Supply Conference Publication, Institution of Electrical Engineers, No. 426, pp. 190-193.

[6]

Schwendtner, M.F. (1996): Technological developments in electricity metering and associated fields, in Metering and Tariffs for Energy Supply Conference Publication, Institution of Electrical Engineers, No. 426, pp. 240-242.

[7]

International Electrotechnical Commission (2003): 62053:2003 - Electricity metering equipment (a.c.).

[8]

American National Standards Institute (2010): ANSI C12.202010 - Electricity Meters - 0.2 and 0.5 Accuracy Classes.

[9]

Verein Deutscher Elektrotechniker (1976): VDE 0410 Regeln für elektrische Meßgeräte.

[10]

International Electrotechnical Commission (1998): IEC 60051:1998 - Direct acting indicating analogue electrical measuring instruments and their accessories.

Periphery System n

Figure 4: Factory organisational structure and the existing metering system.

8

[5]

Department

SubDepartment

Machine n

Shtargot, J. (2008): Advanced Power-Line Monitoring Requires a High-Performance Simultaneous-Sampling ADC, in MAXIM Application Note 4281.

Distribution Network

Factory

Department

[4]

REFERENCES Herrmann, C.; Kara, S.; Thiede, S.; Luger, T. (2010): Energy Efficiency in Manufacturing – Perspectives from Australia and Europe, in: CIRP International Conference on Life Cycle Engineering, pp. 23-28.

[2]

Moore, A. E. (1935): The History of the Integrating Electricity Meter, in: Journal of the Institution of Electrical Engineers, Vol. 77, No. 468, pp. 851-859.

[3]

Colburn, R. (2010): The History of Making the Grid Smart, in: IEEE today’s engineer, online available on: http://www.todaysengineer.org/2010/May/history.asp, last th accessed on 8 December 2010.

IEC

[11] Irwin, L.A. (2010): A High Accuracy Standard for Electricity Meters, in Transmission and Distribution Conference and Exposition, New Orleans. [12] Lerch, R. (2007): Elektrische Messtechnik, Springer-Verlag Berlin Heidelberg. [13] International Electrotechnical Commission (1996): IEC 600441:1996 - Instrument transformers - Part 1: Current transformers. [14] Start, D.J. (1995): A review of the new CENELEC standard EN 50160, in: Issues in Power Quality, IEE Colloquium [15] European Committee for Electrotechnical Standardization (2007): EN 50160:2007 - Voltage characteristics of electricity supplied by public distribution networks. [16] Masetti, C. (2010): Revision of European Standard EN 50160 on power quality: Reasons and solutions, in: 14th International Conference on Harmonics and Quality of Power. [17] Herrmann, C.; Bogdanski, G.; Zein, A. (2010): Industrial Smart Metering – Application of Information Technology Systems to Improve Energy Efficiency in Manufacturing, in: 43rd CIRP International Conference on Manufacturing Systems, Wien, pp. n.a. [18] Hesselbach, J.; Herrmann, C.; Detzer, R.; Martin, L.; Thiede, S.; Lüdemann, B. (2008): Energy Efficiency through optimized coordination of production and technical building services, in: 15th CIRP International Conference on Life Cycle Engineering, Sydney, pp. 624-629. [19] Jahn, M.; Jentsch, M.; Prause, C.R.; Pramudianto, F.; AlAkkad, A.; Reiners, R. (2010): The Energy Aware Smart Home, in: 5th International Conference on Future Information Technology. [20]

Herrmann, C.; Thiede, S.; Zein, A.; Heinemann, T. (2010): Holisitc Approaches for Increasing Energy and Resource Efficiency in Manufacturing, in: Proceedings of the 1st International Conference on Automotive Materials and Manufacturing, Pune.

[21] Herrmann, C.; Thiede, S. (2010): Simulation-based Energy Flow Evaluation for Sustainable Manufacturing Sytems, in: CIRP International Conference on Life Cycle Engineering, pp. 99-104.

10 [22]

[23]

Keynotes Huang, H.; Liu, Z.; Zhang, H.-C.; Sutherland, J.W. (2010): A Proposed Method to Study the Life-cycle Energy Consumption of the Automotive Industry, in: CIRP International Conference on Life Cycle Engineering, pp. 127130. Klocke, F.; Lung, D.; Schlosser, R.; Nau, B. (2009): Energy and Resource Efficient Production – a Core Competence for Manufacturers, in: 16th CIRP International Conference on Life Cycle Engineering, pp. 209-214.

[24]

Herrmann, C.; Thiede, S. (2009): Towards Energy and Resource Efficient Process Chains, in: 16th CIRP International Conference on Life Cycle Engineering, pp. 303309.

[25]

Chiotellis, S.; Seliger, G.; Weinert, N. (2009): Energy-aware Production Planning and Control, in: 16th CIRP International Conference on Life Cycle Engineering, pp. 310-315.

[26]

Müller, E.; Löffler, T. (2009): Improving Energy Efficiency in th Manufacturing Plants – Case Studies and Guidelines, in: 16 CIRP International Conference on Life Cycle Engineering, pp. 465-471.

[27]

Rahimifard, S.; Seow, Y.; Childs, T. (2010): Minimising Embodied Product Energy to support energy efficient manufacturing, in: CIRP Annals – Manufacturing Technology, pp. 25-28.

[28]

[29]

[30]

[31]

Herrmann, C.; Thiede, S. Heinemann, T. (2010): A Holistic Framework for Increasing Energy and Resource Efficiency in Manufacturing, in: 8th Global Conference on Sustainable Manufacturing. Klocke, F.; Schlosser, R.; Lung, D. (2010): Energy and Resource Consumption of Cutting Processes, in: 17th CIRP International Conference on Life Cycle Engineering, pp. 111115. Dietmair, A.; Verl, A. (2010): Energy Consumption Assessment and Optimisation in the Design and Use Phase of a Machine Tool, in: 17th CIRP International Conference on Life Cycle Engineering, pp. 116-121. Devoldere, T.; Dewulf, W.; Deprez, W.; Duflou, J.R. (2008): Energy Related Life Cycle Impact and Cost Reduction Opportunities in Machine Design: The Laser Cutting Case, in: 15th CIRP International Conference on Life Cycle Engineering.

[32]

Devoldere, T.; Dewulf, W.; Deprez, W.; Willems, B.;Duflou, J.R. (2007): Improvement Potential for Energy Consumption in Discrete Part Production Machines, in: 14th CIRP International Conference on Life Cycle Engineering, pp. 311316.

[33]

International Standardization Organisation (2003): ISO 13374-1:2003 – Condition monitoring and diagnostics of machines – Data processing, communication and presentation, Part 1: General guidelines.

[34]

Bottene, A.C.; Franca, T.V.; Ometto, A.R.; Torrisi, N.M.; Filho, A.G. (2009): Methodology to integrate the electrical energy consumption real-time monitoring and related environmental impacts assessment, in: 16th CIRP International Conference on Life Cycle Engineering, pp. 373-376.

[35] Vijayaraghavan, A.; Dorenfeld, D. (2010): Automated energy monitoring of machine tools, in: CIRP Annals – Manufacturing Technology, pp. 21-24. [36]

Rohdin, P.; Thollander, P. (2006): Barriers to and driving forces for energy efficiency in the non-energy intensive

manufacturing industry in Sweden, in: Energy, vol. 31, issue 12, pp 1836-1844. [37] International Electrotechnical Commission (2009): IEC 610101:2009 - Safety requirements for electrical equipment for measurement, control, and laboratory use - Part 1: General requirements. [38] European Parliament and (2004): 2044/22/EC directive on measuring instruments, in: Official Journal of the European Union, L 135. [39]

International Electrotechnical Commission (2001): IEC 60359:2001 – Electrical and electronic measurement equipment – Expression of performance.

[40] Schleich, J. (2009): Barriers to energy efficiency: A comparison across the German commercial and services sector, in: Ecological Economics, Vol. 68, pp. 2150-2159. [41]

Herrmann, C.; Zein, A.; Winter, M.; Thiede, S. (2010): Procedures and Tools for Metering Energy Consumption of Machine Tools, in: 3rd International Scientific Conference with Expert Participation – MANUFACTURING.

[42] Sioshansi, F.P. (1991): Electronic metering and two-way communications – The electric power industry, in Utilties Policy, Vol. 1, No. 4, pp. 294-307. [43] Mak, S.T. (2010): Sensor Data Output Requirements for Smart Grid Applications, in Power and Energy Society General Meeting, IEEE, ISSN 1944-9925, pp. 1-3. [44] McEachern, A.; Eberhard, A. (2009): A new, ultra low cost th power quality and energy measurement technology, in: 20 International Conference on Electricity Distribution, ISBN: 978-1-84919126-5, pp. 1-4. [45] Stephenson, P.; Paun, M. (2000): Consumer Advantages from Half-Hourly Metering and Load Profiles in the UK Competitive Electricity Market, in: International Conference on Electric Utility Deregulation and Restructuring and Power Technologies, pp. 35-40 [46] Solding, P.; Petku, D.; Mardan, N. (2009): Using simulation for more sustainable production systems, in: International Journal of Sustainable Engineering, Vol. 2, No. 2, pp. 111122. [47] Elias, E.W.; Dekoninck, E.A.; Cully, S.J. (2009): Quantifying the Energy Impacts of Use, in: 16th CIRP International Conference on Life Cycle Engineering, pp. 444-451. [48] Dietmair, A.; Zulaika, J; Sultika, M; Bustillo, A.; Verl, A. (2010): Lifecycle Impact Reduction and Energy Savings through Leight Weight Eco-Design of Machine Tools, in: 17th CIRP International Conference on Life Cycle Engineering, pp. 105-110. [49] Li, W.; Kara, S. (2011): An Empirical Model for Predicting Energy Consumption of Manufacturing Processes: A Case of Turning Process, in: Proceedings of the Institution of Mechanical Engineers, Part B, Journal of Engineering Manufacture.

Implementing Life Cycle Engineering efficiently into Automotive Industry Processes Stephan Krinke Volkswagen AG, Head of Group Research Environmental Affairs Product, Wolfsburg, Germany

Abstract Life cycle assessment (LCA) is a powerful tool which supports life cycle engineering. It can be used as an environmental management instrument within the product development. For successful life cycle engineering the formal incorporation of life cycle thinking into the company policy is a necessary pre-requisite. Additional success factors which have to be met are the transformation of LCA results into measurable targets for engineers. Based on given environmental targets, such as a certain target value for greenhouse gas emissions, LCA can be used to calculate a specific technical target such as the weight of a component, the fuel consumption of a vehicle or the minimum amount of recycled content in a product. The transformation of pure LCA results into measurable target values, which can be understood by engineers, will clearly show the added value which LCA can give in terms of life cycle engineering.Even for very complex products with a huge variety of different materials and a complex value chain life cycle assessment can be performed with a reasonable time demand, with good quality and integrated efficiently into business processes. Keywords Design for Environment; Automotive; LCA; Life Cycle Engineering



Environmental management based on figures and facts

The automotive industry is since decades one of the industrial focus areas for environmental technologies and environmental protection.



Identification of hot spots for product optimization along the entire value chain

But how can the environmental performance of a complex product such as an automobile be measured? The aspects which directly or indirectly influence the environment are manifold:



LCA is an internationally accepted method and a firm basis for a dialogue with stakeholders



LCA is part of company ratings which directly influences the interest rate and financial power of the company

1

INTRODUCTION

Starting with the production of raw materials and going along the value chain the entire production affects the environment. Especially the automotive industry is one of the industry sectors with a very complex value chain, including nearly all kind of materials such as metals, polymers, glass and ceramics. The usage phase of the vehicle also effects the environment due to the combustion of fuel and the herewith linked emissions such as CO2, contributing to climate change. Other tailpipe emissions such as carbon monoxide, nitrogen oxides and hydrocarbons contribute to local air quality (e.g. summer smog). The quantity of these impacts depends on the fuel consumption and the emission standard of the vehicle. And last but not least the driving behavior of the customer, which influences the fuel consumption, has an impact on the environment. During the end-of-life phase materials are recovered or recycled from the end-of-life vehicle and can be used as secondary (raw) materials in other applications. Therefore the environmental assessment of a vehicle has to cover the entire life cycle. One of the most suitable instruments to measure the potential environmental impact of a product is life cycle assessment [1, 2]. Volkswagen started in 1991 with a research study for the life cycle inventory (LCI) of the Golf III which was published as first automotive LCI of a complete vehicle worldwide in 1996 [3]. In the following years LCIs of different vehicles of the Volkswagen Group were published [4, 5, 6, 7]. Today the Volkswagen Group has incorporated life cycle thinking as a main principle of the product development. The advantages of this approach are:

In the following chapters the environmental strategy of the Volkswagen group and the implementation of life cycle engineering into the environmental management will be explained. 2

ENVIRONMENTAL STRATEGY

The key element of the Volkswagen group strategy 2018 is to position the Volkswagen group as a global economic and environmental leader among automobile manufacturers. We intend to set new environmental standards in vehicles, powertrains and lightweight construction. 2.1

Environmental challenges

The main environmental challenges for the automotive industry today and in future are climate protection, health and local air quality and resource protection. Therefore these three items are incorporated into the environmental principles product of the Volkswagen Group. This standard is the basis for the product related environmental strategy. 2.2

Environmental strategy of the Volkswagen Group

The environmental strategy of the Volkswagen group has two main pillars: The environmental standard production and the environmental principles product. The latter addresses the three main environmental challenges (climate protection, health and local air quality and resource protection) and incorporates the life cycle engineering as a main principle in product development.

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_2, © Springer-Verlag Berlin Heidelberg 2011

11

12

Keynotes

Environmental Strategy Volkswagen Group „Individual ecological mobility“ Group Management Group Environmental Strategy Committee

Environmental Standards Product

Environmental Standards Production

Climate

- Emissions - Consumption -…

Infrastructure - Energy - Water - Waste -…

Resources

- Alternative fuels - Recycling -…

Health

Production processes

- Pollutants - Noises -…

Guidelines

Preamble

Environmental Policy

- Press shop - Paint shop - Foundry -…

Regional Environmental Conferences / Environmental-Audits ISO 14001 / EMAS Figure 1: Environmental strategy Volkswagen Group. The Volkswagen group is committed to developing vehicles and components in such a way that they have better environmental properties than their predecessors over the entire life cycle. Life cycle assessments are used to analyze and document the environmental performance of vehicles, technologies and processes.



Reliable, meaningful and measurable targets for product development



Communication strategy

3

For the Volkswagen group the environmental standards production and product are the basis for the environmental strategy. But for a successful environmental management system this is only the starting point.

SUCCESS FACTORS FOR LIFE CYCLE ENGINEERING

Whereas the first ideas of life cycle based analysis were developed 30 years ago, it still remains a challenge to implement life cycle assessment successfully as environmental management tool into business processes. In this chapter we describe the key success factors for such an implementation. The success factors are: 

Integration into company policy and processes



Reasonable time demand

3.1

Integration into company policy and processes

The commitment of the top management is crucial for the success of any environmental policy and strategy.

For the Volkswagen brand we developed an environmental management scheme according to Figure 2. Responsible for the implementation of environmental aspects into the product development is the environmental officer product.

Environmental Management at Volkswagen Networking and directing worldwide activities in environmental protection

Head of the Group Research Division

Board of Research and Development

Group Environmental Strategy Committee

Environmental management officer of the Volkswagen brand

Environment

Environmental officer product

Environmental protectors for R&D Volkswagen

Environmental Affairs Strategy

Vehicles

Environmental officer for production

Environmental Affairs Product

Modules

Environmental Affairs Production

Material controlling

LCA & raw material analysis

Environmental officers at the locations Wolfsburg

Emden

Hanover

Zwickau

Pamplona

Figure 2: Environmental management at Volkswagen.

Other locations

Keynotes

13

Environmentally compatible product development Volkswagen brand Product development over time

Development stages and tasks Environmental Analysis

Environmental Control

Material controlling

Research

Advance engineering

Vehicle targets

Characteristics catalog

Performance specifications

Product description book

LCAs and strategic environmental topics Raw material analysis

Model update

Follow-up Environmental commendations

Supervision of vehicle projects Screening of environmental related laws and activities of competitors

Product communication

Environmental targets, performance specifications and standards Environmental product Environment and descriptions innovation roadmaps Global material legislations

Material controlling Material data acquisition (MISS/IMDS) Legends Tasks Instruments

Figure 3: Environmentally compatible product development for the Volkswagen brand. Figure 3 shows an overview of different tasks and instruments along the product development which usually takes around 48 months until the start of production.

sure that the entire life cycle is taken into account during the development of our products.” This target is signed by the board member for the technical development for the Volkswagen brand.

Different teams act along the product development. The team environmental analysis has the task to perform LCA and strategic raw material analysis for different components and technologies. The focus of this work is the early phase of the product development including research. Strategic raw material analysis focuses on long term risk assessment [8] such as 

Supply and demand today and in future



Production costs



Geostrategic risks



Market power of the raw material suppliers

Life cycle inventory data and the herewith linked bill of materials is a powerful basis for raw material risk assessment which can not be performed without that information. The task of the LCA is to compare different technologies in the early phase of product development. The challenge of this task is that the information required for the LCA is often not fully available in the early phase of the product development. E.g. the body-in-white concept is known from the material perspective, but the exact weights of the different components are unknown. Here LCA should be applied in such a way that the unknown variables are calculated as measurable target values. In our example where we do not know the exact weight of all components the sum of the component weight can be calculated as target, which has not to be exceeded in order to achieve an environmental goal such as a maximum greenhouse gas emission potential. Another important aspect for the implementation of life cycle engineering is the formal inclusion of the suppliers. Volkswagen included in its supplier conditions that on request the supplier has to deliver life cycle inventory data for his parts and components [9]. Additionally the IMDS system (www.mdsystem.de) is a reliable data basis for information about the material composition and the bill of materials of a certain part. The most important aspect is that the Volkswagen brand included in its environmental objectives “that we will develop each model in such a way that, in its entirety, it presents better environmental properties than its predecessor. As we do so, we will always make

Figure 4: Environmental objectives of the Volkswagen brand.

14

3.2

Keynotes

Reasonable time demand

Data quality

LCA is a very comprehensive tool which offers a detailed insight in the environmental profile of a product. Performing an LCA of a complex product can be divided into two steps: The first is the data collection of the product. Here the part list of the product is required. For every single component the material composition must be quantified and the herewith linked production process chain must be defined. This step can be improved in terms of time efficiency via the implementation of IMDS data for the components and the linkage to other internal ISsystems of the company. Anyhow this still remains a time consuming step and can take even today up to 30 days. The final result of step 1 is a so called transfer file, which describes for a vehicle every single component by its bill of material and the respective production chains (see Figure 5). The second step is the transfer of this information into a LCA model. Within Volkswagen we developed an in-house solution which automatically builds up the LCA model based on the information of the transfer file and the so called correlation list [10]. The correlation list correlates each material and each production process to a respective LCI data set. The advantage of this approach is not only a huge reduction in time demand but also huge increase in consistency and quality of the LCA results. Time and Resource Demand for LCA of Cars ~ 1-30 days

transfer file

interface 1

~ 0-2 days

mapping file

other internal data sources

complete transfer file

For commodities generic data sets can be used as a first approach. For the modeling of special materials, which are new on the market or based on new technologies, a data acquisition in cooperation with the respective supplier is strongly recommended. At that point a formal requirement for data acquisition of life cycle inventory data in the supplier contracts is very helpful. For highly innovative industries, such as the automotive industry, it is of utmost importance to use high-quality inventory data in order to assess the environmental profile of new materials and new technologies. This is a challenge because the knowledge of new technologies and new materials is of course limited. But this does not mean that LCA can not be applied. Also in this case the area of unknown knowledge can be transformed by LCA into a measurable target value. If, for instance, the energy consumption of a new production process is still unknown, an LCA can be used to calculate the acceptable maximum energy consumption in order to achieve a certain environmental target. Anyhow there is a parallel between the automotive industry and life cycle assessment: High-tech powertrains need high-quality fuels – high-tech LCA need high-quality inventory data. Therefore today and in the future the provision of high-quality inventory data will remain an important and necessary task, especially for science and consultancy.

Situation today ~ 1 day

Foreground data, such as the bill of materials, information about production processes or energy consumption in the use phase, describes the characteristics of the product. From our experience this foreground data is of major relevance and has a strong influence on the overall LCA results.

interface 2

3.4 internal data sources

IMDS

specify vehicle

data base

technical drawings

product model

IMDS

 close data gaps  check weights  check materials manual processing

map material/ process information to available data sets in database

predefined process

electronic data

Figure 5: Time and resource demand for LCA of vehicles. Therefore life cycle assessments, even for complex products with a huge variety of different parts and materials, can be performed with a reasonable time demand.

3.3

Reliable and development

measurable

targets

for

the

product

Life cycle assessment is an environmental management tool that delivers scientific sound results, not less but also not more. A good environmental management system is therefore characterized by the capability to transform LCA results e.g. in terms of a greenhouse gas profile of different technologies into a technical target which can be understood, measured and monitored by an engineer. These targets can be fuel consumption, electric power consumption or the weight of a certain component. The real challenge of life cycle engineering is to bring together two different worlds: The world of the LCA expert, who models the product in terms of environmental impacts versus the world of the engineer who develops the product and takes technical measure that influence the environment. In order to derive reliable, meaningful and measurable targets the following aspects should be considered. Stable and reliable results As LCA is a model outcome every LCA result should be tested by sensitivity analysis in order to prove whether the result, or much more important, a derived technical recommendation, is stable while varying certain model parameters or assumptions.

Communication strategy

It is most important that products with special environmental features or technological improvements are also communicated as such. A company which invests in environmental performance and technology leadership should also use these characteristics in the communication and marketing. Therefore the challenge in that area is to translate LCA results into a communication that will be understood by the respective target groups. It is notable that economical and environmental optimization oftentimes are in line, especially with regard to the fuel consumption. In the case of the automobile industry we have to differentiate between private customers and fleet customers as two different kinds of target groups. Whereas private customers mostly focus on fuel consumption and emission levels in terms of costs, they do not reflect what we call total cost of ownership (TCO). While TCO means that higher purchase prices can be amortized over life time at the customer, the private customer has in many cases a limited willingness to pay for additional environmental features, even if they offer the opportunity to get the economical break-even within a time scale of 2-3 year. In contrast to that, fleet customers base their decisions often on TCO calculations. For an OEM this means that fleet customers have a willingness to pay for environmental technologies such as BlueMotion, if the economical break even will be reached within a few years. But also other environmental aspects might be important for fleet customers, e.g. a company can improve their sustainability ranking by improving the company fleet cars. For the Volkswagen brand we developed the so-called environmental commendations (www.environmentalcommendation.com). Environmental commendations for new vehicle models and technologies highlight ecological progress compared with predecessor models and previous technologies. We use environmental commendations to inform our customers, our shareholders and other stakeholders how we are making our

Keynotes products and production processes more environmentally compatible and what we have achieved in this respect. The underlying LCA not only covers the time when the vehicle is on the road but its entire life cycle from production through to use and disposal. This reflects the fact that we assume responsibility for the entire supply chain, including the production of raw materials and parts for our vehicles. We engage in dialogue with our suppliers to identify environmental measures that can be taken. The information of environmental commendations is based on an LCA, which has been verified and certified by the technical inspection organization TÜV NORD. The TÜV certificate confirms that the LCA is based on reliable data and that the methods used to compile it comply with the requirements of the ISO standards 14040 and 14044.

4

15 vehicles steeltechnologies.

and

aluminum

lightweight

are

established

INTELLIGENT LIGHTWEIGHT DESIGN OVER LIFE CYCLE

In this chapter we show how an LCA can be applied as environmental management tool within the product development. Lightweight design measures are chosen for this example. Modern lightweight design is one of the key technologies for an efficient future mobility, because it contributes to reduce the fuel consumption and the herewith linked CO2-emissions. Based on the Volkswagen’s environmental standard for products this means that any lightweight design measure should also have an environmental benefit over the entire life cycle. Approximately one third of the fuel consumption in the NEDC (New European Driving Cycle) depends on the mass of the vehicle. Lightweight materials such as aluminum or magnesium are energy intensive in the production as shown in Figure 6.

Figure 6: Greenhouse gas emission for the production of different materials. Figure 6 also shows the range of greenhouse gas emissions for the production of different metals. The reasons for this range are manifold: The amount of recycled material, the CO2-intensity of the used energy mix, different kinds of protecting agents and their impact on climate change are only a few aspects which influence the greenhouse gas balance of such a material. It is also important to note that a comparison of materials can not be done based on Figure 6. A comparison can be done by including the entire life cycle and by assessing products which fulfill the same functions. E.g. a body-in-white with the same crash performance will have different weights depending on the material-mix applied and the design of parts. For lightweight concepts the herewith linked CO2-emissions in the production phase are often, but not always, higher than those ones for conventional construction. These additional CO2-emissions which occur in the production phase should be compensated as fast as possible during the use phase due to lower fuel consumption of the lightweight design. Only when we achieve the ecological breakeven, we speak of an “intelligent“ lightweight design as shown in Figure 7. Volkswagen has different strategies to reduce the weight of a vehicle. Besides different material concepts the integration of different functionalities contributes to reduce the number of parts. For the body-in-white construction, which accounts for up to 35% of the overall vehicle weight in the series production of passenger

Figure 7: Lightweight design and environmental break-even. The question whether a specific lightweight concept has a better greenhouse gas balance than a competing concept, can be answered only by assessing the entire vehicle. An important question is whether a lightweight measure will lead to a smaller engine or not. Of course any lightweight measure reduces the fuel consumption. But this reduction is low (0,15 l/100km*100kg for gasoline engines) compared with a fuel reduction of 0,35 l/100km * 100kg which can be achieved by additional measure of the engine. What is clear from the above examples is, that it is not possible to make general claims along the lines that „material A is always better or always worse than material B“. Whether a lightweight design measure reduces life cycle greenhouse gas emissions or not will primarily depend on the following factors: the extent of the weight savings by material and material-adopted design, whether powertrain modifications can be implemented and the quality of secondary (recycled) materials derived from the end-of-life vehicle. In practice, one and the same lightweight design measure might allow powertrain modifications to be made on vehicle A but might not, by itself, be sufficient to warrant such modifications on vehicle B. Saying this, it is often the case in practice that components or assemblies are optimized and assessed in isolation from each other, so that the significance of each measure in the causality chain that leads ultimately to powertrain modifications cannot always be clearly determined. Therefore lightweight measures should always be assessed from the perspective of the entire vehicle and not from the part perspective. As can be seen in Figure 8, the potential benefits of the various lightweight materials extend even further. The table shows the main actors – and potential actions – at the different life cycle stages. For example the material manufacturing stage offers the opportunity to significantly reduce specific CO2-emissions per kg of material produced by reducing specific energy consumption and/or through the use of renewable, low-carbon energy sources. The use of secondary (recycled) materials can likewise help to reduce environmental impacts – for example some cast alloys already use up to 90 % recycled content. On the process side, too, measures such as use of climate-friendly shielding gases as a replacement for SF6, or the reduction of offcuts and scrap, all have a part to play. In the vehicle use phase meanwhile, fuel-efficient vehicle design measures by the OEM must be complemented and maximized through the optimal use of this potential by customers e.g. by ecodriving trainings. Finally, at the recycling stage, reprocessing of lightweight materials into high-quality secondary materials will

16

Keynotes

influence the range of potential applications of such materials and thus the associated positive environmental impacts.

Figure 8: Environmentally friendly lightweight design, aspects and measures. Seen from this overall perspective therefore, it is clear that environmentally friendly lightweight product development offers a wide range of different measures. In addition to the engineers in the automotive industry, the other stakeholders in the value chain (materials manufacturers, suppliers, recycling companies) likewise have their part to play in further improving their products and enhancing the life cycle environmental impact of vehicle concepts of the future.

5

CONCLUSIONS

As demonstrated above, life cycle assessment is a powerful tool which can be used as an environmental management instrument within the product development. For successful life cycle engineering the formal incorporation of life cycle thinking into the company policy is a necessary pre-requisite. Additional success factors which have to be met are the transformation of LCA results into measurable targets for engineers. Based on given environmental targets, such as a certain target value for greenhouse gas emissions, LCA can be used to calculate a specific technical target such as the weight of a component, the fuel consumption of a vehicle or the minimum amount of recycled content in a product. The transformation of pure LCA results into measurable target values, which can be understood by engineers, will clearly show the added value which LCA can give in terms of life cycle engineering. Even for very complex products with a huge variety of different materials and a complex value chain life cycle assessment can be performed with a reasonable time demand, with good quality and integrated efficiently into business processes.

6

REFERENCES

[1]

International Organization for Standardization (2006): ISO 14040: Environmental Management – Life Cycle Assessment – Principles and Framework, International Organization for Standardization, Geneva.

[2]

International Organization for Standardization (2006): ISO 14044: Environmental Management – Life Cycle Assessment – requirements and guidelines, International Organization for Standardization, Geneva.

[3]

Schweimer, G.W.; Schuckert, M. (1996): Sachbilanz eines Golf. In: VDI Bericht 1307 Ganzheitliche Betrachtungen im Automobilbau. Wolfsburg.

[4]

Schweimer, G.W. (1998): Life cycle inventory of 3-L Lupo. Volkswagen AG, Wolfsburg.

[5]

Schweimer, G.W.; Bambl, T.; Wolfram, H. (1999): Sachbilanz Seat Ibiza. Volkswagen AG, Wolfsburg.

[6]

Schweimer, G.W.; Levin, M. (2000): Life cycle inventory of Golf A4. Volkswagen AG, Wolfsburg.

[7]

Schweimer, G.W.; Roßberg, A. (2001): Sachbilanz Seat Leon. Volkswagen AG, Wolfsburg.

[8]

Rosenau-Tornow, D.; Buchholz, P.; Riemann, A.; Wagner, M. (2009): Assessing the long-term supply risks for mineral raw materials - a combined evaluation of past and future trends. In: Resources Policy 34, 161–175.

[9]

VW standard 91100 www.vwgroupsupply.com

[10] Koffler, C.; Krinke, S.; Schebek, L.; Buchgeister, J. (2007): Volkswagen slimLCI – a procedure for streamlined inventory modelling within Life Cycle Assessment (LCA) of vehicles. In: International Journal of Vehicle Design (Special Issue on Sustainable Mobility, Vehicle Design and Development), Olney: Inderscience Publishers.

Leveraging Manufacturing for a Sustainable Future David Dornfeld Laboratory for Manufacturing and Sustainability (LMAS), University of California, Berkeley, California

Abstract Manufacturing offers many opportunities for reducing environmental impact, utilizing resources more efficiently and, overall, greening the technology of production. These opportunities are most often related to process, machine or system improvements that impact only the operation of the process, machine or system. But, there is more potential in manufacturing enhancements to have a larger impact on the life cycle impact of the product the manufactured item is used in. This is referred to as “leveraging” and several examples of this are given, along with definitions of the fundamental terms. The potential for leveraging in manufacturing to have an impact on sustainable manufacturing and some future requirements are described. Keywords: Process; Machine; System Improvement; Life Cycle Impact; Make versus Use

1

INTRODUCTION

Manufacturing offers many opportunities for reducing environmental impact, utilizing resources more efficiently and, overall, greening the technology of production. These opportunities are most often related to process, machine or system improvements that impact only the operation of the process, machine or system. But, there is more potential in manufacturing enhancements to have a larger impact on the life cycle impact of the product the manufactured item is used in. This is referred to as “leveraging” and identifies manufacturing-based efficiencies in the product that are due to improved manufacturing capability but which, in the long run, have their biggest effects on the lifetime consumption of energy or other resources or environmental impacts. First, what is meant by the term “leveraging”? We understand a lever to be a device to increase mechanical advantage, as a bar used with a fulcrum to pry a heavy load allowing a larger load to be moved than with simple force alone. Leveraging is used as a transitive verb, usually in financial discussions such as [1]: “The use of credit or borrowed funds to improve one's speculative capacity and increase the rate of return from an investment.” The general idea is to employ resources in such a way as to insure a larger return on the effort (or in financial terms, money) than might otherwise be realized. How does this relate to manufacturing? And, in specific green manufacturing? This will depend on the component being manufactured by a machine or process and its eventual use in a product. This paper will first provide some definitions so that the use of terms like green manufacturing, sustainable manufacturing, etc. will be understood. Then, the concept of leveraging manufacturing will be explained and several examples of will be given of situations that provide leveraging along with some that do not. Finally, future directions in sustainable manufacturing driven by leveraging are suggested.

2 2.1

BACKGROUND AND TERMINOLOGY Green and sustainable

The familiar Brundtland Commission definition of sustainable development - “Sustainable development is development that meets the need of the present without compromising the ability of future generations to meet their own needs” [2] does not really speak to manufacturing but makes the key point that we need to at least “do no harm.” The US Department of Commerce defines sustainable manufacturing as “the creation of manufacturing products that use materials and processes that minimize negative environmental impacts, conserve energy and natural resources, are safe for employees, communities, and consumers and are economically sound” [3]. We define green manufacturing here as a first step towards sustainability. These first steps were proposed as green manufacturing “technology wedges” in [4] after a concept proposed by Pacala and Socolow [5] to address the big gap between the present trajectory and impact of CO2 on the atmosphere (business as usual – BAU) and a sustainable level – and how to close this gap in 50 years. They argued that, rather than trying to find one solution to correct this increasing mismatch between what is required and what is being done, we should concentrate on “technology wedges” – small advances and improvements that, when added up, have the effect of a large change. These wedges make a lot of sense in the context of manufacturing and sustainability. We can visualize sustainability as a relationship between consumption or impact as part of normal business practice compared to a “sustainable level.” For example, in California we store rainfall during the winter months as snow in the Sierra Nevada mountains. The amount of snow determines the amount of water we have to use in the next season for residential, commercial and agricultural use. If we use water at a rate that will exhaust the supply before the next rainfall – that is not a sustainable situation. We are using too much and should find a way to conserve or reduce usage. We could make the same argument for impact, for example, green house gas generation. The atmosphere has a

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_3, © Springer-Verlag Berlin Heidelberg 2011

17

18

Keynotes

certain capacity to accommodate green house gases. Exceeding that risks a build up that will endanger future generations according to the predictions of atmospheric scientists. We can illustrate this as seen in Figure 1 below, from [6]. The figure illustrates the normal trend of consumption or impact over time. A small reduction of either one results in a reduced rate of impact but does not provide enough change to achieve a sustainable situation. The application of technology wedges to, collectively, bridge the gap between present rate of consumption or impact and a sustainable level is illustrated with the green triangles. With sufficient wedges, the gap can be closed.



Pollution (air, water, land)



Ecological footprint - “fair share” - footprint



Exergy (available energy) or other thermodynamic measures

To be able to understand the effect of the improvement or change being measured, these can be represented in terms of a "return on investment" - for example, greenhouse gas return on investment (GROI). Other forms of return measure include: 

Energy payback time



Water (or materials, consumables) payback time



Carbon footprint



Efficiency improvement (for example, wrt exergy)

Then, a measure of the change in the T term of the impact équation can be determined. For green manufacturing these need to be linked to traditional design and manufacturing parameters. And they need to be assessed over all three scopes of ISO 14064 (1- direct emissions from on-site or company owned assets, 2- indirect emissions created on behalf of the company from energy generation or supply, 3- all others resulting from business operation including business travel, shipping of goods, resource extraction and product disposal). 2.3

Figure 1: Illustration of sustainable consumption and technology wedges, [6]. It is our role of manufacturing researchers to develop the wedge technologies. Individual wedges might be considered as “green” manufacturing steps. If there are sufficient greening steps we can achieve sustainable manufacturing. 2.2

Tracking progress

To insure that real progress is being made it is necessary to define metrics to measure change. Recall the “master equation” for impact attributed to John Holdren and Paul Ehrich [7]. This equation, sometimes referred to as IPAT, defines human impact (I) on the environment as the product of population (P), affluence (A, measured as GDP/capita), and technology (T, measured as impact per unit of GDP). Manufacturing has its impact on the T part of the equation – the impact per unit of technology. This is the impact per GDP of manufactured products. By reducing that impact, we start to “bend the curve” of the consumption or impact curve seen in Figure 1. The challenge is to come up with technology wedges that will reduce the T part of the équation at a rate sufficiently fast to offset population growth while at the same time make a dent in the impact that is already too high. Metrics are used by engineers for analyzing information and data to enable better decision making, including trade-offs among several alternatives, and for design. For green manufacturing these metrics could include: 

Global warming gas emission (e.g. CO2, methane CH4, N2O, chlorofluorocarbons, CFC’s) 

per capita



per GDP



per area/nation



Recyclability (or percent recycled)



Reuse of materials



Energy consumption

Leveraging

We can define two different classes of leveraging of manufacturing. The difference is due to the magnitude of the impact. That is, whether it impacts only the performance of the manufacturing process, machine or system or whether it impacts the performance of the product resulting from the application of the process, machine or system. An additional distinction must be made for products used in manufacturing – for example, machine tools. In the case of an improvement, say in energy consumption of a process, we would require that, at minimum, the “cost” of the improvement (in embedded energy, carbon footprint, etc.) would be more than offset but the reduction in energy consumption or carbon footprint in operation of the “improved” process. This is the basic definition of energy payback or green house gas return on investment. The magnitude of the impact reduction can be measured simply by knowing the number of manufactured products coming from the process over the life time of the process. This is a minimum amount of leveraging for any contemplated process improvement to insure that we are making progress. A second, more impressive, leveraging is due to process (or machine or system) improvements that have an inordinately high ability to reduce the impact of the product of the manufacturing operation (or machine or system) over the lifetime of the product use. The original process improvement may not have been made as part of a greening analysis of the process but is due to the introduction of new technology, machine capability or materials. It is this second type of leveraging that is likely to have the greatest potential for reducing the T term in the impact equation – making a larger than normal reduction in the product impact/GDP during the product’s life time. Why this distinction is important is discussed in the next section. 3 3.1

WHY LEVERAGING IS IMPORTANT Does manufacturing matter?

The base of this discussion is an assessment of whether or not manufacturing is a significant component of energy and resource consumption and the impact from this consumption, and, then, whether or not changes in manufacturing can really help overall. A review of all the data, pie charts and discussions about how much

Keynotes of the world’s energy use is attributed to manufacturing is not presented here.

19 consumption, and that is worth another 20%. Now we are down to .8% (20% of 4%).

Allwood et al [8] point out that industrial carbon emissions are predominately due to production of goods in steel, cement, plastic, paper, and aluminum. With the demand for these materials expected to double at least by 2050, during which the global carbon emissions are desired to be reduced by at least 50%, simply improving process efficiency will fall far short. Allwood suggests several strategies for industrial emissions reduction in addition to process efficiency, increased recycling, and carbon sequestration and storage, as: (1) reducing demand for materials; (2) nondestructive recycling; and (3) radical process innovations which allow shorter, less energy intensive process routes to yield the completed component. These all address the T term in the IPAT equation. But, for “general product manufacturing” is there enough that can be accomplished by manufacturing improvement? Specially if we apply this to what many of use consider our core process capabilities – like machining? 3.2

Figure 2: Primary energy consumption for VW Golf manufacture [9].

Automobile manufacturing example

If we think about where the major energy consumption associated with a product occurs we can divide the space up into two regions – manufacturing and use. We see that "things that don't move or need power to operate" like bridges, furniture, etc. are dominantly manufacturing phase consumers of resources and, by extension, impact. Things that do "move and need power to operate" like automobiles, airplanes, buildings, etc. are use phase heavy. Interesting to note are the items that are close to the break-even (imagine a 45 degree line on a plot of use vs manufacturing impact graph for products). So, what about automobiles? At a presentation at the ICMC Conference in Chemnitz in September 2010 by a representative of the automaker VW, the speaker mentioned that, by their analysis, about 20% of the impact of a typical VW Golf A4 car came from manufacturing while 80% was due to the use phase. One can find data on the GolfA3 (marketed from 1991-1999, also called the Polo) from some time ago and the comparison was similar. Figure 2, from [9], shows the energy consumption during the manufacturing phase of the GolfA3 in Gj/auto. Materials and part suppliers account for much of the embedded energy in the manufacturing phase. Machined components, such as the gear box and engine are a small percentage of the total (accounting for about 10% overall or about 25% with materials and parts from suppliers included). If one looks at the impact of the auto, including car production, fuel production and use phase, Figure 3 from [9], it is clear that the fuel production and consumption in the use phase dominates all categories of emissions to air and water with the exception of dust generated by material production and casting of some components and painting of the vehicle and biological oxygen demand impacts on water. Looking a bit closer at the data above, does this make sense in terms of reducing the impact/GDP? If we focus only on the manufacturing phase we may not be encouraged - specially if the predominant impact is in the use phase. Consider the VW Golf example of 20% manufacturing phase impact versus 80% use phase impact. If we think about the areas many in our community work in a lot, machining, and we assume about 20% of the manufacturing is machining or machining related, that gives us a potential for improvement of 20% of 20% or only 4% (and then only if we get rid of all machining!). Let's assume that some of the better technology for improving machining efficiency is employed, say some specialty tooling material that reduces machining power

Figure 3: Use vs manufacturing phase impacts for VW Golf [9]. One could argue that this is hardly worth the effort it would seem. Of course, if you are paying the electricity bill for the factory and this 8% technology wedge is added to a lot of others in machine operation it can add up to real savings. But, still not impressive compared to use phase impacts. That is, impact over the full life cycle of the auto. More recent data from Volkswagen for the Golf A4 indicates that some improvements have been made (for example reduction of primary energy used in production, use and end of life due primarily to improved fuel consumption (a 20% improvement from 8.1 liter of fuel/100 km to 6.5 l/100 km for the gasoline engine) [10]. 3.3

Accounting for more of manufacturing’s impact

The question is, then, what is the true leverage effect of manufacturing on the life cycle impact of a consumer product – one that has its dominant impact in the use phase rather than the manufacturing phase? If we are speaking of a manufacturing machinery builder, like a machine tool company, then we can argue that the machine tool has its largest impact in the use phase so that improvements in energy efficiency of the machine will been seen over its life [11] since it is the “product.” The thesis here is simple. If improvements in manufacturing yield a substantial reduction in the life cycle impact of a product, should not manufacturing get some of the “credit” for this improvement. And, by similar reasoning, can we claim this as a part of “green manufacturing” contribution towards sustainability since it is a major element in reducing the technology impact of the product – the T term in the IPAT equation? The next section gives some examples of this leveraging effect.

20 4 4.1

Keynotes EXAMPLES OF LEVERAGING Basic influences

Manufacturing has a number of fundamental effects on a product. In no particular order, manufacturing can: 

guarantee a certain level of precision or accuracy of the produced component



allow the use of advanced materials (enhance strength to weight, improved surfaces, wear resistance, thermal stability, etc.)



allow reductions in process steps or sequences



combine processes for enhanced effects as in hybrid processes or mill-turn machine tools



achieve complex shapes or features to improve performance



and so on

reduction of almost 2.5 kg/km CO2. And this is over the life of the aircraft – many millions of kilometers. The next example relates to a similar impact on product use for an automobile. It is also due to enhancement in manufacturing capability due to precision manufacturing. The improvement for the Boeing aircraft example was based on tightened tolerances allowing increased structural performance by better control on dimensions - resulting in lower weight components. Looking at improvements in engine performance for automobiles we can see similar improvements. The performance (power density in kW/l) of diesel passenger car engines is shown in the graph in Figure 4 from [15]. With better tolerances, better

There are more but you can get the idea. How these manufacturing induced effects influence the life-cycle performance of the product must be clearly understood to explain the full potential of leveraging. This influence usually comes from the extension of one of the above listed effects onto the energy consumption or “environmental performance” of the product the manufactured components are used in. A simple example might be a spindle motor for a machine tool. If the production technique for the motor, using advanced magnetic materials, allows the construction of a motor that extracts more useful work from the energy supplied to it, then the manufacturing effect is leveraged over the life of the spindle. Alternatively, if the improvement in energy consumption is due to controller related performance enhancement, as the 40% reduction in energy consumption illustrated by Mori Seiki due to overall system component improvements and optimum acceleration of spindle and servo motor during machining [12], this is not due to manufacturing leveraging but, certainly, improves the life cycle impact of the machine tool – the product in this case. 4.2

Leveraging examples

Two examples are presented here that illustrate the concept of leveraging manufacturing with life cycle impacts on the product that the manufactured component(s) is (are) used in. And the life cycle impact is substantial and most of the benefits are due to manufacturing. Both of these examples relate to improved machining tolerances and their impact on product performance. On an aircraft airframe (a large one like a B747 or the A380) savings in weight correspond directly to savings in fuel. And many other aspects of an aircraft scale with weight. This is, to some extent, true also for an automobile. That is the second example If the machining process for large airframe components is under control and precision manufacturing principles applied, a reduction in machining tolerances from approximately +/- 150 microns to +/100 microns on the features of the airframe can account for a weight reduction of 4500 kg/aircraft and substantial fuel savings (8%) [13]. This allows an increase of 10% in passenger load (the engines don't need to carry as much plane), or increase in cargo payload and a substantial reduction in manufacturing cost of the aircraft (less material and improved assembly) and the accompanying reduction in scrap. And less fuel consumption means reduced CO2 impact from aircraft operation. The accumulated savings over the life of the aircraft are incredible. The fuel consumption per km is estimated as 11.88 L/km (or about 5 gallon per mile). Thus, the CO2 emission rate can be estimated at 30.64 kg/km [14]. A reduction in fuel consumption of 8% results in a

Figure 4: Change in power density over time for Diesel engines [15]. surface finishes, better control of orifice size and shape on the fuel injector nozzles (with diameters on the order of 60 microns), tighter control on cooling channels and fluid flow in the engine due to enhanced casting techniques, and so forth, the engine (still working on the same old Diesel principles) performs dramatically better. The "dog leg" in the chart above corresponds to the introduction of high performance, precision, manufacturing to the power train manufacturing in the automobile. In the years since 2000, the power density has been improved by double (in 2007) and anticipated to quadruple by 2020, Similar improvements can be seen in the transmission as well. And, with advanced sheet metai forming technologies (another manufacturing technology enhancement) and replacement of metal components with non-metallics (manufacturing and materials enhancement) more improvements would be anticipated. This is not to suggest that precision technologies had not been employed before. But, the engine and associated fuel injectors, etc. were designed to take advantage of increasing manufacturing performance and, as a result, yielded tremendous product performance as well. And that is how to reduce the technology impact per GDP. Manufacturing dramatically increased the efficiency of fuel utilization in the internal combustion engine. The small percentage of manufacturing phase improvement has a giant leverage effect on use phase impact. Since the principal element in use phase impact of the automobile, the reduction in consumption (due to increased power density of the engine), hits both the fuel production impact as well as the fuel consumption impact there is additional impact. In the Golf A3 data for emissions, Figure 3, 90% of the CO2 impact was due to the use phase (81% from driving and 9 % from fuel production). A doubling of the fuel economy, by manufacturing induced engine efficiency

Keynotes

21

improvements, by precision machining and processing will essentially halve that (same distance driven) - or account for, in the case of the Golf A3, a reduction of some 16 tons of CO2. And if, in the process of manufacturing enhancement, we save most of our 4% impact from machining, that's .4 ton of CO2. So, for our .4 ton we get a return of 16 tons (a factor of 40!).

7

4.3

REFERENCES

[1]

http://www.thefreedictionary.com/leveraging, 1/16/2011.

[2]

Brundtland Commission, i.e. World Commission Environment and Development (WCED) (1983).

[3]

http://www.trade.gov/competitiveness/sustainablemanufa cturing/how_doc_defines_SM.asp; accessed June 21, 2010.

[4]

Dornfeld, D. and Wright, P., (2007): “Technology Wedges for Implementing Green Manufacturing”, NAMRI Trans., 35, pp. 193-200.

[5]

Pacala, S. and Socolow, R., (2004): “Stabilization Wedges: Solving the Climate Problem for the Next 50 Years with Current Technologies,” Science 13 August 2004: Vol. 305. no. 5686, pp. 968 – 972.

A second issue is whether or not manufacturing can rightfully claim credit for any or all of these improvements under leveraging. Traditional design textbooks outline the design process in stages with clever designs being turned into real products through manufacturing. So, for sure, the role of manufacturing as a design enabler is undisputed. In that case, we can claim the benefits of leveraging manufacturing as well.

[6]

Dornfeld, D., (2010): “Sustainable Manufacturing – Greening Processes, Systems and Products,” Proc. ICMC Sustainable Production for Resource Efficiency and Ecomobility, Fraunhofer Institute for Machine Tools and Forming Technology, Chemnitz University of Technology, Chemnitz, September, 2010.

[7]

Ehrlich, P. R. and Holdren, J. P. (1971): Impact of population growth, Science, 171, 1212-1217.

5

[8]

Allwood, J., Cullen, J., and Milford, R. (2010): “Options for Achieving a 50% Cut in Industrial Carbon Emissions by 2050,” Environ. Sci. Technol., 44 (6), pp 1888–1894.

[9]

Volkswagen AG, and Harald Florin, PE Europe/IKP-University of Stuttgart, Germany from a presentation of A. Horvath, UCBerkeley, 1995.

The fine print

There are constraints of course. The technology enhancement (the “wedge”) needed to improve precision of the machine tool to enable some of the product performance increases may not be strictly “green” (meaning there is a cost in terms of embedded energy, energy/unit product, or other measure). Trends in machine and process design are showing that one can enhance the performance of the manufacturing process and also realize reduced impacts. Recall the Mori Seiki example cited earlier. But, this needs to be carefully accounted for.

SUMMARY

This paper has proposed a view of the potential for manufacturing to play a more significant role in reducing the environmental impact of technology. The manufacturing capabilities that yield aircraft or automobile engines with dramatically reduced fuel consumption, or structural components for aircraft that allow higher payloads per unit of aircraft structure, or advanced processes that yield lower power electronics for reduced energy consumption, and so on, are examples of leveraging manufacturing. We cannot claim all benefits in product performance stem from manufacturing. An enhanced wash cycle on a home laundry that reduces water and energy consumption has likely very little to do with manufacturing technology improvements. But we should stand up for those manufacturing driven improvements that, on their own, are responsible for substantial environmental impact reductions. The challenge raised by researchers, like Allwood, pointing out the fundamental changes needed in production technologies (specially for materials processing and efficient material use) must be complimented by the tremendous potential for leveraged manufacturing. It points out, at least, the significant role that manufacturing (broadly defined and over all processes and systems) can play in creating a sustainable future. Finally, we need some numbers! The arguments presented here are based substantially on empirical observations. A more careful analysis of the tradeoffs of competing technologies with respect to potential leveraging effects must be done for several case studies. That is on the agenda for our future work. 6

ACKNOWLEDGMENTS

The author acknowledges the researchers and affiliates of the Laboratory for Manufacturing and Automation (LMAS) and partners in the Sustainable Manufacturing Partnership (SMP) for their helpful discussions and support of this research. For more information see lmas.berkeley.edu and smp.berkeley.edu.

accessed on

[10] Schweimer, G., and Levin, M., “Life Cycle Inventory for the Golf A4” posted on line at www.volkswagenag.com/.../Golf_A4__Life_Cycle_Invento ry.../golfa4_ english.pdf; accessed 1/18/11. [11] Diaz, N., Choi, S., Helu, M., Chen, Y., Jayanathan, S., Yasui, Y., Kong, D., Pavanaskar, S., and Dornfeld, D. (2010): “Machine Tool Design and Operation Strategies for Green Manufacturing,” Proc. 4th CIRP International Conference on High Performance Cutting, Gifu, Japan. [12]

Mori, M. (2010): “Power consumption reduction of machine Tools,” présentation at 2010 CIRP General Assembly CWGEREE, August, Pisa.

[13] Thompson, D. (1995): presentation at Symposium on Research Issues in Precision Manufacturing, Univ. of California, Berkeley, September, 1995. [14]

http://micpohling.wordpress.com/2007/05/08/math-howmuch-co2-released-by-aeroplane/; accessed 1/18/11.

[15]

Berger, K. (2005): Daimler, Presentation at CIRP January 2005 Meeting, WG on Burr Formation, Paris.

Sustainability Engineering by Product-Service Systems Günther Seliger Department of Machine Tools and Factory Management, Chair of Assembly and Factory Management, Technische Universität Berlin, Berlin, Germany

Abstract Product-Service Systems offer high potentials for increasing the use productivity of resources. Functionality can be provided in specification how, on place where and in time when needed for the user by modern communication and logistics. Business models change from selling products to selling functionality due to fixed costs of under utilized products being higher than additional costs for communication on demand and supply, and for transport of artifacts to places of performance. Remanufacturing, disassembly and reassembly enables for same products and components performing as required in consecutive different usage phases thus avoiding disposal of valuable resources. Methods for product design with respective components, performance supervision, maintenance of components, configuration for different usage specifications, user’s and provider’s qualification, ubiquitous access on information about demand and supply to create efficient functionality markets, all represent product related services for the functionality business thus achieving more functionality with fewer resources. Keywords: Sustainability Engineering; Value Creation; Product-Service Systems

1

INTRODUCTION

Sustainability Engineering is on exploiting the dynamics of fair competition to achieve the required sustainability of our global living conditions by processes of knowledge creation and innovation. Product-Service Systems (PSS) exploit design potentials for new business models by shaping interrelations between tangible products and intangible services. They enable for innovative function, availability and result oriented business models. These models can help in reducing resource consumption and waste generation by fewer resources providing more functionality. Supplier’s motivation is changed from selling ever higher numbers of products to the customer with ever lower costs of manufacturing to selling ever more functionality to the customer with ever lower input of resources. The old manufacturing paradigm of producing big lot sizes for low costs per piece is challenged by providing more functionality with fewer resources. Tangible resources are partly substituted and partly supplemented by intangible services. Sustainability in its three dimensions of economic, environmental and social concern helps in directing the processes of technological innovation. Economic challenge is in market competitivity of resource saving product service design. Environmental challenge is in resource efficiency and effectiveness, e.g. no longer disposing non renewable resources by consequent adaptation for consecutive different usage phases, also in substituting non renewable by renewable resources within the constraints of sufficient renewable resource generation. Social challenge is in establishing the awareness of users and developers for mankind’s threat if not adapting ways of living to fair wealth distribution within environmental constraints. How can PSS contribute to meet the challenge of sustainability by competitive offers of minimal necessary tangible products integrated with required service functionality? The threat of ignoring the conflict potentials of unequal global wealth distribution, the saving potentials in resource exploitation for useful applications is illustrated. Chances of PSS approaches for exploiting these potentials are described.

2

CHALLENGES OF SUSTAINABILITY

Predominantly all over the world industries are still working in source-sink economic patterns relying on resource availability without limitations. Non renewable resources are often exploited for only one usage phase with consecutive disposal. However, there are huge potentials of recycling of products, components and materials. Also, substituting non renewable by renewable resources within their limits of regeneration can help avoiding upcoming shortages in resource supply for a growing population with expectations on higher standards of living. Earth’s resources are limited. Out of the present global population of about 6.7 billion people -9.5 billion are prognosed for 2050-, less than one billion belong to the industrialized world in Europe, North America, Japan, South Korea, Australia, and few islands of wealth. China with its population of 1.3 billion and India with 1.1 as well as other developing and emerging countries are striving to catch up. If the lifestyles of the upcoming nations are shaped by the existing, predominating technologies, then the resource consumption will exceed every accountable economic, environmental and social bound. The question arises, which production technologies can serve as basis for dealing with this growth, in an economically, environmentally and socially responsible manner. Independent of the exact limits of access to virgin non-renewable resources, alone due to the increasing material demands of more people with increasing standards of living, non-renewable resources worn out after usage phases of products must not be disposed any more but regained in product or material cycles. Due to limited availability and increasing demand an increasing increase in prices for non renewable resources as aluminum, copper and iron can be observed. Between 2006 and 2009 the costs for import of raw materials to Germany have grown from 31 to 86 billion Euros, including 16 billion Euros for metals. The price for copper e.g. increased from 3300 Dollars per ton in the beginning of 2009 to 6000 Dollars per ton in August 2010, an increase to 10,000 Dollars per ton is expected for 2011. Expanding application areas

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_4, © Springer-Verlag Berlin Heidelberg 2011

22

Keynotes for copper are expected in electrical vehicles and infrastructure for electrical energy supply. Rare earth materials are required for luminous diodes, batteries and photovoltaics, all areas with expected market growth in applications but limitations in raw material purchase. Recycled material becomes the only source of raw material available in the long term [1]. Already 56 percent of copper applied for manufacturing in Germany has been recycled. Keeping ownership on materials to avoid consequences of fluctuating prices for a stable functionality business might be a competitive approach for innovative PSS. Energy availability is a fundamental premise for any material wealth creation. Nearly one third of primary resources for global energy conversion presently stems from crude oil. Estimates on remaining reserves lie between 1000 and 3000 billion barrels. The date of peak-oil, i.e. the date from when on oil production remains constant or even decreases, is expected for 2020 at latest. Obviously saving primary resources for energy consumption in global dimensions is a huge challenge in responsible management of resources. The amount of primary resources for energy consumption worldwide has increased from 2000 to 2008 by 25% to over 500 EJ 18 15 (EJ = 10 Joule) or over 140 PWh (Peta Watt hour = 10 Wh). Germany with 80 million people accounting for one percent of the world's population of 6.7 billion consumes energy of 14 EJ or 4 PWh accounting for about three percent of world consumption. Crude oil with 30%, natural gas with almost 20% and coal with 25% have taken about three quarters of primary resource contribution for energy consumption and caused CO2 emissions of nearly 30 Gt 9 (10 t). Biomass with over 10%, nuclear with 6% and renewable energy are contributing another quarter of world primary resources for energy consumption [2] [3]. Figure 1 shows a gross quantitative assessment of the global energy flow without losses in transformation from primary resources to useful applications. Passenger and goods transport each account for one eighth of consumption in final application, industrial production for one third, and two fifth are for infrastructure with substantial proportions for building, heating and food production. Between primary resource input and final consumption, there are many different processes and production facilities. The key elements of this transformation are the direct fuel use in machinery and equipment with approximately three fifths and electrical generation with two fifth shares. The movement of vehicles and machinery is generated with about one third, and process heat with about half of primary energy use. The consecutive steps and different paths in conversion of primary resources to energy driven operations offer big potentials for

23 increasing efficiency and effectiveness. Often these potentials are already baled out within the balance frame of respective entrepreneurial institutional activities. By integrated product and service innovation PSS independently from traditional balance frames can create new business models of providing more functionality in application by less investment in instrumental facilities. E.g. providing customers with energy saving equipment thus saving electricity consumption can be cheaper than investing in additional power stations. Diesel engines directly driven by fuel might save conversion losses of electrical power generation required for electrical drives. Overcoming grown thinking, living and working habits requires new means of convincing people by teaching and learning, by softly integrating innovative artefacts in existing living environments. Mutual dependencies of tangible products and intangible services must be thoroughly considered for successful implementation [4]. The ecological footprint represents a measure for the consumption of renewable resources. About one quarter of earth’s surface, accounting for 11.3 billion hectares, can be considered as biologically productive area contributing to the regeneration of resources. The average amount of biocapacity per capita on earth is calculated by dividing the productive area by the number of people on earth, what results in 1.8 global hectares biocapacity per capita. Since approximately 1985, resource consumption on a global level is higher than the ecological capacity. For 2050, an impossible biocapacity of two globes would be required if the trend of increasing renewable resource consumption would be not stopped. Half of global population is still living without access on electricity and telecommunication, earning less than two Dollars per day. One fifth of global population disposes of four fifths of global wealth. Environmental damages caused by unbalanced resource exploitation and considerable lacks in human education lead to social conflicts and terror. Presently there are 25 local wars on the earth. Culture and education for billions of people have become the dominant social challenge for human survival on earth. PSS approach seems to be promising means to cope with this challenge. Also the global population growth must be stopped by better standards of living without increasing resource consumption. Social stability can only be achieved if mankind is able to create jobs and living conditions of human dignity worldwide and not only in the technologically developed regions of East Asia, North America and Western Europe. Rapid technological development, diversity, creativity, entrepreneurship and dynamism in competition and cooperation

Figure 1: Quantitative assessment of global energy conversion in primary resource shares without losses in transformation.

24

Keynotes

shape the living environments for the global citizens from the regions of prosperity, but also bring an irresponsible waste of resources. The responsibility of the wealthy minority enables for technological development based on criteria of sustainability in order to harmonize the quality of life and resource use. This challenge offers with great opportunities in sustainable services, products and processes for value creation. Sustainable development with social innovation is also important to open the hungry market of more than 5 billion people who still have not enough purchasing power.

sustainability. Referring to requirements of communication, to training and educaton, to maintenance and repair, to knowledge creation and information access for continuous improvement, to setting up competitive offers for resource saving functionality markets, PSS can considerably contribute to sustainable value creation.

Due to the unbalanced development along developed, emerging and developing countries, it is difficult to reach a new agreement after Kyoto Protocol to reduce the carbon emission. Carbon emission relates with the economic development and environmental protection. Governments are conflicting about individual national wealth development, access on resources and responsibility for climate change. But all of them are concerned about how to reduce the CO2 emissions to protect the environment. The rationally required sustainable global development can stimulate the forces of human initiative and creativity. Sustainable global development could eliminate the unfair distribution of opportunities by technological and social innovation [5]. Mankind’s wealthy minority has the responsibility to identify innovative paths for sustainability engineering. Great opportunities are opened in sustainable services, products and processes for value creation. Social innovation can help to open the new markets of more than 5 billion people. Technologies from developed and emerging countries can empower help for the poor people to help themselves. Product-Service Systems (PSS) offer chances to fulfill the challenge of sustainable development. The potentials of PSS in resource saving and qualification may succeed to develop economies and civilization in the global discourse. 3

VALUE CREATION

Value creation can be modelled considering both, actual entrepreneurial activities in globalized markets and requirements of sustainable development. Market dynamics can be powerful drivers in achieving sustainable develoment for global mankind along economical, evironmental and social criteria by technological innovation. Figure 2 describes an architecture for sustainable global value creation. Value creation factors are integrated in modules to be designed along economic, environmental and social criteria of sustainability. Cooperation and competition among entrepreneurs drive for horizontally and vertically integrating modules thus constituting value creating networks. There are different levels of hierarchy in value creation. From manufacturing tool and operation via value creating cells and systems, whole factories to national and international entrepreneurial conglomerates or knowledge generating educational communities. Each of them from top-down pespective is considered as a network consisting of modules and from a bottom-up perspective as a module together with other modules contributing to a network. Modules or networks can be set up under different infrastructural conditions in industrialized, emerging or developing countries respectively regions within countries. Value creation in an engineering perspective addresses the development of artefacts for useful applications thus shaping areas of human living. From the module view in a bottom-up perspective entrepreneurs try to get their specific value contribution integrated in higher level networks, whereas, from the network view in a top-down perspective entrepreneurs try to purchase original elements enriching their product system from lower level modules. The dynamics of demand and supply in this mutual dependency offers chances for directing global value creation to pathes of

Figure 2 : Architecture of Sustainable Value Creation.

4 4.1

POTENTIALS OF PRODUCT-SERVICE SYSTEMS Business Model

Product-Service Systems (PSS) are an integrated product and service offering that delivers values in industrial applications. PSS must be understood as a new product consisting of integrated product and service shares, which comprises the integrated and mutually determined planning, development, provision and use. PSS includes the dynamic adoption of changing customer demands and provider abilities. The partial substitution of product and service shares over the lifecycle is possible. There are different models for PSS, the individual business models can be differentiated by further criteria [6]. They differ in the responsibility of production result, personnel, service initiative and finally the ownership of the products, e.g. machine tools. This means the provider takes over responsibilities in the production process by delivering service personal, initiating services and ensuring the production quality, see Figure 3.

Figure 3: Specification of innovative use models [6].

Keynotes

25

A competitive provider offers product functionality, availability or a result in quality, time and location as required by the user. Multiple usage phases make a PSS competitive by maximizing the utilization of resources and can be achieved by disassembly, component adaptation, and reassembly. The opportunity to optimize the use phase is the key for success in consequence of more freedom of business and engineering development. The PSS business model takes as its starting point the goal of achieving an integrated functional solution to meet client demands, moves away from phase based servicing and discrete resource optimization, to system resource optimization which is utility based. The resulting PSS can produce synergies in profit, competitiveness and environmental benefits. The potential eco-efficiency of a PSS relies on system optimization in resource use and emissions because of the stakeholders’ convergence of interests [7]. Further PSS enables an equipartition for the use of technology. It allows the adoption of the right technology and a competitive production also for low-budget small medium enterprises (SMEs) and emerging countries at the time, place and in the specification which is needed. PSS can lead to reduced resource use and waste generation. The increase in sales of services can balance reductions in sold products. Employment lost in manufacturing can be balanced by jobs created in services. As a business concept, PSS have the potential to improve access to technology worldwide. With PSS, consumers worldwide would have less need to buy, maintain, dispose of, and eventually replace a product. In fact, the quality of the service, and thus consumer satisfaction, may improve with PSS because the service provider has the incentive to use and maintain equipment properly, increasing both efficiency and effectiveness. The incentive also exists for producers to design closed-loop systems for equipment based on designs for higher durability and recyclability [7]. To be competitive on the market the PSS providers have a strong interest in using a minimum of production resources, which means maximum utilization and usage of products and components. Therefore a provider will use production equipment out of a PSS in a new or other PSS. Resources will have several life cycles. This is possible because of the shift of the ownership in PSS and leads to a cycle economy. Human beings in the phases of planning, development and delivery of PSS play a major role; especially the human-machine interaction in the phase of delivery is in the focus. Different qualification of technicians and company-spanning cooperation in the field of industry demand a specific support concept during the delivery of services. Figure 4 addresses the economical, environmental and social motivation and technical progress, being sustainability contributions of PSS.

Figure 4: Contribution on Sustainability by PSS.

In developed countries, which already have a large environmental footprint arising from a high rate of per capita resource consumption, PSS can facilitate the transition toward a more service-oriented, sustainable society. The service industry gets the chance to find new and increasing market opportunities. Other benefits include reduced dependance on externally produced resources and reduced load on waste disposal facilities. For emerging countries, PSS may represent a more promising and environmentally sound path to economic development since it enables them to bypass the development stage characterized by individual ownership of goods. A cycle economy is not only environmentally reasonable but also a chance for new businesses. Selling functionality instead of selling products is advantageous once additional costs for information processing and logistics are less than costs for underutilized capacity (Figure 5).

Figure 5: Selling functionality instead of selling products. From the point of qualification the use of technology is limited. Especially in developing countries the qualification level of worker and technicians is not comparable to the one in the developed world. However, the provider has to take care that his products are usable, as promised in the contract. The challenge is to qualify the local worker and technician from the customer or contractors and supervise their work from distance. 4.2

Knowledge Management

The close co-operation with suppliers and service producers as well as with final consumers can cope with these gaps. While relationships with suppliers are addressed by ISO 14000-series standards and environmentally conscious purchasing practices, downstream practices are addressed by extended producer responsibilities and Product Stewardship concepts. Integrated Chain Management (ICM) specifically addresses the issue of involving several actors in order to improve the environmental performance of products. However, problems associated with ICM are also going to be relevant for PSS due to a similar value chain basis that is extended in PSS into a value creation network. These problems include trade-offs between co-operation and internal environmental management; the problem of choosing wrong actors who do not have the power or knowledge to change or influence events; information sharing and transparency, and barriers from material flows crossing borders and a variety of regulatory frameworks in different countries. By sharing information the provider will be enabled to identify the customer needs and enhance his business relation with new features satisfying the customer needs. By this a long relationship can be established, which has to be seen as a partnership. Due to the shift in the ownership of products PSS business models give a platform to collect information from every PSS which earlier

26

Keynotes

was only accessible for the customer or by feedbacks of service personnel. This offers providers opportunities to learn more about the PSS behavior and usage by the customer and give the chance to use it for PSS design or redesign. Knowledge generation as well as knowledge and information management is necessary. A definition of knowledge is shown in Figure 6. The adaptation of products and services to the continuously changing technical requirements, application areas and user demands is crucial for the competitiveness of the PSS business model. Different configurations have profound impact on the performance of the system in terms of reliability and productivity, product quality, capacity scalability, and costs. Adapting the functions to the customer needs, the design to reduce idle and operation costs and an ongoing adjusting of service times requires knowledge about the system behavior and prognostics about the system conditions. This knowledge needs to be generated and managed.

system that supports the supply chain and communication processes in the whole PSS life cycle with knowledge. The VLCU acquires data from the usage phase, communicate and process it with the help of data mining algorithms to knowledge about the system behavior. This includes rules about the process flow of the PSS and its operations, as well as prognoses and classification of the PSS health condition or its components [6]. The processing to knowledge can be done by using data mining algorithm. These algorithms can be used to formulate rules about the PSS system behavior, e.g. a decision tree model. Other algorithms like Support Vector Machines or Statistical Pattern Recognition can be used for condition prognostics based on the actual system condition and wear [9]. In this concept the generated knowledge is available for all actors in the PSS supply chain. Beside the VLCU concept there are product accompanying information systems, supervising the product or components condition and allow condition based maintaining [6][5]. This is crucial for a PSS as it also facilitates to reduce unseen breakdowns and so a breach of contract, e.g. the promised availability. 4.3

Figure 6 : Definition of knowledge by North [8]. The development of PSS has the challenge to handle the increased complexity of the integrated PSS products and services. To ensure an efficient development of a PSS and to provide decision support, knowledge out of the usage phase or experience from previous developments and PSS provision phases should be used. To support a competitive design of PSS, knowledge needs to be generated about correlations between product and service shares in order to fulfill the required needs and demands. This knowledge is crucial for a successful combination of product and service shares, whose influences are very complex and not always known. The PSS life cycle data, especially from the operation phase, is the source to discover this knowledge.

Performance Supervision and Maintenance

In the PSS of aircraft turbines there is a continuous condition supervision to ensure the availability, but also to schedule maintenance planning at the place and the time it is needed. Data from the engine in use are transmitted to the provider. Input factors are planned future running times and available parts on the following destinations of the engine, respective aircraft. While in earlier times the engine was owned by the airline, spare parts and technicians needed to be stationed on every airport from every airline. Nowadays costs could be reduced by having just one team and depot for every airport. An aircraft engine is a very complex machine, the knowledge about it is best on the side of the engine company, e.g. Rolls Ryoce, GE or Pratt&Whitney. Those decide best when wear parts need to be replaced and because of the PSS business model they run today, they maximize use by condition based maintenance (CBM) methods or multiple usage phases, e.g. by running the engine on different aircrafts. Figure 7 shows the typical parameters measured for engine health management on a Rolls Royce Trent Engine. Aircraft Communications Addressing and Reporting System (ACARS) digital data-link systems are used as the primary method of communication. This transmits the Aircraft Condition Monitoring System (ACMS) reports via a VHF radio or satellite link whilst the aircraft is in-flight. A worldwide ground network transfers this data to the intended destination [10].

Due to the modern IT based engineering, business communication and documentation, most data along the life cycle of a PSS are already available in digital form and worldwide accessible via internet, e.g. machine datasheets, service protocols or personal database. Companies offering machine services already document plenty of detailed data about the service processes. Currently this is being used as an information base to compare new situations with historical data. The challenge lies in accessing, acquiring, communicating and finally processing it to knowledge. The continuous supervision of products and processes as well as processing of data by intelligent algorithms is an enabler to do prognostics of the system condition. Following the Business Intelligence idea an integrated approach for all participations or companies in a supply chain network of a PSS is required. An integrated concept has been developed – the so called Virtual Life Cycle Unit (VLCU). It is an information technology

Figure 7: Engine health management sensors RR Trent Engine [11].

Keynotes 4.4

27

Education

The PSS connect the providers and customers in multifaceted work places at which people determine during their operations the sustainable impact of products and processes. Worker or technicians need knowledge to have the ability in an application do something within the required time and quality. The integrated form of services in the PSS business model also includes the humans. To get access to technology the worker or technicians need to be qualified to do this. Constant availability, different qualifications of users and company-spanning cooperation in the field of industry demand a specific support concept during the delivery of services. Therefore easy and online education systems are required. In order to cope the challenge on qualification the use of modern IT systems offer great solution potentials. One way is the support of less and insufficiently qualified users. As a part of a support concept, e.g. in a maintenance scenario, the creation of a “shared vision” can be a possibility for the diagnosis and solving of a problem (Figure 8).

generate stimuli in people of different age, cultural background and qualification to activate interest and therewith initiate a learning cycle. The state-of-the-art of information and communication technologies (ICT) offers further innovative teaching concepts. By supervising the workers action and give direct instructions to him. So called Teachtools are enablers to incorporate physical and with technical information means to coach and train skills in technological, social, environmental and managerial fields. The learning motivation is addressed and creative competencies are fostered through practical application and project oriented problem solving at the workplace. This environment is ideal for forms of action-orientedand discovery-learning, which guide the learner through a selfdefined learning process. The learner on his learning path meets different kinds of teaching objects, like pictures, drawings, movies or texts. The teachtool suggests learning objects and the learner chooses which teaching objects suites his interest best. His journey will provide him with additional information for a more sustainable design and usage of the products and processes which he is working with. The learning processes can take place in all kinds of value creating activities done in a manual workplace, for example assembly, agriculture or teaching workplaces. The regional infrastructure, education level and values of various participants are to be hereby observed, in order to indentify deficiencies in the qualification of persons. A variety of best fitting teaching material or objects can be identified, which raises the chance that the learning processes will be performed at a high level of efficiency. Web-based intelligent agents are used to identify the qualification gap of the people and to support the learner with the appropriate teaching contents and highly effective methods. In [12] such a teachtool has been presented. An image based recognition of manual work processes in combination with an expert system has been developed and verified, see Figure 9.

Figure 8: Shared Vision System [5]. During the production of a work piece the machine informs the user about a breakdown. After a detailed inspection the user realizes, that her/his qualification for the removal of the failure is insufficient. To minimize downtimes of the machine, expensive journeys of service staff and last but not least mistakes in the problem diagnosis, the user can establish an audio-visual contact to a remote service expert of the machine manufacturer by a sharedvision system. Now this service expert can analyze the problem in time. Furthermore he can guide the user to a solution of the problem. As the gaze direction shows the focus of attention the visualization of the gaze direction of both involved persons can enhance the communication. Perceiving the mutual gaze movement therefore means an additional intuitive source of information. To ensure the quality of e.g. a service, the technician might have to be supervised in a way, that his actions are documented and in case of a mistake he/she immediately be informed. This can be done under the umbrella of technician security, but of course also to ensure the quality, economically and resource consumption of the PSS. A wrong installed ball-bearing might wear faster, which means it results in higher lifetime costs because of higher resource consumption. This is not sustainable in economic and environmental way. Novel tools for education and innovation dissemination guide people during their work to reflect their operations, to gain knowledge and to generate and adopt innovative ideas. They

Figure 9: Image-based recognition of a manual work process [12]. With the help of teachtools and shared vision systems, PSS providers are enabled to qualify every person to do services on their machines or use them. This means, that the technology is available to be used for everyone, especially the in the beginning mentioned 5 billion people, having not access to such technology nowadays. 5

SUMMARY

Sustainability engineering meets the challenges of economic competitivity, of responsibly managing environmental resources and of developing social competencies for worldwide wealth generation. Technological innovation can be directed along these guidelines of sustainability. The dynamics of value creation in the framework of global markets enables for network integration of partners under different infrastructural conditions. Product-Service Systems are means to cope with the challenge of more functionality with fewer resources. Selling functionality by service integration substitutes the traditional approach of selling tangible products in innovative business models. Knowledge management and education by

28

Keynotes

modern information and communication technology helps in implementing the new paradigms of resource efficiency and effectiveness. 6

ACKNOWLEDGEMENT

We express our sincere thanks to the Deutsche Forschungsgemeinschaft (DFG) for funding this research within the Collaborative Research Project SFB/TR 29 on Industrial ProductService Systems – Dynamic Interdependencies of Products and Services in the Production Area. 7

REFERENCES

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Angerer, G. et al. (2009): Rohstoffe für Zukunftstechnologien: Einfluss des branchenspezifischen Roh-stoffbedarfs in rohstoffintensiven Zukunftstechnologien auf die zukünftige Rohstoffnachfrage, ISI-Schriftenreihe Innovationspotenziale, Fraunhofer IRB Verlag, Stuttgart.

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Cullen, Jonathan M., Allwood, Julien M. (2010): The efficient use of energy: Tracing the global flow of energy from fuel to service, in: Energy Policy Vol. 38 (2010), 75-81, Elsevier.

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VDI. (2010): Stellungnahme Energiepolitik, Berlin.

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Herrmann, C. (2010): Ganzheitliches Life Cycle Management: Nachhaltigkeit und Lebenszyklusorientie-rung in Unternehmen, Springer, Berlin.

[5]

Seliger, G. (2007): Sustainability in Manufacturing, Springer Verlag Berlin Heidelberg.

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Meier, H., Roy, R., Seliger, G. (2010): Industrial ProductService Systems – PSS, in: CIRP Annals - Manufacturing Technology, Vol. 59, Issue 2, pp. 607-627.

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United Nations Environment Program. (2002): ProductService Systems and Sustainability: Opportunities for sustainable solutions.

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North, K. (2005): Wissensorientierte Unternehmensführung: Wertschöpfung durch Wissen, 4. Auflage, Gabler Verlag, Wiesbaden.

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Lee, J., Ni, J., Djurdjanovic, D., Qiu, H., Liao, H. (2006): Intelligent Prognostics Tools and E-Maintenance, Computers in Industry 57, pp. 476-489.

[10]

Rolls Royce, Monitoring System, http://www.rollsroyce.com/technology_innovation/systems_tech/monitori ng_systems.jsp.

zu

Klimaschutz

und

[11] http://www.rolls-royce.com/Images/ehm_1_tcm9225476.jpg. [12] Postawa, A., Kleinsorge, M., Krüger, J., Seliger, G. (2010): Bildgestütztes Erkennen manueller Arbeitsprozesse Automatisierte Erkennung manueller Verrichtungsschritte im Remanufacturing von Lichtmaschinen, in: wt-online, vol. 92010.

Solvis Zero-Emission Factory – The ‘Solvis way’ – Structure and Subject 1

Helmut Jäger 1

SOLVIS GmbH & Co KG, Braunschweig, Germany

Abstract The philosophy of Solvis is simple: The optimal use of solar energy with mature technology and as little use of the environment as possible – for the good of everyone. The central pillar of the product range of this employee-run company is the SolvisMax solar boiler. It combines a solar stratified storage tank with a heating boiler in one unit, thus providing hot water and supporting heaters. To produce ecological products also in an environmentally-friendly building, Solvis moved 2002 into its zero-emissions plant. The concept and structure of this new plant are described within this keynote-paper. Keywords: Sustainable Building Concepts, Zero-Emission Factory

1

INTRODUCTION

To produce ecological products also in an environmentally-friendly building, Solvis moved 2002 into a zero-emissions plant (Figure 1). The Energy consumption was reduced by 80 percent over conventional in-dustrial plants. 100 percent of the supply of heat and power comes from regenerative energy, which is hence CO2-neutral. With a floor area of nearly 15,000 m², the building is the largest zeroemissions plant in Europe. The building has already received several awards, among them the European Solar Prize 2002 and the worldwide Energy Globe 2003 and also as the “the most energyefficient commercial property” of Germany with the Energy Performance Certificate for buildings according to the German Energy Conservation Regulations 2007.

Figure 1: The Solvis zero-emission factory

2

THE 'SOLVIS WAY' - STRUCTURE AND SUBJECT

The administrative areas included in the production site at Grotrian Steinweg Strasse personify the situation of the building's main access and an enclosed 'atrium' as a high-quality external space within the building volume, that is otherwise optimised with regard to the A / V relationship. The lengthways opening-up of the building is carried out as a central internal opening-up; internal movements of persons meet the product lines here. The internal central way, as a themed lengthways axis of the building, became the central situation of the building, the 'backbone' of the overall system, acquired its conceptual, contextual significance as 'Solvis way'.

The constructional realisation of the Solvis way and connected administrative areas was carried out as a reinforced concrete construction, for reasons of thermal storage capacity, in the direction of the nocturnal cooling possibilities of the building masses, and for reasons of optional fire safety classification. On the ground floor, all the necessary ancillary rooms for the functions and sanitary installations are enclosed in the 'Solvis way' and the complete building technical installation can be seen on the first floor.

Figure 2: Solar collectors above the atrium The Solvis way gives the building concept its specific identity, as a space for coordinated organised building technical installations, and is the identity-forming central area for Solvis, the manufacturer of building technical installations. The production and storage areas were conceived as a widespanned lightweight wood construction over 27.50 m connected on both sides to the primary reinforced concrete construction of the Solvis way, taking the primary energy contents of the building materials. The connections of the internal lengthways axes of the wooden construction to the massive construction enabled all horizontal loads from the wide-spanned roof construction to be absorbed. The two external lengthways axes of the wide-spanned wood construction were implemented as column constructions with nonbearing wooden element facades, alternatively as high-temperature insulated wooden frame constructions.

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_5, © Springer-Verlag Berlin Heidelberg 2011

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Keynotes ENERGY AND DAYLIGHT CONCEPT

The goals of the planning stage were high quality workplaces with the same standard with short communication paths and production without emissions of climatic gases. Because of the production processes, emissions from the energy requirements for electricity and heat are the only potential sources of pollution, the conception of a zero-emissions factory is therefore above all an energy concept for reducing the electricity and heat requirement and a concept for a CO2-neutral energy supply. Thanks to the external supporting framework of the wooden truss construction of the production areas with the 27.50 m span, the building volume that was to be heated and ventilated was reduced by 1.20 m headroom (15 % of the complete enclosed space). Loading zones for trucks connect to the production and storage areas. These zones were integrated into the thermal shell of the production areas. The solar energy plant is built on the loading zone that is oriented to the southwest. The supports for the hall's external supporting framework hold the thermal collectors. The high-quality thermal protection and the compactness of the cubage of the overall project enable a heating requirement of < 30 kWh/m²/a. The sun (PV, collectors) is available as the supplier of energy without CO2-equivalent; as a regenerative supply of energy rapeseed oil is used as a supplementary source of electricity and heat, and a rapeseed oil fired block-type thermal power station is in use. With energy supply from excess energy from a PV generator and the substitution of electricity from conventional generation, CO2neutral energy supplies can be achieved with internal electricity generation even with conventional rapeseed oil cultivation. The target values for the heat with 40 kWh/m²/a and for the electricity consumption for the building's technical installations with 20 kWh/m²/a result from the tresholds of the federal economics ministry's subsidy concept for solar-optimised buildings. In addition, restrictions to 20 kWh/m²/a heat and 12.5 kWh/m²/a electricity for the building's technical installations and operations result from the objective of CO2-neutral energy supplies and the maximum available space of 600 m² for the installation of PV modules and solar collectors. The target values demonstrate that, together with a very low heating requirement, in particular the electricity requirement for the building's technical installations should be very low. For this reason, the main focuses for improvements are on energy-efficient ventilation, a good supply of daylight and adapted lighting, and integration of the solar energy supply. 4

ROOM AIR CONDITIONS AND THERMAL INSULATION IN SUMMER

Thermal insulation in summer in the offices is guaranteed by an external two-part heat protection. A reduction of the g-value (total energy transmittance) is achieved by using triple heat protection glass. In addition, the opening parts of the windows are designed as wooden panels with vacuum insulation, so that a reduction of the heat yield in summer is achieved without increasing heat losses. These are reduced considerably by means of a consistent reduction in internal loads, e.g. by performance management in electronic data processing and by demand-oriented lighting controls. Because of the dense layout, it is necessary to lose heat in summer through nighttime ventilation (change of air: 3/h). There is a mechanical ventilation system to make the building safe from breakins. There are 245 working hours with temperatures in excess of 25°C; this is less than 9% of the working hours.

5

HEATING REQUIREMENT

A low heating requirement is achieved on the one hand by a good thermal installation standard and on the other hand by an efficient ventilation plant with heat recovery in the production areas. Precondition for achieving the heat supply level of >75% is a very airtight building shell. The building achieves a very low change of air volume of 0.22 1/h at 50 Pa partial vacuum/excess pressure. This value was verified by a blower door measurement. A heat requirement of 220 MWh/a results for the building (determined by dynamic building simulation); this is 27 kWh/m²/a in relation to the net floor area with internal loads of 150 Wh/m²/d. 6

DAYLIGHT USE AND LIGHTING

The production halls receive an average daylight quotient of 3% through the fanlights, so that there is a supply of daylight adjusted to requirements. The lighting is dimmed automatically in dependence on the daylight by an external brightness controller; on the one hand this reduces the costs in comparison with a decentralized controller and, on the other, the dependence of the sensors on the reflection properties of the surfaces in the inside of the building is avoided. The offices are well supplied with daylight (daylight quotient in the area of the workplaces average 4.5%, daylight autonomy: 77% in 0.75 m room depth, 47% in 2.75m room depth); as in the production halls the lights are grouped with a daylight-dependent controller and dimmer. 7

ELECTRICITY REQUIREMENT

Even now, a major part of the electricity (approx. 55%) is required for lighting and computers/communications. For this reason, in the main 'conventional' energy saving measures were carried out in the field of electricity supply. These include lighting controllers, TL5 fluorescent lights, flat screens, low-energy actuators for pumps and ventilators and energy-saving operations for the computer systems. Thanks to a vacuum drainage system the water requirement is reduced by 80% in comparison with conventional drainage systems. The remaining wastewater is fed into the municipal sewer, because the clarified sludges are processed further in a block-type power station. 8

SOLAR ENERGY SUPPLY

The heating is supplied by a rapeseed oil factory heating and power station (180 MWh/a.), a collector plant (20 MWh/a.) and by the heat waste from the development department (20 MWh). The current demand is covered by a 60 kWh PV-plant (45 MWh/a.) and via the rapeseed oil factory heating and power station (115 MWh). Thus the energy supply is provided by regenerative energy sources. The primary energy demand for heating and current is 700 MWh/a., which equates to 90 kWh/m² p.a. The collector plant and the PVGenerator achieve a solar contribution of 22%. Additional expansion of the photo-voltaic current generation is limited from an economic point of view and also because of the lightweight construction of the hall. The non-insulated sprinkler tanks set up in the building serve as a buffer store for the 150 m² thermal collector system and thus as low-temperature radiant heating system. The waste heat from the burners in the development area is fed via a busbar to the buffer store of the rapeseed oil factory heating and power station. In winter, the waste heat from the EDP central office serves as a heating support for the warehouse, in summer a circulation fan is used here.

Keynotes

Figure 3: Solar collectors on top of the Solvis plant

9

BUILDING EXTENSION

By firm growth a building extension became necessary of 5.400 m². The new building part is used completely as central storage depot. By four lowerable stages it is possible to load at ground level up to 30 trucks daily. With a new automated production line, in which the smaller compact collectors are manufactured, Solvis is in the position to produce altogether annually up to 300,000 m² collector areas. Three laser welding machines make a capacity with absorber production of up to 500,000 m² possible. Additionally further offices and a training area on approx. 1,000 m² extended. For the measures the photovoltaic-plant was supplemented around 2.000 m², a thermal long term storage with 100.000 litres of volume supports the heat supply. With these additional activities Solvis invested 10 million Euros. 10 CONCLUSION The target values for heating consumption of 40 kWh/m²/a. and a current consumption of 20 kWh/m² p.a. for the building facilities are considerably undercut, the primary energy consumption being 90 kWh/m²/a. The excellent thermal insulation as well as the consistent planning and implementation of low-energy building facilities means that the new production building of the company Solvis can be completely supplied using regenerative energy sources and in the future will become a zero-emission factory with CO2-neutral rapeseed oil production. Through the minimisation of its regenerative energy resource requirements, the Solvis zero-emission factory has also become a model of how buildings could be supplied with energy within industrial and commercial construction in the future.

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Manufacturing and the Science of Sustainability Timothy G. Gutowski Massachusetts Institute of Technology, Cambrige, MA 02139

Abstract A new area, called Sustainability Science, is engaging large system scientists to address the challenges that face the future of human society on planet earth. In this paper, the methods and frameworks of diverse disciplines are reviewed and compared with those of the manufacturing community. The results show significant differences between disciplines, including the level of urgency expressed. Synthesizing these divergent viewpoints, this paper makes suggestions for needed research on “sustainable manufacturing”. The main message is that manufacturing needs to significantly increase the boundaries of its analysis to be able to understand its effect at the global scale. Keywords: Weak Sustainability; Genuine Investment; Eco-Systems Ecology; Panarchy; Resource Accounting; Triple Bottom Line; Scale; Human Well-Being

1

INTRODUCTION

Recent papers have identified an emerging area of research called sustainability science. This new area of study looks at the complex interactions between the methods of society and eco-system services and human well-being, over long time scales and at global dimensions. The earliest manifestations of this new science involve the natural sciences (biology, ecology, etc.) on the one hand, and the social sciences (sociology, economics etc.) on the other, with systems modelers of many persuasions in the middle [1], [2], [3], [4]. Manufacturing, as one of the major sub-systems that connects eco-systems services to human well-being has an important role to play in this new emerging field [5],[6], [7], [8]. In this paper, we review various approaches to understanding the concept of sustainability and compare them to sustainability initiatives in the manufacturing sector. 2

wealth, called genuine investment, must be equal to or greater than zero. Genuine investment is the sum of the values of all capital stocks including manufactured capital, human capital and natural capital. The accounting is done in dollars which means that economic equivalents of these different types of capital must be obtained. The difficulties in establishing prices for components of natural capital are acknowledged, and a representative calculation is made for countries, regions, similar economic groups, and the world, and announced yearly in the World Bank’s publication The Little Green Data Book. Figure 1 gives the recent accounting for the World [11]. The results (given in percent of gross national income – GNI) indicate that the world’s manufactured capital assets grew at 7.9 %, the human capital assets (represented by education expenditures) grew at 4.2 % and the natural capital assets declined at 5.0 %. The result is greater than zero (+7.2 %; note the rounding error) and so by this calculation the world is sustainable.

ALTERNATIVE VIEWS OF SUSTAINABILITY

A major thesis of this paper is that until there is reasonable agreement on a working idea of what sustainability means, it will be difficult or impossible to measure progress or describe a way forward. In this section, brief summaries of alternative views of the concept of sustainability within recognized scientific disciplines are offered. The reviews include; 1) economics, 2) eco-system ecology/resilience, 3) resource accounting, and 4) the business approach called the triple bottom line (TBL). 2.1

Economics

Starting from the concept of sustainability as defined in the UN document “Our Common Future” [9], economists in collaboration with ecologist have put forth an operational scheme for estimating society’s sustainability [10]. In this paper, sustainability is defined as the requirement that our so-called inter-temporal social welfare must not decrease over time. The inter-temporal social welfare is calculated as the present discounted value of the flow of utility from consumption from the present to infinity. Under certain conditions, this is equivalent to the more transparent requirement that genuine wealth per capita must not decline. Hence the change in genuine

Figure 1: Results from the 2010 Little Green Data Book produced by the World Bank indicate a positive genuine investment. This is the so-called weak form of sustainability which allows substitution between capital stocks. In other words, depletions in natural stocks can be compensated by additions to manufactured and human capital stocks. Substitutability, and its implied value

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_6, © Springer-Verlag Berlin Heidelberg 2011

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system and technical feasibility, is an issue for any aggregate measure of resources, and is not unique to economics. Economics, however, seems to take it to the farthest extreme by allowing for the compensation of lost eco-system services, with human engineered products and institutions. This is not only an extremely optimistic statement about human abilities, but also implies a vision of the future without nature, or at least with much less natural capital than we now enjoy. Because many people are uncomfortable with this vision and because the technical feasibility of substituting for ecosystem services on a global scale is in doubt, many people criticize the weak form of sustainability. See for example Daly and Daly and Farley [12], [13]. At the same time, the idea to aggregate resources in an attempt to measure some aspect of sustainability seems potentially worthwhile, and should be further explored [14]. In fact, the economists carry this approach much further than outlined here, by attempting to include the contributions to our economic productive base provided by human institutions [10]. See Dasgupta for a short, concise description of this calculation [15], and for more detail see [10], [16]. 2.2

Ecosystems Ecology

Ecosystems ecology brings a very different perspective to the issue of sustainability, one that may not be familiar to manufacturing engineers. Overall, ecosystem ecologists do not see sustainability as an equilibrium state, but rather as a process that naturally includes phases of decline and recovery. The central question is, can the system accommodate change and still retain controls on function and structure [17]. This inquiry is closely aligned with the new study of resalience, see for example the website for the resalience alliance [18]. A cornerstone of this effort is a systems dynamic conceptualization called panarchy [19]. Panarchy is a stylized representation of the dynamics of an adaptive system based upon observations from ecosystems ecology. It is hypothesized that other adaptive systems (including ecological, social and economic systems) may go through similar transitions. It places a useful emphasis on dynamics and transitions, identifying four crucial stages in the prototypical transition: 1) growth, 2) conservation, 3) release, and 4) reorganization. The scheme is shown graphically in Figure 2. The authors identify two metaparameters that can indicate where one is in this scheme; “potential” equivalent to the “y” axis in Figure 2, and “connectedness” equivalent to the “x” axis. A third variable, out of the plane of Figure 2 (the “z” axis) is “resilience”. If a system is not resilient it may move off of the pattern shown in the figure to a new pattern or to a dead end or “trap”. The researchers have identified two important traps. One is the so called “Rigidity Trap”. As described by Gunderson and Hollings, “Rigidity traps occur in social-ecological systems when institutions become highly connected, self-reinforcing and inflexible”. The other is the so called “Poverty trap”. As described in the resilience literature, “this is a situation in which connectedness and resilience are low and the potential for change is not realized” [19]. Ecosystem ecologists offer many examples of these behaviors in nature and speculate on the application of this framework to other systems. For example, in Gunderson and Holling, a testable hypothesis is proposed for applying the panarchy framework to industrial systems, for example the Bell telephone Co. in the U.S. For those who study business cycles, there seems to be some similarity with concepts such as the Kondratiev long wave, see [20], [5]. Overall the resilience literature is highly integrative bringing together scientists from different fields of study. Much of the earlier work however is mostly conceptual, such as the panarchy framework. A recent paper identifies specific global limits for several ecological problems described in the next section [21].

Figure 2: Graphic representation of an adaptive cycle for a complex system. 2.3

Resource Accounting

Resource accounting is the physical equivalent of the economics approach to counting identified resources needed to maintain some aspect of sustainability. The accounting is done in physical units, rather than monetary units, and usually employs some version of a “sources” and “sinks” view of the planet. That is, human activities interact with the planet by extracting energy resources, materials, biological entities and other sources, process them, and then deposit the residuals back to the planet that acts as a sink capable of absorbing a certain amount of these wastes. This approach may be done with varying degrees of rigor depending largely on how well the system is defined and the tools employed. Thermodynamics would be among the most rigorous physical accounting approaches [22], [23], [24], [25]. While using physical units greatly limits the degree of aggregation one can usefully accomplish, large categories of natural capital type resources are commonly counted. Prominent examples include: Primary energy resources measured in units of energy; climate change gases, measured in CO2 equivalents; water use measured in weight or volume; acidification potential measured in hydrogen ion equivalents; material resources measured in weight, and biological extinction measured in rates of species loss. In fact, all scientific investigations of sustainability ultimately resort to some form of resource accounting to state a problem or measure progress. And it is the resource accounting arguments which ultimately make the strongest and clearest statements concerning the current unsustainable practices of humanity. Examples of unsustainable trends come from a variety of sources, of particular importance are the effects on global eco-system services addressed in the International Panel on Climate Change [26], and the Millennium Ecosystems Assessment [27], [28]. These reports and others point to a broad array of disturbing and potentially disastrous trends including climate change, ocean acidification, nitrogen and phosphorous overloading, freshwater depletion, biodiversity loss and land system change. See also [21]. The most notable features of the resource accounting approach are; 1) that attention is directed predominantly to the natural environment, and 2) that much of the news is quite concerning if not alarming. This contrasts starkly with the much more optimistic view given by Arrow et al [10] and the seemingly non-committal view of Gunderson and Hollings [19]. In particular, an optimistic case can be made that humans can employ forward looking mechanisms and institutions to anticipate potential future disruptions, and plan accordingly [19]. At the same time, humans can game these very same mechanisms (as the recent financial crisis clearly illustrates) and fail to perceive potential precipitous decline. This potential

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inability to adapt would be an example of the so-called “Rigidity Trap” described by Carpenter and Brock [17] and others.

3

2.4

Here we propose three questions concerning sustainable behaviors. The questions are intended to expose the limitations of simple notions concerning sustainability.

Triple Bottom Line

The triple bottom line is a business response to the need for corporate performance measures that go beyond shareholder value, and include social responsibility and sustainability. The term is generally attributed to John Elkington writing in the California Business Review in 1994. Triple Bottom Line accounting includes not only corporate financial performance, but also an evaluation of potential impacts on people and planet. While it may appear to include some of the same topics as in the genuine wealth calculation mentioned earlier, the focus is on the firm and the accounting has not been standardized. In practice, it is more a portfolio approach, where the different spheres of activities are treated separately. While this method is indeed a step forward in terms of corporate acknowledgement of social and environmental issues, it is clearly a work in progress and whether it could actually have an impact on sustainability needs to be tested. The main problems are that the accounting is limited in scale, the methods may not be fully disclosed, and business as usual can often be dressed up to look like a new contribution to sustainability. Later examples will show this explicitly. 2.5

Summary

This brief synopsis of alternative views of sustainability is offered to illustrate the range of views on this topic and the uncertainty that faces the development of a science of sustainability. It seems that in a situation where we would all want clarity, it is not to be had. The problem resides not only in the vast complexity of the global environmental-social-economic system, and the weakness of the “unsustainable signal” as experienced by the average inhabitant of the planet, but also in the hugely ambitious agenda contained in the simple word “sustainable”. Even some of the most fundamental concepts are seen quite differently by the various disciplines engaged in this study. For example, consider the test question, would the addition of many more people to the planet improve or decrease the sustainability of human society? Those who see resources as limited will divide finite resources by a growing population and tend to answer in the negative. However a subset may say the opposite. The difference depends on whether one sees additional people as a potential resource, or primarily as consumers of the resources. An interesting contribution in this area is offered by the Harvard economist Michael Kremer who has shown that the rate of technological progress correlates very closely with population levels [29]. That is, the more people there are, the more new ideas and opportunities for development, and so the more we advance. This view is discussed in a popular book by Harford [30] to illustrate how contradictory the solution to sustainability might be. However to many, this view seems to deny any biophysical limits to growth. In fact, it may sound like a Malthusian mistake with the opposite sign. Indeed, those who come to this problem from a natural resource accounting point of view, would probably cast humans first in the role of consumers, and secondly as those who could modify the consumption process. The alternative views presented here are in stark contrast. This result, that even a most basic question, such as the role of human beings in sustainability, has no simple uncontestable answer, is not unique. Other basic questions, often the foundation for action plans in “sustainable manufacturing” are equally complex. The result is this; there is plenty to study concerning manufacturing and the science of sustainability and the sooner these produce results, the sooner manufacturing will be able to clearly address the problem.

THREE QUESTIONS PRACTICES

ON

SUSTAINABLE

INDUSTRIAL

Gulf Oil Spill in the U.S. A simple question might be to ask how would one evaluate the performance of the company BP during the recent oil spill in the Gulf of Mexico? Indeed by any measure this was a lose-lose-lose proposition. The company lost economically, the environment lost (although we do not know the extent of the damage yet) and indeed many local people lost by losing income and potentially their livelihood, and having their environment damaged. This was the largest oil spill in U.S. history, and at about 200 million gallons likely the largest of its kind in world history. At the same time BP has been known for promoting renewal technologies and providing investment funds for many of these. Also some may have seen BP’s response as proactive. So how would you rate BP’s behavior? Are they sustainable? The easy answer to this question is “no”, but as this paper is being written the investigations into the roles of the various players is currently in progress, and the extent of the ecological damages may take years to understand. Hence, in this case we may look to the bigger picture proposed by both the ecosystem ecologist and the economists and ask a larger question - not how did BP perform, but how did (or will) the overall system perform? The answer to this question may lie more in how the institutions which control deep water drilling and are charged with guarding ecosystems, while at the same time providing energy resources, respond to this disaster. Similarly we may ask the question how do the consumers, who ultimately drive the need for deep water drilling, respond? Are they aware of the consequences of their actions or is the signal too weak to produce a response? We leave the question unanswered but use it as an example of how we have to expand our analysis framework to get ultimate answers to these questions. Solid State of Lighting Consider the question – should an improvement in the energy efficiency of lighting be considered a engineering contribution to sustainability? This topic is currently of great interest because of significant new improvements to solid state lighting and recent studies concerning the life cycle energy use of solid state lighting [31], [32]. Anyone who owns an LED flashlight already knows that this form of lighting is very efficient because the batteries last for a very long time. However, it is also true that solid state devices are made by semi-conductor type manufacturing process which can be very energy intensive. So the question is, when viewed over the product life cycle i.e. manufacturing and use, is solid state lighting more efficient than incandescent and/or florescent lighting? Recent LCA studies indicate that the answer to this question is yes, the solid state devices can provide an equivalent amount of illumination for a much smaller amount of energy – something like 3 to 5 times less energy depending upon the exact nature of the comparison [31]. This would seem then, one face value, to be a very significant improvement and certainly a candidate for being called a contribution to sustainability. But there is more to this story. A further study of this issue looked more into the nature of our demand for lighting, and explores the question – “just exactly how much lighting do we want?” That is, will we be happy with what we got, and continue to use the same amount of illumination and therefore save energy with solid state lighting, or will we take advantage of this efficiency improvement and actually increase our amount of illumination and thereby potentially offset some or all of our expected savings? [33]. This is

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the kind of question that economists can address, using economic growth models and other models to connect our demand for illumination to other factors. As it turns out, the result to our question can be surmised roughly from available empirical data. That is, observations from over 300 years, for various geographic units, indicate that the demand for lighting per capita, , is directly proportional to per capita gross domestic product (gdp) divided by the cost of lighting CoL [33], as given in equation 1.

~

gdp CoL

(1)

This result, and one that can be derived from it, giving the total power used on lighting, are shown in Figure 3 [33]. The data show two things; 1) the wealthier we are, the more lighting we want, and 2) the lower the cost of lighting, the more lighting we want. Most notably, the graph shows no sign of saturation. We may saturate in the future, but that is a debatable point (and one that is discussed further in the reference [33]). The evidence so far however is not good for energy savings, and in fact the paper (using a more complex economic argument) predicts more energy use with solid state lighting not less. Efficiency data from an earlier paper puts this into perspective. Figure 4 shows historical improvements in the efficiency for two technologies: steam engines and lamps plotted on a “linearized” logistics curve [34]. Here we are interested in lamps. Current solid state lighting would appear roughly in the upper right hand corner of the figure. What becomes apparent from this figure is that while solid state lighting indeed represents a significant improvement in the energy efficiency of lighting, it is not, from a historical perspective, unique. That is, going from paraffin candles to Edition’s first lamp, or from tungsten filament incandescent lamps to sodium vapor lamps where also significant improvements in there own right. We return then to our original question, should an improvement in the energy efficiency of lighting be considered an engineering contribution to sustainability? Or does it look remarkably like business as usual? This seems as a core question for those who want to study manufacturing and sustainability. Remanufacturing and Energy The third question is, does remanufacturing save energy? In many references one can find comments that remanufacturing is the best option for end-of-life product. The obvious benefits are that remanufacturing can generally save some (usually large) portion of the invested energy used in both the materials production as well as the manufacturing. (The assumption is usually made that the

(a)

(b)

Figure 3: a) Empirical data showing the correlation between illumination and GDP divided by the cost of lighting b) Converts the data to show energy usage by illumination see [Tsao 2010].

Figure 4: Historical efficiency data for steam engines and lamps from Ausubel and Marchetti 1997. remanufactured product is a substitute for a new product.) But a recent study of remanufacturing of eight different products reveals that energy saving may not always be in favor of remanufacturing [35]. The result depends heavily on whether the product has an energy intensive use phase. That is, if the product has a power cord or an internal combustion engine attached to it, then the use phase of the life cycle will very likely dominate the energy use. Since it is a major product design trend to power-up previously “passive” products, the use phase is coming to dominate energy use for many products. Furthermore, since the first powered design will likely be inefficient, the ironic implication is that future energy efficiency improvements in the design could act to undermine remanufacturing. The study found that in 25 case studies, 8 showed clear energy savings for remanufacturing, 6 showed clear energy savings for buying new, and 11 cases were too close to call. The results depended heavily upon use phase energy efficiency trends and could change dramatically with time. For example, while it made sense from an energy savings point of view, to replace a damaged compressor and extend the life of a refrigerator in the 1960’s, in the 1990’s it was better to buy a new refrigerator. Ultimately however, if products can move asymptotically to a steady highly efficient state, the case where remanufacturing saves energy could be restored. It remains to be seen if such a scenario obtains. 4

RESEARCH QUESTIONS

A review of the sustainability science literature shows considerable uncertainty in regards to a definition of sustainability, disagreement concerning the roles of major players in this problem, and the lack of a clear path forward. This contrasts sharply with many of the ideas put forth as “sustainable manufacturing”. These are primarily programs of self improvement (and to some extent self preservation) and technology development to address market opportunities. They appear to be based upon a much clearer vision of the mission, usually involving resource accounting arguments, (but addressed at a relatively small scale). A resource accounting framework provides a clearer enunciation of the problems, and a basis for measurement and hypothesis testing. At the same time however, it must be recognized that even if one accepts the resource accounting approach, this must be woven into a larger picture that addresses how these resource depletions at various scales might interact and ultimately how they provide for human needs. Furthermore one must study the problem at a sufficient scale so that actions at the manufacturing level can be followed to higher levels, ultimately to a global scale. One can even go farther in the analysis to anticipate the temporal pattern of these actions. It appears that even when we do good, the scale of our actions can lead to new effects not anticipated. For example, consider the substitution of MTBE for TEL, and HCFC’s for CFC’s. In each case

36 an improvement on a unit basis is accompanied by an expansion in use, and a realization of yet new problems. Note that at the time of its introduction, CFC’s could have been easily characterized as “green”, an improvement, or even “sustainable”. See Allenby’s comments in [36]. The problem is that the scale of human activity is so large that whatever we do it will affect the environment. The study of sustainable manufacturing needs to reorient itself so that this concept is at the center of the discussion. Several critical areas for sustainable manufacturing research are identified below. 1. Scale – Manufacturing must expand the boundaries of analysis if it wants to understand its impact on sustainability. This does not mean just to distant components of manufacturing, but also to social and environmental effects. There are indeed many dimensions to this expansion, several of them are mentioned in the following points. See [37], [38], [39]. 2.Measuring Human Well-Being – The ultimate goal of sustainability is to maintain some level of human well being extending indefinitely into the future. While human well being is admittedly a complex topic, there are many credible studies that have explored this topic and proposed various measures. Examples range from the happiness index to the GINI coefficient of inequality, to the UN’s human development index (HDI), the index for sustainable economic welfare (ISEW) and the genuine progress indicator (GPI) [39], [16], [40], [41], [42] [43]. Additionally, some researchers are working on the development of a so-called Social Life Cycle Assessment [44]. While each of these can be challenged in some way, they all appear to offer more or additional sensitivity to the human condition compared to the usual default measure, which is the per capita gross domestic product (GDP) or some similar financial measure. In fact many of these human well being indicators show that while per capital GDP may be rising in many developed countries, measures of human well being are staying flat or even declining. These measures should be central to the sustainability discussion and need further and vigorous development. Even in their current state of development, application of these measures to the stake holders involved in manufacturing’s actions would be enlightening. The results should show both the benefits and disadvantages of manufacturing. Furthermore, they may provide important insights that would allow one to differentiate between various manufacturing activities. Given the global nature of manufacturing, one would have to address how these large geographical boundaries would be treated. 3. Measuring Resources – Resource Accounting is based upon the widely held premise that there are certain types of resources that need to be maintained in order to provide for the sustainable development of human society. These identified resources generally correspond to certain natural capital stocks and ecosystem services or the accounting is done on the anthropogenic emissions or actions that degrade and threaten these services. While sustainability issues can exist at all scales for society, primary concern must be focused on those problems that exist at the global scale. Several publications attempt to list these major global scale challenges. See [45], and [21]. Resource accounting approaches can use alternative accounting schemes. Two extreme cases would be highly aggregated measures (such as the genuine investment accounting scheme of the economists) or by considering individual levels of specific resources and emissions. Both methods have advantages and disadvantages. When using highly aggregated methods, one would need to acknowledge potential interactions or stay away from these in the accounting scheme. Highly aggregated measures would have significant advantage in modeling and developing conceptual frameworks for future evolutionary paths of society. On the other

Keynotes hand, identifying specific resource issues allows for a much more in depth analysis. These could address in greater detail potential limits of the global system and complex interactions between the various dimensions of the problem. In the aggregate resource accounting method, the issue of substitutability would need to be addressed in some detail. Note that the application of the genuine wealth calculation or some variation on this theme to manufacturing could result in the differentiation between the benefits provided to society by different products, for example infrastructure products versus consumer goods. While this is a very value laden issue, there is wide agreement in the psychological literature that all needs are not equal. That is, one could attempt to link product, to need, to sustainability. For engineers a particular attractive aggregate accounting scheme could be based upon the consequences of the second law of thermodynamics. These would include estimating exergy losses and entropy production at the global scale. See [22], [46], [24], [25], [23]. Concerning accounting schemes that address individual global scale problems, a recent paper by Rockstrom et al identifies 9 potential problems and makes a first estimate of quantified global limits for seven of them. That list includes; 1) climate change, 2) ocean acidification, 3) ozone depletion, 4) nitrogen and phosphorus cycle overloading, 5) global fresh water withdrawals, 6) land system change, 7) biological diversity, 8) atmospheric aerosol loading, and 9) chemical pollution. The paper claims that three of these, climate change, nitrogen and phosphorus cycles overloading and biological diversity, have already transgressed the safe operating space for the global environment. The obvious challenge for manufacturing is to connect their effects on these problems from the manufacturing scale to the global scale. 4. Mechanisms of Interdisciplinary Study – Increasing the scale of analysis will inevitably involve crossing interdisciplinary boundaries. How to do this gracefully and rigorously is an important challenge. In the review of sustainability science literature it seems that the ecologist and economists have started the process of successful interdisciplinary studies. This issue strongly affects the professional development of young academics. 5. Subdivisions by Topic Area – Several major themes emerge that both span the breath of the sustainability research area, but at the same time provide a focus which allows measurement and modeling. These area include: 4.1

Energy resource use and efficiency

The effect of energy efficiency on conservation and growth has been discussed since at least 1865 when Stanley Jevons published his book on coal. Since then it has been measured (the direct rebound effect), analyzed and debated primarily in the economics literature, and proposed as the driver of economic growth by Ayres. See [47], [48], [49], [50], [51]. This topic is among the most important that needs to be understood. Proposals to increase energy efficiency without an understanding about how society would use those advances could lead to surprisingly different results than expected, as illustrated in the earlier sections in this paper. 4.2

Materials use and efficiency

Materials connect manufacturing to the environment both as a source of raw materials and as a sink for the residues. And materials connect manufacturing to people by providing for their needs and quality of life. Current trends show a growing need for more materials as the world develops, the use of more elements in the periodic table (leading to complex mixtures) and increased needs for higher purity materials. Furthermore, materials are energy intensive and newer materials generally have even higher energy

Keynotes

37

requirements. While the materials with the largest use have been around for some time leaving only finite opportunities for energy and CO2 efficiency improvements, newer materials may present major opportunities. How materials are used, substituted and recycled is central to sustainable manufacturing. From the manufacturers point of view: how will materials use in future products be affected in light of potential restrictions, reporting requirements and standards, constrained supplies, fluctuations, and potential increases in prices and recycled content? See [52], [53], [54], [55]. 4.3

Technology innovation

development,

business

practices

Clark, W.C., Dickson, N.M., (2003): Sustainability science: The emerging research program, PNAS, Vol. 100, No. 14, pp 80598061.

[3]

Levin, S.A., Clark, C.W., (2009): Toward a Science of Sustainability, Report from Toward a Science of Sustainability Conference,held in Airlie Center – Warrenton, Virginia, funded by National Science Foundation.

[4]

Fiksel, J., Graedel, T., Hecht, A.D., Rejeski, D., Sayler, G.S., Senge, P.M., Swackhamer, D.L., Theis T.L., (2009): EPA at 40: Bringing Environmental Protection into the 21st Century, Environ. Sci. Technol. No. 43, pp 8716-8720.

[5]

Jovane, F., Yoshikawa, H., Alting, L., Boer, C.R., Westkamper, E., Williams, D., Tseng, M., Seliger G., Paci, A.M. (2008): The incoming global technological and industrial revolution towards competitive sustainable manufacture, CIRP Annals – Manufacturing Technology, No. 57, pp 641-659.

[6]

Seliger, G., Kim, H-J., Kernbaum, S., Zettl, M. (2008): Approaches to sustainable manufacturing. Int. Journal of Sustainable Manufacturing, Vol. 1, Nos. 1/2, pp. 58-77.

[7]

Gutowski, T., Murphy C., Allen, D., Bauer, D., Bras, B., Piwonka, T., Sheng, P., Sutherland, J., Thurston, D., and Wolff, E. (2001): WTEC Panel Report on: Environmentally Benign Manufacturing (EBM),” International Technology Research Institute, World Technology (WTEC) Division: Baltimore, Maryland, USA, and Environmentally Benign Manufacturing: Observations from Japan, Europe and the United States, Journal of Cleaner Production, Vol. 13, pp. 117.

[8]

Murphy, C.F., Allen, D., Allenby, B., Crittenden, J., Davidson, C.I., Hendrickson, C., Matthews H.S. (2009): Sustainability in Engineering Education and Research at U.S. Universities, Environ. Sci. Technol. Vol. 43, pp 5558-5564.

[9]

UN Our Common Future, Report of the World Commission on Environment and Development, (1987): World Commission on Environment and Development.

and

Many people are banking on innovating our way out of the sustainability problem. This is a major paradigm for technology optimists. Given that we have only first begun this journey, as we focus our attention many new developments can be expected. Skeptics on the other hand will counter that new technologies have never really been evaluated from a global perspective before. The game is changing, and the hurdles to success may be much higher. New technology needs to be encouraged and guided by informed social and environmental analysis. For manufactures this will be similar to concurrent engineering and the quality movement. We must move away from pampered products that only perform well in a highly constrained environment. There will be many new opportunities here for manufacturing. The bottom line is that to connect manufacturing to the new Science of Sustainability, much larger boundaries of analysis need to be considered. While an evaluation at the level of the firm is a desirable goal, without a credible framework that connects the firm to the planet the local evaluation risks being meaningless.

Kates, R.W., Clark, W.C. Corell, R., and 20 additional authors (2001): Environment and Development: Sustainability Science (Policy Forum), Science, Vol. 292, No. 5517, pp. 641-642.

[2]

Measurements, Metrics and Tools

The measurement of anthropogenic outputs and ecological and social responses are an area of considerable potential for sustainable manufacturing. Manufacturing engineers can develop these and this activity does not necessarily depend directly upon the definition of sustainability. Further manufacturing can contribute to the analysis of the data, and interpretation and use of it in models. While it is rewarding to see that LCA has grown in application, many tough problems remain concerning allocation, boundaries standardization and accuracy. At the same time tools that move beyond single product evaluations are a critical need for manufacturing. Indeed many modeling problems exist at many levels. 4.5

[1]

Geography and supply chains

The spatial arrangement of supply and demand presents a challenging and as yet largely unexplored area for sustainability research. In a recent book David Mackay analyzes the energy needs and the renewal energy resource potentials for England and comes to the conclusion that it cannot supply its own needs [56]. It must be engaged in some kind of trade to do so. This is a sobering and useful conclusion that highlights the problem; what does a sustainable world look like? Who trades with whom and for what reasons? For example, a recent study suggests that if the price for carbon goes to $100/tonne CO2, laptop and notebook computer manufacturing for the U.S. market should move back from China to the U.S. [57]. From the manufacturers point of view, how will supply chains be affected in terms of changing labor rates, shifting markets, materials availability and centers of manufacturing, and potentially increasing energy prices and carbon taxes imperfectly applied in different countries across the world? 4.4

5. REFERENCES

[10] Arrow, K. Dasgupta, P., Goulder, L., Daily, G., Ehrlich, P., Heal, G., Levin, S., Mäler, K-G., Schneider, S., Starrett, D., Walker, B., (2004): Are We Consuming Too Much?, Journal of Economic Perspectives, Vol. 18, No. 3, pp. 147-172. [11] The Little Green Data Book, World Bank, 2010. [12] Daly, H., (2005): Economics in a Full Economy, Scientific American, pp 100-105. [13] Daly, H.E., Farley, J. (2004): Ecological Economics – Principles and Applications, Island Press, Washington, Covelo, London. [14] Ayres, R.U., van den Bergh, J.C.J.M., Gowdy, J.M., (1998): Viewpoint: Weak Versus Strong Sustainability, Tinbergen Institute Discussion papers No. 98-103/3, available at: http://ideas.repec.org/p/dgr/uvatin/19980103.html. [15] Dasgupta, P., (2007): Economics – A Very Short Introduction. Oxford University Press, New York. [16]

Dasgupta, P. (2001): Human Well-Being and the Natural Environment, Oxford University Press.

[17] Carpenter, S.R., Brock, W.A., (2008): Adaptive Capacity and Traps, Insight, Ecology and Society, Vol. 13, No.2, pp.40.

38

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[18]

Resaliance Alliance webpage: www.resaliance.org.

[19]

Gunderson, L.H., Holling, C.S., (Editors), (2002): Panarchy – Understanding Transformations in Human and Natural Systems, Island Press.

[20] Grubler, A. (1990): The Rise and Fall of Infrastructures – Dynamics of Evolution and Technological Change in Transport, Physica-Verlag Heidelberg. [21]

[22]

Rockstrom, J., Steffen, W., Noone, K., Persson, A., Chaplin, F. Stuart III, Lambin, E., Lenton, T.M., Scheffer, M., Folke, C., Schellnhuber, H.J., Bykvist, B., de Wit, C.A., Hughes, T., Leeuw Sander van der, Rodhe, H., Sorlin, S., Snyder, P.K., Costanza, R., Svedin, U., Falkenmark, M., Karlberg, L., Corell, R.W., Fabry, V.J., Hensen, J., Walker, B., and Liverman, D., (2009): Planetary Boundaries: Exploring the Safe Operating Space for Humanity, in Ecology and Society 14(2): 32. Szargut, J. (2005): Exergy Method – Technical and Ecological Applications, WIT Press, Southampton, U.K., Boston, USA.

[34]

Ausubel, J.H., Marchetti, C., (1997): Electron: Electrical Systems in Retrospect and Prospect, in Technological Trajectories and the Human Environment, Ausubel, J.H., Langford, H.D. (Editors), National Academy Press, Washington D.C.

[35] Gutowski, T G., Sahni, S., Boustani, A., Graves,S.C. (2011): 'Remanufacturing and Energy Savings, submitted to Environmental Science and Technology. [36]

National Research Council (2006): Sustainability in the Chemical Industry – Grand Challenges and Research Needs, The National Academies Press, Washington D.C.

[37] Costanza, R., Cumberland, J., Harman, D., Goodland, R., Norgaard, R. (1997): An Introduction to Ecological Economics, St. Lucie Press, Boca Raton, Florida. [38]

Daly, H., Townsend, K.N. (1996): Valuing the Earth – Economics, Ecology, Ethics, The MIT Press, Cambridge, MA., and London England.

[39]

[23] Wall, G., M. Gong, (2001): On Exergy and Sustainable Development, Part I: Conditions and Concepts. Exergy, An International Journal, Vol. 1, No. 3.

Jackson, T., (2006): The Earthscan Reader in Sustainable Consumption. Earthscan U.K. and U.S.

[40]

Nordhaus, W. and J. Tobin, (1972): Is growth obsolete? Columbia University Press, New York.

[24]

Bakshi, B.R., Gutowski, T.G., Sekulic, D.P. (2011): Thermodynamics and the Destruction of Resources. Cambridge University Press.

[41]

Daly, H., Cobb, J., 1989. For the Common Good. Beacon Press, Boston.

[25]

]Gutowski, T., Sekulic, D. P., Bakshi, B.R., (2009): Preliminary Thoughts on the Application of Thermodynamics to the Development of Sustainability Criteria, IEEE International Symposium on Sustainable Systems and Technology, Tempe, AZ. May 8-20.

[26]

Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M.C., Avery, K., Tignor, M., Miller, H.L.J., editors. International Panel on Climate Change (IPCC) (2007): Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, UK.

[42] ]Diefenbacher, H. (1994): The Index of Sustainable Economic Welfare in Germany, in C. Cobb & J. Cobb (eds.), The Green National Product, University of Americas Press, 1994. [43] Hamilton, C. (1999): The Genuine Progress Indicator: methodological developments and results form Australia, Ecological Economics, vol. 30, pp.13-28. [44] Jorgensen, A., Le Bocq, A., Nazarkina, L., Hauschild, M., (2008): Methodologies for Social Life Cycle Assessment, Int. J. LCA, Vol. 13, No. 2, pp. 96-103. [45] Graedel, T.E., Allenby, B.R., (2003): Industrial Ecology, second edition, Prentice Hall.

[27]

Millennium Ecosystem Assessment (MEA). (2005a). Ecosystems and human well-being:synthesis. Island Press, Washington, D.C., USA.

[46] Hermann, W.A., (2005): Quantifying global exergy resources, Energy, No. 31, pp. 1685-1702.

[28]

Millennium Ecosystem Assessment (MEA). (2005b). Ecosystems and human well-being: biodiversity synthesis. Island Press, Washington, D.C., USA.

[48] Herring, H., Sorrell, S. (2009): Energy Efficiency and Sustainable Consumption – The Rebound Effect. Energy, Climate and the Environment Series, Palgrave, Macmillan.

[29]

Kremer, M., (1993): Population Growth And Technological Change:One Million B.C. to 1990. Quarterly Journal of Economics, Vol. 108, No 3, pp. 681-716.

[49] Sorrell, S., (2010): Energy, Growth and Sustainability: Five Propositions, SPRU Electronic Working Paper No. 185, University of Sussex, SPRU – Science and Technology Policy Research. Brighton, U.K.

[30] Harford, T., (2008): The Logic of Life – The rational economics of an irrational world, Random House, New York. [31]

[32]

[33]

OSRAM Report (2009): Life Cycle Assessment of Illuminants A Comparison of Light Bulbs, Compact Fluorescent Lamps and LED Lamps, Executive Summary by OSRAM Opto Semiconductors GmbH, Regensburg, Germany and Siemens Corporate Technology, Berlin Germany. Matthews, D.H., Matthews, H.S., Jaramilo, P., and Weber, C.L., (2009): Energy Consumption in the Production of HighBrightness Light Emitting Diodes, IEEE International Symposium on Sustainable Systems and Technology, Tempe, AZ., May 18-20. Tsao, J.Y., Saunders, H.D., Creighton, J.R., Coltrin, M.E., Simmons, J.A., (2010): Solid-state lighting: an energyeconomics perspective, Journal of Physics D: Applied Physics, No. 43, 354001, IOP Publishing Ltd.

[47] Jevons, S., (1865): The Coal Question, Macmillan, London.

[50]

Ayres, R.U., Warr, B. (2009): The Economic Growth Engine: How Energy and Work Drive Material Prosperity, Edward Elgar Cheltenham, U.K., Northampton, MA. USA.

[51] Ayres, R.U., Ayres, E.H. (2010): Crossing the Energy Divide: moving from fossil fuel dependence to a clean-energy future, Pearson Education, Inc., Wharton School Publishing. [52] Graedel, T.E., Cao, J. (2010): Metal spectra as indicators of development, PNAS, Vol. 107, No. 49, pp. 20905-20910. [53] Allwood, J.M., Cullen, J.M., Milford, R.L. (2010): Options for Achieving a 50% Cut in Industrial Carbon Emissions by 2050 Environ. Sci. Technol, 44 (6), pp 1888–1894. [54] Allwood, J.M., Ashby M.F., Gutowski, T.G., Worrell, E. (2011): Materials Efficiency, a White paper, accepted for publication, Resources, Conservation and Recycling.

Keynotes [55]

Gutowski, T.G., Liow, J.Y.H., Sekulic, D.P. (2010): Minimum Exergy Requirements for the Manufacturing of Carbon Nanotubes , IEEE/International Symposium on Sustainable Systems and Technology, Washington D.C., May 16-19.

[56]

Mackay, D. JC. ((2009): Sustainable energy – without the hot air, UIT Cambridge Ltd. England.

[57]

Colon-Jimenez, E. (2010)” CO2 Price Impact on Dell’s Supply Chain: A Framework for Carbon Footprint Economic Analysis, Master of Science and Master of Business Administration Thesis, Sloan School of Management, Massachusetts Institute of Technology, Cambridge, MA.

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Indian Solar Thermal Technology – Technology to Protect Environment and Ecology Deepak Gadhia 1

1

Green Force Enviro Pvt. Ltd., India

Abstract Rising fuel costs and global warming are pushing the development of renewable energy supplies. Solar energy is most promising as unlike wind it is evenly and uniformly spread and more predictable. 1 % of the solar energy received on earth would meet the total energy requirements of the world. It has been calculated that even if only 2 % of Indian deserts were to be used for putting up solar concentrators that would suffice to produce all present India’s power need i.e. 140,000 MW. In the near future, solar energy may become part of the total commercial energy basket with its share rising in proportion to the new challenges. This study report shall provoke readers to act in their limited “circle of influence” by using technologies that have already delivered results worldwide. India is a leader among the nations in having a special Ministry for the promotion of Renewable Energy (MNRE). Even though there is no lack of funds and ideas, the results are still not commensurate with the potential that exists in India. This paper introduces a case study for the establishment of renewable energy supplies in India. Sustainable entrepreneurship as well as potentials and challenges from a life cycle perspective are described. Keywords: Solar Concentrators; Sustainable Business Models; Renewable Energy 1

INTRODUCTION

In the 30 member countries of the OECD, where electricity markets are well developed and the economical situation as well as the size of populations are more or less stable, the growth of electricity generation is evidently slower than in the non-OECD countries. Considering the strong economic growth that is projected for the developing non-OECD countries such as China and India, where a high percentage of the population does not even have access to electricity yet, a substantial increase of electricity generation will be needed to meet the industrial as well as the residential demand. The World Energy Outlook 2008, published by the International Energy Agency (IEA), projects that China and India will account for more than half of the growing total energy demand until 2030, considering that India is the second largest country in the world and has a significant economic growth of about 8% with over 1 billion inhabitants [1]. Relying on existing patterns and the strong use of fossil energy carriers to cope with the resulting energy demand would unfavourably influence global climate conditions. India’s government recently presented an action plan which specifically focuses on an increasing usage of renewable energies to reduce environmental impact without disturbing economic growth. Certainly a continuous energy supply is crucial for long term economic growth. Having in mind that 60% of India’s rural population are not or not sufficiently connected to electricity underlines the importance of decentralized and renewable energy supply structures. Solar energy is specifically addressed by the government and with over 300 sun days a year the country is predestined for this renewable energy source. Therefore India has a special Ministry for New and Renewable Energy (MNRE). The Ministry has been working hard to develop renewable energy, widen the base of manufacturers and providing incentives for users to make renewable energy products affordable and accessible. Recently, the Ministry committed itself to the aim that by 2012 more than 10 % of India’s power shall come from renewable energy. At present, the share is about 5 %. For the first time in Indian history, the share will be higher than that of nuclear energy.

Till now, major contribution in renewable power comes from wind energy. To promote Solar Concentrator Technology, Indian government through MNRE provides subsidy of Rs 5,000 (approx 90 Euro) per square meter of Concentrator reflecting area to NGOs and non-profit institutions as well as accelerated depreciation benefits and subsidies of Rs 3,500 (approx 55 Euro) to the industry. The only drawback of going for government support and subsidies at present is that to get subsidies the buyer has to undergo a tendering procedure. The matter with MNRE has been taken up to do away with tendering as it causes delays and forces the companies to buy from someone who may quote low but has never proven his supplying capacities. In addition to the government support, the industry can sell carbon credits under the Clean Development Mechanism (CDM) of the Kyoto Protocol. 2

SOLAR CONCENTRATOR TECHNOLOGY

Solar Concentrators are one example for decentralized and renewable energy supply structures as they are demanded in India and have been known for centuries. Everyone knows that fires can be ignited using magnifying glasses. But only recently, technologies for its commercial use are being developed. There are various types of solar concentrators that can be broadly classified into Line Concentrators, Trough Concentrators, Heliostats, and Parabolic Solar Concentrators. At present, due to high costs and the complex curved mirror technology, Line Focus Concentrators are viable only in larger capacities. The same is true for Heliostats as the cost of the Central Tower is high and thus a minimum size of MW is needed. Parabolic Solar dishes can be of any size and thus having modularity can be of smaller sizes enabling its use for cooking, process heat and process cooling while they may also be scaled up to the range of a MW Power Plant. In this technology, parabolic dishes concentrate solar rays at a point achieving high temperatures. The temperature in the focus can be 500 to 2000 degree centigrade depending on the Concentration Ratio (CR). Of all solar technologies, Parabolic Dish Solar Concentrators have made maximum impact in India and have relevance and future.

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_7, © Springer-Verlag Berlin Heidelberg 2011

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41

There are four applications (technologies) in Solar Concentrators that have found their foothold and made mark in India: 

For Domestic Cooking: Seifert Parabolic Solar Concentrator (SK 14) are small size parabolic dishes of 1 meter or 1.4 meter diameter in which blackened cooking vessels are put in its focus and due to temperatures above 250 degree centigrade food gets cooked fast, conveniently and free. There are thousands of such solar cookers being used in rural India.



For Community Cooking: Scheffler Concentrators (Figure 1) are concentrators made out of segments of parabola with flexible curvatures to achieve a stationary focus and thus the light can be reflected in the kitchen and cooking can take place in comfort. These advantages led to their being used for community cooking preparing food for 50-100 people.



Institutional Cooking, Process heating, and Cooling applications: With the help of the German company HTT GmbH, a solar steam generating system was developed. Now there are about 50 large systems in India that provide cooking energy at institutions for 500 to 25,000 people twice a day.



Scheffler Concentrators have also been successfully installed and tried out by Gadhia Solar for uses like solar air-conditioning ( a 100 TR= 350 KW system has been successfully installed at a Hospital by us in India), laundry and ironing, sludge drying, wastewater evaporation, incineration, food processing, desalination, and others. With this, the Solar Concentrator Systems are bound to spread and newer applications are being developed.

Figure 2: Installed Scheffler Concentrators, Project from 2001 Gadhia Solar Energy Systems is an innovative solar thermal energy company, focused on providing energy solutions by using parabolic concentrated technologies. Since its inception, Gadhia Solar has been technologically, solution focused company driven by strong passion for environmental and social contribution. Gadhia Solar has implemented some of the world's largest solar thermal systems in the last two decades (Figure 2, Figure 3). It offers cost effective, reliable hot water solutions, solutions for drinking water, water evaporation and desalination system of industrial scales, centralized solar air conditioning and heating systems, as well as complete customized solutions for industrial applications from pharmaceuticals to chemical to food processing industries [3].

Figure 3: Installed Scheffler Concentrators, Project from 2008/09 Figure 1: Scheffler Solar Concentrators.

3

ESTABLISHMENT OF TECHNOLOGY IN INDIA

SOLAR

CONCENTRATOR

After studying Process and Environmental Engineering and doing Post Graduation in Energy Consultancy and Energy Management at TU Berlin after his return to India Deepak Gadhia founded the company Gadhia Solar Energy Systems Pvt. Ltd. He discovered the potential of solar energy more by chance than by plan. Mr. Gadhia came into the field to help his wife Dr. Shirin Gadhia who runs the NGO Eco Center ICNEER and who was looking for a solution to offer to poor when she told them not to cut forest and was confronted with their question: “Than how do we cook?.” On getting in the field Deepak Gadhia realised that 50% of the world’s population cook on open fire and that pollution in the kitchen is the third largest killer. Thus he saw business opportunities and started his company that evolved and grew [2].

The company Gadhia Solar with the help of GTZ registered its Solar Kitchen Projects under the CDM Gold Standard and the CER (Certified Emission reduction Certificates) arising out of use of Solar kitchens would be purchased by GTZ for German Ministry to compensate for the CO2 emission of the Solar Meet held in Bonn making it a Carbon Neutral Conference. 3.1

Products

Systems from Gadhia Solar are built up of dishes (in sizes of 9 m², 16 m² or 32 m² depending on specific application) that incorporate the basic principle and therefore the advantage of high efficiency of the parabolic dish concentrators. However there is a major difference regarding the functional principle. While parabolic dish concentrators like dish-Sterling systems have to move the absorber unit connected to the dish during sun tracking, the Gadhia system can use stationary mounted receiver units. That means that receiver constructions and piping systems are significantly easier to design and the linking of several dishes for efficient energy generation systems is enabled [3].

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Keynotes

The design bases on the idea of the Scheffler dish, which was invented by Mr. Wolfgang Scheffler in Kenya in 1983. The basic idea that did lead to the development of the Schefflerreflectors was to make solar cooking as comfortable as possible [4] [5]. At the same time the device should be build in a way that allows it to be manufactured in any rural welding workshop in southern countries after a certain period of training with locally available materials. To make cooking simple and comfortable the cooking-place should not have to be moved, even better: it should be inside the house and the concentrating reflector outside in the sun [5]. The technology to achieve these desired requirements is based on changing the shape of the parabolic dish concentrator and led to the term fixfocus principle which shall be explained hereafter (see also Figure 4).

differing and has to be adjusted as well for a sharp and small focal area. This is only possible by shaping the reflector after another parabola for each seasonal inclination-angle of the sun, i.e. for each day of the year. This means the reflector has to change its shape at regular intervals. The reflector-frame is build for equinox. By inclining and elastically deforming the reflector-frame all other parabolas can be achieved with sufficient accuracy [5]. The dishes were already used in diverse applications in the context of decentralized cooking (with just one dish), water treatment or steam generation in systems with more than 100 dishes e.g. for cooking in pilgrim shelters or women's refugees. Besides basically a wide range of promising fields of applications is possible which typically involve larger amounts of solar concentrators to run the system efficiently, e.g. steam generation for process heat (for industrial purposes), co-generation of steam (process heat) and electricity (approx. 1 MW), and generation of electricity (power plant with at least 5MW) [3]. 3.2

a b

c

Figure 4: Gadhia Solar concentrator - functional principle (a), concentrator (b) and system with several dishes (c) [3]. The reflector is a small lateral section of a much larger paraboloid. The inclined cut produces the typical elliptical shape of the Scheffler-Reflector. The direct beam radiation falling onto this section of the paraboloid is reflected sideways to the focus located at some distance of the reflector. The concentrator system is tracking the suns’ daily movement one the one hand and the seasonal movement on the other hand. The axis of daily rotation is located exactly in north-south-direction, parallel to earth axis and runs through the centre of gravity of the reflector. The focus is located on the axis of rotation to prevent it from moving when the reflector rotates. The distance between focus and centre of the reflector depends on the selected parabola. During the day the concentrated light will only rotate around its own centre but not move sideways in any direction. That way the focal area or hot spot stays fixed and is therefore called fix focus. After sunset the system has to be set back into morning position. As previously mentioned, the unique feature of the concentrator system is the fixed hot spot near the ground. The adjustable paraboloid dish can concentrate the radiation onto a defined target area for all positions of the daily and seasonal sun movement. Adjustment of the dish shape is necessary because in the course of the seasons the incident angle of the solar radiation varies in relation with the perpendicular to earth-axis. The paraboloid has to perform the same change of inclination in order to stay directed at the sun. Changing only the inclination of the dish is not sufficient to obtain a sharp focal point. Even though the position of the focus stays fixed the focal length is

Potentials and Challenges from a Life Cycle perspective

As the previous chapters show the current and predicted economic background in context to solar thermal electricity generation is quite positive in India as well as worldwide. Gadhia Solar as leading and well known company for solar thermal solutions in India naturally wants to take part in these developments. Their products are characterized by unique technological properties like the fixed focus dishes which may give them technological advantages in terms of efficiency. However, until now Gadhia Solar has not installed power plants for large scale electricity generation yet. Quite obviously there are some challenges that have to be solved when establishing business with large scale solar power plants. Based on previous statements two critical success factors can be derived [6]: 

be able to cope with high production volumes to face capacity increase and upscaling of systems



reducing costs of electricity generation to encounter high cost pressure in competition with other energy sources

Considering economies of scale and scope it is obvious that both factors are closely connected to each other. Against this background the following paragraphs shall give a more detailed look on challenges along the life cycle of a solar thermal power plant based on Gadhia Solar concentrators (Figure 4). Thereby, while India being the home country and also primary market of Gadhia Solar it is absolutely crucial to consider the specific conditions there.

Figure 4: Life cycle of solar concentrator systems [6]. Product Design Whereas the influence on costs is mainly given in the design phase, in the sense of a “Design for X” it is naturally necessary to consciously consider all other life cycle phases already here. In order to cope with high production volumes and cost pressure specifically design for manufacturing and assembly (DFMA) is of major relevance. In this context it is important to take a look at improving the product structure, increasing the amount of common parts and the careful definition of interfaces with appropriate selection of subassemblies and joining technologies. Main objectives of DFMA are the reduction of product costs assembly

Keynotes time (enables faster product throughput/higher capacity) and the amount of parts (e.g. fewer parts in stock) both resulting in lower product costs (labor and material). Studies underline that reductions of about 50% in all categories compared to the initial state are realistic [7]. Hereby it is crucial to take certain specific critical conditions or restrictions regarding transportation (e.g. road conditions, space on trucks), qualification of personnel (e.g. easy activities, safety issues) and usable technologies (e.g. no electricity on installation site) into account. Critical points in mechanical and electrical system design in the considered system of Gadhia Solar include parts like the steam pipeline (design of all components for optimizing the system to produce superheated steam for power generation), the mirror surfaces (foils, adhesive bonding of reflective coated glass, improvement of the long time behaviour of the mirror surfaces, cleaning, weather proof coatings), the frame (redesign for light weight and carbon foot print, using of space frame, computation and optimization of the welded structure), the day time sun tracking and the seasoning adjustment (e.g. design for automatical use in power plants). [6] Production As described above the proposed fields of applications using the Scheffler solar concentrator involve a very significant increase (factor 5-10 of current production capacity per year) of the necessary number of concentrators. This larger production volume is a totally new requirement for the whole production process chain which consists of the rather manual manufacturing of parts and subassemblies in a production plant (in Valsad, Gujarat) and their final assembly on the actual installation site. Significantly higher production volumes need a redesign of the production system. However, connected technical (e.g. production system design /material flow, selection and dimensioning of specific production processes / machines) and organisational (e.g. planning and control of production, organisational structures, qualification) measures to adapt the production system will lead to economies of scale with positive effect on product costs. Again, while being quite different compared to e.g. European countries Indian specific conditions and requirements (e.g. qualification of employees, given infrastructure, cost structure/ prices for machinery and raw materials, integration of local content) need to be considered. As a final result the production process chain based in India shall be able to timely deliver as many qualitatively sound solar concentrators as needed for the proposed fields of application – under consideration of additional targets like competitive costs and also low environmental impact. [6] Product usage and End of Life As a long term investment good with a desired life span of at least 10-15 years the use phase naturally has a major impact regarding the ecological and economical performance of solar concentrators over the life cycle. Whereas current solutions considering systems with approximately 100-200 mirrors totally different approaches are needed to cope with the desired shift to power plant system with several hundred dishes. Critical aspects in this context are the significant effort needed to ensure efficient functionality of the whole system through adjusting / control (e.g. daytime and seasonal adjustment of the mirrors, control of system regarding heat usage / storage et cetera) or maintenance measures (e.g. ensuring high availability, cleaning of mirrors, strategy for monitoring and controlling of the system states) despite being strongly exposed to the elements. While large amounts of concentrators are in use, it is important to be able to appropriately dispose them after use (e.g. no hazardous materials). Additionally, aspects like reuse or material recycling should be considered in product design (e.g. common parts as spare parts) to gain advantages over the life cycle. [6]

43 4

MOTIVATION FOR FURTHER ACTIVITIES

Like all countries, India too has rolled out a very ambitious 20 GW Solar Energy Mission. This will fuel the demand but also create an increased demand for engineers, skilled workers, technicians, installers, after sales service providers, marketeers, and consultants. To overcome the shortage that will emerge Green Academies must be developed with the support of the International Labour Organisation (ILO). Muni Seva Ashram, an Indian NGO in India in which Deepak Gadhia is a trustee, plans to start a Green Academy called ASPIRE (Academy for Sustainable Practices, Innovations in Renewable Energy) to meet that demand. Green Industries and Green Jobs are the future. They offer great opportunities to Entrepreneurs who are willing to enter into fields like solar energy, biogas etc. Besides the incentives of subsidies and carbon credits for renewable energy and of saving fuel many industries and institutions are purchasing renewable energy systems with the aim to “Go Green” and contribute to the protection of the environment and to reducing the problems of global warming. They understand the need to act. While some time ago all the decisions were taken considering economics only people are now willing to pay a bit more if that helps to protect the environment and the ecology. For the survival of mankind, it is imperative that economy and ecology go hand in hand. 5

SUMMARY AND ACKNOWLEDGEMENTS

The paper presents a case study for the establishment of renewable energy supplies in India and its underlying and enabling sustainable entrepreneurship. While being a promising approach for the future, probable developments demand manufacturers of solar thermal systems to be able to cope with high production volumes and significant cost pressure. This was underlined by the case study of Gadhia Solar where additional influencing parameters were also presented. This paper was developed in context of a cooperation between Gadhia Solar Energy Systems Pvt. Ltd. And the Technische Universität Braunschweig. 6

REFERENCES

[1]

World Energy Outlook, 2008, International Energy Agency (IEA), www.worldenergyoutlook.org.

[2]

Gadhia, D. (2010): Solar Concentrators in India - Technology to Protect Environment and Ecology, in: TU INTERNATIONAL, No. 66, pp. 12-13, Berlin, Germany

[3]

Gadhia Solar Energy Systems Pvt. Ltd., 2009, company information, e.g. www.gadhia-solar.com.

[4]

Tyroller, M., 2004, Solarsterilisator für Entwicklungsländer, München.

[5]

Scheffler, W., 2009, Solare Brücke Reflektoren, www.solare-bruecke.org.

[6]

Herrmann, C., Thiede, S., Kuntzky, K., Böhm, S., Frauenhofer, M., Gadhia, D. (2009): Indian Solar Thermal Technology: Potentials and Challenges, in: Proceedings of the 7th Global Conference on Sustainable Manufacturing, pp.169-174, Chennai, India.

[7]

Boothroyd Dewhurst Inc., 2009, Design for Manufacture and Assembly (DFMA), www.dfma.com.

-

Die

Scheffler

Assessment of Energy and Resource Consumption of Processes and Process Chains within the Automotive Sector 1

1

1

2

2

2

R. Schlosser , F. Klocke , B. Döbbeler , B. Riemer ,K. Hameyer , T. Herold , 3 4 5 6 W. Zimmermann , O. Nuding , B. A. Schindler , M. Niemczyk 1

Laboratory for machine tools and production engineering (WZL) of the RWTH Aachen University, 2 Institute of Electrical Machines of the RWTH Aachen University, 3 4 5 6 Daimler AG, Robert Bosch GmbH, PE International GmbH, Effizienz-Agentur NRW

Abstract Within this paper a methodology for the assessment of energy and resource consumption within manufacturing processes is described and two case studies from the automotive sector were evaluated. On basis of the Life Cycle Assessment approach the energy and material flows within single manufacturing processes were acquired concerning the two selected case studies. With the generated knowledge about energy and material use it was possible to show up optimisation potentials for the reduction of the ecological impact of the determined products within the manufacturing phase. The work shown in the paper was conducted within the project BEAT which is kindly financed by the Federal Ministry of Education and Research in Germany (BMBF). Keywords: Manufacturing Process Evaluation and Characterisation; Total Process Efficiency; Sustainability

1

INTRODUCTION

Due to the scarcity of resources and the increasing global demand to use these resources for products and power generation, the commodity prices on the international energy and commodity market are increasing heavily as shown in Figure 1. Although the prices on the markets crushed during the last world economic crisis, as highlighted in grey in Figure 1, they are constantly growing again. This vast increase in prices emerges to one of the central problems which manufacturing industry has to face [1][2].

200 150 100 50 0

Ja n 0 Ja 0 n 0 Ja 1 n 0 Ja 2 n 0 Ja 3 n 0 Ja 4 n 0 Ja 5 n 06 Ja n 0 Ja 7 n 0 Ja 8 n 0 Ja 9 n 10

Price trend based on 2005 / %

250

crude oil (import price index) natural gas (import price index) energy (manufacturing price index for special contracted companies) steel (manufacturing price index) copper (manufacturing price index) Figure 1: Development of energy and commodity prices. In economic as well as in ecological perspective, the resource consumption of products has to be planned to be more sustainable. Therefore products have to be designed to be resource and energy efficient along the total life cycle. To achieve this aim, it is possible

to influence the energy and resource consumption in one or more product life cycle phases. The change of one product life cycle phase might also effect the energy and resource consumption in another phase in a positive or in a negative way. For this reason it is essential to evaluate all changes across the whole life cycle, to guarantee an overall reduction in energy and resource consumption [3]. The necessity for this can be shown by the following example: The manufacturing industry will primarily focus on the resource efficiency during the manufacturing process. The customers of energy or material consuming goods, like a machine tool on the other hand, intend to have low resource consumption during the use stage. The analyse of the whole life cycle including preproducts production, manufacturing itself as well as scenarios for use stage and end-of-life is therefore essential for the manufacturers of these goods [4]. With the increasing impact of material and energy costs in the use stage of a machine tool even in high wage countries, it is important to identify and optimise the energy and material demand. Former studies identified that manufacturing processes can be influenced most, if the processes with the highest average power consumption are optimised. Therefore heat treatments are generally considered with a high optimisation potential. Within this paper further investigations of the project BEAT (“Bewertung der Energieeffizienz alternativer Prozesse und Technologieketten”, engl.: Assessment of the energy efficiency of alternative processes and process chains), which is kindly supported by the Federal Ministry of Education and Research (BMBF) in Germany, are presented and it will be shown that this assumption is not sufficient for machining operations in the automotive sector. 2

A LIFE CYCLE ASSESSMENT APPROACH FOR THE EVALUATION OF THE ENERGY AND RESOURCE CONSUMPTION OF PROCESS CHAINS

Throughout recent years, the objective of manufacturing processes was to reduce the manufacturing costs. Due to a lack of data it was

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_8, © Springer-Verlag Berlin Heidelberg 2011

45

46

Automotive Life Cycle Engineering

assumed that the major cost drivers are staff and machine costs. The detailed analysis of energy and material was not in the focus of optimisation potential. This can be proven best on the basis of the available inventory data in Life Cycle Assessment. Until today the data on machining of metal parts is poor. A model for the prediction of the material and energy consumption with reasonable preciseness during a typical machining process like milling or turning is not yet available [5]. It is common practise within companies that costs for energy are assigned towards the machine tools rather by the amount of square meters used by the machine tool than by the real usage data. It is generally known that the best procedure to compare different production processes with respect to their energy and material consumption and the associated environmental impacts is done by a Life Cycle Assessment according to DIN EN ISO 14040/14044. Within the Life Cycle Assessment material and energy flows of all life cycle phases are determined (compare Figure 2) and the environmental impacts are calculated by means of using scientifically based characterisation factors. Only the relative comparison of the results for the different impact categories enables the evaluation of the values [6][7].

Energy Resource

Waste Raw material production

Energy Resource

Waste Production

Energy Resource

Emissions Waste

Use

Energy Resource

Emissions

Emissions



Detailed measurements on the machines will identify “hot spots” within the processes and help to develop options for savings even in today’s state of the art processes.



Better understanding on the material and energy consumption of different machining processes, which means the development of ecodesigns for whole process chains.

An additional benefit is a better understanding of hidden costs, in most cases declared as overhead, which also contain energy and auxiliary material (range from 5% to 50%). 3

INDUSTRIAL SECTOR

CASE

STUDIES

IN

THE

AUTOMOTIVE

Within the BEAT Project the following two industrial case studies of the partners Bosch and Daimler were investigated. The case studies were chosen due to their high volume relevance of the parts. 3.1

Gear manufacturing

The research object of the Daimler AG is a production line for the manufacturing of the 4th gear wheel (idler gear) of the front-shift transmission (type FSG) in the Rastatt (Germany) plant. The FSG is the manual transmission of the A and B class, with an annual production volume of 100,000 units. The used process chain is displayed in Figure 3. The basic structure of the process chain is soft machining of the forged part and hardening followed by hard finishing processes, such as hole and gear grinding. Within the project the process chain from turning to gear grinding is captured and evaluated as this part of the process chain is done within the Rastatt production plant.

Forging

Waste Recycling/ Disposal

Emissions

Turning Hobbing

Figure 2: Balance shell for Life Cycle Assessment with in- and outgoing energy and resource flows. As stated above, even from the cost perspective machining operations have not been in focus of the Life Cycle Assessment studies so far. Assumptions and estimations have to be used due to missing data for these processes. Recent studies have shown, that the costs of energy used in machining operations are as high as the costs for tools [8]. For this reason it is absolutely crucial to further analyse and measure the energy and material consumption of typical machining processes. Alternative processing routes may become interesting on a cost perspective as well as for ecological reasons. So far optimisations of technologies and process chains have been driven by the lowest production costs as a sum of machine costs and staff costs. This may change in future due to rising costs for material and energy. A detailed data collection for process chains with reference to the considered products is necessary. This allows the extension for comparisons to alternative process routes and for a “technical” cost calculation. While the work load for such an inventory analysis may seem to be very high, its effect may be even bigger. This approach will help the companies to reduce the consumption in two ways.

Deburring Shaping Washing Carburisation Quenching Washing Tempering Hole grinding Tooth flank grinding Washing Figure 3: Case study gear manufacturing with its process chain.

Automotive Life Cycle Engineering 3.2

47

Valve injector manufacturing

The research object of the Robert Bosch GmbH is a production line for the manufacturing of the valve injector of a magnetic common rail injector in the Bamberg (Germany) plant. Common rail systems are produced since 1997 and the total volume is clear about 50 million systems so far. The applied process chain is displayed in Figure 4. The basic structure of the process chain is soft machining of bar material and hardening followed by hard finishing processes.

Turning, Drilling Washing Heat treatment Eroding Rounding Flow Rate Check Laser marking Grinding Deburring Figure 4: Case study valve injector manufacturing with its process chain. 4

ENERGY AND RESOURCE CONSUMPTION ALONG THE PROCESS CHAIN

For the evaluation of the process chain it was essential to define the balance shell first. It is not useful to respect only the energy and resources which are needed for the process itself, as the enabling energy and resources for a machine tool cannot be neglected for the process. Within the BEAT project, the machine tools were chosen as the relevant balance shell for the evaluation. Besides it has been decided, that the first level of central systems (directly connected to the machine tool) is also measured and converted on the single machine tools by the consumption of functional units of each machine tool. Nevertheless it is not practical to measure even more layers of central systems as the influence and therefore the relevance of these systems is very small in comparison to the direct energy and resource flows. As in most manufacturing plants the real energy and resource flows in the machine tool are not known, a first step within the BEAT project was the qualitative detection of all flows in and out of each machine tool and central unit. An extract of the example of the gear manufacturing can be seen in Figure 5. Electrical energy is a major flow as it is required almost everywhere. Therefore its correct data acquisition is important and will be further investigated in the next chapter.

Figure 5: Energy and resource flows within gear manufacturing.

48 5

Automotive Life Cycle Engineering TECHNOLOGY REQUIREMENTS FOR DATA AQUISITION OF ELECTRICAL ENERGY

In general converter-fed motors are applied to modern machine tools to allow the required dynamic operation. From the electrical point of view a machine tool can be simplified as done in Figure 6, including the converter and one electrical machine, e.g. a speed variable main spindle.

the load (machine tool) and is not converted into mechanical power. The reactive power is defined as

Qn  S n2  Pn2 ,

(3)

with the apparent power:

S n  U rms ,n  I rms ,n ,

(4)

and the root-mean-squared values:

1 2 xt  dt , T T

X rms 

x  u, i .

(5)

The calculation of the root-mean-squared values has to be synchronised by the zero crossing of the voltage or the current. This synchronisation fails if the sample frequency of the measurement instrument is too small. By this reason it is not possible to use power quality analysers for power measurements at pulsed voltages behind the converter. Figure 6: Simplified electrical representation of a machine tool. For a significant data acquisition of the electrical energy flow, the voltage and current shapes have to be considered. The nearly sinusoidal input voltage of the converter is rectified in the first module. The converter feeds the connected motor with voltage pulses of a switching frequency of 2-16 kHz. These voltage pulses lead to a current flow which can be controlled in magnitude and frequency as it is required by the process. Due to the switched voltage the current has a high fraction of higher harmonics beside the fundamental wave. For a reliable data acquisition the sample frequency of the measuring instrument has to be adapted to this higher harmonics. Electrical power measurement devices can be differentiated into power analysers and power quality analysers. A major difference is the sample frequency. Modern power analysers have sample rates up to 3 MS, resulting in a sample frequency of 500 kHz per channel for a 3-phase power measurement. This sample frequency allows a power measurement at the input and at the output of the converter. Power quality analysers, which have an extensive advantage in price compared to power analysers up to a factor of 5-10, are generally used for long term power quality measurements of power grids. They have sample rates of 128 - 512 samples per cycle, resulting in a sample frequency of 6.4 kHz - 25.6 kHz for 50Hz grids [9]. To understand the impact of the sample frequency on the measurement accuracy some basic principles of electrical power measurement have to be considered. The instantaneous input power of an electrical load is given by:

1  un t   in t dt. T T

7000

(1)

The phase voltage un(t) and the phase current in(t) are sampled with the sample frequency of the measurement instrument. It has to be considered that the error of the measurement will increase for a decreasing sampling frequency. The instantaneous power can be separated into active and reactive power. The active power less the internal losses of the electrical drive, e.g. friction, switching and ohmic losses, is dissipated into motion. The active power for each phase n is defined as

Pn 

8000

(2)

For a holistic energy analysis the reactive power has to be regarded as well. The inductive behaviour of electrical machines causes a reactive current flow leading to additional ohmic losses onto the supply conductors. Reactive power oscillates between the grid and

6000 active power [W]

pn t   u n t   in t .

Beside the sampling frequency, the method of the current measurement has an arbitrative influence on the quality of the measured data. The use of serial connected high-precision shunt resistances necessitates an unacceptable disconnection of the machine tool from the grid. This interruption of the machining process can be avoided by using current probes. Current probes are often based on the principle of a transformer. Their accuracy is lower compared to shunt resistances due to stray fluxes and external influences. Compared to power analysers, which use generally shunt resistances, power quality analysers are equipped with current probes. To quantify the ability of power quality analysers to acquire the energy consumption of machine tools, a comparative measurement is performed. Using a simple configuration as depicted in Figure 6, the energy consumption is measured at the terminals of the converter. The process of a machine tool is simulated using a controlled asynchronous machine as a main spindle connected back to back to a controlled permanent magnet synchronous machine. The power analyser measures the current with Hall Effect current sensors with an accuracy of 0.3 %. The sample rate is adjusted to 500 kHz per channel. The power quality analyser works at sample frequency of 6.4 kHz per channel and uses current probes with an accuracy of ±0.7 % ± 2 mA and a phase angle error of ± 1.5º. The rms-values are averaged over a period of 1s. Figure 7 and Figure 8 depict the measured active and reactive input power at the converter terminals for different applied loads of the asynchronous machine.

5000 4000 3000 2000 Power Quality Analyser Power Analyser

1000 0

0

50

100

150 200 time [s]

250

300

350

Figure 7: Energy measurement of the active power by a power analyser compared to a power quality analyser.

Automotive Life Cycle Engineering

49

Epart, indirect:

6000

The direct manufacturing energy per part is the sum of the energies of the single manufacturing processes

reactive power [VAr]

5000

m

E part , direct   E part ,man j

4000

Epart,manu_j:

1000

Power Quality Analyser Power Analyser 0

50

100

150 200 time [s]

250

300

350

The relative deviation between the measured active energy is 0.14 %. The reactive energy has a relative deviation of 0.16 %. These matching results of the comparative measurement demonstrate the usability of power quality analysers at the terminals of machine tools within the project despite the lower sample frequency and the less accurate current measurement. Power demand and energy consumption in a turning process

Figure 9 displays the composition of power demands, forming the overall process energy depending on the process times. During one cycle several different power demands can be distinguished. The electrical energy can be divided in energy which flows directly into the balance shell, in other words in the machine tool, and in indirect energy from the periphery (central unit systems) which is necessary to enable the manufacturing process. On the one hand there is a constant portion containing periphery (illumination, air conditioning ...) and machine aggregates (basic demand = standby demand). On the other hand the variable portion depends largely on the actual process as well as on auxiliary and feed movements [10].

Power /kW12 10

direct

Process

indirect

Idle

process energy consumption energy consumption during idling

Esb,j:

energy consumption in standby mode

Eoff,j:

energy consumption while machine tool is switched off

If the idling and process mode cannot be separated, both energy consumptions can be calculated by the mean process and idling power multiplied with the time per unit. The energy consumption of the other machine tool state can be proportionally added.

E part , man j  Pprocess, mean  t process  t process  Psb , mean 

Figure 9: Power consumption in cutting processes. The energy consumption per part in manufacturing can be calculated as the sum of the direct and indirect energy per part.

energy consumption per part

Epart, direct:

direct energy consumption per part

poff p process

psb p process

 (9)

 t process  Poff , mean .

Pprocess, mean:

mean process power

Psb, mean:

mean standby power

Poff, mean:

power consumption while the machine tool is switched off

tprocess:

process time

psb:

proportion of standby

poff:

proportion of the machine tool is switched off

pprocess:

proportion of the productive time

m

i 1 j 1

Standby Illumination, air conditioning, compressed air, central coolant lubricant supply… Time /s

Epart:

(8)

Eidle,j

n

E part  E part , direct  E part , indirect

in

Eprocess,j

E part , indirect  

4

0

part

The indirect energy from the periphery has to be estimated by defining a functional unit (FU) of each auxiliary energy and resource flow. A functional unit for compressed air is for example Nm³.

6

2

per

E part ,man j  E process , j  E sb , j  Eidle , j  E off , j

Figure 8: Energy measurement of the reactive power by a power analyser compared to a power quality analyser.

8

direct energy consumption manufacturing process j

The energy of a single manufacturing process consists of the real process energy, the energy consumed in the idling mode and a proportional part of the energy consumed in standby mode and while the machine tool is switched off.

2000

5.1

(7)

j 1

3000

0

indirect energy consumption per part

(6)

Eaux ,i  FU machine tool j , part FU total ,i

(10)

Eaux,j:

energy consumption of auxiliary device j

FUtotal:

total amount of functional units

FUmachinetool, part:

amount of functional units used on a machine tool for a product

The following chapter will show the results of measurements of the direct energy for the valve injection process chain, which were generated up to now. Further research work is outstanding. 5.2

Energy consumption within valve injector manufacturing

Corresponding to the described proceeding above, every process was measured and calculated within both case studies. In the following Figure 10 and Figure 11 the results are shown for the valve injector process chain. The results are especially interesting if

50

Automotive Life Cycle Engineering

the average power consumption of the single processes is compared with the influence on the energy per part. As it can be seen, the extensively used assumption, that the optimisation of the highest power consumers would bring the best benefit, does not really make sense, if the energy per unit is taken into account.

7

ACKNOWLEDGMENTS

The authors gratefully acknowledge the financial support of the Federal Ministry of Education and Research (BMBF) and the project supervision of the Project Management Agency Forschungszentrum Karlsruhe, Division Production and Manufacturing Technologies (PTKA-PFT) for the project BEAT - Bewertung der Energieeffizienz alternativer Prozesse und Technologieketten (Assessment of the energy efficiency of alternative processes and process chains).

Turning Washing Heat treatment Eroding Rounding Flow Rate Check Laser marking Grinding Deburring

Figure 10: Distribution of power consumption along the process chain. 8

REFERENCES

[1]

Herring, H., (2000) Is Energy Efficiency Environmentally Friendly? Energy & Environment 11, No. 3, pp. 313 - 325.

[2]

Herrmann, H., Zein, A., Thiede, S., Bergmann, L. Bock, R., (2008) Bringing sustainable manufacturing into practice – the machine tool case, in: Sustainable Manufacturing VI, Global Conference on Sustainable Product Development and Life Cycle Engineering, Pusan, Korea, pp. 272 - 277.

[3]

Graedel, T., (1996) Industrial Ecology: Defnition and Implementation, in: Socolow, R. et al.: Industrial ecology and global change, Cambridge University Press, pp. 23 - 42.

[4]

Figure 11: Distribution of influence of the processes on the required energy per part.

Gerschwiler, K., Jahns, P., Klocke, F., Lingg, G., Lung, D., Schlosser, R., Werner, A. R., Zeller, R., (2008) Ressourcenschonende Produktion, in: AWK 2008 – Wettbewerbsfaktor Produktionstechnik, pp. 81 - 124.

[5]

The reason why high energetic processes, as heat treatment, in the shown case studies didn’t have such a big influence on the direct electrical energy per part is that in the heat treatment and washing process much more parts are treated at the same time than on a machine tool.

Büdicker K., (2003) Reduktion und Verwertung von Abfällen anhand ausgeführter Beispiele der Wälzlagerherstellung, VDI Berichte Nr. 1779.

[6]

N.N., (2009) Environmental management – Life cycle assessment – Principles and framework, DIN ISO EN 14040.

[7]

N.N., (2006) Environmental management – Life cycle assessment – Requirements and guidelines, DIN ISO EN 14044.

[8]

Bode, H.-O., (2007) “Einfluss einer energieeffizienten Produktion auf Planungs- und Produktprämissen am Beispiel der Motorenfertigung”; in XII. Internationales Produktionstechnisches Kolloquium, Berlin, pp. 299-305.

[9]

N.N, (2009) IEEE Recommended Practice for Monitoring Electric Power Quality, IEEE Std 1159-2009.

Turning Washing Heat treatment Eroding Rounding Flow Rate Check Laser marking Grinding Deburring

6

SUMMARY AND OUTLOOK

This paper presented and discussed research work within the framework of the BMBF supported project BEAT. It was possible to show a suitable proceeding for the assessment of energy demands of manufacturing processes with the focus on the energy per unit. The case studies showed that the energy per unit is quite different from the average power consumption of a process, as the units in a process might have an even bigger impact on the energy per unit as the amount of power consumption. Nevertheless, for a comprehensive balance of manufacturing processes further information are still missing and have to be generated in the future.

[10] Bhattacharya, A., Das, S., Majumder, P., Batish, A., (2009) Estimating the effect of cutting parameters on surface finish and power consumption during high speed machining of AISI 1045 steel using Taguchi design and ANOVA, In: Production Engineering, Vol. 3, No. 1, pp. 31 - 40.

Assessment of Alternative Propulsion Systems for Vehicles 1

2

1

1

Christoph Herrmann , Kuldip Singh Sangwan , Mark Mennenga , Philipp Halubek , Patricia Egede 1

1

Technische Universität Braunschweig, Institute of Machine Tools and Production Technology, Product- and Life-CycleManagement Research Group, Braunschweig, Germany 2

Birla Institute of Technology & Science, Pilani, India

Abstract Concern for the environment, the approaching end of fossil fuels and the dependence on oil exporting countries has revived the interest in alternative propulsion systems for vehicles. However, an assessment of alternative propulsion systems with respect to sustainability is very complex due to the variety of technologies as well as unsecure and conflicting economic, ecological and social consequences. This study provides a framework for assessing alternative propulsion systems for vehicles using the AHP methodology. A criteria catalogue is derived from existing approaches and the analysis of propulsion systems, their market situation and surrounding conditions. Its application is illustrated by the assessment of two exemplary propulsion systems. Keywords: Alternative Propulsion Systems; Technology Assessment with the Analytic Hierarchy Process; Criteria Catalogue

1

INTRODUCTION

The need and demand for automotive mobility is continuously rising. Today, around 800 million vehicles are in operation worldwide. This number has been reached during the last 100 years but could double in the next 30 years as the vehicle production augments extensively each year. Between 2002 and 2015 the number of produced vehicles is estimated to rise by 33% from 57 to 76 million vehicles a year [1]. The primary reason for these numbers is the economic development and growth of countries like Brazil, Russia, India and China. A comparison of the distribution of vehicle ownership of these countries with industrialized countries shows the present potential. For example, in Germany 566 cars are registered for 1000 people [2] whereas in India only 7 vehicles are registered [1]. Today, 90 % of the 800 million cars in service are operated with conventional engines [3]. However, concern for the environment, the approaching end of fossil fuels and the dependence on oil exporting countries has revived the interest in alternative propulsion systems [4]. The use of propulsion systems other than the fourstroke combustion engine and fuels other than diesel and petrol is not a new idea. In the beginning of the automobile history different directions were explored and pursued. For example, the original diesel engine developed by Rudolph Diesel was designed to run on vegetable oil [5]. Furthermore, the first automobile with an electric drive was introduced in 1892 [2]. However, eventually the petrol and diesel engines superseded the other options because their fuel was cheap and their efficiency superior [3]. Innovative propulsion systems (e.g. for electric or hydrogen vehicles) are expected to create a more sustainable mobility. An assessment of these systems with respect to sustainability has to cover the variety of alternatives as well as unsecure and conflicting economic, ecological and social consequences from multidimensional perspectives (e.g. consequences coming from the propulsion system itself or the energy and infrastructure supply during usage). Today, precise statements on the effectiveness and efficiency of individual propulsion systems are not yet possible.

2

OVERVIEW ON ALTERNATIVE PROPULSION SYSTEMS

Propulsion systems consist of an engine and an energy source. An overview of alternative propulsion systems is shown in Figure 1. A variety of engines is available other than the well established diesel and petrol engine. One option is the exclusive use of an electric motor with either a fuel cell or a battery as source of energy. Another option is the use of alternative combustion engines with either an external or internal combustion. Finally, two different engines can be combined to form a hybrid. The most common type is the combination of an electric motor with a combustion engine, alternative or conventional, building a hybrid electric vehicle (HEV) [1] [6]. Alternative fuels are those other than the conventional fuels based on mineral oil (petrol and diesel). They can be categorized according to the primary energy from which they originate. Two groups are distinct: non-renewable and renewable energy. Nonrenewable energy includes the fossil resources crude oil, natural

Figure 1: Alternative propulsion systems [1], [4], [6].

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_9, © Springer-Verlag Berlin Heidelberg 2011

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gas and coal along with nuclear power. Fuels converted from fossil sources like Compressed Natural Gas (CNG) are known as fossil fuels. Solar, wind and water energy as well as biomass are considered renewable. Corresponding fuels like biodiesel or biogas are referred to as renewable fuels [4].

Third, the time horizon regarding the assessment of propulsion systems can differ from system to system. Thus, considerable know-how of the development of individual technologies and markets is required when conducting the assessment.

The term alternative propulsion system refers to the use of alternative fuels or alternative engines. Petrol, (bio) diesel, (bio) gas, Liquefied Petroleum Gas (LPG), synthetic fuels and alcohols can be combined with combustion engines and hybrid engines whereas electricity can be combined with electric and hybrid engines. Hydrogen can be used for all three types of engines.

4

3

CHALLENGES OF THE ASSESSMENT

The assessment of different propulsion systems with respect to global sustainability and the suitability for a local area, e.g. an urban or rural area, is a challenging topic. In addition to the complex technical assessment, different stakeholder perspectives, life cycle phases as well as evaluation dimensions and time horizons have to be considered. First, the assessment has to incorporate different views on assessment criteria. For example, when evaluating propulsion systems regarding costs, different types of costs are relevant for different stakeholders. Development costs are important for manufactures of propulsion systems, while costs for infrastructure development, e.g. the costs for energy supply, are crucial for the participating governments. Costs occurring during the operational use are relevant for customers. Thus, an assessment method has to reflect the preference profiles of different stakeholders. Second, the impact of different propulsion systems has to be considered regarding their impact in all life cycle phases with respect to the economic, ecological and social dimension. To structure the complex life cycle orientation, it is useful to refer to frameworks, such as the Model of Total Life Cycle Management and to include the different life cycle phases from product idea to disposal in the assessment [7]. Furthermore, life cycle orientation includes the intersection of two different life cycles such as the engine and the energy source in the case of propulsion systems (see Figure 2). In the use-phase of the engine the impact of the energy source has to be considered as well, e.g. impacts resulting from the production of electricity when assessing electric vehicles. life cycle of the fuel life cycle of the engine

ASSESSMENT METHODOLOGY

An assessment of alternative propulsion systems requires methods in which different criteria can be incorporated. For that the field of Multi Criteria Decision Making (MCDM) provides Multi Attribute Decision Making (MADM) and Multi Objective Decision Making (MODM) methods. MADM methods are suitable for problems with a given number of alternatives, MODM methods are used for an infinite number of alternatives [8]. Within this study the MADM method AHP has been chosen to identify a propulsion system which is suitable for a distinct area. AHP was developed by Saaty [9] and relies on a five step procedure: (1) construction of a hierarchy, (2) pairwise comparisons of all elements, (3) determination of priorities, (4) verification of consistency, and (5) aggregation of the results. If the result of step (4) is not satisfactory the process must be revised starting from (2). Thereby comparisons should be reconsidered and possibly more information should be requested [10] [11]. Step 1 – Construction of a hierarchic structure The elements related to the decision making problem are arranged in a hierarchical structure resulting in a composition made up by the central goal, the assessment criteria and the alternatives to be ranked. Figure 3 shows an example of such a hierarchy. Starting with the goal at the top of the hierarchy tree, the decision problem is broken into clusters of criteria and sub criteria on the lower levels concluding with the alternatives at the bottom. The depth of the structure has to be chosen to suit the problem as it is the goal to give an overall view of the decision problem and to allow a comparison of elements of equal importance. Step 2 – Pairwise comparisons of all elements Pairwise comparisons are conducted by the decision maker to generate matrices of which the principal eigenvector is determined to derive priorities for each element. These comparisons are supposed to be made with the scale shown in Table 1. Comparisons are conducted on all elements of a cluster with respect to the parent criterion using integers or fractions. For a criterion the pairwise comparison indicates its importance with respect to the other criterion. For alternatives the comparison expresses the ability to fulfill the criterion. Whenever possible, the comparisons of alternatives should be based on reliable data which is proportional to desirability. If such information cannot be obtained then personal judgments can also be conducted using SAATY’s assessment scale.

Figure 3 : Hierarchy with four levels [9]. Figure 2 : Considering the impact of primary and secondary product [7].

Automotive Life Cycle Engineering Scale

53

Definition

Explanation

1

Equal importance

Two activities contribute equally to the objective

3

Moderate importance of one over another

Experience and judgment favor one activity over another

5

Essential or strong importance

Experience and judgment strongly favor one activity over another

7

Very strong importance

An activity is strongly favored and its dominance demonstrated in practice

9

Extreme importance

The evidence favoring one activity over another is of the highest possible order of affirmation

2, 4, 6, 8

Intermediate values between the two adjacent judgments

When compromise is needed

Table 1: Assessment Scale by Saaty [9]. Step 3 – Determination of priorities Three different types of priorities can be distinguished: local, global and total (or final) priority. Local priorities represent the importance of elements with regard to the next higher level and are obtained by solving the eigenvector problem of the matrices found in step 2. Global priorities give the importance of an element in the overall context of the hierarchy. To determine the global priority of an element, the local priorities of all elements leading directly up to the goal have to be multiplied. The final priority expresses the ranking or the score of the alternatives. Step 4 – Verification of consistency A distinguishing feature of AHP is the verification of the consistency of the information entered by the decision maker. This step ensures coherent data. Due to the comparisons, a consistent matrix is improbable when applying AHP even if only a few criteria are compared. In order to verify the inconsistency of a matrix, SAATY defined a ratio that expresses the percentage to which the result equals the outcome of a probability distribution. According to him an inconsistency ratio of 10 % is acceptable because it allows new information that might be added to have an impact on the decision. Step 5 – Aggregation of results In order to obtain the total priority, every path from the goal down to the alternative has to be considered. Starting at the top the global priority of the parent element is multiplied with the local priority of the element below. These products are added up until the last level is reached. By aggregating all results from each path, the final priority of each alternative can be determined. The ranking of the alternatives represents the preferences of the decision maker. 5

CRITERIA CATALOGUE FOR ASSESSING ALTERNATIVE PROPULSION SYSTEMS

To assess alternative propulsion systems with AHP, a criteria catalogue is needed. The presented criteria have been derived either from existing approaches used in previous assessments or from lists of criteria illustrating future requirements of fuels and engines, such as [1], [3], [4] and [12] to [18]. It includes the characteristics of alternative fuels and engines, the market situation and surrounding conditions in order to cover the wide range of influences and aspects of alternative propulsion systems. The criteria catalogue is presented in Table 2. It comprises the identified main and sub criteria which are relevant for the decision making process as well as a brief description. The structure of the assessment criteria includes four levels: At the top of the hierarchy is the goal of the decision process, i.e. the assessment of alternative propulsion systems. The second level

Assessment criteria

Description

Safety Fire safety Explosion safety Electrical safety Toxicity safety Environmental impact

Risks regarding fire Risks regarding explosion Risks regarding electric shock Risks regarding toxicity

Sound / noise Global warming Photo-oxidant formation Eutrophication Acidification Resource consumption Land use Economic Impact Cost of the propulsion system Costs for infrastructure development Economic benefit Availability Resource availability Infrastructure availability Staff availability Food availability Performance & capability Cruising range Performance Torque Speed Life span Temperature sensitivity Fuel Sensitivity User acceptance Useable space Intuitive operation Refuel rate

Noise (sound), which are harmful or disturbing by their volume and structure to humans and the environment. Increase in the average temperature Contamination of the atmosphere Overfertilization of an eco-system Reduction of ph-value in an eco-system Type and number of resources consumed Need of land Total costs of the development, production, distribution, usage, redistribution, recycling of the propulsion system, etc. Total costs of gas stations, supply networks, workshops, training, roads, reverse supply chains, etc. Employment, gross domestic product, welfare, etc. Access to technical and / or economically recoverable resources Existence infrastructure to bring the resources to the place of usage (gas stations, roads, workshops, …) Existence staff (workers, engineers, …) Conflicts regarding food Range per volume, range per kilogram Technical capability Max. torque Max. speed Deterioration, max. life, max. charge cycles, etc. Performance at different ambient temperatures and operating temperatures Performance with different fuels Possible reduction of cabin or trunk size Simple use, repairable Duration of charging, duration of the refueling

Table 2: Criteria for assessing alternative propulsion systems. contains six main criteria: safety, environmental impact, economic impact, availability, performance and capability as well as user acceptance. Each of these criteria is divided into sub criteria. For example, the main criterion environmental impact includes noise, global warming, photo-oxidant formation, eutrophication, acidification, resource consumption and land use. On the fourth level, these effects are divided into the different life cycle phases of a propulsion system (see Figure 4) as mentioned in chapter three. On this basis, decision makers start the weighting of the criteria according to their preferences as described in chapter four. Decision makers can be individuals as well as interest groups on the one hand or a group of people evaluating simultaneously on the other hand. The scoring of different propulsion systems is evaluated with respect to their characteristic regarding each individual criterion. This requires expertise of the decision maker or wellgrounded data on the performance of different propulsion systems. 6

CASE STUDY: ASSESSMENT OF ALTERNATIVE PROPULSION SYSTEMS IN INDIA

The proposed criteria catalogue will be used for the assessment of two propulsion systems for CNG and biodiesel made from jatropha as both fuels are currently promoted in India. As an example, the view of the Indian government is elaborated in detail. The perception is obtained from public available literature as indicated in the following section. Likewise, the views of the customers and manufacturers in India are derived from [20], [21] and [23].

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Automotive Life Cycle Engineering

Safety Environmental impact Economic impact Availability Performance & Capability User acceptance

Safety

Environ. impact

Econ. impact

−

1/5

1/4

1/3

9

9

5

−

2

4

9

9

4 3

1/2 1/4

− 1/2

2 −

9 9

9 9

1/9

1/9

1/9

1/9

−

1

1/9

1/9

1/9

1/9

1

−

Avail.

Perf. and Cap.

User accept.

Table 3: Weighting of main criteria by government. Figure 4 : Four level structure of the criteria catalogue. Problem description – CNG vs. biodiesel in Dehli The urban traffic situation in emerging countries faces major challenges. Problems like environmental and noise pollution, fatalities and injuries as well as congestion and other mobility problems are much more severe compared to Northern America or Europe. Several reasons contribute to this situation. The rapid growth of the population combined with often uncontrolled urbanization has overpowered many cities. The demand for transportation by far exceeds the capacity which can be provided. Choosing a non-motorized mode of transportation like walking or cycling is often very difficult and dangerous urging people to choose motorized vehicles [19], [20]. Even though the city of Delhi still faces difficulties, improvements have been made. In 2003 the Indian capital was awarded the Clean Cities International Award by the U.S. Department of Energy because of the immense attempt to decrease pollution [21]. In the beginning of the 1990s India’s Ministry of Environment & Forests started a series of efforts to ameliorate air quality. More rigorous emission standards for vehicles, the withdrawal of old, ill-maintained vehicles, the introduction of CNG and higher quality fuels as well as the construction of the Metro Rapid Transport Service are some of the changes introduced [19]. To make further progress and improve air quality the next step would be to change the current fleet to newer, less polluting vehicles. However, the negative impact of banning older and more polluting vehicles could be immense. Many residents depend on their mobility to reach their place of work and would not be able to afford newer vehicles [20]. Against this background biodiesel is currently also promoted in India. The government targets a blend of 20% biodiesel and 80% fossil diesel by 2011-2012. In this process the plant jatropha has been identified as a potential feedstock for biodiesel because it has several advantages. Jathropha is a shrub which makes harvesting easier in comparison to trees. The plant has a short ripening period which makes it less time consuming to grow. In addition, the seed collection is not in the monsoon period like most other plants. Thus, it allows farmers to generate an income in a time during which they usually have less work and less income. It is furthermore very robust and not edible. Hence, animals do not feed on the plant [22]. The question arises whether the use of both fuels, CNG and biodiesel from Jatropha, is meaningful or if one alternative is much more favorable than the other. Pairwise comparisons of criteria In this case study CNG and a diesel blend of 20% biodiesel made from jatropha and 80% fossil diesel are compared. In order to demonstrate the weighting of criteria, pairwise comparisons of the main criteria are displayed for the governmental view in Table 3. As stated above the measures which have been taken so far show that the government is willing and able to invest in the transport sector to decrease impacts on the environment. Thus, a special

interest in environmental concerns can be deduced [21]. The automotive industry has also been identified as an important part of the nation’s economy and the Automotive Mission Plan sets goals for the years of 2006 to 2016 to strengthen this sector of the economy. Hence, it can be assumed that economic aspects of the automotive industry are of high importance to the government. The availability of resources and labor play a crucial role in the success of economic ambitions and are ranked accordingly [23]. Safety issues of propulsion systems are currently not targeted essentially as many other sources of danger are of larger amplitude. The number of fatalities is rising because the traffic system in general is mal controlled [20] [23]. The criteria performance & capability as well as user acceptance are assumed to be of marginal importance for the government. Likewise pairwise comparisons are conducted for all sub criteria in order to derive the local priorities for each element. Pairwise comparisons of alternatives To finalize the assessment, the two alternatives CNG and biodiesel must be compared with regard to all sub criteria. For reasons of clarity the sub criteria are reduced to the second level in this case study. Thus, the assessment includes a life cycle consideration whenever possible and reasonable. Table 4 shows the results of the pairwise comparisons with respect to each sub criterion from the governmental point of view. Regarding safety, the danger of fire is higher in the case of liquid fuels because it spreads on surfaces and cannot evaporate as fast as gas. In contrast, gas is more likely to explode which requires special security measures. With respect to the electrical hazard there is no indication that one propulsion system is more dangerous than the other. However, the two substances differ significantly with respect to their hazardous effect. On the one hand natural gas has no active toxic effects on humans but it can cause affixation because it lowers the oxygen content of air [24]. In addition, it cannot be seen or smelled if no odorants are added. On the other hand the diesel blend is toxic even though biodiesel is less toxic than fossil diesel [25]. In total, CNG and the diesel blend are considered equal with respect to toxicity. Regarding the environmental impact, the combustion of the diesel blend is considered better than the use of CNG in the categories global warming and the use of resources [26] [27]. A gas engine has less harmful effects in the categories eutrophication, acidification[26] [27], photo-oxidant formation [27] [28] and land use. Regarding the category noise, only differences in the use phase are considered. A gas engine is considered less noisy than a diesel engine [29]. With respect to the costs of the propulsion system, it is assumed that differences occur only in the operational use as the engines are comparatively similar and equally mature. The cost for CNG in Delhi is lower compared to a blend of fossil diesel and jatropha diesel [22] [30] while the costs of the vehicles are very similar [31]. Thus, a natural gas vehicle is considered superior. For the development of the infrastructure elaborate programs are necessary. For example, the government plans to establish 2500 nurseries for jatropha

Automotive Life Cycle Engineering

55

plants. Furthermore, farmers must be educated and the genetic properties of the plant must be improved [22]. In contrast, natural gas is readily available [32]. Hence, it can be concluded that the cost of infrastructure development is higher for biodiesel because the required measures are much more elaborate and comprehensive. This implies that the economic benefit for the country is higher because it offers new possibilities for farmers and support for research and development [22]. With respect to the use of resources natural gas is preferred. Natural gas is made completely out of fossil resources, the diesel blend to 80%. However, natural gas is preferable because India has much larger supplies of natural gas than of crude oil [33]. Also the production of jatropha diesel is not on a commercial level, yet [22]. With regard to the availability of the required infrastructure and staff the diesel blend is preferred because it can use all systems already present. Both fuels do not compete with food as long as jatropha is not cultivated on land that is intended for food. The technical properties of the two fuels are very alike [1], [34]. However, comparing the cruising range and fuel sensitivity an engine using diesel blend is superior. The cruising range of a CNG vehicle lies in between 200 and 300 km [3], whereas the diesel blend reaches values very similar to fossil diesel. Diesel blends of different rations can be used in the same engine without alterations allowing flexibility in the choice of fuels [35]. With regard to the criterion user acceptance, it can be assumed that the diesel blend is more user friendly than the gas engine. Both can be operated intuitively but the CNG tanks reduce the usable space in the vehicle. Additionally the refuel rate with gas is slower [3].

Criterion

Diesel blend: CNG

Safety

Criterion

Diesel blend: CNG

Availability

Fire safety

1/3

Resource

1/2

Explosion safety

3

Infrastructure

4

Electrical safety

1

Staff

4

Toxicity safety

1

Food

1

Environmental impact

Performance and Capability Cruising 4 range

Noise

1/3

Global warming

3

Power

1

Photo-oxidant formation

1/2

Torque

1

Eutrophication

1/9

Rotational speed

1

Use of resources

5

Life span

1

Acidification

1/7

Use of land

1/7

Economic impact Cost of propulsion system Cost of infrastructure development Economic benefit

1/4 1/3 5

Temperature sensitivity Fuel sensitivity User acceptance Intuitive operation Useable space Refuel/ reload rate

1 4

1 4 3

Table 4: Comparison of the performances of biodiesel and CNG.

Aggregation of results

7

In order to obtain the total priority every path from the goal down to the alternatives has to be considered and the values have to be aggregated. The resulting ranking of the alternatives is presented in Figure 5. It represents the preferences of the stakeholders regarding CNG and the diesel blend. The values of all different groups have been calculated in the same way as demonstrated.

Within this study an assessment of alternative propulsion systems using the AHP methodology was presented. The underlying criteria catalogue was derived from existing approaches used in previous assessments and the analysis of alternative fuels and engines, the market situation and surrounding conditions. Thereby, a wide range of influences and aspects of alternative propulsion systems are covered. The criteria catalogue provides the possibility to assess alternative propulsion systems from economic, ecological and social perspectives on a qualitative level. Inherent in AHP is the possibility to consider preference profiles of different stakeholders. Furthermore, the impact of propulsion systems across the entire life cycle and the impact of secondary products are considered as well. The presented methodology is usable for all presented alternative propulsion systems. Its application was shown by an assessment of two different propulsions systems.

Figure 5 shows that CNG is preferred slightly by consumers and the government whereas the manufacturer has no preference regarding the alternatives. Indian consumers prefer CNG as they are very price sensitive and the operational costs for CNG are lower in comparison to the diesel blend. From the governmental perspective the main reason for preferring CNG is smaller local environmental impact regarding photo-oxidant formation, eutrophication, acidification and use of land. However, all values alternate around the value of 0.5. Thus, it can be assumed that no alternative dominates the other. The result of the comparison shows that the diesel blend can be an alternative when considering global environmental impact as it reduces the global warming potential in comparison to CNG. However, neither of the two alternatives will lead to a break through regarding the challenges of urban traffic in India. Thus, further alternatives need to be considered and assessed to make further progress in the areas of sustainability and air quality in Delhi.

Total priority

CNG

diesel blend

0,5

SUMMARY AND OUTLOOK

As stated above (see chapter 3), the assessment of propulsion systems with respect to different time horizons is challenging. It is conceivable that an assessment of propulsion systems for 2015 differs from an assessment for 2025. This leads to uncertainties and requires considerable know-how regarding the development of technologies and markets. Although AHP allows for conducting sensitivity analyses these uncertainties are not reflected adequately with the proposed method. A distinct project focus of the BMBF funded project STROM, Strategic options of the automobile industry for the migration towards sustainable propulsion systems in established and emergent markets (www.strom-sustainability.de), is therefore to incorporate insecurities such as the maturity of the technology in the decision making process. For this purpose, methodological support will be developed in future.

0

8

Figure 5: Total priorities of CNG and Biodiesel.

The presented research work is partially financed by the German Federal Ministry of Education and Research (BMBF) and the German Academic Exchange Service (DAAD). The authors would

Government Manufacturer Customer

ACKNOWLEDGEMENTS

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Automotive Life Cycle Engineering

like to acknowledge the support of the BMBF for funding the research project “STROM - Strategic options of the automobile industry for the migration towards sustainable propulsion systems in established and emergent markets” under the reference 01UN1006A and the DAAD for funding the research cooperation “Lean and Green – A new passage to India” under the reference 50082745. 9 [1]

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Concept and Development of Intelligent Production Control to enable Versatile Production in the Automotive Factories of the Future 1

1

1

Sarfraz Ul Haque Minhas , Christian Lehmann , Ulrich Berger 1

Chair of Automation Technology, Brandenburgische Technische Universität, Cottbus, Germany

Abstract The automotive industry is being confronted with numerous challenges among which the increased product customization, short product life cycles and faster time to market are inducing a lot of complexities in controlling the current production systems. Consequently, the production systems are incapable of handling changing product variety and volume in a productive way and often involve intensive redesigning and reconfiguration processes. This paper introduces the concept of versatile production setups, an intelligent approach for selecting appropriate resources and optimal parameter settings to enable fast changeability as well as for reducing quality assurance time to achieve productivity in production processes. Keywords: Versatile Production Setups; Plug and Produce; Reconfigurability Ease

1

INTRODUCTION

The European manufacturing industry particularly the automotive industry has entered a new era in which they have to compete in a global economy. This has led them to confront many challenges like fast globalization, unpredictable and heterogeneous markets, increased product customization [1] [2], short innovation and product life cycles [3], reduced development time and faster time-to -market. This situation has induced a lot of complexities in controlling the current production systems [4] by imparting negative influence on productivity. Moreover, the increase in derivatives of vehicle models and growing trend towards the integration of new materials in the car Body-in-White development to enable reduction in weight and fuel consumption as well as the eco-efficient design, the quest for new and advanced material processing and production technologies has increased. This trend can be observed from the fact that multifunctional materials [5] as well as light weight materials [6] are being integrated into the car Body-in-White to make the manufacturers more competitive. Consequently, the future automotive production systems have to handle a huge variety of materials as well as various products of individualized geometries. The current production systems are quite flexible in switching from one variant to another however they are not capable of handling their high variations in a productive manner. The main reason is that the changing product design and integration of new materials are pushing the manufacturers to redesign/modify their production setups. It has led to a situation in which they will have to rely heavily on the system developers/suppliers for redesigning/upgrading their production facilities. This increased reliance will hinder them to achieve higher production rates. This is because the production system redesigning/upgrading is highly time consuming and cost intensive process. Currently about 75% of the vehicle production and 50% of automotive research and development is being done by suppliers and technical consultants [7]. The rapid customization and reduced product life cycle [8] demands from the manufacturers to configure their production system in the shortest possible time to enable fast ramp up of materials and technologies. It also requires achieving smooth and

effective production control in order to reduce production costs and time substantially. Moreover, it also demands them significant improvement of their production processes as well as the product quality. 2 2.1

AUTOMOTIVE PRODUCTION CONTROL: LIMITATIONS AND ANALYSIS Mass Customization: A challenge for the Production

Nearly every European automotive manufacturer is experiencing increased product complexity and reduced lifecycle time, whilst manufacturing a larger number of variants within shorter time-tomarket. A dramatic shift from production-push and economy of scale towards customer-pull and economies of scope is a solution to these problems. The current situation of product customization in the automotive industry is mainly attributed to the creation of new production segments and enrichment of existing ones with more possibilities for their individualization. The idea of platform sharing among different models has enabled the automotive manufacturers to offer a much wider range of product families, with different appearances and styles. On contrary to that, the migration principle [9] is helping certain automotive manufacturers to produce many models with additional variants from different OEMs. In this context, the shift towards development of Body-in-White on modular and scalable concept aims at offering broader range of customized products whilst maintaining low development costs. It concludes that the product development process is mainly accompanied by design reuse i.e. by taking more carryover of parts or by platform sharing for various vehicle segments. Additionally, the product development and process planning of diversified products is enabled with the help of powerful CAD/CAM and PLM systems. However, the handling as well as production of these products in the production setups is still a bottleneck. This situation occurs due to frequent variation in product features and materials, and the respective inappropriate adaptation, thereby generating internal complexities in the production systems. The state of the art automotive production process comprises of the technologies for

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_10, © Springer-Verlag Berlin Heidelberg 2011

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manufacturing diversified components and technologies for joining/or assembling them to complex customized products. A clear analysis of their production setups shows that they are mainly dedicated to the process (machining/joining/assembly) technology for which they are designed. A typical example is the production setup for welding automotive Body-in-White components. It is dedicated to weld automotive components of specific material combinations and certain range of dimensions only. Similarly, the production setups for joining technologies other than Welding e.g. adhesive bonding is dedicated for joining automotive components of specific material combinations and dimensions. The increasing multifunctional and light weight materials (as mentioned already) with changing Body-in-White shapes have influenced significantly, the automotive production setups by integrating various forming, joining and assembling technologies/techniques. It has not only increased the size of automotive production setups but also the complexity in its control. The increase in size of automotive production setups has compelled the automotive manufacturers to expand their production facilities which are hindered by limited and costly space requirements. The best option left in this situation is to allow reconfiguration of production setups by making them adaptable for other technologies and to achieve systematic reconfiguration process from their design to the job sequencing at the shop floor thereby implementing intelligent production control. 2.2

State of the Art Production Setups

The state of the art automotive production setups are comprised of various but distinct production/manufacturing cells connected to single/various lines. These production setups are quite flexible in handling various variants in their respective production setups. There exist two innovative categories of the production setups known as modular production setups and cellular production setups respectively. The modular production setups are relatively advanced setups that are designed to improve throughput by increasing the efficiency of parallel joining cell/subassembly lines feeding into the final assembly lines. They involve joining /assembling separate vehicle modules such as chassis, interior, body on their dedicated assembly lines connected with process dedicated joining cells [10, 11]. Another category refers to cellular layout based automotive production setup [12] which is considered as one of the major steps in accessing JIT. They are comprised of machines and robots gathered together to carry out multiple tasks such as material handling and welding typically run by single operator or a multi-person work cell. Each one of these setups exhibits the following complexities during their adaptation/reconfiguration:  

Limited flexibility in programming of industrial robots due to the manufacturer dependent programming environment, Offline verification of industrial robot programs which in high variation would limit the adaptation and consume lot of time, leading to high production time and cost,



Complicated synchronized implementation,



Large number of interfaces within the production cell and noncompatibility issues with the centralized controller,



Fixed but highly branched program (spaghetti code) execution corresponding to the sensor data inputs and



Large volume of measured data and the resulting difficulty in database connectivity with certain Human Machine Interfaces such as Personal Digital Assistants (PDAs) for fast and remote interaction.

simulation

of

robots

and

its

In addition to all these aforementioned complexities, there are also limitations to reuse the automotive production setups dedicated to one process technology for any other technology. For example, the

production cell dedicated for adhesive gluing of car windows is inflexible to incorporate other joining technologies. It implies that in future automotive factories, the extinction of any of the process technology will require redesigning of the associated production cell to be used for some other process technology. The upgrading process will be highly cost inefficient and time consuming which may last from several weeks to several months. Moreover, the input coming to the production system in terms of nature of jobs will be of very distinct nature that will involve distinct processes/operations for distinct Body-in-White components. As a consequence, the production ramp-up time as well as the setup time will rise sharply resulting in decrease in the production throughput and increase in time-to-market. A comprehensive approach is therefore needed to resolve those complexities that the future automotive production setups are foreseen to experience. It also requires eliminating those limitations that the current production setups are having. 2.3

Derivation of Requirements Production Control

for

future

Automotive

From the discussion above, it can be further added that the market conditions and required production efficiencies of today are keeping mass production an acceptable business model for the present automotive factories. This trend is being diminished in favor of mass customization. Therefore the future automotive production setups need to be highly reactive and productive in managing change. This change is characterized by variations of the product volume (high, medium, low) as well by variations in terms of materials, forms and dimensions. It is a noteworthy fact that these variations influence greatly on the design, planning and control of these production systems. Moreover, as the high product variety is the main complexity driver in planning and controlling of the production systems, the method for sequencing of the production tasks (jobs) to achieve optimal configuration of the production setups is needed considering reduction in ramp-up time of materials and technologies. Also, an intelligent concept for production control is required to achieve reduced setup time, fast throughput, quality assurance time and their associated costs. From the requirements, it is deduced that the production system must be designed on versatile architecture where it can support the intelligent production control. It is particularly important for optimal reconfiguration of production setups using the same resources for distinct processes or operations. The intelligent production control also requires the sequencing and reordering of jobs to attain high reconfigurability ease in reconfiguration of production setups. 3 3.1

CONCEPT FOR INTELLIGENT PRODUCTION CONTROL Concept for Versatile Production Setups

The concept of versatile production setups for automotive factories of the future is derived from the idea presented in [13] which identifies their structuring into seven levels. Moreover, the factory should be designed considering the changeability enablers (modularity, scalability, adjustability, universality, compatibility, mobility, convertibility etc.). The production design based on these enablers will address the impact of product variations and frequency (volume per certain amount of time) on the design of production setups. Therefore, the versatile production setups must be characterized by their adaptable functionality and scalable capacity. It can add, remove, and change/replace software and hardware modules to support a broad product range with required cost and quality. These hardware and software modules can be related to the cells, machines, process equipments, sensors, actors, handling and fixation units etc. Figure 1 highlights the essential

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features/attributes needed to enable versatile production based on reconfigurable control. Web

Automotive manufacturer

Production planning

Configurator interface Product sequencing

Layout definition

Product Design

Design rules, components/modules libraries, control programs

Digital Simulation

Production metrics (Production throughput, cycle time, collisions, offline robot programs)

Production setup controller (Parameter Settings) Production control

Product design, rules

Actual production metrics Control parameters of the defined layout

Technology data catalog

End customers

Production Setups (Process applications: Machining/Joining/Assembly)

Figure 1 : Modules and subsystems of versatile production setups. These essential features/ attributes are the following: i)

ii)

Integration of customer in product design process to analyze their demands and offer them best matching products. It can be achieved through web based collaboration or by employing other methods for analyzing the end user requirements. Introduction of an intelligent production setup configurator as an interface between the product design phase and the production planning phase named as Configurator interface. This configurator helps in optimizing the components and modules of the production system and the features that these production setups should contain and the functions that they should perform.

iii) Integration of knowledge base with the digital simulation to analyze the production related metrics well before the production layout is configured helps in achieving the production goals. iv) Introduction of production setup controller to enable configuration or reconfiguration of the production setups based on optimal scheduling of jobs intelligently. The optimization of production resources carrying the adaptable functionality (e.g. responsive to variable range product features, various materials) as well as the scalable capacity (adaptation to different range of tasks, production volumes) against a definite customization is mathematically modeled using the Axiomatic Design approach. Compared to other available designs approaches like TRIZ, axiomatic design methodology offers a generic framework and hierarchical structure to achieved precise and simple optimization of production resources. The methodology is used to analyze a certain range of product characteristics and the selection of corresponding optimal processing technology e.g. joining technology/assembly technology. The precision in optimal selection can be achieved provided the pure knowledge base approach is adopted. However, this approach will have limited implementation due to the complexity and level of effort needed to acquire domain knowledge as well as design knowledge. So a knowledge reuse up to an achievable level is extremely important to assist the automotive manufacturers in preventing any errors that may generate in the selection process. The technology data catalog is therefore introduced to serve this purpose. It acts as an intelligent subsystem of the versatile production system that stores the application-specific knowledge and provides the best practice settings in the reconfiguration process.

The concept of versatile production setups is implemented by considering the innovative joining processes in automotive Body-inWhite development. The concrete reason behind this consideration is the increasing integration of advanced materials besides aluminum and steel to support eco-efficient design of vehicles. Foreseeing this trend, the increase in material pool will also increase the number of joining technologies with limited scope. Currently, welding process e.g. laser welding is widely used automated joining technology in Body-in-White development and is delivering best quality joining. However, new materials are limiting its scope as it is applicable only to joining of similar materials. This in turn, has enhanced the exploitation of adhesive bonding in future joining applications. Therefore, versatile production setups must support various joining processes to be carried out using the same resources with minimum changeover. This changeover can be made in process monitoring, handling systems and the process equipment while executing the sequenced tasks using versatile production setups. 3.2

Concept for Production Planning and Control

The production systems of the future will experience immense level of complexities in production planning due to distinct characteristics of individualized products. Therefore, the production system needs to be reconfigured efficiently and precisely. The reconfigurable production planning and scheduling is divided into two phases. In the first phase, the reconfigurable production setup layout is to be defined followed by the allocation of production resources and their reconfiguration in the product sequencing phase. In the layout definition phase, the structuring of the resources is made in a way to accommodate a broad range of products using the same resources. This phase takes the input from the simulation and analysis module (see Figure 1) which also gives the evaluation metrics about the overall cycle time as well as the allocation to make the layout definition phase more precise. These metrics are evaluated to achieve high throughput by minimizing the buffer and transportation time of each part. The second part is the product sequencing phase where the products are sequenced optimally using intelligent algorithms. Each mass customized product has to be produced in the given product layout, therefore jobs specifications are analyzed and sequenced in a way to achieve high reconfigurability ease in the reconfiguration process. The high reconfiguration ease is dependent upon the variation in the product specifications that are to be manufactured at the particular production setup. A similar issue but from the other domain has been addressed in [14] for generating an optimized work plan based on feature technology in NC machine tools. A further extension of this work is already implemented and mentioned in [15] for planning and scheduling of machine operations. The perspective planning and machining operations are transferred into a directed graph. The results acquired after the implementation of the Floyd-Warshall algorithm [16] (Jungnickel, 1990) deliver "cost-efficient" sequencing order of the NC operations [17]. A similar methodology is adopted for the production domain i.e. in joining and assembly processes to achieve high reconfigurability ease. It is required that the intelligent production control implements the optimal parameter settings in versatile production setups and executes the tasks in a generated sequence from the planning module. The job sequencing based on high reconfigurability ease helps reduction of setup time and ensures high throughput from the production system. Additionally, it should also assist in reducing production costs and high process reliability and product quality.

60 4 4.1

Automotive Life Cycle Engineering DEVELOPMENT OF INTELLIGENT PRODUCTION CONTROL

4.2

Development of Versatile Production Setups

Development of Intelligent Production Planning and Control

The development of versatile production setups is initiated after the optimal selection of production setup components. The crucial factors that drive the optimal selection process are the desired production goals and set of customer demands. The optimization can be done through mathematical design approach i.e. the Axiomatic Design that translates customer requirements from the customer domain into the functional requirements (functional domain) and the designed parameters. The mapping process between functional requirements (FR) and design parameters (DP) is expressed mathematically in terms of the characteristic vectors that define the design goals and design solution.

After defining the versatile production setups, the optimal sequence and ordering of the jobs is done. In this process, the Technology Data Catalogue (TDC) which acts as a knowledge base provides all relevant applicable technologies corresponding to the joining tasks. The sequencing system has manifold access to the PPR (process, product, resource) hub to get information about the produced mass customized product and other relevant information such as materials, joining technique applicability and tolerances. The sequencing (see Figure 3) classifies joining cells as:

 FR1   X    FR2   0

0   DP1    X   DP2 

(1)

Some of the functional requirements from the functional domain are the following:



Capability: At this joining cell, the joining task can be executed



Incapability: At this joining cell, the joining task cannot be executed due to certain constraints (productivity issues)



Non-designated: The assignment of tasks at this particular joining cell is not possible at the desired allocation time; therefore this alternative branch will be assigned higher weight.



Selected: This particular joining cell is selected for sequencing along with parameter settings.

‫ܴܨ‬ଵ = respond to market quickly (delivery time)

Joining Layout

‫ܴܨ‬ଶ = perform joining operations for Body-in-White with high accuracy ‫ܲܦ‬ଵ = short setup time

Sequencing & Parameter Settings (PS)

‫ܲܦ‬ଶ = reconfiguration of the joining cell

I) Identifying the relevant process incapability

II) Determining the allocation

Joining cell with three alternative parameter settings Selected

III) Selecting the joining cell with parameter settings

Capability

Non-designated

Incapability

Figure 3 : Sequencing of product workflow in production layout.

Figure 2 : Versatile joining cell (conceptual and virtual model). The functional requirements are further decomposed at different levels to determine the detailed design parameters. The information axiom of the axiomatic design selects the appropriate components of the versatile production setups. The versatile production setup (versatile joining cell) is developed on modular and scalable architecture with plug and produce components to enable quick and error-free configuration/reconfiguration of the cell (see Figure 2). These components are related to process equipment, handling and process monitoring systems as well as actuators. For versatile joining cell, the changeover can be made from one joining technology to another, similar to the CNC machines where different machining operations are carried out by changing the tool. It means that the adhesive dispenser is replaced by laser welding head upon requirement considering the safety standards. The adhesive dispensing nozzles can be exchanged during the joining operation if adhesive beads of different forms and dimensions are to be applied. Variant flexible gripper adapts itself in case it has to handle parts of distinct forms and sizes.

The product information as well as the joining task is taken into the processes of the joining layout (see Figure 3(I)) with the help of the variant process planning documents which are stored in the PPR hub. At this point, the system can determine the capable joining cells that can contribute in accomplishing various joining tasks. The branches with the incapable joining cells are marked as nonsequenced. The capable joining cells with different parameter settings are then assigned. In the second step (see Figure 3(II)), the designation of each joining cell is checked for the desired allocation time. If the cell is not allocated, then the effort of the corresponding branch will be increased sharply provided that the other alternatives are incapable of doing the same task. In the third step, the effort of the remaining joining cells with concrete parameter settings is designated (III) with the help of introduced metrics. Thus, each parameter settings of every remaining joining cell are assigned with individual effort. The application of Johnson’s algorithms known from graph theory determines the sequence of joining cells with configuration that has in total the least sum of efforts (high reconfigurability ease). The sequenced work plan is used to process the mass customized products in the selected joining setup. The calculation of this optimal work plan can be done in realtime, because of the low runtime of algorithms.

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In the versatile joining cell, each of the joining tasks (JT) can be split into more than one sub tasks (ST). This is however, mainly dependent upon the type (form) of joining interface (JI) as well as its dimensions. Joining tasks (JT) can be mathematically described as n

JT   JSTi

(2)

i 1

A subtask in this particular case is defined as an activity performed in which no alteration is made in the configuration (related to hardware/software) of the subsystems of the joining cell. The joining sub task is a set of 7-tuple and can be mathematically described as JST= {M, T, P, HU, F, S, JI}

(3)

Where M= manipulator, T= technology, P= path, HU= handling unit F= fixture, S= sensoric, JI= joining interface It is important to mention here that every JST (3) provides the parameters of the joining process and can be named as changeover (reconfigurability) parameter setup. The production is controlled by quick reconfigurability (high reconfigurability ease) by taking up the products with minimum change in JT tuple parameter values between two consecutive tasks in the sequence as well as delivery time of the product. This concludes that the reconfigurability effort is strongly dependent upon the minimum change in JT tuple and the delivery time of the product. By this approach, the setup time of the joining cell is reduced significantly. 5

KR16 takes the subassembly floor module components and moves them under the stationary dispenser for adhesive application. The KR15 robot takes the glued components from the turn table and places it outside the joining cell (in a heating oven or conveyor). To achieve efficient reconfiguration, distributed control architecture is adopted in which the cell controller is separated from an additional controller. This additional controller is directly connected to the process sensors and actuators and handles the measurement data from the joining process separately to enable quick reconfiguration of process sensors and actors. The Cell controller is mainly responsible for controlling the sequential operation of the cell components. It is a standardized embedded controller SIMATIC S7 and is connected to the cell components over Profibus/ProfiNet as a standardized interface. The measurement controller is a programmable automotion controller from National instruments that provides the PC based functionalities. Its user friendly graphical programming environment i.e. Labview, is particularly suitable for analyzing measurement data as well as developing real time control programs in a short time. Hence, the fast configuration/reconfiguration of the cell is achieved. The on-process quality assurance is a highlighting topic of this development to control the adhesive bead form and position in real time scenario. The sensor actor head unit as a plug and produce device (see Figure 4 (b)) is an independent solution for online correction of the robot path and therefore can be reconfigured quickly.

TECHNICAL IMPLEMENTATION: VERSATILE PRODUCTION SETUPS AND PRODUCTION CONTROL

The scenario for the implementation of versatile production setups and respective reconfigurable control is based on production cell development for joining automotive subassemblies. The cell setup (hardware and software) is grouped into modules to achieve versatility in the setups. This means that the cell can be configured from adhesive bonding to laser welding in a very short time depending upon the material combinations selected as well as the required quality. The commonality between cell components required for both processes is determined to enable easy and fast configuration. The current state of the art joining cell is flexible in handling and fixturing systems only. The innovative aspect of the implementation is on versatile production setups in which different cell subsystems such as the process equipment, manipulators, handling units as well as monitoring unit are divided into modules and sub modules to allow easy replacement of components during reconfiguration. To lower complexity in first place, a semi automatic and modular adhesive bonding cell (see Figure 4(a)) is implemented to allow joining multi-variant subassemblies of automotive Body-in-White floor module components. The cell consists of KUKA KR 16 and KR 15 robots assembled around a turn table KUKA KPF1-MB1000. The KUKA KR 16 robot can be configured or reconfigured for two purposes. It can be a part of handling system to take the sub assembly (adapter and seat cross members) under the stationary process application head i.e. either adhesive dispenser or laser welding head. It can also be configured by either taking the adhesive dispenser or laser welding head to enable joining of parts. The process application unit i.e. adhesive dispenser can be reconfigured by exchanging various different nozzles (round, triangular, semi rectangular), allowing application of adhesive beads of variable forms and dimensions, thus enabling a wide range of subassemblies to be glued together in the same facility. The second robot KR15 can be used for transporting the material in or out of the cell as well as to the next cell. A turn table transports the subassemblies from one robot to the other. Additionally, it also serves as an extra axis to the robot to achieve application of adhesive on complex surfaces. The KUKA robot

Figure 4 : (a) Joining cell setup (b) Sensor-actor head unit. The independent solution in this context means that it can be attached to any robot type or installed on the stationary dispenser to influence the adhesive bead position and form. This solution saves time and associated costs involved in post visual checking processes that are currently carried out in adhesive and sealing applications in the automotive industry. Thus, there is a significant reduction of quality assurance time in Body-in-White joining processes in future. It is imperative to highlight that this particular setup supports the foreseen layout of the future automotive production setups in which production will be carried out in the reconfigurable cells. Moreover, the role of automated guided vehicles for material transport will be expanded as they will replace current conveyor systems. It will not only make them smart but also scalable to allow reconfiguration of factory space. 6

CONCLUSIONS AND OUTLOOK

The increasing new materials integration in automotive vehicles as well as the related processing technologies is reducing the life span

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Automotive Life Cycle Engineering

of automotive production setups. Furthermore, the reduced product life cycle and the faster delivery are also influencing negatively to the ramp-up of technologies and processes in the automotive industry. Therefore, the automotive industries of the future need versatile production setups to cope with the huge investment and the time involved in redesigning them. These setups are developed on modular and scalable hardware and software components. These components act as plug and produce devices and modules respectively, thereby enabling quick reconfiguration. The production setups design needs to be optimized based on the product requirements from the market. Axiomatic design methodologies through knowledge exchange from the technology data catalog can optimize the design of the versatile production setups. The intelligent production control approach handles changing product variety and volume in a productive way. This is done by intelligent planning of the resources to achieve optimize layout in the production system. This is followed by the product sequencing with minimum reconfigurability effort combined with optimal parameter settings of the versatile production. This concept is implemented on the versatile joining cell for joining Body-in-White components, achieving lower ramp-up time, setup time as well as quality assurance time, thereby elevating productivity. An extension to this work is of much wider scope in context of resolving mass customization induced complexities in future automotive production systems. The work aims at reaching an efficient level of decentralization in production. Therefore, the productivity will be enhanced by configuring the production system through web based collaboration mechanism. 7

ACKNOWLEDGMENTS

The work reported in this paper is regarded as a part of dissemination activity and is supported by European Commission FP6 NMP Program, "Integration Multi-functional materials and related production technologies integrated into the Automotive industry of the future" (FP6-2004-NMP-NI-4-026621). A further development that is currently being made on this work will be supported in future by EC FP7 Factories of the FUTURE Research Project e-Custom "A Web-based Collaboration System for Mass Customization" (NMP2-SL-2010-260067), to control production systems through web based collaboration among its participating actors. 8

REFERENCES

[1]

Molina A., Rodriguez C. A., Ahuett H., Cortés J. A, Ramirez M., Jiménez G., Martinez S. (2005): Next-generation manufacturing systems: key research issues in developing and integrating reconfigurable and intelligent machines, International Journal of Computer Integrated Manufacturing, vol. 18, no. 7, pp. 525-536.

[2]

Gerwin D., Barrowman N. J. (2002): An evaluation of research on integrated product development, Management Science, vol. 48, no. 7, pp. 938-953.

[3]

Mallick D. N., Schroeder R. G. (2005): An integrated framework for measuring product development performance in high technology industries, Production and Operations Management, vol. 2, no. 14, pp. 142-158.

[4]

Blecker T., Abdelkafi N., Kaluza B., Kreutler G. (2004): Mass customization vs. complexity: A Gordian Knot?, Proceedings of 2nd International Conference "An Enterprise Odyssey: Building Competitive Advantage" pp. 890-903.

[5]

Salonitis K.,Pandremenos J.,Paralikas J., Chryssolourics G. (2009): Multifunctional Materials Used in Automotive Industry: A Critical Review, Engineering Against Fracture: Proceedings of the 1st Conference, Springer Science & Business Media B.V.

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Goede M., Stehlin M., Rafflenbeul L., Kopp G., Beeh E. (2009): Super Light Car-lightweight construction thanks to a multi-material design and function integration, Journal of European Transport Research Review, vol. 1, no.1, pp.5-10.

[7]

Christensen T. B. (2009): Integration of Environmental Technology in Modularized Production Systems in the Automotive Industry, Proceedings of Joint Action on Climate Changes conference.

[8]

Kuhn, A. (Editor), Wiendahl, H.-P., Eversheim, W., Schuh, G. (2002): Schneller Produktionsanlauf von Serienprodukten, Ergebnisbericht der Untersuchung (Fast Production startup from serial production, Findings from the investigation) "fast ramp-up", Dortmund: Verlag Praxiswissen.

[9]

Meichsner T. P. (2009): Migration Manufacturing – A New Concept for Automotive Body Production, Book Chapter in Changeable and Reconfigurable Manufacturing Systems, pp. 373-387.

[10] Marinin K. J., Davis T. R.V. (2002): Modular assembly strategy in international automotive manufacturing, International Journal of Automotive Technology and Management, vol. 2, no. 3-4, pp. 353-362. [11] Fredriksson P. (2002): Modular assembly in the car industry an analysis of organizational forms’ influence on performance, European Journal of Purchasing & Supply Management, vol. 8, no. 4, pp. 221-233. [12] Kirk S.,Tebaldi E. (1997): Design of robotic facilities for agile automobile manufacturing, Journal of Industrial Robot, vol. 24, no. 1, pp. 72-77. [13] Wiendahl H.-P., ElMaraghy H.A., Nyhuis P., Zäh M.F., Wiendahl H.-H., Duffie N., Brieke M. (2007): Changeable Manufacturing - Classification, Design and Operation, CIRP Annals - Manufacturing Technology, vol. 56, no. 2, pp. 783809. [14] Cai, J., Weyrich, M., Berger, U. (2005): Ontological Machining Process Data Modelling for Powertrain Production in Extended Enterprise, Journal of Advanced Manufacturing System (JAMS), vol. 4, no. 1, pp. 69-82. [15] Berger, U., Kretzschmann, R. (2007): Development of a holistic guidance system for the NC process chain for benchmarking machining operations, Proceedings of the 12th IEEE Conference on Emerging Technologies and Factory Automation. [16] Jungnickel D. (2008): Graphs, Networks and Algorithms, 3rd ed., Springer. [17] Hamelmann S. (1996): Systementwicklung zur Automatisierung der Arbeitsplanung (System development for the automation of work planning), Fortschriftberichte VDIReihe 20 Nr. 195, VDI Verlag Düsseldorf.

Resource Efficiency – what are the Objectives? Marko Gernuks 1

1

Volkswagen AG, Group Research Environmental Affairs Product; Wolfsburg, Germany

Abstract This paper shows that resource efficiency pursues the three objectives reducing environmental impacts, improving supply security and saving costs. Firstly, a differentiation is established between objectives and measures to achieve them. Secondly, methods to assess improvements relating to these objectives are discussed and applied to the case study of vehicle lightweight design. The presented example of substitution of steel by aluminum illustrates that trade-off between objectives may occur. Thus, a reliable assessment of measures to enhance resource efficiency must consider impacts on each objective separately. An aggregation to only one resource efficiency indicator lacks transparency and is not appropriate. Keywords: Resource Efficiency; Life Cycle Assessment; Methodology

1

INTRODUCTION

There is general agreement regarding the importance of resource efficiency, and almost every company can point to resource-efficient products. But more detailed discussion reveals that resource efficiency has many different meanings, which vary depending on the particular standpoint. In a range of presentations and publications, techniques such as substitution, recycling, lightweight design etc. are presented as resource-efficient, even though no commonly accepted definition of the term exists, as yet. This paper does not intend to provide a definition of resource efficiency, but aims to clarify the objectives of resource efficiency. The term "resources" as used here refers to non-energetic raw materials. Furthermore, the challenges of defining appropriate assessment indicators for resource efficiency are described and aspects that have to be taken into account are discussed. 2

OBJECTIVE OR MEASURE?

In the absence of general agreement on what resource efficiency really is, no differentiation has yet been established between resource efficiency objectives on the one hand and measures to achieve them on the other. Taking recycling as an example, it is first necessary to ask the question – why recycle? Why is it desirable to strive for closed-loop material use? Essentially the assumption is that closed-loop recycling will have a reduced environmental impact compared to primary production. Cost savings are also expected, as well as enhanced resource supply security. It follows from this that recycling is a measure to achieve the objectives: 

reducing environmental impacts,



improving resource supply security, including lowering import dependency, e.g. for metals, and



cost savings in production.

Besides recycling, other potential measures to achieve the above-

mentioned objectives include substitution, extended product lifetime or use of renewable raw materials. But none of these measures are objectives themselves, as it makes no sense to recycle material without reducing environmental impacts, improving supply security or saving costs. Taking the proposed differentiation between objectives and measures as a basis, as a next step a framework for the assessment of resource efficiency can be developed. I.e. measures can be assessed with regard to their efficiency in achieving improvements with regard to the three objectives. The following sections discuss challenges with regard to the respective assessment procedures and provide proposals as to how to tackle these. 3

ASSESSMENT OF ENVIRONMENTAL IMPACT

An important aspect in assessing environmental impacts is the definition of system boundaries. For raw materials often only the impact of the production phase is considered when performing such assessments. However, materials choices may significantly influence environmental impacts during the product use phase as well. This can be demonstrated by the practical example of lightweight vehicle design (cf. Figure 1). The aim of the car manufacturers is to reduce vehicle weight in order to reduce fuel consumption and thus also CO2 emissions. In this context the substitution of steel by the lightweight material aluminum is a promising measure. Depending on the specific vehicle part that is substituted by aluminum, a weight reduction of 10 to 40% compared to steel is possible [1]. At first sight, this might be thought to represent a big improvement in resource efficiency. Looking at the CO2 emissions during production, however (Figure 1), it becomes clear that aluminum causes significantly higher CO2 emissions than steel at this stage, even if the full lightweight design potential of 40% is realized. If the system boundaries were restricted to material production, steel would clearly be the preferable alternative to aluminum. However, a

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_11, © Springer-Verlag Berlin Heidelberg 2011

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[kg CO2-eq] 20

Production

Use phase

15

10

5

0

Aluminum Aluminium Steel Stahl Steel (1 kg)

Al Al Al (1 kg) (0.8 kg) (0.6 kg)

0 km

150,000 km

Figure 1: Greenhouse gas emissions of lightweight vehicle design based on replacing steel with aluminum (data source: GaBi 4.3). broader view taking into account the entire life cycle, including production and the product use phase, reveals a different picture. A 40% weight reduction would result in the additional CO2 emissions from aluminum production (compared to steel) being offset in the course of the product use phase. If only a 20% weight reduction were implemented, a break-even would not be achieved within the assumed lifetime of 150,000 km. From this example two conclusions can be derived: 1. Materials that cause higher emissions in production can nevertheless be environmentally beneficial overall, due to advantages during the product use phase. 2. No material is inherently "good" or "bad". It depends on the specific application of the material, and thus a case-specific analysis is indispensable. In this example the realized weight reduction when substituting steel by aluminum is crucial. Apart from the definition of system boundaries, for the assessment of environmental impacts it must be decided what impacts to take into consideration. As well as looking at greenhouse gas emissions (measured in kg CO2-equivalent), cf. Figure 1, further impacts such as acidification, photochemical ozone creation or land use should also be taken into account for a full assessment of environmental performance. For all these topics the ISO standard 14040 and 14044 for Life Cycle Assessment [2] provides very sophisticated and clear guidelines. Certainly, LCA studies based on ISO 14040 require a considerable effort, but the procedure is indispensable for a reliable assessment of the environmental impacts of raw materials and their applications. 4

ECONOMIC ASSESSMENT

As with the assessment of environmental impacts, for the economic assessment too system boundaries must be defined. This is very much dependent on perspective. For companies, the economic assessment might at first sight appear straightforward. Raw materials prices are readily available. Taking the example of aluminum versus steel, aluminum results in

significantly higher costs: steel prices recently stood at around € 0.60 per kg [3] whereas aluminum cost about € 1.7 per kg [4]. Taking the 40% weight reduction into account, 0.6 kg aluminum would still cost € 1. In this simple economic comparison steel would be preferable. However, again this is only part of the story. In car manufacturing, further economic aspects must be taken into consideration – for example the cost impact of different body-in-white assembly technologies. In addition to production costs alone, depending on the perspective of the analysis more comprehensive approaches may be appropriate when making the economic assessment. For instance, the Total Cost of Ownership (TCO) approach could be of interest from the standpoint of customers. The probable higher price of a car with more aluminum parts might be economically acceptable if lower costs during utilization, due to lower fuel consumption, would lead to lower total costs over the life cycle as a whole. 5

ASSESSMENT OF RESOURCE SECURITY

In the current debate on resource efficiency, it is often claimed that it is necessary to reduce resource consumption due to the increasing scarcity of raw materials. However, geologists from various European countries who were part of the European expert group on defining critical raw materials concluded that in general there is no geological scarcity of raw materials [5]. Nevertheless, raw materials prices have increased enormously over recent years and the reasons must be examined. In cooperation with the Federal Institute for Geosciences and Natural Resources (BGR) Volkswagen has developed a methodology to assess raw materials risks [6]. This comprises 5 risk indicators: 

Current supply / demand situation,



Raw material production costs,



Geostrategic risks,

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65



Risk through mining company concentration, and

6



The future trend in supply / demand.

For the implementation of resource efficiency in corporate management systems a common understanding of the term itself, and also clear objectives, are crucial.

Figure 2 illustrates the criteria for the geostrategic risks indicator. The x-axis shows country concentration, the calculation of which is based on the number of countries in which a particular raw material is produced. The highest possible value of 10,000 would mean 100% of a raw material is produced in only one country. On the yaxis the result of weighted country risk, based on the World Bank Index (WBI), is displayed. The WBI consists of six criteria, such as a corruption index, which are aggregated to a risk value for each country. The country risk for a raw material is then weighted according to the respective country's share of world production.

CONCLUSIONS

As a first step this paper establishes a clear differentiation between objectives and measures to achieve them. As a second step, assessment methods for the objectives reducing environmental impacts, improving supply security and costs savings are discussed. The discussed methods are in common use and often already part of corporate management systems. Although the use of these methods might be time-consuming and requires expert knowledge, they are indispensable for the reliable assessment of resource efficiency. A further key conclusion of this article is that measures aimed at enhancing resource efficiency may involve trade-offs. The presented case study of steel substitution by aluminum to reduce vehicle weight shows potential reduction of environmental impacts on the one hand, but possible negative economic effects on the other. An aggregation of the assessment results for the three objectives to a single indicator, which is the practice currently followed in the resource strategy of the German government [8], is not meaningful, due to the resulting lack of transparency about possible negative effects.

Taking again the example of aluminum versus steel, the criteria used in figure 2 reveal no significant risk for either metal, be it with regard to country concentration or country risk. However, a disaggregated assessment taking into account all five indicators mentioned above might reveal some specific risks for the metals in question. To summarize, although there is generally no risk of geological depletion of raw materials, industry's access to them could nevertheless be subject to a variety of other risks. Therefore, a range of risk indicators should be applied to identify specific risks for the raw material under consideration. Given the diversity of risks, a corresponding variety of specific measures is necessary to reduce the supply risk. The risk may be reduced through measures such as hedging, diversifying suppliers, substitution or enhanced recycling. However, there is no universal solution; appropriate measures must be considered on a case-specific basis for each raw material.

Before any reasonable regulatory measures on resource efficiency can be introduced, it will first be necessary to achieve general agreement on objectives, measures and their effects. This should be a main task of further research work. Companies will have to decide if a specific management system for resource efficiency is reasonable, especially if they have already established sustainability monitoring instruments which pursue almost similar objectives.

-1.5

Weighted country risk of production (based on World Bank Index)

high

metal (refined)

metal (ore)

-1.0

Sn

0.0

Au

Ag Ni Ni

0.5

Cu

1.0

1.5 400

REE

Sn

-0.5

Mn Zn Cd

Fe Bauxit Al Pb Pb Zn Cu

Te

Co Bi FeCr Cr Si Mo

V

W

Sb Mg Nb

Pd Pt

Zr

Ti

Bi

Ta Li high

low 1,000

2,000

Country concentration (Herfindahl -Hirschman Index of production 2008) Figure 2: Supply risk criteria, based on [7].

10,000

66 7

Automotive Life Cycle Engineering REFERENCES

[1]

International Organization for Standardization - ISO 14040 (2006): Environmental Management Life Cycle Assessment – Principles and Framework. 2nd ed. Geneva: International Organization for Standardization.

[2]

Krinke, S., Koffler, C., Deinzer, G., Heil, U., (2010): An integrated life cycle approach to lightweight automotive design, in: ATZ, Volume 112. pp. 36-42.

[3]

Metal Bulletin (2010): EU domestic prices for hot rolled coil, Metal Bulletin, 6 December, Number 9178, p. 24.

[4]

Metal Bulletin (2010): LME settlement prices for Aluminum high grade, Metal Bulletin, 6 December, Number 9178, p. 20.

[5]

European Commission (2010): Report of the Ad-hoc Working Group on defining critical raw materials, Version of 30th July 2010.

[6]

Rosenau-Tornow, D., Buchholz, P., Riemann, A., Wagner, M. (2009): Assessing the long-term supply risk for mineral raw materials – a combined evaluation of past and future trends, in Resource Policy 34 (2009), pp. 161-175.

[7]

Steinbach, V.: Verfügbarkeit von Hightech-Rohstoffen. Presentation of the BGR at the Euroforum conference Technologiemetalle. Frankfurt, 21-22nd September 2010.

[8]

Statistisches Bundesamt (2010): Nachhaltige Entwicklung in Deutschland – Daten zum Indikatorensystem 2010. Statistisches Bundesamt, Wiesbaden, p. 7.

Comparative Life Cycle Assessment of Remanufacturing and New Manufacturing of a Manual Transmission 1

1

Jens Warsen , Marlisa Laumer , Wolfgang Momberg 1

2

Volkswagen AG, Group Research Environmental Affairs Product, Wolfsburg, Germany 2

Volkswagen AG, Remanufacturing Powertrain, Kassel, Germany

Abstract A newly manufactured 5-speed manual transmission is compared with a genuine remanufactured transmission of identical design. The Life Cycle Assessment covers the entire product life cycle from production through to disposal. In all the environmental impact categories considered, the remanufactured transmission performs significantly better than the newly manufactured unit. The environmental improvements are attributable to the substantial reduction in material and energy consumption. Transport of used transmissions to the remanufacturing facility accounts for only a small fraction of total life cycle environmental impacts. Energy consumption is reduced by 33 % for the remanufactured transmission compared with a newly manufactured transmission. Keywords: Comparative LCA; Remanufacturing; Transmission

1

INTRODUCTION

Volkswagen is committed to developing vehicles and components with better environmental properties than their predecessors over the entire life cycle. Life Cycle Assessments (LCA) are used to document the environmental performance of vehicles, technologies and processes. We have been using Life Cycle Assessments to enhance the environmental compatibility of our cars and their individual components since 1996. As part of an integrated product policy, the LCA considers not only individual environmental aspects such as the driving emissions of the vehicle but its entire life cycle. The Life Cycle Assessment issued by Volkswagen are in accordance with ISO 14040/44 [1, 2] and are verified by independent experts, e.g. by TÜV NORD. Volkswagen today has a 60 year history of remanufacturing. The so called „Exchange Parts Programme“, a take-back scheme for used vehicle components, was launched back in 1947 in order to meet raw material shortages in the post-war era. Initially the scheme was confined to five product groups: fuel pumps, clutch pressure plates, steering boxes, carburettors and cylinders with front and rear axles and industrial engines following during the subsequent years. Being extremely successful, the programme saved substantial amounts of raw material and energy as a large part of the components usually can be directly reused. For these component parts the complex production process of smelting, casting and forming is saved. Nonetheless genuine part quality is guaranteed for all remanufactured components. The aim of this LCA-study is to analyse and compare the environmental impacts of a newly manufactured transmission model with a genuine remanufactured transmission of identical design. More detailed information about this analysis can be found at www.mobility-and-sustainability.com. 2 2.1

MATERIALS AND METHODS Data origin of LCI analysis

The data used for preparing the Life Cycle Assessment can be

subdivided into product data and process data. “Product data” describes the product itself, and among other things includes information on parts, quantities, weights and materials. “Process data” includes information on manufacturing and processing steps such as the production of materials and semifinished goods, fabrication and the provision of electricity and other consumables. This information is either obtained from commercial databases or compiled by Volkswagen as required [3, 4]. The data selected are as representative as possible. This means that the data represent the materials, production and other processes as accurately as possible from a technological, temporal and geographical point of view. For the production processes carried out at the Kassel plant chiefly primary data is used. Upstream supply chains and external production steps are modelled using published industrial data. As the transmissions are remanufactured centrally by Volkswagen in Kassel, as far as possible data related to Germany is applied. Where German data is not available, European and occasionally global conditions are reflected. The Life Cycle Assessment model for transmission production was developed using Volkswagen‘s slimLCI methodology [5]. The transmission parts list was used as data source for product data, and data on weight and materials was taken from the Volkswagen material information system (MISS). This information was then linked to the corresponding process data in the Life Cycle Assessment software GaBi. 2.2

Data quality

Material inputs, processing procedures and the selection of data in GaBi are standardised to the greatest possible extent, ensuring that the information provided by VW slimLCI is consistent and transparent. In sum, all information relevant to the aims of this study was collected and modeled completely. The modelling of components on the basis of transmission parts lists ensures that the model is complete, especially with respect to the manufacturing phase. In addition, as the work processes required are automated to a great extent, any differences in the results are due solely to

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_12, © Springer-Verlag Berlin Heidelberg 2011

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changes in product data and not to deviations in the modelling system. 2.3

Impact assessment

The Impact Assessment is based on CML methodology [6]. The assessment of environmental impact potentials in accordance with this method is based on recognized scientific models. A total of five environmental impact categories were identified as relevant and were then assessed in this study:

key technical data of this transmission. The two transmissions are comparable as the remanufactured unit is guaranteed to have the same quality as a genuine newly manufactured gearbox. 5-speed front wheel drive car transmission Torque

250 [Nm]

Max Power

132 [kW]

Length

370 [mm] 41.3 [kg] , with oil



eutrophication potential (EP)

Weight



ozone depletion potential (ODP)

Design

Twin-shaft gearbox



photochemical ozone creation potential (POCP)

Synchromesh

3rd to 5th gears: single-cone Borg-Warner,



global warming potential (GWP) for a reference period of 100 years



acidification potential (AP)

3.1

CASE STUDY Objective and target group of the assessment

The objective of this Life Cycle Assessment was to compare the environmental profiles of newly manufactured and remanufactured transmissions. For this purpose, a manual 5-speed MQ 250 transmission, currently Volkswagen`s highest-volume transmission, and a corresponding remanufactured unit have been assessed. 3.2

Reverse gear Reverse brake (input shaft) Housing

Besides this, primary energy demand has been also recognized. These six categories were chosen because they are particularly important for the automotive sector, and are also regularly used in other automotive related Life Cycle Assessments [7, 8, 9]. 3

1st and 2nd gears: triple-cone Smith

Function and functional unit

The functional unit for the Life Cycle Assessment was defined as the manufacture of a Type MQ 250 transmission. Table 1 shows the

Diecast aluminium

Table 1: Technical data of MQ 250 transmission. 3.3

Scope of assessment

Figure 1 shows the scope of this Life Cycle Assessment. It was defined in such a way that all relevant processes and substances are considered, traced back to the furthest possible extent and modeled at the level of elementary flows. The material fractions generated during recycling are the only exception. The manufacturing phase was modelled including all manufacturing and processing stages for all transmission parts and components. The model includes the transport of the old transmission to the plant, the dismantling, cleaning and testing of the old transmission, the production of replacement parts and the reassembly of the transmission. The model therefore covers all steps from the extraction of raw materials and the manufacture of semifinished products right through to assembly.

Figure 1: Scope of Life Cycle Assessment.

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69

Figure 2 shows a more detailed plan of the transmission remanufacturing process. The model includes the transport of the old transmissions from main distribution warehouses of the individual markets to the central remanufacturing plant at Kassel. The average distance travelled by an old transmission is 1,086 km. The national collection process is not considered as details of workshops dealing with transmissions in the individual countries are not known and the environmental impact of transport is, in any case, negligible (cf. Figure 5). The model reflects the means of transport mainly used in the markets and the distances concerned. The average distances for each means of transport are shown in Table 2.

Truck Train Ship (overseas)

The service life phase is identical for both transmission types as remanufactured transmissions are reprocessed to genuine component quality and therefore meet the same technical requirements as newly manufactured units. Within the differential approach adopted for the Life Cycle Assessment, the service life phase is therefore not relevant and is outside the scope of the assessment (see Figure 1). The recycling phases of the two transmission types are also identical and are therefore also excluded from the scope of the assessment. This applies both to the separate consideration of a new and a remanufactured transmission which have reached the end of their useful lives and are consigned to recycling and to such transmissions which are remanufactured.

Overall share in transport (rounded)

Distance considered [km]

35.6 %

387

4

170

4.1

529

Figure 3 presents the Life Cycle Inventory results for selected parameters during the manufacturing phase of the production of a new transmission and the remanufacturing of a transmission. The emissions of all the gases considered are significantly reduced by remanufacturing. In absolute terms, the emission values are very different, but the relative reductions are of the same order of magnitude. The greatest savings are achieved with respect to carbon monoxide (a reduction of 47 %), which is a key factor in local air quality (photochemical ozone creation potential). Regarding the emission of carbon dioxide the remanufacturing leads to a reduction of 73 kg CO2

15.7 % 48.7 %

Table 2: Average transport distance for a returned transmission. The model is based on the data records of the GaBi software. As regards the respective assumptions concerning capacity utilisation, consumption, etc., the parameters described in the software documentation [10] apply. On average, experience indicates that the parts which are found to be reusable on inspection account for at least 50 % of the mass of a transmission. The remaining parts are consigned to recycling and replaced by new parts. These new parts include a large number of small wear parts, which are replaced on all transmissions as a standard part of the process.

RESULTS Life Cycle Inventory

Figure 2: Transmission remanufacturing process.

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Figure 3: Life Cycle Inventory Values. 4.2

Life Cycle Impact Assessment

On the basis of the Life Cycle Inventory data, the Life Cycle Impact Assessment is drawn up for all the environmental impact categories. The interactions of all the emissions recorded are considered and potential environmental impacts are determined based on CML methodology. Figure 4 compares the absolute environmental impacts of the production of a new transmission with those caused by transmission remanufacturing. The relative reductions in environmentally relevant emissions are also indicated. For example, global warming potential can be reduced by 28 %, or 63 kg of CO2 equivalents, on average by the reuse of components in a remanufactured transmission. The greatest savings are in the area of eutrophication potential (minus 42 %), followed by local air quality (represented by photochemical ozone creation potential) with minus 41 %). Energy consumption is reduced by 33% for the remanufactured transmission compared with a newly manufactured MQ 250. Figure 5 compares the environmental impacts of the various stages in the production of a new transmission and transmission

remanufacturing. The environmental impacts shown in each of the categories have been normalised using the normalisation factors in Table 3. The environmental impact of transmission remanufacturing is due mainly to the energy and materials required for producing new parts to replace components of the old transmission which cannot be reused. The remanufacturing process itself, including dismantling, cleaning, testing and reassembly, accounts for a substantially lower share of the environmental impacts. Environmental category

Unit

EP

15906

ODP

31

PO4 equivalents R11 equivalents

POCP

7228

C2H4 equivalents

GWP

4440050

CO2 equivalents

AP

21553

SO2 equivalents

Table 3: EU 15 normalisation factors (in thousand metric tons).

Figure 4: Environmental impacts of transmission production.

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71

Figure 5: Normalised environmental impacts of the various production stages. 5

CONCLUSION

This study demonstrates the benefits of the remanufacturing of transmissions with regard to the environmental profile of the components. The remanufactured transmission performs significantly better than the newly manufactured component in terms of all environmental impact categories considered. The savings are chiefly due to lower power consumption and material requirements as a result of the reuse of components. The remaining environmental impact of transmission remanufacturing is largely determined by electric power and material requirement for the manufacture of new replacement parts. Thus, for further optimization, subsequent analyses and activities will have to focus on these two aspects. 6 [1]

REFERENCES International Organization for Standardization (2006): ISO 14040: Environmental Management – Life Cycle Assessment – Principles and Framework, International Organization for Standardization, Geneva.

[2]

International Organization for Standardization (2006): ISO 14044: Environmental Management – Life Cycle Assessment – requirements and guidelines, International Organization for Standardization, Geneva.

[3]

Arning, S. (2005): Identifikation Ergebnisbeeinflussender Größen bei Getriebe-Ökobilanzen, Diploma thesis, Volkswagen AG, Wolfsburg.

[4]

Laumer, M. (2011): Vergleichende Umweltbilanz gemäß DIN ISO 14040 über die Wiederaufbereitung eines PkwSchaltgetriebes gegenüber der Neufertigung, Diploma thesis, Volkswagen AG, Wolfsburg.

[5]

Koffler, C.; Krinke, S.; Schebek, L.; Buchgeister, J. (2007): Volkswagen slimLCI – a procedure for streamlined inventory modelling within Life Cycle Assessment (LCA) of vehicles. In: International Journal of Vehicle Design (Special Issue on Sustainable Mobility, Vehicle Design and Development), Olney: Inderscience Publishers.

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[6]

Guinée, J. B.; Lindeijer, E. (2002): Handbook on Life Cycle Assessment: Operational guide to the ISO standards, Dordrecht [et al.], Kluwer Academic Publishers.

[7]

Krinke, S.; Bossdorf-Zimmer, B.; Goldmann, D. (2005): Ökobilanz Altfahrzeugrecycling – Vergleich des VW-SiConVerfahrens und der Demontage von Kunststoffbauteilen mit nachfolgender werkstofflicher Verwertung. Volkswagen AG, Wolfsburg.

[8]

Krinke, S.; Nannen, H.; Degen, W.; Hoffmann, R.; Rudloff, M.; Baitz, M. (2005): SunDiesel – a new promising biofuel for sustainable mobility. Presentation at the 2nd Life-Cycle Management Conference Barcelona.

[9]

Schmidt, W. P.; Dahlquist, E.; Finkbeiner, M.; Krinke, S.; Lazzari, S.; Oschmann, D.; Pichon, S.; Thiel, C. (2004): Life Cycle Assessment of Lightweight and End-Of-Life Scenarios for Generic Compact Class Vehicles. In: IntJLCA (6), pp. 405416.

[10] http://documentation.gabi-software.com

Coordination of Design-for-Recycling Activities in Decentralized Product Design Processes in the Automotive Industry 1

1

Kerstin Schmidt , Thomas Volling , Thomas S. Spengler 1

1

Institute of Automotive Management and Industrial Production, Technische Universität Braunschweig, Braunschweig, Germany

Abstract Design processes in the automotive industry are distributed over various companies. If inappropriate contract structures are used within such collaborations, inefficiencies in the design process occur due to existing uncertainties and differing objectives of the partners. To coordinate design-for-recycling activities in collaborative design processes a mathematical model for the analysis of those processes is developed. We apply the model to a fixed-price and an incentive contract. The analysis shows that fixed-price contracts lead to inefficiencies, while incentive contracts can reduce inefficiencies. We demonstrate the use of this model based upon an illustrative example to show its applicability. Keywords: New Product Development; Design-for-Recycling; Automotive Industry

MOTIVATION

Recycling is an important issue for a sustainable economic management in the automotive industry. In recent years, 8 to 9 million tons of waste from used cars were generated in the European Union. On average, 25 % of this waste could not be recycled and needed to be brought to landfill. Furthermore, it is expected that the amount of waste will increase to somewhere between 14 and 17 million tons until 2015. [1, 2] In order to improve the management of end-of life vehicles, the European Union adopted the Directive on end-of life vehicles [3] in 2000. Among other things, the directive aims at setting specific targets on the 1 2 3 reuse , recycling and recovery of waste from end-of life vehicles for 2006 and 2015. For 2006, reuse and recovery rates of at least 85 % and reuse and recycling rates of at least 80 % are required. From January 2015 these rates shall be increased to a minimum of 95 % and 85 %, respectively. The greatest impact on the reusability, the recyclability and 4 recoverability of a vehicle is given in the design phase of this new vehicle. For this reason, a variety of Design-for-Recycling activities exist in the automotive industry. The legislator tries to impair the product design as well: in 2005 the European Union adopted the Directive on type-approval of motor vehicles with regard to their reusability, recyclability and recoverability [4]. Due to this directive, since December 2008 automotive manufacturers (OEMs) are obligated to demonstrate the statutory rates when the type-approval of a new vehicle is done. While the OEM bears responsibility for the compliance with the recycling rates, his influence is often limited. In current practice, 1

‘Reuse’ means any operation by which components of end-of life vehicles are used for the same purpose for which they were conceived. [3] 2 ‘Recycling’ means the reprocessing in a production process of the waste materials for the original purpose or for other purposes but excluding energy recovery. [3] 3 ‘Recovery’ means the use of combustible waste as a means to generate energy through direct incineration with or without other waste but with recovery of the heat. [3] 4 In the following, for shortening, we only speak of ‘Recyclability’. The same holds for ‘recycling rates’ and ‘recycling-relevant’.

design processes are distributed over various companies. Figure 1 shows the increasing relocation of the development performance to suppliers over the last ten years. OEM 2000 2005 *2010

Supplier 67% 57% 49%

33% 43% 51%

*Estimation

1

Figure 1: Relocation of development performance to suppliers. [5] Hence, the components of a vehicle are not designed centrally at the OEM, but at a variety of specialized suppliers. For this reason, the recycling rates depend on the specifications of each component of the vehicle and thus on the design effort of the suppliers. To ensure the compliance with the recycling rates, the collaboration between OEM and suppliers is based on contracts. These contracts include recycling-relevant specifications of the components the suppliers develop. The design of appropriate contracts for these collaborations poses a challenge. Reasons can be found in differing objectives of the legally and economically independent companies. Furthermore, uncertainties exist due to the fact that the contracting is done at the beginning of the design process, when no accurate assertions about the future components’ specifications are available. If inappropriate contracts are used in these collaborations, inefficiencies can occur. On the one hand, statutory recycling rates can be exceeded, resulting in additional design effort for the suppliers, without any additional utility for the OEM. On the other hand, recycling rates can be violated, which means that the new vehicle cannot be certified to the intended date, resulting in a loss of utility for the OEM and additional design effort of suppliers. Thus, the economic risk for suppliers and OEM increases. Overcoming these difficulties requires an improved coordination between the partners before and during the design process. A formal modeling approach for the analysis of contracts and their coordination ability in distributed design processes, to best of our

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_13, © Springer-Verlag Berlin Heidelberg 2011

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knowledge, is still missing. The economics of contracts have been studied in a variety of quantitative academic contributions [6, 7]. Particularly in supply chain management settings of independent OEMs and suppliers are analyzed. A comprehensive review of contract analysis in this field is provided by [7]. In the context of supply chain management, a central phenomenon causing inefficiencies is uncertainty. In these situations the flexibility to change a chosen course of action is usually associated with better performance [8]. Accordingly, uncertainty and thus risk is being shared with respect to the contractual agreement. Of particular interest for the research presented are flexible contract types [8, 9]. However, differences between supply chain management and design processes currently prevent an easy adoption of the mentioned flexible contracts. First approaches to the flexibilization of contracts in design processes are given by [10, 11, 12]. Since these contributions focus on a general analysis of the effectiveness of incentive contracts, a formal modeling approach for the analysis of contracts and their coordination ability in distributed design processes is still missing. To this end, a mathematical model for the analysis of decentralized design processes in the automotive industry is presented and applied to the case of the efficient compliance with recycling rates. The rest of the paper is structured as follows. After modeling and analyzing decentralized design processes in the next section, we present an approach to improve decentralized design processes in section 3. In section 4 we demonstrate the use of this approach based upon an illustrative example to show its applicability. Finally, we draw our conclusions and give a short outlook on our future research in section 5.

vehicle are fully detailed until they have the readiness for start of production (SOP). [13] Since the development of a new vehicle is distributed between the OEM and his suppliers, the suppliers need to be integrated into the OEM’s design process. The integration of the suppliers as well as the conclusion of the contracts is done in the first phase of the design process (see Figure 2). At this early point of time, the contracting is done although only first assertions about the product specifications and thus about the component specifications are available. For this reason, uncertainties arise in the design process, since the component specifications, resulting at the end of the design process, cannot be predicted with certainty. To support the cooperation between the OEM and his suppliers during the design process, at fixed points in time the development status of the components is evaluated, necessary coordination is done and decisions are made [14, 15]. At the end of the design process, in the fourth phase, the integration of the suppliers’ components is done (see Figure 2). Based on the realized specifications of the developed components the determination of the recycling rates is conducted. The compliance with the statutory recycling rates is an important precondition for the conferral of the type-approval for the new developed vehicle and thus for its market launch. The determination of the recycling rates is based on the four steps of an assumed recycling process: pre-treatment ( pt ), removal ( re ), metal removal ( mr ) and treatment of non-metallic residue ( nm ). In each step, the sum of the masses m is determined, which are considered to be recyclable. Thus, simplified the recycling rate R rec results from the following equation [16]: R rec 

2

MODELING AND ANALYSIS OF DECENTRALIZED DESIGN PROCESSES

In this section we study current decentralized design processes in the automotive industry. We focus on the characteristics of current design processes in the first step and present a model for the analysis of these processes in the second step. In the third step we concentrate on the analysis of decentralized design processes. 2.1

Design processes in the automotive industry

Design processes in the automotive industry mainly consist, with the exception of company-specific deviations, of four phases: goal alignment, concept, preliminary development and serial development (see Figure 2). Integration of suppliers, conclusion of contracts Goal alignment Integration of components, Concept Type-approval of new vehicle Preliminary development Serial development 84 78 72 Month before SOP

60

48

40

36

30

24

20

12 10

6

SOP

Figure 2: Illustrative design process in the automotive industry. [13] In the first phase (goal alignment), the vehicle parameters as well as the vehicle targets are to be defined as part of the product specifications. In the second phase (concept), first vehicle designs are developed based on the product specifications. In the third phase (preliminary development), vehicle designs from the previous phase are analyzed and compared. A final vehicle design is selected and refined. Furthermore, legal requirements like recycling rates are taken into account. At the end of this phase, the prototype construction of the vehicle begins. In the fourth phase (serial development), the engineering drawings of all components of the

m pt  mre  mmr  m nm mvehicle

100

(1)

This method cannot only be applied to the calculation of the recycling rate of the vehicle itself, but also to the calculation of the recycling rate of the components. Therefore, the sum of the recyclable masses mi of each step of each component is divided by the mass of the component itself. The recycling rate of the entire vehicle R rec then results from the following equation, with Rirec indicating the recycling rates of n different components, i  1,..., n , under the assumption, that the vehicle consists of n components: R rec 

m1  R1rec  m2  R2rec  ...  m n  Rnrec m1  m 2  ...  m n

(2)

The recyclability of a vehicle does not depend on all components to the same degree. For example, all fluids, batteries, oil filters, tires, catalytic converters and airbags are considered to be 100 % recyclable, when calculating the recycling rates. The recycling of the metallic parts of end-of life vehicles succeeds by the effective separation in the shredder and in the subsequent sorting steps (magnetic separators, eddy current separators, float-sink systems) to about 97 %. Currently, the high-quality recycling of plastics, vehicle glass and shredder light fraction, resulting from the shredding process, is improvable. For example, the recycling rate of the shredder light fraction is only at 54 %, despite a weight percentage of 20 % on end-of life vehicles. Another challenge is the specific removal and recovery of the increasingly occurring precious-metalliferous car electronic components. [16, 17] Thus, the highest influence on the recyclability of a new vehicle is given by the components with a high share of polymer and composite materials and electronic components. In particular, components like the instrument panel and the underbody protection play a decisive role for the recyclability of a new vehicle. Due to these facts, the high complexity of current automotive design processes can be reduced by concentrating only on those

Automotive Life Cycle Engineering - Recycling components, which have a high influence on the recyclability of the vehicle, when modeling decentralized design processes in the next section. 2.2

Model description

We consider three independent actors with full information: one OEM and two suppliers. The two suppliers S i each develop one component with a recycling-relevant specification s i  [ s imin , s imax ] , with i  1, 2 indicating the two different suppliers/components, of a new vehicle for the OEM. For example, the recycling-relevant specification si of a component can be equal to a specific recycling rate Rirec . Since the OEM and his suppliers are legally and economically independent companies, the collaboration is regularized by contracts. In the automotive industry, contracts are usually based on unit price and amounts, while the development costs of the suppliers are included into the unit price. Since we firstly want to concentrate on the design phase, we assume that the OEM pays a lump-sum transfer payment t i to the suppliers at the end of the design process. The transfer payment functions can differ depending on the contract type that regularizes the collaboration. For example, the transfer payment functions can have a step-wise, a linear or an exponential shape. The compliance with the statutory recycling rates for the new vehicle, the OEM bears responsibility for, depends on the recyclingrelevant specifications si of the two components. Different combinations of the recycling-relevant specifications si lead to the compliance with the statutory recycling rates. We assume that these combinations, can be described approximatively by the functional relationship s 2  r (s1 ) .

75 density function P ( s1 , s 2 ) and integrating on the two intervals, with the interval limits depending on the efforts of the suppliers. This results in the following expected utility function n( w1 , w2 ) of the OEM, with d specifying the slope of the turning point, d   : n ( w1 , w2 )  s1max

The expected utility of the OEM depends on the compliance with the recycling rates of the new vehicle and thus on the expected specifications s i of the suppliers’ components. If the recycling rates are met, the utility of the OEM is one, otherwise it is reduced by the costs related to a deferred start of production. To model this stepwise character of the utility in a continuously and differentiable manner, it is approximated by a Sigmoid-function, which is normalized to the interval [0,1] . Through the turning point of the Sigmoid-function the function r ( s1 ) is running, so that the substitutional interdependencies between the two component specifications are taken into account. Since the efforts wi of the suppliers are stochastically independent, the existing uncertainties get included by multiplying the Sigmoid-function with the combined

1  P ( s1 , s 2 ) d ( s 2 ) d ( s1 ) 1  exp( d  r ( s1 ))  exp(  d  s 2 )

(3)

An overview of the model is given in Figure 3. s1 n(w1,w2)

OEM s2

S1

c1(w1)

S2

c2(w2)

t1 t2

Figure 3: Model of decentralized design processes. Figure 4 shows the course of events within the model for decentralized design processes: The OEM determines the transfer payment functions t i in the first step. Based on the transfer payment function the suppliers decide about their optimal effort wi and start the development of their component in the second step. Due to the chosen effort the interval limits for the component specification are realized and thus the expected component specifications s i are resulting in the third step. Dependent on the realized component specifications the transfer payments t i ( s i ) paid to the suppliers by the OEM as well as the utility of the OEM are resulting in the last step. ti ( s i )

The recycling-relevant specifications si of the two components, resulting at the end of the design process, depend on the design effort wi of the suppliers. Furthermore, the design effort wi quantifies the development costs ci ( wi ) of the suppliers, which are normalized to the interval [0,1] . Since uncertainties exist in the design process, the resulting recycling-relevant specification s i achievable with a specific design effort wi cannot be predicted with certainty. We assume, that the probability f ( si ) of achieving a certain specification s i is uniformly distributed in the interval [ s imin , simax ] . However, the suppliers may influence the expected component specification s i with their efforts wi . Due to practical relevance it has to be assured that the expected component specification is zero, if the effort is zero. Furthermore, the interval nearly shall remain the same size and the component specification shall converge to a technological threshold with increasing effort. According to these requirements, the coherence between component specification and effort is implemented as follows: The interval limits depend on wi : simin  ln( ai  wi  1) and simax  ln(bi  wi  1) , with bi > a i > 0. Thus, a greater effort shifts the interval limits to the right, so that an increase in effort leads to a higher expected value s i .

s 2max

s1min s2min

OEM: Decision about transfer payment function

wi

si

Supplier: Decision about effort

Supplier: Realization of component specification

wi

si

OEM: Resulting transfer payment and utility

ti ( si )

t i ( si )

Figure 4: Course of events within the decentralized design process. Based on this model, an illustrative model analysis is done in the next section. 2.3

Illustrative model analysis

Centralized setting In the centralized setting ( c ) one decision maker, who has full information, develops and integrates both components (see Figure 5). s1 n(w1,w2)

OEM s2

S1

c1(w1)

S2

c2(w2)

t1 t2

Figure 5: Decision situation in the centralized setting. Hence, his aim is to maximize the total profit  of the design process. His profit function results from the expected utility n minus the development costs ci as follows:

 ( w1 , w2 )  n ( w1 , w2 )  c1 ( w1 )  c 2 ( w2 )

(4)

The optimal efforts wi ,c as well as the resulting expected component specifications s i ,c result from the analytical determination of the extreme point of the profit function  .

76

Automotive Life Cycle Engineering - Recycling

These results provide as a benchmark for the analysis of the coordination ability of different kinds of contracts in the decentralized setting. Decentralized setting In the decentralized setting, the decision situation of the suppliers is considered when collaboration is based on contracts (see Figure 6). s1 n(w1,w2)

OEM s2

S1

c1(w1)

S2

c2(w2)

t1 t2

tih,iin

ŝi

si

Figure 7: Fixed-price contract.

hi

simin

simax

s max

ˆ

i

i

(5)

To analyze the decentralized setting with fixed-price contract ( fp ) the decision situation of the suppliers is considered. We assume that the OEM chooses the required component specification sˆi according to the optimal specification s i ,c in the central case. The ˆ profit functions  is,i fp of the suppliers are based on the transfer payment functions minus their development costs. The suppliers then determine their effort wi by maximizing their profit function: ˆ

ˆ

 is,i fp ( wi )  t is,i fp ( wi )  ci ( wi )

(6) ˆ

Since the realized specifications, and thus the resulting transfer payments, depend on the suppliers’ effort, the expected transfer payment function arises as follows: The existing uncertainties are included by multiplying the transfer payment function hi ( s i ) with the density function P ( s i ) and integrating on the interval, with the interval limits depending on the effort of the supplier. The expected transfer payment function t ih,iin results as follows: s max

Figure 8: Incentive contract.

1  P ( si ) d ( si ) 1  exp( k  sˆi )  exp(  k  s i )

In incentive contracts not a certain design specification is set by the OEM, but an interval on design specifications. For every specification within the interval the suppliers get an agreed transfer payment hi ( si ) (e.g., the transfer payment function increases linear with respect to the achieved specification). Additionally, the suppliers are able to select a component specification within this interval and thus an effort to achieve this specification, which fits best to their structure of development costs and hence to their uncertainties. Figure 8 outlines a simplified incentive contract.

i t ih,iin ( wi )  s min hi ( si )  P ( si ) d ( si )

si

Since the realized specifications and thus the resulting transfer payment depend on the suppliers’ effort, the expected transfer payment functions arise as follows: To model the binary-character of the transfer payment in a continuously and differentiable manner, it is approximated by a Sigmoid-function, which is normalized to [0,1] . The turning point of the Sigmoid-function is described by the required component specification sˆi . The existing uncertainties are included by multiplying the Sigmoid-function with the density function P ( s i ) and integrating on the interval, with the interval limits depending on the effort of the supplier. The expected transfer ˆ payment function t is,i fp , with k specifying the slope in the turning point, k   , results as follows: i t is,i fp ( wi )  s min

IMPROVING DECENTRALIZED DESIGN PROCESSES

In this section we present the conceptual design of an incentive contract to make decentralized design processes in the automotive industry more flexible and thus less inefficient.

Figure 6: Decision situation in the decentralized setting.

ˆ

Hence, new types of contracts are necessary to improve the cooperation between OEM and suppliers in distributed design processes. For this purpose, we present the conceptual design of an incentive contract in the next section. 3

Currently, in the automotive industry fixed-price contracts are most commonly used. In these contracts the OEM determines certain recycling-relevant specifications sˆi for the components that have to be fulfilled by the suppliers. Based on these parameters, the OEM then specifies the transfer payment function determining the amount to be paid by him to the suppliers. In this fixed-price contract, a component specification equal or higher than the required specification leads to a payment equal or higher compared to the development costs of the suppliers, while a specification lower than the required specification leads to a payment corresponding to the development costs reduced by the penalty costs. Figure 7 outlines a simplified fixed-price contract.

tis,i fp

specifications sˆi and thus get the agreed transfer payment with certainty. Consequently, inefficiencies in the design process occur and increased development costs and overdesigned components are resulting.

The analysis shows, that the optimal efforts wis, ifp and thus the ˆ expected component specifications sis,ifp are higher than in the centralized setting. Due to the fixed-price contract the suppliers choose a higher effort than necessary to achieve at least the design

(7)

To analyze the decentralized setting with incentive contract ( in ) the decision situation of the suppliers is considered. The profit functions  i,hiin of the suppliers are based on the transfer payment functions minus their development costs. The suppliers then determine their effort wi by maximizing their profit function:

 ih,iin ( wi )  t ih,iin ( wi )  ci ( wi )

(8)

The analysis shows, that the optimal efforts wih,ini and the resulting expected component specifications sih,ini are higher than in the centralized setting, but lower than in the decentralized setting with fixed-price contract. Thus, using incentive contracts enables to reduce the overdesign of the components and to make a contribution to the coordination of decentralized design processes. The reason for the reduced overdesign of the suppliers is their higher flexibility and the missing risk to get no transfer payment. Due to the higher flexibility for the suppliers the risk of the OEM increases, since the chosen efforts of the suppliers can lead to the non-compliance with the statutory recycling rates. Therefore it is necessary for him to set the contract parameters hi ( si ) advisedly. The application of the model will be illustrated in the next section. 4

ILLUSTRATIVE EXAMPLE

To show the applicability of the previously presented model to analyze different kinds of contracts towards their coordination ability, we employ it in an illustrative example of a decentralized design process in the automotive industry in this section. In the first step, the setting of this example is specified. In the second step we concentrate on the analysis of this illustrative example.

Automotive Life Cycle Engineering - Recycling 4.1

Setting of the illustrative example

In the considered setting, two independent suppliers each develop one component for a new vehicle of an OEM: the underbody protection and the instrument panel. To grant the type-approval of the new vehicle at the end of the design process, the OEM has to demonstrate that the vehicle is able to achieve the statutory recycling rates. For the sake of simplicity it is assumed that the recycling rates of all components, except the underbody protection and the instrument panel, cannot be improved. Thus, the resulting recycling rate of the vehicle only depends on the recycling rates of the two components developed by the suppliers. To meet the statutory recycling rates for the vehicle, the combined recycling rate of the two components needs to be 60 %. To achieve this goal, specific recycling-relevant specifications s i of the components are required. In this illustrative example, the recycling-relevant specifications are equal to the recycling rates of the components: s i  Rirec . Until now a coating with mineral-filled PVC has been provided by supplier S1 to protect the underbody. Since such a protective layer cannot be removed from steel with a tolerable outlay, only the steel could be recycled. Thus, nearly 100 % of the mineral/plastic mixture of the underbody protection is going to landfill. To improve the recyclability and thus the recycling rate of the underbody protection, the supplier identified two options. On the one hand a suitable and partially distinguishable layer thickness and alternative materials can lead to the reduction of the proportion of nonrecycable materials. The implementation of this option leads to a recycling rate of s1min for the underbody protection. However, the basic problem of the nondetachable connection between the underbody and the underbody protection remains. Thus, on the other hand the protective layer applied to the underbody can be substituted by underbody cladding made of glass-fiber reinforced polypropylene. Furthermore, the cladding is fixed to the underbody by means of screws and thus in a detachable way. The implementation of this option leads to a recycling rate of s1max for the underbody protection. In addition to these two options combinations of these two options are possible. As a result the following interval on the recycling rate s1 results for supplier S1 : s1  [ s1min , s1max ] . [18] Currently, the instrument panel of supplier S 2 consists of plastic materials, which lead to a recycling rate of s 2min . To improve the recyclability and thus the recycling rate of the instrument panel, those materials can be provided which can be used again as ground material in the production of equivalent parts or can be supplied to a production residue recycling system. In case of the instrument panel for example materials like thermo-plastic SMA-GF 10 recyclate meet these demands. The implementation of these materials leads to a recycling rate of s 2max for the instrument panel. Depending on the extent to which these materials can be used for the instrument panel, the recycling rate s 2 resulting for supplier S 2 lies in the following interval: s 2  [ s 2min , s 2max ] . [18] The achievable recycling rates s i as well as the interval limits depend on the design efforts wi of the supplier. Although the technologies to improve the recycling rates of the two components are known by the suppliers, uncertainties exist with regard to the recycling rates s i achievable with a specific design effort wi . We assume, that the probability f ( si ) of achieving a certain recycling rate si is uniformly distributed in the interval [ s imin , simax ] , with the interval limits depending on the effort wi : s imin ( wi ) and s imax ( wi ) . Since the design effort wi determines the development costs c iex ( wi ) of the suppliers, it is assumed that the development costs of supplier S1 and supplier S 2 can be approximated by linear functions: c1ex ( w1 )  0.013  w1 and c 2ex ( w2 )  0.016  w2 .

77 The combined recycling rate of 60 % of the two components, the OEM aims at, can be achieved by a variety of combinations of the recycling rates of the two components. Under the assumption that the masses mi of the underbody protection and the instrument panel are 10 kg and 50 kg respectively these combinations can be described by the following functional relationship:

0 .6 

m1  s1  m 2  s 2

 0 .6 

m1  m 2

10  s1  50  s 2  s 2  0.72  0.2  s1 (9) 10  50

Thus, the expected utility function n ex ( w1 , w2 ) of the OEM in this illustrative example results as follows: n ex ( w1 , w2 ) 

s 2max

4.2

s1max s 2max

1

s1min s2min  1  exp( d  (0.72  0.2  s 

1 1   s 2min s1max  s1min

1

))  exp(  d  s 2 )



   d ( s 2 ) d ( s1 )  

(10)

Analysis of the illustrative example

In this section the centralized setting is analyzed first to determine a benchmark. Afterwards the coordination ability of a fixed-price and an incentive contract is analyzed in the decentralized setting. Centralized setting In the centralized setting ( c ) the OEM develops the underbody protection as well as the instrument panel and integrates both components into the new vehicle. His aim is to meet a recycling rate of 60 %, which maximizes his utility, with minimal effort and thus with minimal costs. His profit function results as follows:



ex

( w1 , w2 )  n ex ( w1 , w2 )  c1ex ( w1 )  c 2ex ( w2 )

(11)

The following optimal efforts w1ex,c  6.45 , w2ex,c  5.53 and thus the following expected recycling rates s1ex,c  83 % , s 2ex,c  79 % of the suppliers components are resulting. They provide as a benchmark for the analysis in the decentralized setting. Decentralized setting with fixed-price contract ( fp ) In this decentralized setting the OEM determines the transfer payment function for the fixed-price contracts concluded with the suppliers. Since the OEM has full information, he chooses the required recycling rates sˆiex for the components developed by the suppliers as well as the maximal transfer payment in accordance to the optimal expected specification in the centralized setting. For the sake of simplicity it is assumed, that the suppliers accept the contract in any case. ˆ

The expected transfer payment functions t is,i fp,ex result as follows: ˆ

t1s,1fp,ex ( w1 ) 

max

s max

ˆ

1

1

s1 s1min 1  exp( k  0.83)  exp(  k  s )  s max  s min d ( s1 ) 1 1 1

2 t 2s2, fp,ex ( w2 )  s min 2

1 1  d (s2 ) 1  exp( k  0.79 )  exp(  k  s 2 ) s 2max  s 2min

(12)

(13)

To analyze the decision situation of the suppliers the profit function ˆ  is,i fp,ex of the suppliers is considered as follows: ˆ

ˆ

 is,i fp,ex ( wi )  t is,i fp,ex ( wi )  ciex ( wi )

(14) ˆ

ˆ

The following optimal efforts w1s,1fp,ex  13.94 , w2s,2fp,ex  9.53 and thus ˆ ˆ the following expected recycling rates s1s,1fp, ex  100 % , s 2s,2fp,ex  100 % of the suppliers components are resulting. Compared to the results of the centralized setting fixed-price contracts lead to an increase in effort of about 116.12 % and 72.33 %, respectively. The suppliers choose such a high effort to maximize the probability to achieve the

78

Automotive Life Cycle Engineering - Recycling

required recycling rate sˆiex and thus to get the agreed transfer payment, taking into account the development costs. Consequently, increased development costs and overdesigned components are resulting. Decentralized setting with incentive contract ( in ) In this decentralized setting the OEM determines the transfer payment function hiex ( s i ) as well as the interval limits for the inventive contracts concluded with the suppliers in dependence to the structure of their development costs: h1ex ( s1 )  0.188  s1

for s1  [57 %, 100 %]

(15)

h 2ex ( s 2 )  0.272  s 2

for s 2  [60 %, 98 %]

(16)

The expected transfer payment functions t ih,iin,ex result as follows: s max

1 t1h,1in,ex ( w1 )  s min h1ex ( s1 )  1

s max

1 d ( s1 ) s1max  s1min

2 t 2h,2in,ex ( w2 )  s min h2ex ( s2 )  2

1 d ( s2 ) s2max  s2min

(17)

(18)

To analyze the decision situation of the suppliers the profit function  ih,iin,ex of the suppliers is considered as follows:

 ih,iin,ex ( wi )  t ih,iin,ex ( wi )  ciex ( wi )

(19)

The following optimal efforts w1h,in1 , ex  7.2 , w2h,2in,ex  6.31 and the following expected recycling rates s1h,1in,ex  89 % , s 2h,2in, ex  86 % of the suppliers components are resulting. Compared to the results of the centralized setting incentive contracts lead to an increase in effort of

6

REFERENCES

about 11.63 % and 14.11 %, respectively. Compared to the results of the decentralized setting incentive contracts lead to a decrease in effort. Reasons for the reduced overdesign of the suppliers can be found in their higher flexibility and their missing risk to get no transfer payment. Consequently, incentive contracts contribute towards a reduced overdesign of the components and thus contribute to the coordination of decentralized design processes. 5

CONCLUSION AND OUTLOOK

In this paper we presented a mathematical model for the analysis of decentralized design processes in the automotive industry and applied it to the case of the efficient compliance with recycling rates. We analyzed a centralized setting and compared the results to a decentralized setting with a fixed-price contract. The analysis showed that fixed-price contracts lead to inefficiencies. We then introduced the conceptual design of incentive contracts to make decentralized design processes in the automotive industry more flexible. Inefficiencies could be decreased by dividing the development risk between the OEM and his suppliers. Finally, we demonstrated the use of this concept based upon an illustrative example to show its applicability. Although the scope of the analysis lies on rather general characteristics, it captures the key elements of design processes in the automotive industry in both structural as well as logical respects. Our future research will concentrate on the mathematical analysis and evaluation of further contract types. This lays the basis for empirical testing using case study methodology. The vision is to support automotive companies in the design of efficient development contracts.

[1]

Andersen, F.M.; Larsen, H.V.; Skovgaard, M. (2008): Projection of end-of-life vehicles: Development of a projection model and estimates of ELVs for 2005-2030, in: ETC/RWM working paper 2008/2.

[10] Kruse, J.; Thomsen, C.; Ernst, R.; Volling, T.; Spengler T.S. (2005): Introducing flexible quantity contracts into distributed SoC and embedded system design processes, in: Proceedings of the conference on Design, Automation and Test in Europe, pp. 938-943.

[2]

Fergusson, M. (2007): End of Life Vehicles (ELV) Directive: An assessment of the current state of implementation by Member States, Study requested by the European Parliament's Committee on the Environment, Public Health and Food Safety (IP/A/ENVI/FWC/2006-172/Lot 1/C1/SC2).

[11] Kruse, J.; Thomsen, C.; Ernst, R.; Volling, T.; Spengler T.S. (2005): Towards flexible systems engineering by using flexible quantity contracts, in: Proceedings of the conference on Automation, Assistance and Embedded Real Time Platforms for Transportation, pp. 480-488.

[3]

Directive 2000/53/EC of the European Parliament and of the Council of 18 September 2000 on end-of life vehicles.

[4]

Directive 2005/64/EC of the European Parliament and of the Council of 26 October 2005 on the type-approval of motor vehicles with regard to their reusability, recyclability and recoverability.

[12] Rox, J.; Schmidt, K.; Winter, A.; Spengler, T.S.; Ernst, R. (2010): Estimating and mitigating design risk in a flexible distributed design process, in: IEEE Embedded Systems Letters, Vol. 2, No. 2, pp. 35-38.

[5]

Roland Berger & Partner (2000).

[6]

Bolton, P.; Dewatripont, M. (2005): Contract theory, The MIT Press, Cambridge.

[7]

Tsay, A.A.; Nahmias, S.; Agrawal, N. (1999): Modeling supply chain contracts: A review, in: Quantitative models for supply chain management, Kluwer Academic Publishers, Norwell, pp. 299-336.

[8]

[9]

Anupindi, R.; Bassok, Y. (1999): Supply contracts with quantity commitments and stochastic demand, in: Quantitative models for supply chain management, Kluwer Academic Publishers, Norwell, pp. 197-232. Tsay, A.A. (1999): The quantity flexibility contract and supplier-customer incentives, in: Management Science, Vol. 45, No. 10, pp. 1339-1358.

[13] Böhme, M. (2004): Ein methodischer Ansatz zur parametrischen Produktmodellierung in der Fahrzeugentwicklung, VDI Verlag, Düsseldorf. [14] Frad, A. (2009): Umwelt- und Recyclingbewertung als Bestandteil des Automotive Product Lifecycle Management, Vulkan-Verlag GmbH, Essen Ruhr. [15] Hab, G.; Wagner, R. (2006): Projektmanagement in der Automobilindustrie, GWV Fachverlage GmbH, Wiesbaden. [16] DIN ISO 22628 (2002): Straßenfahrzeuge - Recyclingfähigkeit und Verwertbarkeit - Berechnungsmethode, Beuth Verlag GmbH, Berlin. [17] Umweltbundesamt (2010): Altfahrzeugaufkommen und -verwertung. [18] VDI Richtlinie 2243 (2002): Recyclingorientierte Produktentwicklung, Verein Deutscher Ingenieure, Beuth Verlag GmbH, Düsseldorf.

A Strategic Framework for the Design of Recycling Networks for Lithium-Ion Batteries from Electric Vehicles 1

1

1

Claas Hoyer , Karsten Kieckhäfer , Thomas S. Spengler 1

Institute of Automotive Management and Industrial Production, Technische Universität Braunschweig, Braunschweig, Germany

Abstract In this paper, we develop a strategic framework for the design of recycling networks for spent lithium-ion batteries from electric vehicles. The framework provides an overview of possible configuration alternatives and an integrated approach for network planning and process configuration tasks. It describes requirements on a network as well as on a process level. For that purpose, we analyse general framework conditions concerning battery return, materials, and recycling processes. On that basis, it is possible to develop a mathematical optimisation model which enables decision support concerning the optimal evolvement of recycling sites, capacities, and processes over time. Keywords: Strategic Network Planning; Recycling; Spent Lithium-Ion Batteries

1

INTRODUCTION

Efficient and reliable lithium-ion batteries are a key technology for electric mobility due to their high specific power, energy density, and lifetime [1]. For the production of lithium-ion batteries, nonferrous metals like copper, cobalt, nickel, and lithium are required, which leads to two main problems. On the one hand, the extraction or production of these metals is partly associated with high environmental impacts. On the other hand, the mining deposits are geographically concentrated and partially scarce. In 2008, seven countries accounted for 85 % of the world’s production of mined cobalt, nearly the same holds for lithium [2]. Particularly for the EU this may lead to a shift of dependency from oil-producing countries to countries that are producing cobalt, lithium, or their alloys. Recycling of the batteries has two main benefits. First, recycling may extend the reserves-to-production ratio of scarce resources, reduce energy-intensive primary production and therefore defer the opening or extension of mines. Natural resource savings of more than 50 % are possible [3]. Second, from a national point of view, recycling may have a stabilising, damping or even reducing effect on prices of and dependency on primary raw materials by providing a secondary feedstock. Beyond that, landfill and incineration of traction batteries are forbidden, and all batteries must be orderly recycled. For Germany, a recycling efficiency of 50 % by weight has to be achieved as from September 2011 [4; 5]. Up to now, neither recycling processes nor the necessary infrastructure exist that would allow for an industrial recycling of these batteries. Thus, a powerful recycling network must be established. Decisions about the evolvement of recycling sites, capacities, processes, and transportation links over time must be made. This is complicated due to heavy uncertainties about the development of the electric vehicle market and battery technology, as well as immature recycling processes. Against this background, the objective of this paper is to deliver a framework for the design of a recycling network for spent lithium-ion batteries from electric vehicles. To build up the framework, in a first step we analyse specific problem characteristics. Based on this

analysis, we develop a framework including the description of actors and requirements that need to be considered to design recycling networks for spent lithium-ion batteries. A planning approach will be presented. Different network constellations in dependence of identified decoupling points and two extreme market scenarios are examined. The results are discussed in a last step. 2 2.1

TERMINOLOGY AND BATTERY CONSTRUCTION Electric Vehicles

In this contribution, the term electric vehicles includes any electric vehicle with a lithium-ion battery used for traction. Electric vehicles may be classified into hybrid-electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV) and battery electric vehicles (BEV). The most important differences between the vehicle types are specifications like mass and materials, costs, and the lifetime of the required battery. 2.2

Lithium-ion batteries

Lithium-ion batteries are rechargeable batteries with promising properties for electric mobility, which is mainly due to their high power density and specific energy [1]. In this paper, the term lithium-ion battery embraces all rechargeable secondary batteries based on the exchange of lithium ions to produce electrical energy. A lithium-ion battery used for traction is constructed on three fabrication levels: cell, module, and system level. Multiple cells are connected in series to raise voltage, resulting in modules. Modules are connected in series and in parallel to raise voltage and capacity. The resulting battery system additionally includes thermal management, monitoring, protection, charge/discharge balancing, and car integration components [1]. Lithium-ion battery cells consist of a cathode, an anode, a separator, an electrolyte, and a casing. Cathode and anode conductors are usually made of aluminium and copper foil, respectively. The cathode is coated with either a mix of lithium and other metals (LiMeO2) or lithium-iron-phosphate (LiFePO4). Metals (Me) used in the former are cobalt, nickel, manganese, and

J. Hesselbach and C. Herrmann (eds.), Glocalized Solutions for Sustainability in Manufacturing: Proceedings of the 18th CIRP International Conference on Life Cycle Engineering, Technische Universität Braunschweig, Braunschweig, Germany, May 2nd - 4th, 2011, DOI 10.1007/978-3-642-19692-8_14, © Springer-Verlag Berlin Heidelberg 2011

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aluminium. The anode is usually coated with graphitic or amorphous carbon, or lithium-alloying metals [6]. Anode and cathode material can be combined almost freely. All of them have both specific advantages and disadvantages related to power, lifetime, safety, and costs of the cells. Lithium-ion cells can further be classified by their type of electrolyte: liquid-type, gel-type and solid-type cells. The latter two are often referred to as lithiumpolymer batteries. The type of electrolyte used determines the type of separator and vice versa.

essentially influence decisions about total capacity, sites, and required equipment of the recycling network. Sink-related uncertainties can be classified into the three categories product reuse, component reuse, and material reuse opportunities. To design the network infrastructure connecting sources and sinks, the transforming processes and the resulting material flows have to be considered. Process-related uncertainties exist with respect to the optimal combination and configuration of processes.

Since hybrid electric vehicles and battery electric vehicles substantially differ in their requirements regarding power and energy, lithium-ion cells can be divided into high-power cells for HEVs and high-energy cells for BEVs. Table 1 summarises typical materials and mass portions for lithium-ion batteries. For highenergy batteries, the active materials of the anode and cathode make out the largest portion of the battery mass, followed by the electrolyte. The same holds for the costs of the materials [1]. Part

Material(s) [1; 6; 7]

Mass portions [1] HighEnergy

HighPower

Cell level Cathode conductor

Aluminium foil

Cathode active material

Lithium and cobalt, nickel, manganese, or aluminium, or a mix of them, or Lithium-IronPhosphate; Carbon black; Binder (PVDF)

Anode conductor

Copper foil

2%

5%

41 %

19 %

4%

10 %

Anode active Graphitic carbon, amorphous material carbon, or lithium-titanate; Binder (PVDF)

17 %

4%

Electrolyte

Lithium salts (e. g. LiPF6) dissolved in organic solvents

16 %

11 %

Separator

Polyolefins or Polyvynilidenfluorid

2%

4%

9%

28 %

9%

19 %

Cell package Aluminium, stainless and others and/or plastics

steel,

Module and system level Electric conductors

Copper cables

Electronics

Printed circuit assemblies including semiconductors

Module packaging

Polypropylene

System packaging

Aluminium, stainless and/or plastics

Total

3.1

Uniqueness of the Planning Situation

Different recycling networks exist which could serve as a basis for a recycling network for lithium-ion batteries, including legally independent networks for vehicles, lead-acid starter batteries, portable batteries, and electronic waste. However, these networks are not fully qualified for an efficient and environmental recycling of lithium-ion batteries. On the one hand, a high amount of spent batteries would overstrain the capacities of the mostly smallest businesses. Lithium-ion batteries are more complex, heavier, and more hazardous, hence, more difficult to treat than the mentioned products. The dangerous-good property of the batteries complicates the usage of existing transport links. On the other hand, novel and unexplored processes with high economies of scale are required which contravenes the mostly decentralised organisational form of the networks. New actors like battery material producers come into play. These circumstances would demand a restructuring of existing networks anyway. Moreover, a particular challenge to the planning of the recycling network is the directive 2006/66/EC of the European Union. It forces battery and electric vehicle producers to conceive and establish an effective collection and recycling solution before market penetration. Because neither the electric vehicle market nor the battery technology are evolved to a steady state, this planning and investment situation is heavily uncertain. 3.2

steel,

Source-related uncertainties

Quantity of battery returns 100 %

100 %

Table 1: Typical materials for lithium-ion batteries. 3

Figure 1: Generic network structure for lithium-ion battery recycling.

GENERAL CONDITIONS

Figure 1 shows the generic structure of a recycling network connecting material flows between sources and sinks with different transforming processes. Sources, sinks, and processes of the recycling network are fraught with uncertainties. Source-related uncertainties can be classified into quantity, spatial distribution, and specifications of the battery returns. These parameters

Lithium-ion batteries from electric vehicles become available for recycling at the end of life of the electric vehicle or the end of life of the battery itself. Given that, the quantity of spent battery returns is particularly driven by the development of the electric vehicle market over time and the battery lifetime. The forecast of the electric vehicle market is currently subject to many market studies. These most often use scenario technique to determine sales and stocks for specific points in time on an aggregate level [8]. For Germany, the government aims at a market penetration of 1,000,000 PHEVs and BEVs in 2020 [9]. The forecasts are significantly depending on assumptions about oil

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prices, energy supply, public interest in climate change, and more stringent greenhouse gas legislation [8].

3.4

The battery lifetime is expected to be highly dependent on the used active materials and the type of vehicle the battery is used in [10]. It is estimated to be around five years for BEVs, ten years for PHEVs, and up to fifteen years for HEVs [10; 11]. However, these numbers are based on extrapolation, not experience, and it remains unclear how the lifetime will be distributed.

Basically, recycling processes for lithium-ion batteries can be classified into disassembly, mechanical conditioning, hydrometallurgical conditioning, and pyrometallurgical conditioning. In disassembly, battery systems are broken down subsequently to module and cell level which is the prerequisite for a remanufacturing of batteries. Reusable components and large material fractions, for example the battery casing and electronics, are separated before further conditioning processes are applied to the cell materials. In mechanical conditioning, materials of the cells are separated by different comminution, sizing, and concentration processes. Examples are crushing, screening, and magnetic separation. Pyrometallurgical conditioning involves the thermal treatment of the materials at high temperatures. It can be combined with the production of steel, and of ferromanganese or other alloys. Hydrometallurgical conditioning typically combines leaching, solution concentration and purification, and metal recovery methods, including electrometallurgy. With hydrometallurgical processes, pure non-ferrous metals can be recovered from active materials after mechanical conditioning or from the slag of pyrometallurgical processes.

The spatial distribution of battery returns determines transport distances and therefore costs. Decisions about sites for the collection of spent batteries and for the recycling facilities are influenced by that, given that cost minimisation or profit maximisation is preferred and all batteries must be collected. It is not clear yet whether electric vehicles with low cruising ranges will be sold rather in urbanised than in rural areas. Based on that, not only the amount but also the spatial distribution of battery returns can be considered as highly uncertain. Composition of battery return Mass, size, construction, and materials of lithium-ion batteries vary dependent on their application. To give an example, a battery for a mid-sized all electric vehicles with a range of about 200 kilometres would weigh about 300 kilograms [12]. A battery for a plug-in hybrid vehicle with an electric range of 50 kilometres would weigh just about 100 kilograms [13]. This diversity and the highly uncertain technology development demands either highly flexible equipment or manual work, which tends to result in high investments or costs, respectively. 3.3

Sink-related uncertainties

Product reuse opportunities Spent batteries from electric cars which may not be suitable for powering vehicles anymore are expected to be qualified for further stationary use, e. g. storage of energy from fluctuant power generation like wind or solar power [1]. Direct product reuse then would decelerate the return of spent batteries. However, it is not expected to happen in a large scale while the batteries are not further standardised so that they can be easily stocked, connected, and monitored outside of vehicles. Component reuse opportunities

Process combinations As listed in chapter 2.2, lithium-ion batteries can consist of a variety of different materials. Single materials can be recovered selectively with certain processes. Therefore, a combination of different processes is necessary to recover all relevant materials [14]. Figure 2 depicts a comprehensive overview of different process combination possibilities and the recovered materials. It includes potential decoupling points that by way of example occur if a disassembly or mechanical conditioning is intended or necessary. The prerequisite for spatial decoupling is the transportability of the intermediate products, which appears to apply mainly for cells as well as for the coating powder, and, to a less extent, for the intermediate products from pyro- and hydrometallurgical processes. Batteries Disassembly

Mechanical Conditioning

Pyrometallurgy

Hydrometallurgy

Disassembly

Mechanical Conditioning

Hydrometallurgy

Hydrometallurgy

Pyrometallurgy

Hydrometallurgy

Pyrometallurgy

Hydrometallurgy

Disassembly

Material reuse opportunities The high cobalt-price of approximately 40 USD per kilogramme was the driver for the recycling of smaller lithium-ion batteries, but also one important reason to replace parts of the cobalt with other metals [1] or entirely move away from cobalt-containing cathode active materials. By that, the economical incentive of recycling may diminish. Especially lithium-iron-phosphate does not contain any cobalt or nickel (which is priced at about 20 USD per kilogramme). Lithium, in the form of lithium carbonate, is much cheaper at about 6 USD per kilogramme and the mass fraction of it on cell level is just about 3 %. From today’s point of view, the costs of conditioning may excess the revenues. However, lithium prices are expected to rise as the demand is growing dramatically.

Recycling processes

← Decoupling Point

Standardisation is also important to enable component reuse. With standardised battery constructions, electronic interfaces, and cell types, spent batteries could be remanufactured easily by replacing worn components with new ones, resulting in as-good-as-new batteries. Additionally, cells with a similar state from different spent batteries could be assembled to lower-quality batteries, and electronic components could be used as spare parts.

Recycling processes

Casing, Electronics

Recovered materials

Spatial distribution of battery returns

Process-related uncertainties

Copper, Aluminium

Pyrometallurgy

Cobalt, Nickel

Lithium

Figure 2: Combination possibilities of conditioning processes and recovered materials, based on [15]. Exemplary process combinations A promising process to recover all valuable materials is currently subject of investigation at LithoRec. The analysed process begins with demounting the spent battery from the car. After transportation to a disassembly line, the battery will be disassembled to cell level. Cells will be dismantled and the volatile liquids (electrolyte with conductive salts) are absorbed for further conditioning. The coated electrodes will be separated with mechanical processes, resulting in aluminium and copper fractions and coating powder. The coating

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powder, which contains the active material, will be treated in chemical conditioning processes to recover lithium, nickel, cobalt, and manganese, or lithium-iron-phosphate, which will then be available for production again. See Figure 3 for an illustration. The LithoRec process promises to be suitable for large-scale recycling, since a large amount of materials is recovered, including battery components, all metals, and the valuable electrolyte. However, the process is still under investigation.

treatment of the cells could then be realised centrally, exploiting high economies of scale. In summary, the processes chosen and the battery types processed determine the remanufacturing option, recoverable materials and their degree of purity as well as the spatial decoupling potential. While some combinations of processes would be able to recover new active material like LiCoO2, some would result in pure cobalt and lithium-carbonate, among copper and aluminium. Thus, different sinks must be considered in each case. By this means, the decision about processes considerably influences the network structure and must be integrated into strategic network planning. 4 4.1

FRAMEWORK Scope and corporative actors

The framework for the design of a network for the recycling of spent lithium-ion batteries involves different kinds of actors of the economy, namely the battery material producers, battery producers, vehicle producers, vehicle dealers, and vehicle treatment operators. The battery material producer is predestined to recover the materials, since this would be near to his core competence. By this means he can influence the characterisation of the raw materials directly and, concurrently, prevent potential competitors.

Figure 3: Combined mechanical and hydrometallurgical processes. [3] describe a combined pyrometallurgical and hydrometallurgical recycling process for lithium-ion batteries, amongst others, which is already applied at Umicore in Sweden and Belgium. Here, a mix of different consumer lithium-ion batteries is treated in a pyrometallurgical smelting process located in Sweden, ending in a slag containing aluminium, silicium, calcium, and lithium, and an alloy of cobalt, nickel, copper, and iron. The alloy is then transported to Belgium and treated with hydrometallurgical processes to separate the materials, while the materials in the slag may be consumed in lower value production processes. Although this process is already applied, it appears to be less suitable for recycling vehicle batteries in large scale, because valuable materials like aluminium and lithium are lost in the slag. However, in combination with subsequent hydrometallurgical processes, the recovering of these materials should be possible. 3.5

Network design and process configuration

As shown, the quantity and material specifications of the batteries which are to be used as educts fundamentally influence the eligible processes and their products (recovered materials, components, etc.). The configuration of processes, in turn, determines the spatial decoupling potential. In centralised concepts, all batteries would be treated in a single facility to realise economies of scale, resulting in low average costs due to high capacity utilisation. In contrast, a decentralised concept with many small facilities would enable short transportation links and thus low transportation costs. Processes with spatial decoupling points can provide both advantages. Decentralised pre-treatment with low economies of scale, e. g. manual disassembly, would allow for a concentration of the material flow to reduce transportation costs while reducing transport mass and volume by the separation of casings. The subsequent

Although the production of batteries may not be the core competence of vehicle producers today, it will most probably be in the future. Both, battery producers and vehicle producers, can be in charge for the correct treatment of the batteries by law, and both rely on the continuous supply with raw battery materials. So, a clear distinction is not necessary. From the producer’s point of view, the recycling must be carried out in a cost-minimising or profitmaximising manner. At the same time, he is bound to collect and recycle every battery that is given to him by the end-users. Thus, he cannot minimise costs by cherry-picking, but he can share his fixed costs and use economies of scale by the joint operation of a crossproducer network. All mentioned actors of the production chain are reliant on a continuous supply of raw materials. As mentioned in chapter 1, this may become a problem in the light of scarce and geographically concentrated resources. Given that, all producers will be interested in the supply from a secondary feedstock, even though the recovered materials may be costlier or a little less capable than primary materials. The vehicle dealer is involved since he will be the first address for users of electric vehicles if their battery is spent. His task will be the replacement of the spent battery with a new one. Thus, he is interested in an easy and free-of-charge solution for the redistribution of the received spent battery, without wanting to relevantly participate in the network. Nevertheless, his participation will be needed to gather information about the battery conditions. Exactly the same holds for the treatment operator who is engaged with the treatment of end-of-life vehicles. He, however, will try to charge the vehicle manufacturer with additional fees for the demounting of the battery, or alternatively sell it to others. These deliberations show that all actors should be interested in an optimised collection and recycling of spent batteries because the requirements of the actors mostly converge. This can only be achieved by planning and operating the network collaboratively. For the actors, economic interests are prior. Beyond that, they have to respect legal conditions and customer requirements. Therefore, environmental aspects have to be considered as well. For this reason, this framework addresses the design of a sustainable cooperative recycling network with focus on the producers who are legally responsible for its provision.

Automotive Life Cycle Engineering - Recycling 4.2

Requirements

As shown in chapter 3, a recycling network for lithium-ion batteries is subject to many uncertain factors that change over time. This requires a long-term planning horizon, in which uncertainties must be represented adequately. Decisions with respect to the design of the network include the selection of facility locations, processes, capacities, and the point in time of their implementation. Due to the described interdependencies between optimal network structure and recycling processes, these decisions must be done simultaneously. Possible synergy effects by the inclusion of existing sites and processes of recycling networks for vehicles, starter batteries, portable batteries, and electronic waste as well as their actors have to be examined. Sites of treatment operators and vehicle dealers are sources of the networks and could be used for regional collection and even for the disassembly of spent batteries. The processes for the recycling of the batteries, including mechanical, chemical, and thermal treatment, differ in many aspects. They must be represented in an adequately aggregated manner. Their eligibility must be assessed with respect to their differences in: 

material flows, including educts, raw materials and supplies, products, and their quality;



energy consumption;



environmental impacts in terms of pollutant emissions;

83 their prices, sources, production and mining methods, reuse potentials, and their scarcity will be analysed. Next, known and promising conditioning processes for these materials and the possible combinations will be screened. A preselection is necessary to narrow down the choice. This will be done by a comparison of the processes with respect to multiple criteria, namely monetary, ecological, social, flexibility, and safety criteria. For that purpose, aggregated material and energy flow sheet models of the processes will be used. For the equipment of the preselected processes, investment needs and costs depending on different capacities will be estimated in a pre-calculation, unless they are known. Potential decoupling points of the processes will be identified to determine the possibility of a decentralised recycling network. Transportation costs regarding the batteries and the different intermediate products will be estimated. Sources and sinks of the network will be identified. Subsequently, location factors for the collection and recycling sites will be established. Appropriate sites for recycling facilities will be classified regarding the different requirements of the various recycling processes. Again, a pre-selection of sites will be necessary. The inclusion of site-specific investments and costs will be investigated to couple interdependencies between expenses for sites, buildings, and equipment. To give decision support, a multi-staged dynamic facility location problem with the specific requirements of reverse logistics problems will be developed and then used in a mathematical optimisation. Input data are:



investments and costs, influenced by economies of scale;



subsequent expandability;



degree of flexibility regarding the processable materials and volumes;



long-term battery return estimations;



costs for transportation and storage of the batteries;



potential spatial decoupling of single process steps;



locations of existing sources and sinks;



hazard potential, particularly for the employees.



distances between these locations and potential collection and recycling sites;



costs and investment needs for facilities and processes;



ecological factors, e. g. CO2-emissions.

To represent centralised and decentralised installation concepts, a multi-stage recycling network must be considered. Processdependent material flows between sources and sinks have to be included. The structure of the network should be flexible to enable subsequent changes with respect to the combination of processes, their spatial decoupling, and capacity expansions. Furthermore, an option to store batteries to delay expenses, balance capacity utilisation, and use economies of scale has to be assessed. 4.3

Approach

The objective of our approach is to give decision support to investors regarding the provision of an optimised sustainable recycling network for lithium-ion batteries, including the selection of facility locations, processes, capacities, and the point in time of their implementation. Thus, this planning task can be classified into strategic network planning within the APS matrix. Strategic network planning approaches have been discussed in the literature for related recycling networks with similar characteristics, for instance, vehicle recycling [16], portable battery recycling [17], electrical equipment recycling [18], and large household appliances recycling [19]. Further similarities can be found in the strategic planning of a biofuel production network presented in [20]. These approaches mainly include location, transport, and capacity decisions; the latter is explicitly regarding uncertainties and process decisions. They provide the basis for the following approach, whereas some of the requirements listed in chapter 4.2 are not satisfied. E. g. none of the approaches considers a multiple objective optimisation. In the first step of our approach the materials which have to be recovered from the batteries due to economical, ecological, or strategic reasons will be identified. For that, the development of

The optimisation will be done with respect to different objective functions. Prevailing uncertainties will be considered by the application of scenario technique, robust optimisation, and sensitivity analysis. The findings will end in an extensive robust investment plan for the design of a sustainable recycling network for spent lithium-ion batteries. 4.4

Exemplary Network Alternatives

Scenario A: Centralised Network In scenario A, a centralised network with a combined pyrometallurgical and hydrometallurgical recycling process is established. Based on an unimportant electric vehicle market, the battery technology is not further developed or standardised. Because of the low amount of lithium-ion vehicle batteries produced, a shortage of resources does not occur, and cobaltbased active materials are prevalent. Only few batteries are available for recycling; consequently, a dedicated recycling network is not economical. In the network, batteries are collected from few specialised garages and brought to a centralised recycling facility that recovers materials from any kind of batteries containing cobalt or nickel to realise high capacity utilisation. Lithium, aluminium, and manganese are not recovered. The more valuable materials cobalt, nickel, and copper are recovered in high purities in a subsequent hydrometallurgical process at the same location and are sold to any kind of markets. Scenario B: Decentralised Network In scenario B, a decentralised network with a combined disassembly, mechanical and hydrometallurgical recycling process

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is established. A prospering electric vehicle market leads to strong technology advances regarding the lithium-ion batteries. These are produced at large scale, which leads to temporary shortages of raw materials. While miscellaneous compositions are used for the production of the cells, lithium-iron-phosphate emerges as the prevailing active material. The spent batteries are collected from dealers all over the country and are brought to decentralised disassembly facilities. Here, they are first used for energy storage until depletion. Afterwards, the batteries are disassembled to cell level. All materials except for the cells are brought to regional recycling facilities. The cells are transported to a centralised recycling facility where they are subject to mechanical and hydrometallurgical recycling. New active material is produced from the recovered lithium, nickel, manganese, and cobalt, and is sold to battery producers, as well as the recovered lithium salts and the electrolyte. 5

CONCLUSION AND OUTLOOK

In this paper, we presented a strategic framework for the design of recycling networks for lithium-ion batteries from electric vehicles. We analysed prevalent uncertainties related to potential sources, sinks, and processes for the recycling. The analysis showed that in particular the quantity of the return of batteries can be considered as uncertain, due to the early development stage of the electric vehicle market and missing experience regarding the lifetime of batteries. This complicates decisions about capacities in the network. Additionally, the uncertainties in the battery material composition and the price development for recoverable materials complicate process decisions. It is not clear which processes will emerge as eligible options for the sustainable recycling of batteries. We highlighted that the decision about processes considerably influences the network structure and must be integrated into the planning of the network. Based on that, we derived a framework, including an analysis of potential actors and requirements that must be considered designing a recycling network for lithium-ion batteries, and an integrated planning approach. Our future research will concentrate on the analysis of eligible processes and the implementation of the approach in a mathematical multi-objective optimisation model. 6

ACKNOWLEDGEMENT

The presented research work is part of the project “LithoRec – Recycling von Lithium-Ionen-Batterien”. LithoRec aims at developing and assessing sustainable processes and full life-cycle concepts for the recycling of spent lithium-ion batteries in Germany. We would like to acknowledge the support of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety for funding the research cooperation under the reference 16EM0023. 7

REFERENCES

[1]

Gaines, L., Cuenca, R. (2000): Costs of Lithium-Ion Batteries for Vehicles. Operated by The University of Chicago, under Contract W-31-109-Eng-38, for the United States Department of Energy, Argonne, Illinois. http://www.doe.gov/bridge.

[2]

U.S. Geological Survey (20