Energy Development

First Edition, 2011

ISBN 978-93-81157-47-3

© All rights reserved.

Published by: The English Press 4735/22 Prakashdeep Bldg, Ansari Road, Darya Ganj, Delhi - 110002 Email: [email protected] 

Table of Contents Chapter 1- Introduction to Energy development Chapter 2 - Renewable Energy Commercialization Chapter 3 - Wind Power Chapter 4 - Nuclear Power Chapter 5 - Tidal Power

Chapter- 1

Introduction to Energy development

Schematic of the global sources of energy in 2006.

Energy production from 1989 to 1999 Energy development is the effort to provide sufficient primary energy sources and secondary energy forms for supply, cost, impact on air pollution and water pollution, mitigation of climate change with renewable energy. Technologically advanced societies have become increasingly dependent on external energy sources for transportation, the production of many manufactured goods, and the

delivery of energy services. This energy allows people who can afford the cost to live under otherwise unfavorable climatic conditions through the use of heating, ventilation, and/or air conditioning. Level of use of external energy sources differs across societies, as do the climate, convenience, levels of traffic congestion, pollution and availability of domestic energy sources.

Renewable sources

The wind, Sun, and biomass are three renewable energy sources Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished.) Renewable energy is an alternative to fossil fuels and nuclear power, and was commonly called alternative energy in the 1970s and 1980s. In 2008, about 19% of global final energy consumption came from renewables, with 13% coming from traditional biomass, which is mainly used for heating, and 3.2% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.7% and are growing very rapidly. The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewables. Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization. New government spending, regulation and policies helped the industry weather the global financial crisis better than many other sectors. Scientists have

advanced a plan to power 100% of the world's energy with wind, hydroelectric, and solar power by the year 2030, recommending renewable energy subsidies and a price on carbon reflecting its cost for flood and related expenses. While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas, where energy is often crucial in human development. Globally, an estimated 3 million households get power from small solar PV systems. Micro-hydro systems configured into village-scale or county-scale mini-grids serve many areas. More than 30 million rural households get lighting and cooking from biogas made in household-scale digesters. Biomass cookstoves are used by 160 million households. Wind

Wind power: worldwide installed capacity 1996-2008 Wind power harnesses the power of the wind to propel the blades of wind turbines. These turbines cause the rotation of magnets, which creates electricity. Wind towers are usually built together on wind farms. Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 158 gigawatts (GW) in 2009, and is widely used in Europe, Asia, and the United States. At the end of 2009, worldwide wind farm capacity was 157,900 MW, representing an increase of 31 percent during the year, and wind power supplied some 1.3% of global electricity consumption. Wind power accounts for approximately 19% of electricity use in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland. The United States is an important growth area and installed U.S. wind power capacity reached 25,170 MW at the end of 2008. As of November 2010, the Roscoe Wind Farm (781 MW) is the world's largest wind farm.

Hydroelectric

The Gordon Dam in Tasmania is a large conventional dammed-hydro facility, with an installed capacity of up to 430 MW. In hydro energy, the gravitational descent of a river is compressed from a long run to a single location with a dam or a flume. This creates a location where concentrated pressure and flow can be used to turn turbines or water wheels, which drive a mechanical mill or an electric generator. In some cases with hydroelectric dams, there are unexpected results. One study shows that a hydroelectric dam in the Amazon has 3.6 times larger greenhouse effect per kW•h than electricity production from oil, due to large scale emission of methane from

decaying organic material, though this is most significant as river valleys are initially flooded, and are of much less consequence for more boreal dams. This effect applies in particular to dams created by simply flooding a large area, without first clearing it of vegetation. There are however investigations into underwater turbines that do not require a dam. And pumped-storage hydroelectricity can use water reservoirs at different altitudes to store wind and solar power. Solar

The CIS Tower, Manchester, England, was clad in PV panels at a cost of £5.5 million. It started feeding electricity to the national grid in November 2005.

Solar power involves using solar cells to convert sunlight into electricity, using sunlight hitting solar thermal panels to convert sunlight to heat water or air, using sunlight hitting a parabolic mirror to heat water (producing steam), or using sunlight entering windows for passive solar heating of a building. It would be advantageous to place solar panels in the regions of highest solar radiation. In the Phoenix, Arizona area, for example, the average annual solar radiation is 5.7 kW·h/(m²·day), or 2.1 MW·h/(m²·yr). Electricity demand in the continental U.S. is 3.7×1012 kW·h per year. Thus, at 20% efficiency, an area of approximately 3500 square miles (3% of Arizona's land area) would need to be covered with solar panels to replace all current electricity production in the US with solar power. The average solar radiation in the United States is 4.8 kW·h/(m²·day), but reaches 8–9 kWh/m²/day in parts of the Southwest. At the end of 2009, cumulative global photovoltaic (PV) installations surpassed 21 GW and PV power stations are popular in Germany and Spain. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 megawatt (MW) SEGS power plant in the Mojave Desert. China is increasing worldwide silicon wafer capacity for photovoltaics to 2,000 metric tons by July 2008, and over 6,000 metric tons by the end of 2010. Significant international investment capital is flowing into China to support this opportunity. China is building large subsidized off-the-grid solar-powered cities in Huangbaiyu and Dongtan Eco City. Much of the design was done by Americans such as William McDonough. Agricultural biomass

Sugar cane residue can be used as a biofuel Biomass production involves using garbage or other renewable resources such as corn or other vegetation to generate electricity. When garbage decomposes, the methane produced is captured in pipes and later burned to produce electricity. Vegetation and wood can be burned directly to generate energy, like fossil fuels, or processed to form alcohols. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel. Ethanol fuel is also widely available in the USA. Vegetable oil is generated from sunlight, H2O, and CO2 by plants. It is safer to use and store than gasoline or diesel as it has a higher flash point. Straight vegetable oil works in diesel engines if it is heated first. Vegetable oil can also be transesterified to make biodiesel, which burns like normal diesel. Geothermal Geothermal energy harnesses the heat energy present underneath the Earth. Two wells are drilled. One well injects water into the ground to provide water. The hot rocks heat the water to produce steam. The steam that shoots back up the other hole(s) is purified and is used to drive turbines, which power electric generators. When the water temperature is below the boiling point of water a binary system is used. A low boiling point liquid is used to drive a turbine and generator in a closed system similar to a refrigeration unit running in reverse. There are also natural sources of geothermal ennergy some can come from volcanoes, geysers, hot springs, and steam vents. The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Tidal Tidal power can be extracted from Moon-gravity-powered tides by locating a water turbine in a tidal current, or by building impoundment pond dams that admit-or-release water through a turbine. The turbine can turn an electrical generator, or a gas compressor, that can then store energy until needed. Coastal tides are a source of clean, free, renewable, and sustainable energy.

Fossil fuels

The Moss Landing Power Plant burns natural gas to produce electricity in California. Fossil fuels sources burn coal or hydrocarbon fuels, which are the remains of the decomposition of plants and animals. There are three main types of fossil fuels: coal, petroleum, and natural gas. Another fossil fuel, liquefied petroleum gas (LPG), is principally derived from the production of natural gas. Heat from burning fossil fuel is used either directly for space heating and process heating, or converted to mechanical energy for vehicles, industrial processes, or electrical power generation. Greenhouse gas emissions result from fossil fuel-based electricity generation. Currently governments subsidize fossil fuels by an estimated $500 billion a year.

Nuclear

Diablo Canyon Power Plant Nuclear power station.

Fission Nuclear power stations use nuclear fission to generate energy by the reaction of uranium235 inside a nuclear reactor. The reactor uses uranium rods, the atoms of which are split in the process of fission, releasing a large amount of energy. The process continues as a chain reaction with other nuclei. The energy heats water to create steam, which spins a turbine generator, producing electricity. Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from several decades for the currently popular Uranium-235 to thousands of years for uranium-238. At the present rate of use, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at a uranium price of US$ 130/kg. The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater. Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent. On the other

hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent. Opponents on the other hand argue that the correlation between price and production is not linear, but as the ores' concentration becomes smaller, the difficulty (energy and resource consumption are increasing, while the yields are decreasing) of extraction rises very fast, and that the assertion that a higher price will yield more uranium is overly optimistic; for example a rough estimate predicts that the extraction of uranium from granite will consume at least 70 times more energy than what it will produce in a reactor. As many as eleven countries have depleted their uranium resources, and only Canada has mines left which produce better than 1% concentration ore. Seawater seems to be equally dubious as a source. Another alternative could be to use thorium as fission fuel. Thorium is three times more abundant in Earth's crust than uranium, and much more of the thorium can be used (or, more precisely, bred into Uranium-233, reprocessed and then used as fuel). India has around 32 percent of the world’s reserves of thorium and intends on using it for itself because the country has run out of uranium.

The status of nuclear power globally: Operating reactors, building new reactors Operating reactors, planning new build No reactors, building new reactors No reactors, planning new build Operating reactors, stable Operating reactors, considering phase-out Civil nuclear power is illegal No reactors Current light water reactors burn the nuclear fuel poorly, leading to energy waste. Nuclear reprocessing or burning the fuel better using different reactor designs would

reduce the amount of waste material generated and allow better use of the available resources. As opposed to current light water reactors which use uranium-235 (0.7 percent of all natural uranium), breeder reactors convert the more abundant uranium-238 (99.3 percent of all natural uranium) into plutonium for fuel. It has been estimated that there is anywhere from 10,000 to five billion years worth of Uranium-238 for use in these power plants. Fast breeder technology has been used in several reactors. However, the fast breeder reactors at Dounreay in Scotland, Monju in Japan and the Superphénix at CreysMalville in France, in particular, have all had difficulties and were not economically competitive and most have been decommissioned. The People's Republic of China intends to build breeders. India has run out of uranium and is building thermal breeders that can convert Th-232 into U-233 and burn it. The possibility of nuclear meltdowns and other reactor accidents, such as the Three Mile Island accident and the Chernobyl disaster, have caused much public fear. Research is being done to lessen the known problems of current reactor technology by developing automated and passively safe reactors. Historically, however, coal and hydropower power generation have both been the cause of more deaths per energy unit produced than nuclear power generation. Various kinds of energy infrastructure might be attacked by terrorists, including nuclear power plants, hydropower plants, and liquified natural gas tankers. Nuclear proliferation is the spread from nation to nation of nuclear technology, including nuclear power plants but especially nuclear weapons. New technology like SSTAR ("small, sealed, transportable, autonomous reactor") may lessen this risk. The long-term radioactive waste storage problems of nuclear power have not been fully solved. Several countries have considered using underground repositories. Nuclear waste takes up little space compared to wastes from the chemical industry which remain toxic indefinitely. Spent fuel rods are now stored in concrete casks close to the nuclear reactors. The amounts of waste could be reduced in several ways. Both nuclear reprocessing and breeder reactors could reduce the amounts of waste. Subcritical reactors or fusion reactors could greatly reduce the time the waste has to be stored. Subcritical reactors may also be able to do the same to already existing waste. The only long-term way of dealing with waste today is by geological storage. Depending on the source different energy return on energy investment (EROI) are claimed. Advocates (using life cycle analysis) argue that it takes 4–5 months of energy production from the nuclear plant to fully pay back the initial energy investment. Opponents claim that it depends on the grades of the ores the fuel came from, so a full payback can vary from 10 to 18 years, and that the advocates' claim was based on the assumption of high grade ores (the yields are getting worse, as the ores are leaner; for less than 0.02% ores, the yield is less than 50%). Advocates also claim that it is possible to increase the number of plants fairly rapidly. Typical new reactor designs have a construction time of three to four years. In 1983, 43 plants were being built, before an unexpected fall in fossil fuel prices stopped most new construction. Developing countries like India and China are rapidly increasing their nuclear energy use. However, a Council on Foreign Relations report on nuclear energy

argues that a rapid expansion of nuclear power may create shortages in building materials such as reactor-quality concrete and steel, skilled workers and engineers, and safety controls by skilled inspectors. This would drive up current prices. However, at present, nuclear energy is in decline, according to a report 'World Nuclear Industry Status Report 2007' presented by the Greens/EFA group in the European Parliament. The report outlines that the proportion of nuclear energy in power production has decreased in 21 out of 31 countries, with five fewer functioning nuclear reactors than five years ago. There are currently 32 nuclear power plants under construction or in the pipeline, 20 fewer than at the end of the 1990s.

Fusion Fusion power could solve many of the problems of fission power (the technology mentioned above) but, despite research having started in the 1950s, no commercial fusion reactor is expected before 2050. Many technical problems remain unsolved. Proposed fusion reactors commonly use deuterium, an isotope of hydrogen, as fuel and in most current designs also lithium. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.

Cost by source The following chart does not include the external, weather-related costs of using fossil fuels.

█ Conventional oil █ Unconventional oil █ Biofuels

█ Coal

█ Nuclear █ Wind

Colored vertical lines indicate various historical oil prices. From left to right: — 1990s average — January 2009 — 1979 peak — 2008 peak Price of oil per barrel (bbl) at which energy sources are competitive.

• • •

Right end of bar is viability without subsidy. Left end of bar requires regulation or government subsidies. Wider bars indicate uncertainty.

Large energy subsidies are present in many countries (Barker et al., 2001:567-568). Currently governments subsidize fossil fuels by $557 billion per year. Economic theory indicates that the optimal policy would be to remove coal mining and burning subsidies and replace them with optimal taxes. Global studies indicate that even without introducing taxes, subsidy and trade barrier removal at a sectoral level would improve efficiency and reduce environmental damage. Removal of these subsidies would substantially reduce GHG emissions and stimulate economic growth.

Increased energy efficiency Energy efficiency is increasing by about 2% a year, and absorbs most of the requirements for energy development. New technology makes better use of already available energy through improved efficiency, such as more efficient fluorescent lamps, engines, and insulation. Using heat exchangers, it is possible to recover some of the energy in waste warm water and air, for example to preheat incoming fresh water. Hydrocarbon fuel production from pyrolysis could also be in this category, allowing recovery of some of the energy in hydrocarbon waste. Already existing power plants often can and usually are made more efficient with minor modifications due to new technology. New power plants may become more efficient with technology like cogeneration. New designs for buildings may incorporate techniques like passive solar. Light-emitting diodes are gradually replacing the remaining uses of light bulbs. Note that none of these methods allows perpetual motion, as some energy is always lost to heat. Mass transportation increases energy efficiency compared to widespread conventional automobile use while air travel is regarded as inefficient. Conventional combustion engine automobiles have continually improved their efficiency and may continue to do so in the future, for example by reducing weight with new materials. Hybrid vehicles can save energy by allowing the engine to run more efficiently, regaining energy from braking, turning off the motor when idling in traffic, etc. More efficient ceramic or diesel engines can improve mileage. Electric vehicles such as Maglev, trolleybuses, and PHEVs are more efficient during use (but maybe not if doing a life cycle analysis) than similar current combustion based vehicles, reducing their energy consumption during use by 1/2 to 1/4. Microcars or motorcycles may replace automobiles carrying only one or two people. Electricity distribution may change in the future. New small scale energy sources may be placed closer to the consumers so that less energy is lost during electricity distribution.

New technology like superconductivity or improved power factor correction may also decrease the energy lost. Distributed generation permits electricity "consumers," who are generating electricity for their own needs, to send their surplus electrical power back into the power grid.

Transmission

An elevated section of the Alaska Pipeline. While new sources of energy are only rarely discovered or made possible by new technology, distribution technology continually evolves. The use of fuel cells in cars, for example, is an anticipated delivery technology. This section presents some of the more common delivery technologies that have been important to historic energy development. They all rely in some way on the energy sources listed in the previous section.

Water Fossil fuels Shipping is a flexible delivery technology that is used in the whole range of energy development regimes from primitive to highly advanced. Currently, coal, petroleum and their derivatives are delivered by shipping via boat, rail, or road. Petroleum and natural gas may also be delivered via pipeline and coal via a Slurry pipeline. Refined

hydrocarbon fuels such as gasoline and LPG may also be delivered via aircraft. Natural gas pipelines must maintain a certain minimum pressure to function correctly. Ethanol's corrosive properties prevent it from being transported via pipeline. The higher costs of ethanol transportation and storage are often prohibitive.

Electricity

Electric Grid: Pilons and cables distribute power Electricity grids are the networks used to transmit and distribute power from production source to end user, when the two may be hundreds of kilometres away. Sources include electrical generation plants such as a nuclear reactor, coal burning power plant, etc. A combination of sub-stations, transformers, towers, cables, and piping are used to maintain

a constant flow of electricity. Grids may suffer from transient blackouts and brownouts, often due to weather damage. During certain extreme space weather events solar wind can interfere with transmissions. Grids also have a predefined carrying capacity or load that cannot safely be exceeded. When power requirements exceed what's available, failures are inevitable. To prevent problems, power is then rationed. Industrialised countries such as Canada, the US, and Australia are among the highest per capita consumers of electricity in the world, which is possible thanks to a widespread electrical distribution network. The US grid is one of the most advanced, although infrastructure maintenance is becoming a problem. CurrentEnergy provides a realtime overview of the electricity supply and demand for California, Texas, and the Northeast of the US. African countries with small scale electrical grids have a correspondingly low annual per capita usage of electricity. One of the most powerful power grids in the world supplies power to the state of Queensland, Australia.

Storage Methods of energy storage have been developed, which transform electrical energy into forms of potential energy. A method of energy storage may be chosen on the basis of stability, ease of transport, ease of energy release, or ease of converting free energy from the natural form to the stable form.

Chemical Some natural forms of energy are found in stable chemical compounds such as fossil fuels. Most systems of chemical energy storage result from biological activity, which store energy in chemical bonds. Man-made forms of chemical energy storage include hydrogen fuel, synthetic hydrocarbon fuel, batteries and explosives such as cordite and dynamite.

Gravitational and hydroelectric Dams can be used to store energy, by using pumped-storage hydroelectricity, excess energy to pump water into the reservoir. When electrical energy is required, the process is reversed. The water then turns a turbine, generating electricity. Hydroelectric power is currently an important part of the world's energy supply, generating one-fifth of the world's electricity.

Thermal There are several technologies to store heat. Thermal energy from the sun, for example, can be stored in a reservoir or in the ground for daily or seasonal use. Thermal energy for cooling can be stored in ice.

Mechanical pressure

Energy may also be stored pressurized gases or alternatively in a vacuum. Compressed air, for example, may be used to operate vehicles and power tools. Large-scale compressed air energy storage facilities are used to smooth out demands on electricity generation by providing energy during peak hours and storing energy during off-peak hours. Such systems save on expensive generating capacity since it only needs to meet average consumption rather than peak consumption.

Electrical capacitance Electrical energy may be stored in capacitors. Capacitors are often used to produce high intensity releases of energy (such as a camera's flash).

Hydrogen Hydrogen can be manufactured at roughly 77 percent thermal efficiency by the method of steam reforming of natural gas. When manufactured by this method it is a derivative fuel like gasoline; when produced by electrolysis of water, it is a form of chemical energy storage as are storage batteries, though hydrogen is the more versatile storage mode since there are two options for its conversion to useful work: (1) a fuel cell can convert the chemicals hydrogen and oxygen into water, and in the process, produce electricity, or (2) hydrogen can be burned (less efficiently than in a fuel cell) in an internal combustion engine.

Vehicles

Energy flow in the U.S., 2008 Fossil fuels Petroleum and natural gas is used to power most transportation. Batteries Batteries are used to store energy in a chemical form. As an alternative energy, batteries can be used to store energy in battery electric vehicles. Battery electric vehicles can be charged from the grid when the vehicle is not in use. Because the energy is derived from electricity, battery electric vehicles make it possible to use other forms of alternative energy such as wind, solar, geothermal, nuclear, or hydroelectric. Compressed air The Indian company, Tata, is planning to release a compressed air powered car in 2008.

Sustainability

Energy consumption from 1989 to 1999 The environmental movement emphasizes sustainability of energy use and development. Renewable energy is sustainable in its production; the available supply will not be diminished for the foreseeable future - millions or billions of years. "Sustainability" also refers to the ability of the environment to cope with waste products, especially air pollution. Sources which have no direct waste products (such as wind, solar, and hydropower) are seen as ideal in this regard.

Fossil fuels such as petroleum, coal, and natural gas are not renewable. For example, the timing of worldwide peak oil production is being actively debated but it has already happened in some countries. Fossil fuels also make up the bulk of the world's current primary energy sources. With global demand for energy growing, the need to adopt alternative energy sources is also growing. Fossil fuels are also a major source of greenhouse gas emissions, leading to concerns about global warming if consumption is not reduced. Energy conservation is an alternative or complementary process to energy development. It reduces the demand for energy by using it more efficiently.

Resilience

Energy consumption per capita (2001). Red hues indicate increase, green hues decrease of consumption during the 1990s. Some observers contend that the much talked about idea of “energy independence” is an unrealistic and opaque concept. They offer “energy resilience” as a more sensible goal and more aligned with economic, security and energy realities. The notion of resilience in energy was detailed in the 1982 book Brittle Power: Energy Strategy for National Security. The authors argued that simply switching to domestic energy would be no more secure inherently because the true weakness is the interdependent and vulnerable energy infrastructure of the United States. Key aspects such as gas lines and the electrical power grid are centralized and easily susceptible to major disruption. They conclude that a “resilient energy supply” is necessary for both national security and the environment. They recommend a focus on energy efficiency and renewable energy that is more decentralized. More recently former Intel Corporation Chairman and CEO Andrew Grove has touted energy resilience, arguing that complete independence is infeasible given the global

market for energy. He describes energy resilience as the ability to adjust to interruptions in the supply of energy. To this end he suggests the U.S. make greater use of electricity. Electricity can be produced from a variety of sources. A diverse energy supply will be less impacted by the disruption in supply of any one source. He reasons that another feature of electrification is that electricity is “sticky” – meaning the electricity produced in the U.S. is more likely to stay there because it cannot be transported overseas. According to Grove, a key aspect of advancing electrification and energy resilience will be converting the U.S. automotive fleet from gasoline-powered to electric-powered. This, in turn, will require the modernization and expansion of the electrical power grid. As organizations such as the Reform Institute have pointed out, advancements associated with the developing smart grid would facilitate the ability of the grid to absorb vehicles en masse connecting to it to charge their batteries.

Future

World energy consumption.

An increasing share of world energy consumption is predicted to be used by developing nations. Source: EIA. Extrapolations from current knowledge to the future offer a choice of energy futures. Some predictions parallel the Malthusian catastrophe hypothesis. Numerous are complex models based scenarios as pioneered by Limits to Growth. Modeling approaches offer ways to analyze diverse strategies, and hopefully find a road to rapid and sustainable development of humanity. Short term energy crises are also a concern of energy development. Some extrapolations lack plausibility, particularly when they predict a continual increase in oil consumption. Energy production usually requires an energy investment. Drilling for oil or building a wind power plant requires energy. The fossil fuel resources (see above) that are left are often increasingly difficult to extract and convert. They may thus require increasingly higher energy investments. If the investment is greater than the energy produced, then the fossil resource is no longer an energy source. This means that a large part of the fossil fuel resources and especially the non-conventional ones cannot be used for energy production today. Such resources may still be exploited economically in order to produce raw materials for plastics, fertilizers or even transportation fuel but now more energy is consumed than produced. (They then become similar to ordinary mining reserves, economically recoverable but not net positive energy sources.) New technology may ameliorate this problem if it can lower the energy investment required to extract and

convert the resources, although ultimately basic physics sets limits that cannot be exceeded. Between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation. The peaking of world hydrocarbon production (peak oil) may lead to significant changes, and require sustainable methods of production.

History of predictions Ever since the beginning of the Industrial Revolution, the question of the future of energy supplies has occupied economists. •

• • • • •

1865 — William Stanley Jevons published The Coal Question in which he claimed that reserves of coal would soon be exhausted and that there was no prospect of oil being an effective replacement. 1885 — U.S. Geological Survey: Little or no chance of oil in California. 1891 — U.S. Geological Survey: Little or no chance of oil in Kansas or Texas. 1914 — U.S. Bureau of Mines: Total future production of 5.7 billion barrels (910,000,000 m3). 1939 — U.S. Department of the Interior: Reserves to last only 13 years. 1951 — U.S. Department of the Interior, Oil and Gas Division: Reserves to last 13 years.

(Data from Kahn et al. (1976) pp. 94–5 infra) •

• •

1956 — Geophysicist M. King Hubbert predicts U.S. oil production will peak between 1965 and 1970 (peaked in 1971). Also predicts world oil production will peak "within half a century" on the basis of 1956 data. This is Hubbert peak theory. 1989 — Predicted peak by Colin Campbell ("Oil Price Leap in the Early Nineties," Noroil, December 1989, pages 35–38.) 2004 — OPEC estimates it will nearly double oil output by 2025 (Opec Oil Outlook to 2025 Table 4, Page 12)rashi

The history of perpetual motion machines is a long list of failed and sometimes fraudulent inventions of machines which produce useful energy "from nowhere" — that is, without requiring any energy input.

Chapter- 2

Renewable Energy Commercialization

The wind, Sun, and biomass are three renewable energy sources

Global renewable energy investment growth (1995–2007) Renewable energy commercialization involves the deployment of three generations of renewable energy technologies dating back more than 100 years. First-generation technologies, which are already mature and economically competitive, include biomass, hydroelectricity, geothermal power and heat. Second-generation technologies are marketready and are being deployed at the present time; they include solar heating, photovoltaics, wind power, solar thermal power stations, and modern forms of bioenergy. Third-generation technologies require continued R&D efforts in order to make large contributions on a global scale and include advanced biomass gasification, biorefinery technologies, hot-dry-rock geothermal power, and ocean energy. There are some non-technical barriers to the widespread use of renewables, and it is often public policy and political leadership that drive the widespread acceptance of renewable energy technologies. Some 85 countries now have targets for their own renewable energy futures, and have enacted wide-ranging public policies to promote renewables. Climate change concerns are driving increasing growth in the renewable energy industries. Leading renewable energy companies include First Solar, Gamesa, GE Energy, Q-Cells, Sharp Solar, Siemens, SunOpta, Suntech, and Vestas. Global revenues for solar photovoltaics, wind power, and biofuels expanded from $76 billion in 2007 to $115 billion in 2008. New global investments in clean energy technologies—including venture capital, project finance, public markets, and research and development—expanded by 4.7 percent from $148 billion in 2007 to $155 billion in 2008. Continued growth for the renewable energy sector is expected and promotional policies helped the industry weather the 2009 economic crisis better than many other sectors. U.S. President Barack Obama's American Recovery and Reinvestment Act of

2009 included more than $70 billion in direct spending and tax credits for clean energy and associated transportation programs. Clean Edge suggests that the commercialization of clean energy has helped countries around the world pull out of the 2009 global financial crisis. Globally, there are an estimated 3 million direct jobs in renewable energy industries, with about half of them in the biofuels industry.

Overview Rationale for renewables Renewable energy technologies are essential contributors to the energy supply portfolio, as they contribute to world energy security, reduce dependency on fossil fuels, and provide opportunities for mitigating greenhouse gases. Climate-disrupting fossil fuels are being replaced by clean, climate-stabilizing, non-depletable sources of energy: ...the transition from coal, oil, and gas to wind, solar, and geothermal energy is well under way. In the old economy, energy was produced by burning something — oil, coal, or natural gas — leading to the carbon emissions that have come to define our economy. The new energy economy harnesses the energy in wind, the energy coming from the sun, and heat from within the earth itself. The International Energy Agency estimates that nearly 50% of global electricity supplies will need to come from renewable energy sources in order to halve carbon dioxide emissions by 2050 and minimise significant, irreversible climate change impacts.

Three generations of technologies The term renewable energy covers a number of sources and technologies at different stages of commercialization. The International Energy Agency (IEA) has defined three generations of renewable energy technologies, reaching back over 100 years: •

First-generation technologies emerged from the industrial revolution at the end of the 19th century and include hydropower, biomass combustion, geothermal power and heat. These technologies are quite widely used.

•

Second-generation technologies include solar heating and cooling, wind power, modern forms of bioenergy, and solar photovoltaics. These are now entering markets as a result of research, development and demonstration (RD&D) investments since the 1980s. Initial investment was prompted by energy security concerns linked to the oil crises of the 1970s but the enduring appeal of these technologies is due, at least in part, to environmental benefits. Many of the technologies reflect significant advancements in materials.

•

Third-generation technologies are still under development and include advanced biomass gasification, biorefinery technologies, concentrating solar thermal power,

hot-dry-rock geothermal power, and ocean energy. Advances in nanotechnology may also play a major role. First-generation technologies are well established, second-generation technologies are entering markets, and third-generation technologies heavily depend on long-term RD&D commitments, where the public sector has a role to play.

Recent growth of renewables During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. For wind power and many other renewable technologies, growth accelerated in 2009 relative to the previous four years. More wind power capacity was added during 2009 than any other renewable technology. However, grid-connected PV increased the fastest of all renewables technologies, with a 60 percent annual average growth rate for the five-year period. Selected renewable energy indicators Selected global indicators 2004 2005 2006 2007 2008 2009 Investment in new renewable 150 billion 30 38 63 104 130 capacity (annual) USD Existing renewables power capacity, 895 930 1,020 1,070 1,140 1,230 GWe including large-scale hydro Existing renewables power capacity, 160 182 207 240 280 305 GWe excluding large hydro Wind power capacity (existing) 48 59 74 94 121 159 GWe Solar PV capacity (grid7.6 13.5 21 GWe connected) Solar hot water capacity 77 88 105 126 149 180 GWth 76 billion Ethanol production (annual) 30.5 33 39 50 69 liters Biodiesel production (annual) Countries with policy targets for renewable energy use

45

49

10

15

17 billion liters

68

75

85

In 2008 for the first time, more renewable energy than conventional power capacity was added in both the European Union and United States, demonstrating a "fundamental transition" of the world's energy markets towards renewables, according to a report released by REN21, a global renewable energy policy network based in Paris.

A 2010 survey conducted by Applied Materials shows that two-thirds of Americans believe solar technology should play a greater role in meeting the country's energy needs. In addition, "three-quarters of Americans feel that increasing renewable energy and decreasing U.S. dependence on foreign oil are the country's top energy priorities". According to the survey, "67 percent of Americans would be willing to pay more for their monthly utility bill if their utility company increased its use of renewable energy".

Economic trends The International Solar Energy Society argues that renewable energy technologies and economics will improve with time, and that they are "sufficiently advanced at present to allow for major penetrations of renewable energy into the mainstream energy and societal infrastructures". Indicative, levelised, economic costs for renewable power (exclusive of subsidies or policy incentives) are shown in the Table below. Renewable power generation costs 2010 Power generator Large hydro Small hydro Onshore wind Offshore wind Biomass power Geothermal power Rooftop solar PV Utility-scale solar PV Concentrating solar thermal power (CSP)

Typical characteristics

Typical electricity costs (U.S. cents/kWh) 3-5 5-12 5-9 10-14 5-12 4-7

Plant size: 10 - 18,000 MW Plant size: 1-10 MW Turbine size: 1.5 - 3.5 MW Turbine size: 1.5 - 5 MW Plant size: 1-20 MW Plant size: 1-100 MW Peak capacity: 2-5 kilowatts20-50 peak Peak capacity: 200 kW to 15-30 100MW 50-500 MW trough

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As time progresses, renewable energy generally gets cheaper, while fossil fuels generally get more expensive. Al Gore has explained that renewable energy technologies are declining in price for three main reasons: First, once the renewable infrastructure is built, the fuel is free forever. Unlike carbonbased fuels, the wind and the sun and the earth itself provide fuel that is free, in amounts that are effectively limitless. Second, while fossil fuel technologies are more mature, renewable energy technologies are being rapidly improved. So innovation and ingenuity give us the ability to constantly increase the efficiency of renewable energy and continually reduce its cost.

Third, once the world makes a clear commitment to shifting toward renewable energy, the volume of production will itself sharply reduce the cost of each windmill and each solar panel, while adding yet more incentives for additional research and development to further speed up the innovation process.

First-generation technologies First-generation technologies are widely used in locations with abundant resources. Their future use depends on the exploration of the remaining resource potential, particularly in developing countries, and on overcoming challenges related to the environment and social acceptance.

Biomass

Biomass heating plant in Austria. The total heat power is about 1000 kW. Biomass for heat and power is a fully mature technology which offers a ready disposal mechanism for municipal, agricultural, and industrial organic wastes. However, the industry has remained relatively stagnant over the decade to 2007, even though demand for biomass (mostly wood) continues to grow in many developing countries. One of the problems of biomass is that material directly combusted in cook stoves produces pollutants, leading to severe health and environmental consequences, although improved cook stove programmes are alleviating some of these effects. First-generation biomass technologies can be economically competitive, but may still require deployment support to overcome public acceptance and small-scale issues.

Hydroelectricity

The Hoover Dam when completed in 1936 was both the world's largest electric-power generating station and the world's largest concrete structure. Hydroelectric plants have the advantage of being long-lived and many existing plants have operated for more than 100 years. Hydropower is also an extremely flexible technology from the perspective of power grid operation. Large hydropower provides one of the lowest cost options in today’s energy market, even compared to fossil fuels and there are no harmful emissions associated with plant operation. Hydroelectric power is currently the world’s largest installed renewable source of electricity, supplying about 17% of total electricity in 2005. China is the world's largest producer of hydroelectricity in the world, followed by Canada. However, there are several significant social and environmental disadvantages of largescale hydroelectric power systems: dislocation of people living where the reservoirs are planned, release of significant amounts of carbon dioxide and methane during construction and flooding of the reservoir, and disruption of aquatic ecosystems and birdlife. Hydroelectric power is now more difficult to site in developed nations because most major sites within these nations are either already being exploited or may be unavailable for these environmental reasons. The areas of greatest hydroelectric growth are the growing economies of Asia. India and China are the development leaders; however, other Asian nations are also expanding hydropower.

There is a strong consensus now that countries should adopt an integrated approach towards managing water resources, which would involve planning hydropower development in co-operation with other water-using sectors.

Geothermal power and heat

One of many power plants at The Geysers, a geothermal power field in northern California, with a total output of over 750 MW Geothermal power plants can operate 24 hours per day, providing baseload capacity. Estimates for the world potential capacity for geothermal power generation vary widely, ranging from 40 GW by 2020 to as much as 6,000 GW.

Geothermal power capacity grew from around 1 GW in 1975 to almost 10 GW in 2008. The United States is the world leader in terms of installed capacity, representing 3.1 GW. Other countries with significant installed capacity include the Philippines (1.9 GW), Indonesia (1.2 GW), Mexico (1.0 GW), Italy (0.8 GW), Iceland (0.6 GW), Japan (0.5 GW), and New Zealand (0.5 GW). In some countries, geothermal power accounts for a significant share of the total electricity supply, such as in the Philippines, where geothermal represented 17 percent of the total power mix at the end of 2008. Geothermal (ground source) heat pumps represented an estimated 30 GWth of installed capacity at the end of 2008, with other direct uses of geothermal heat (i.e., for space heating, agricultural drying and other uses) reaching an estimated 15 GWth. As of 2008, at least 76 countries use direct geothermal energy in some form.

Second-generation technologies Markets for second-generation technologies have been strong and growing over the past decade, and these technologies have gone from being a passion for the dedicated few to a major economic sector in countries such as Germany, Spain, the United States, and Japan. Many large industrial companies and financial institutions are involved and the challenge is to broaden the market base for continued growth worldwide.

Solar Heating

Solar energy technologies, such as solar water heaters, located on or near the buildings which they supply with energy, are a prime example of a soft energy technology. Solar heating systems are a well known second-generation technology and generally consist of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage, and a reservoir or tank for heat storage. The systems may be used to heat domestic hot water, swimming pools, or homes and businesses. The heat can also be used for industrial process applications or as an energy input for other uses such as cooling equipment. In many warmer climates, a solar heating system can provide a very high percentage (50 to 75%) of domestic hot water energy. As of 2009, China has 27 million rooftop solar water heaters.

Photovoltaics

Nellis Solar Power Plant at Nellis Air Force Base. These panels track the sun in one axis.

President Barack Obama speaks at the DeSoto Next Generation Solar Energy Center.

Photovoltaic (PV) cells, also called solar cells, convert light into electricity. In the 1980s and early 1990s, most photovoltaic modules were used to provide remote-area power supply, but from around 1995, industry efforts have focused increasingly on developing building integrated photovoltaics and photovoltaic power stations for grid connected applications. In particularly sunny regions such as Spain, the Middle East, North Africa, the southern USA, India, and parts of China, modern solar modules are close to achieving grid parity. And in countries situated further to the north such as Germany, France, and the Czech Republic, grid parity is expected by 2015. Falling technology prices and the rising costs of fossil fuels are making photovoltaic (PV) power plants increasingly attractive for large investors. As of November 2010, the largest photovoltaic power plants in the world are the Finsterwalde Solar Park (Germany, 80.7 MW), Sarnia Photovoltaic Power Plant (Canada, 80 MW), Olmedilla Photovoltaic Park (Spain, 60 MW), the Strasskirchen Solar Park (Germany, 54 MW), the Lieberose Photovoltaic Park (Germany, 53 MW), and the Puertollano Photovoltaic Park (Spain, 50 MW). Some photovoltaic power stations which are presently proposed will have a capacity of 150 MW or more. At the end of 2008, the cumulative global PV installations reached 15,200 MW. Photovoltaic production has been doubling every two years, increasing by an average of 48 percent each year since 2002, making it the world’s fastest-growing energy technology. The top five photovoltaic producing countries are Japan, China, Germany, Taiwan, and the USA.

Wind power

Worldwide installed wind power capacity 1996-2008

Fenton Wind Farm at sunrise Some of the second-generation renewables, such as wind power, have high potential and have already realised relatively low production costs. At the end of 2009, worldwide wind farm capacity was 157,900 MW, representing an increase of 31 percent during the year, and wind power supplied some 1.3% of global electricity consumption. Wind power is widely used in European countries, and more recently in the United States and Asia. Wind power accounts for approximately 19% of electricity generation in Denmark, 11% in Spain and Portugal, and 9% in the Republic of Ireland. These are some of the largest wind farms in the world, as of July 2010: Installed capacity Country (MW) Capricorn Ridge Wind Farm 662 USA Fowler Ridge Wind Farm 600 USA Horse Hollow Wind Energy Center 736 USA Roscoe Wind Farm 781 USA San Gorgonio Pass Wind Farm 619 USA Wind farm

Tehachapi Pass Wind Farm

690

USA

Solar thermal power stations

Solar Towers from left: PS10, PS20. Solar thermal power stations include the 354 megawatt (MW) Solar Energy Generating Systems power plant in the USA, Solnova Solar Power Station (Spain, 150 MW), Andasol solar power station (Spain, 100 MW), Nevada Solar One (USA, 64 MW), PS20 solar power tower (Spain, 20 MW), and the PS10 solar power tower (Spain, 11 MW). The 370 MW Ivanpah Solar Power Facility, located in California's Mojave Desert, is the world’s largest solar-thermal power plant project currently under construction. Many other plants are under construction or planned, mainly in Spain and the USA. In developing countries, three World Bank projects for integrated solar thermal/combinedcycle gas-turbine power plants in Egypt, Mexico, and Morocco have been approved.

Modern forms of Bioenergy

Neat ethanol on the left (A), gasoline on the right (G) at a filling station in Brazil. Global ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion litres, while biodiesel expanded more than tenfold from less than 1 billion to almost 11 billion litres. Biofuels provide 1.8% of the world’s transport fuel and recent estimates indicate a continued high growth. The main producing countries for transport biofuels are the USA, Brazil, and the EU. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country's automotive fuel. As a result of this and the exploitation of domestic deep water oil sources, Brazil, which for years had to import a large share of the petroleum needed for domestic consumption, recently reached complete self-sufficiency in liquid fuels.

Information on pump, California Nearly all the gasoline sold in the United States today is mixed with 10 percent ethanol, a mix known as E10, and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends. Ford, DaimlerChrysler, and GM are among the automobile companies that sell flexible-fuel cars, trucks, and minivans that can use gasoline and ethanol blends ranging from pure gasoline up to 85% ethanol (E85). By mid-2006, there were approximately six million E85-compatible vehicles on U.S. roads. The challenge is to expand the market for biofuels beyond the farm states where they have been most popular to date. Flex-fuel vehicles are assisting in this transition because they allow drivers to choose different fuels based on price and availability. The Energy Policy Act of 2005, which calls for 7.5 billion gallons of biofuels to be used annually by 2012, will also help to expand the market. The growing ethanol and biodiesel industries are providing jobs in plant construction, operations, and maintenance, mostly in rural communities. According to the Renewable Fuels Association, the ethanol industry created almost 154,000 U.S. jobs in 2005 alone, boosting household income by $5.7 billion. It also contributed about $3.5 billion in tax revenues at the local, state, and federal levels.

Third-generation technologies

Third-generation renewable energy technologies are still under development and include advanced biomass gasification, biorefinery technologies, hot-dry-rock geothermal power, and ocean energy. Third-generation technologies are not yet widely demonstrated or have limited commercialization. Many are on the horizon and may have potential comparable to other renewable energy technologies, but still depend on attracting sufficient attention and RD&D funding.

New bioenergy technologies According to the International Energy Agency, cellulosic ethanol biorefineries could allow biofuels to play a much bigger role in the future than organizations such as the IEA previously thought. Cellulosic ethanol can be made from plant matter composed primarily of inedible cellulose fibers that form the stems and branches of most plants. Crop residues (such as corn stalks, wheat straw and rice straw), wood waste, and municipal solid waste are potential sources of cellulosic biomass. Dedicated energy crops, such as switchgrass, are also promising cellulose sources that can be sustainably produced in many regions of the United States. Selected Commercial Cellulosic Ethanol Plants in the U.S. (Operational or under construction) Company Location Feedstock Abengoa Bioenergy Hugoton, KS Wheat straw BlueFire Ethanol Irvine, CA Multiple sources Gulf Coast Energy Mossy Head, FL Wood waste Mascoma Lansing, MI Wood POET LLC Emmetsburg, IA Corn cobs Range Fuels Treutlen County, GA Wood waste SunOpta Little Falls, MN Wood chips Xethanol Auburndale, FL Citrus peels

Ocean energy The Rance Tidal Power Station (240 MW) is the world's first tidal power station. The facility is located on the estuary of the Rance River, in Brittany, France. Opened on the 26th November 1966, it is currently operated by Électricité de France, and is the largest tidal power station in the world, in terms of installed capacity. First proposed more than thirty years ago, systems to harvest utility-scale electrical power from ocean waves have recently been gaining momentum as a viable technology. The potential for this technology is considered promising, especially on west-facing coasts with latitudes between 40 and 60 degrees: In the United Kingdom, for example, the Carbon Trust recently estimated the extent of the economically viable offshore resource at 55 TWh per year, about 14% of current

national demand. Across Europe, the technologically achievable resource has been estimated to be at least 280 TWh per year. In 2003, the U.S. Electric Power Research Institute (EPRI) estimated the viable resource in the United States at 255 TWh per year (6% of demand). Funding for a wave farm in Scotland was announced in February 2007 by the Scottish Executive, at a cost of over 4 million pounds, as part of a £13 million funding packages for ocean power in Scotland. The farm will be the world's largest with a capacity of 3 MW generated by four Pelamis machines.

Enhanced geothermal systems As of 2008, geothermal power development was under way in more than 40 countries, partially attributable to the development of new technologies, such as Enhanced Geothermal Systems. The development of binary cycle power plants and improvements in drilling and extraction technology may enable enhanced geothermal systems over a much greater geographical range than "traditional" Geothermal systems. Demonstration EGS projects are operational in the USA, Australia, Germany, France, and The United Kingdom.

Nanotechnology thin-film solar panels Solar power panels that use nanotechnology, which can create circuits out of individual silicon molecules, may cost half as much as traditional photovoltaic cells, according to executives and investors involved in developing the products. Nanosolar has secured more than $100 million from investors to build a factory for nanotechnology thin-film solar panels. The company expects the factory to open in 2010 and produce enough solar cells each year to generate 430 megawatts of power.

Renewable energy industry

A Vestas wind turbine

Gamesa Wind Turbine Installed at Bald Mountain in Bear Creek Township, PA

Monocrystalline solar cell Global revenues for solar photovoltaics, wind power, and biofuels expanded from $76 billion in 2007 to $115 billion in 2008. New global investments in clean energy technologies — including venture capital, project finance, public markets, and research and development — expanded by 4.7 percent from $148 billion in 2007 to $155 billion in 2008.

Wind power companies Vestas is the largest wind turbine manufacturer in the world with a 20% market share in 2008. The company operates plants in Denmark, Germany, India, Italy, Britain, Spain, Sweden, Norway, Australia and China, and employs more than 20,000 people globally.

After a sales slump in 2005, Vestas recovered and was voted Top Green Company of 2006. Vestas announced a major expansion of its North American headquarters in Portland, Oregon in December, 2008. GE Energy was the world's second largest wind turbine manufacturer in 2008, with 19% market share. The company has installed over 5,500 wind turbines and 3,600 hydro turbines, and its installed capacity of renewable energy worldwide exceeds 160,000 MW. GE Energy bought out Enron Wind in 2002 and also has nuclear energy operations in its portfolio. Gamesa, founded in 1976 with headquarters in Vitoria, Spain, was the world's third largest wind turbine manufacturer in 2008, and it is also a major builder of wind farms. Gamesa’s main markets are within Europe, the US and China. Other major wind power companies include Siemens, Suzlon, Sinovel and Goldwind.

Photovoltaic companies First Solar became the world's largest solar cell maker in 2009, producing some 1,100 MW of product, with a 13% market share. Suntech was in second place with production of 595 MW in 2009 and market share of 7%. Sharp was close behind the leaders with 580 MW of output. Q-Cells and its 540 MW output was fourth in 2009. Yingli Green Energy, JA Solar Holdings, SunPower, Kyocera, Motech Solar and Gintech rounded out the 2009 Top 10 ranking.

Non-technical barriers to acceptance Newer and cleaner technologies may offer social and environmental benefits, but utility operators often reject renewable resources because they are trained to think only in terms of big, conventional power plants. Consumers often ignore renewable power systems because they are not given accurate price signals about electricity consumption. Intentional market distortions (such as subsidies), and unintentional market distortions (such as split incentives) may work against renewables. Benjamin K. Sovacool has argued that "some of the most surreptitious, yet powerful, impediments facing renewable energy and energy efficiency in the United States are more about culture and institutions than engineering and science". The obstacles to the widespread commercialization of renewable energy technologies are primarily political, not technical, and there have been many studies which have identified a range of "non-technical barriers" to renewable energy use. These barriers are impediments which put renewable energy at a marketing, institutional, or policy disadvantage relative to other forms of energy. Key barriers include: •

Lack of government policy support, which includes the lack of policies and regulations supporting deployment of renewable energy technologies and the presence of policies and regulations hindering renewable energy development and

• • •

supporting conventional energy development. Examples include subsidies for fossil-fuels, insufficient consumer-based renewable energy incentives, government underwriting for nuclear plant accidents, and complex zoning and permitting processes for renewable energy. Lack of information dissemination and consumer awareness. Higher capital cost of renewable energy technologies compared with conventional energy technologies. Difficulty overcoming established energy systems, which includes difficulty introducing innovative energy systems, particularly for distributed generation such as photovoltaics, because of technological lock-in, electricity markets designed for centralized power plants, and market control by established operators. As the Stern Review on the Economics of Climate Change points out: National grids are usually tailored towards the operation of centralised power plants and thus favour their performance. Technologies that do not easily fit into these networks may struggle to enter the market, even if the technology itself is commercially viable. This applies to distributed generation as most grids are not suited to receive electricity from many small sources. Large-scale renewables may also encounter problems if they are sited in areas far from existing grids.

•

•

•

• • •

Inadequate financing options for renewable energy projects, including insufficient access to affordable financing for project developers, entrepreneurs and consumers. Imperfect capital markets, which includes failure to internalize all costs of conventional energy (e.g., effects of air pollution, risk of supply disruption) and failure to internalize all benefits of renewable energy (e.g., cleaner air, energy security). Inadequate workforce skills and training, which includes lack of adequate scientific, technical, and manufacturing skills required for renewable energy production; lack of reliable installation, maintenance, and inspection services; and failure of the educational system to provide adequate training in new technologies. Lack of adequate codes, standards, utility interconnection, and net-metering guidelines. Poor public perception of renewable energy system aesthetics. Lack of stakeholder/community participation and co-operation in energy choices and renewable energy projects.

With such a wide range of non-technical barriers, there is no "silver bullet" solution to drive the transition to renewable energy. So ideally there is a need for several different types of policy instruments to complement each other and overcome different types of barriers. A policy framework must be created that will level the playing field and redress the imbalance of traditional approaches associated with fossil fuels. The policy landscape

must keep pace with broad trends within the energy sector, as well as reflecting specific social, economic and environmental priorities.

Public policy landscape Public policy has a role to play in renewable energy commercialization because the free market system has some fundamental limitations. As the Stern Review points out: In a liberalised energy market, investors, operators and consumers should face the full cost of their decisions. But this is not the case in many economies or energy sectors. Many policies distort the market in favour of existing fossil fuel technologies. The International Solar Energy Society has stated that "historical incentives for the conventional energy resources continue even today to bias markets by burying many of the real societal costs of their use". Lester Brown goes further and suggests that the market "does not incorporate the indirect costs of providing goods or services into prices, it does not value nature’s services adequately, and it does not respect the sustainable-yield thresholds of natural systems". It also favors the near term over the long term, thereby showing limited concern for future generations. Tax and subsidy shifting can help overcome these problems.

Shifting taxes Tax shifting involves lowering income taxes while raising levies on environmentally destructive activities, in order to create a more responsive market. It has been widely discussed and endorsed by economists. For example, a tax on coal that included the increased health care costs associated with breathing polluted air, the costs of acid rain damage, and the costs of climate disruption would encourage investment in renewable technologies. Several Western European countries are already shifting taxes in a process known there as environmental tax reform, to achieve environmental goals. A four-year plan adopted in Germany in 1999 gradually shifted taxes from labor to energy and, by 2001, this plan had lowered fuel use by 5 percent. It had also increased growth in the renewable energy sector, creating some 45,400 jobs by 2003 in the wind industry alone, a number that is projected to rise to 103,000 by 2010. In 2001, Sweden launched a new 10-year environmental tax shift designed to convert 30 billion kroner ($3.9 billion) of taxes on income to taxes on environmentally destructive activities. Other European countries with significant tax reform efforts are France, Italy, Norway, Spain, and the United Kingdom. Asia’s two leading economies, Japan and China, are considering the adoption of carbon taxes.

Shifting subsidies Subsidies are not inherently bad as many technologies and industries emerged through government subsidy schemes. The Stern Review explains that of 20 key innovations from

the past 30 years, only one of the 14 they could source was funded entirely by the private sector and nine were totally funded by the public sector. In terms of specific examples, the Internet was the result of publicly funded links among computers in government laboratories and research institutes. And the combination of the federal tax deduction and a robust state tax deduction in California helped to create the modern wind power industry. But just as there is a need for tax shifting, there is also a need for subsidy shifting. Lester Brown has argued that "a world facing the prospect of economically disruptive climate change can no longer justify subsidies to expand the burning of coal and oil. Shifting these subsidies to the development of climate-benign energy sources such as wind, solar, biomass, and geothermal power is the key to stabilizing the earth’s climate." The International Solar Energy Society advocates "leveling the playing field" by redressing the continuing inequities in public subsidies of energy technologies and R&D, in which the fossil fuel and nuclear power receive the largest share of financial support. Some countries are eliminating or reducing climate disrupting subsidies and Belgium, France, and Japan have phased out all subsidies for coal. Germany reduced its coal subsidy from $5.4 billion in 1989 to $2.8 billion in 2002, and in the process lowered its coal use by 46 percent. Germany plans to phase out this support entirely by 2010. China cut its coal subsidy from $750 million in 1993 to $240 million in 1995 and more recently has imposed a tax on high-sulfur coals. While some leading industrial countries have been reducing subsidies to fossil fuels, most notably coal, the United States has been increasing its support for the fossil fuel and nuclear industries.

Renewable energy targets Setting national renewable energy targets can be an important part of a renewable energy policy and these targets are usually defined as a percentage of the primary energy and/or electricity generation mix. For example, the European Union has prescribed an indicative renewable energy target of 12 per cent of the total EU energy mix and 22 per cent of electricity consumption by 2010. National targets for individual EU Member States have also been set to meet the overall target. Other developed countries with defined national or regional targets include Australia, Canada, Japan, New Zealand, Norway, Switzerland, and some US States. National targets are also an important component of renewable energy strategies in some developing countries. Developing countries with renewable energy targets include China, India, Korea, Indonesia, Malaysia, the Philippines, Singapore, Thailand, Brazil, Israel, Egypt, Mali, and South Africa. The targets set by many developing countries are quite modest when compared with those in some industrialized countries. Renewable energy targets in most countries are indicative and nonbinding but they have assisted government actions and regulatory frameworks. The United Nations

Environment Program has suggested that making renewable energy targets legally binding could be an important policy tool to achieve higher renewable energy market penetration.

Green stimulus programs In response to the global financial crisis, the world’s major governments have made “green stimulus” programs one of their main policy instruments for supporting the economic recovery. Some $188 billion in green stimulus funding had been allocated to renewable energy and energy efficiency. Most of the overall clean energy stimuli are expected to be spent in 2010 and in 2011.

Employment Current employment in the renewable energy sector and supplier industries is estimated at 2.3 million worldwide. The wind power industry employs some 300,000 people, the photovoltaics sector an estimated 170,000, and the solar thermal industry more than 600,000. Over 1 million jobs are found in the biofuels industry, associated with growing and processing a variety of feedstocks into ethanol and biodiesel.

Recent developments

Projected renewable energy investment growth globally (2007-2017) A number of events in 2006 pushed renewable energy up the political agenda, including the US mid-term elections in November, which confirmed clean energy as a mainstream issue. Also in 2006, the Stern Review made a strong economic case for investing in low carbon technologies now, and argued that economic growth need not be incompatible

with cutting energy consumption. According to a trend analysis from the United Nations Environment Programme, climate change concerns coupled with recent high oil prices and increasing government support are driving increasing rates of investment in the renewable energy and energy efficiency industries. Investment capital flowing into renewable energy reached a record US$77 billion in 2007, with the upward trend continuing in 2008. The OECD still dominates, but there is now increasing activity from companies in China, India and Brazil. Chinese companies were the second largest recipient of venture capital in 2006 after the United States. In the same year, India was the largest net buyer of companies abroad, mainly in the more established European markets. Global revenues for solar photovoltaics, wind power, and biofuels expanded from $75.8 billion in 2007 to $115.9 billion in 2008. For the first time, one sector alone, wind, had revenues exceeding $50 billion. New global investments in clean energy technologies — including venture capital, project finance, public markets, and research and development — expanded by 4.7 percent from $148.4 billion in 2007 to $155.4 billion in 2008. After several years with strong political backing and growth, 2009 was a year of refocus, consolidation, or retrenchment for many companies. However, new wind power capacity installed in 2009 grew strongly with record installations of 38 GW worldwide, partly as a result of the rapid rise of Chinese manufacturing. New government spending, regulation, and policies helped the industry weather the 2009 economic crisis better than many other sectors. Most notably, U.S. President Barack Obama's American Recovery and Reinvestment Act of 2009 included more than $70 billion in direct spending and tax credits for clean energy and associated transportation programs. This policy-stimulus combination represents the largest federal commitment in U.S. history for renewables, advanced transportation, and energy conservation initiatives. Based on these new rules, many more utilities strengthened their clean-energy programs. Clean Edge suggests that the commercialization of clean energy will help countries around the world pull out of the current economic malaise.

Sustainable energy Moving towards energy sustainability will require changes not only in the way energy is supplied, but in the way it is used, and reducing the amount of energy required to deliver various goods or services is essential. Opportunities for improvement on the demand side of the energy equation are as rich and diverse as those on the supply side, and often offer significant economic benefits. Renewable energy and energy efficiency are said to be the “twin pillars” of sustainable energy policy. Any serious vision of a sustainable energy economy requires commitments to both renewables and efficiency. The American Council for an Energy-Efficient Economy has explained that both resources must be developed in order to stabilize and reduce carbon dioxide emissions:

Efficiency is essential to slowing the energy demand growth so that rising clean energy supplies can make deep cuts in fossil fuel use. If energy use grows too fast, renewable energy development will chase a receding target. Likewise, unless clean energy supplies come online rapidly, slowing demand growth will only begin to reduce total emissions; reducing the carbon content of energy sources is also needed. The IEA has stated that renewable energy and energy efficiency policies should be viewed as complementary tools for the development of a sustainable energy future, instead of being developed in isolation.

Chapter- 3

Wind Power

A modern wind turbine in rural scenery. Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, wind mills for mechanical power, wind pumps for pumping water or drainage, or sails to propel ships. At the end of 2009, worldwide nameplate capacity of wind-powered generators was 159.2 gigawatts (GW). Energy production was 340 TWh, which is about 2% of worldwide electricity usage; and has doubled in the past three years. Several countries have achieved relatively high levels of wind power penetration (with large governmental subsidies), such as 20% of stationary electricity production in Denmark, 14% in Ireland

and Portugal, 11% in Spain, and 8% in Germany in 2009. As of May 2009, 80 countries around the world are using wind power on a commercial basis. Large-scale wind farms are connected to the electric power transmission network; smaller facilities are used to provide electricity to isolated locations. Utility companies increasingly buy back surplus electricity produced by small domestic turbines. Wind energy, as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, and produces no greenhouse gas emissions during operation. However, the construction of wind farms is not universally welcomed because of their visual impact and other effects on the environment. Wind power is non-dispatchable, meaning that for economic operation, all of the available output must be taken when it is available. Other resources, such as hydropower, and load management techniques must be used to match supply with demand. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand, but as the proportion rises, problems are created such as increased costs, the need to upgrade the grid, and a lowered ability to supplant conventional production. Power management techniques such as exporting excess power to neighboring areas or reducing demand when wind production is low, can mitigate these problems.

History

Medieval depiction of a wind mill

Windmills are typically installed in favourable windy locations. In the image, wind power generators in Spain near an Osborne bull Humans have been using wind power for at least 5,500 years to propel sailboats and sailing ships. Windmills have been used for irrigation pumping and for milling grain since the 7th century AD in what is now Afghanistan, Iran and Pakistan. In the United States, the development of the "water-pumping windmill" was the major factor in allowing the farming and ranching of vast areas otherwise devoid of readily accessible water. Windpumps contributed to the expansion of rail transport systems throughout the world, by pumping water from water wells for the steam locomotives. The multi-bladed wind turbine atop a lattice tower made of wood or steel was, for many years, a fixture of the landscape throughout rural America. When fitted with generators and battery banks, small wind machines provided electricity to isolated farms. In July 1887, a Scottish academic, Professor James Blyth, undertook wind power experiments that culminated in a UK patent in 1891. In the United States, Charles F. Brush produced electricity using a wind powered machine, starting in the winter of 18871888, which powered his home and laboratory until about 1900. In the 1890s, the Danish scientist and inventor Poul la Cour constructed wind turbines to generate electricity, which was then used to produce hydrogen. These were the first of what was to become the modern form of wind turbine.

Small wind turbines for lighting of isolated rural buildings were widespread in the first part of the 20th century. Larger units intended for connection to a distribution network were tried at several locations including Balaklava USSR in 1931 and in a 1.25 megawatt (MW) experimental unit in Vermont in 1941. The modern wind power industry began in 1979 with the serial production of wind turbines by Danish manufacturers Kuriant, Vestas, Nordtank, and Bonus. These early turbines were small by today's standards, with capacities of 20–30 kW each. Since then, they have increased greatly in size, with the Enercon E-126 capable of delivering up to 7 MW, while wind turbine production has expanded to many countries.

Wind energy

Distribution of wind speed (red) and energy (blue) for all of 2002 at the Lee Ranch facility in Colorado. The histogram shows measured data, while the curve is the Rayleigh model distribution for the same average wind speed. Energy is the Betz limit through a 100 m (328 ft) diameter circle facing directly into the wind. Total energy for the year through that circle was 15.4 gigawatt-hours (GW·h). The Earth is unevenly heated by the sun, such that the poles receive less energy from the sun than the equator; along with this, dry land heats up (and cools down) more quickly than the seas do. The differential heating drives a global atmospheric convection system reaching from the Earth's surface to the stratosphere which acts as a virtual ceiling. Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160 km/h (99 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmosphere.

The total amount of economically extractable power available from the wind is considerably more than present human power use from all sources. An estimated 72 terawatt (TW) of wind power on the Earth potentially can be commercially viable, compared to about 15 TW average global power consumption from all sources in 2005. Not all the energy of the wind flowing past a given point can be recovered.

Distribution of wind speed The strength of wind varies, and an average value for a given location does not alone indicate the amount of energy a wind turbine could produce there. To assess the frequency of wind speeds at a particular location, a probability distribution function is often fit to the observed data. Different locations will have different wind speed distributions. The Weibull model closely mirrors the actual distribution of hourly wind speeds at many locations. The Weibull factor is often close to 2 and therefore a Rayleigh distribution can be used as a less accurate, but simpler model. Because so much power is generated by higher wind speed, much of the energy comes in short bursts. The 2002 Lee Ranch sample is telling; half of the energy available arrived in just 15% of the operating time. The consequence is that wind energy from a particular turbine or wind farm does not have as consistent an output as fuel-fired power plants; utilities that use wind power provide power from starting existing generation for times when the wind is weak thus wind power is primarily a fuel saver rather than a capacity saver. Making wind power more consistent requires that various existing technologies and methods be extended, in particular the use of stronger inter-regional transmission lines to link widely distributed wind farms. Problems of variability are addressed by grid energy storage, batteries, pumped-storage hydroelectricity and energy demand management.

Electricity generation

Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5 kV), power collection system and communications network. At a substation, this medium-voltage electric current is increased in voltage with a transformer for connection to the high voltage electric power transmission system. The surplus power produced by domestic microgenerators can, in some jurisdictions, be fed into the network and sold to the utility company, producing a retail credit for the microgenerators' owners to offset their energy costs.

Grid management Induction generators, often used for wind power, require reactive power for excitation so substations used in wind-power collection systems include substantial capacitor banks for power factor correction. Different types of wind turbine generators behave differently during transmission grid disturbances, so extensive modelling of the dynamic electromechanical characteristics of a new wind farm is required by transmission system operators to ensure predictable stable behaviour during system faults (see: Low voltage ride through). In particular, induction generators cannot support the system voltage during faults, unlike steam or hydro turbine-driven synchronous generators. Doubly-fed

machines generally have more desirable properties for grid interconnection. Transmission systems operators will supply a wind farm developer with a grid code to specify the requirements for interconnection to the transmission grid. This will include power factor, constancy of frequency and dynamic behavior of the wind farm turbines during a system fault.

Capacity factor

Worldwide installed capacity 1997–2020 [MW], developments and prognosis. Since wind speed is not constant, a wind farm's annual energy production is never as much as the sum of the generator nameplate ratings multiplied by the total hours in a year. The ratio of actual productivity in a year to this theoretical maximum is called the capacity factor. Typical capacity factors are 20–40%, with values at the upper end of the range in particularly favourable sites. For example, a 1 MW turbine with a capacity factor of 35% will not produce 8,760 MW·h in a year (1 × 24 × 365), but only 1 × 0.35 × 24 × 365 = 3,066 MW·h, averaging to 0.35 MW. Online data is available for some locations and the capacity factor can be calculated from the yearly output. Unlike fueled generating plants, the capacity factor is limited by the inherent properties of wind. Capacity factors of other types of power plant are based mostly on fuel cost, with a small amount of downtime for maintenance. Nuclear plants have low incremental fuel cost, and so are run at full output and achieve a 90% capacity factor. Plants with higher fuel cost are throttled back to follow load. Gas turbine plants using natural gas as fuel may be very expensive to operate and may be run only to meet peak power demand. A gas turbine plant may have an annual capacity factor of 5–25% due to relatively high energy production cost. In a 2008 study released by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy, the capacity factor achieved by the wind turbine fleet is shown to be increasing as the technology improves. The capacity factor achieved by new wind turbines in 2004 and 2005 reached 36%.

Penetration

Kitegen Wind energy "penetration" refers to the fraction of energy produced by wind compared with the total available generation capacity. There is no generally accepted "maximum" level of wind penetration. The limit for a particular grid will depend on the existing generating plants, pricing mechanisms, capacity for storage or demand management, and other factors. An interconnected electricity grid will already include reserve generating and transmission capacity to allow for equipment failures; this reserve capacity can also serve to regulate for the varying power generation by wind plants. Studies have indicated that 20% of the total electrical energy consumption may be incorporated with minimal difficulty. These studies have been for locations with geographically dispersed wind farms, some degree of dispatchable energy, or hydropower with storage capacity, demand management, and interconnection to a large grid area export of electricity when needed. Beyond this level, there are few technical limits, but the economic implications become more significant. Electrical utilities continue to study the effects of large (20% or more) scale penetration of wind generation on system stability and economics. At present, a few grid systems have penetration of wind energy above 5%: Denmark (values over 19%), Spain and Portugal (values over 11%), Germany and the Republic of Ireland (values over 6%). But even with a modest level of penetration, there can be times where wind power provides a substantial percentage of the power on a grid. For example, in the morning hours of 8 November 2009, wind energy produced covered more than half

the electricity demand in Spain, setting a new record. This was an instance where demand was very low but wind power generation was very high.

Wildorado Wind Ranch in Oldham County in the Texas Panhandle, as photographed from U.S. Route 385

Intermittency and penetration limits Electricity generated from wind power can be highly variable at several different timescales: from hour to hour, daily, and seasonally. Annual variation also exists, but is not as significant. Related to variability is the short-term (hourly or daily) predictability of wind plant output. Like other electricity sources, wind energy must be "scheduled". Wind power forecasting methods are used, but predictability of wind plant output remains low for short-term operation. Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, this variability can present substantial challenges to incorporating large amounts of wind power into a grid system. Intermittency and the non-dispatchable nature of wind energy production can raise costs for regulation, incremental operating reserve, and (at high penetration levels) could require an increase in the already existing energy demand management, load shedding, or storage solutions or system interconnection with HVDC cables. At low levels of wind penetration, fluctuations in

load and allowance for failure of large generating units requires reserve capacity that can also regulate for variability of wind generation. Wind power can be replaced by other power stations during low wind periods. Transmission networks must already cope with outages of generation plant and daily changes in electrical demand. Systems with large wind capacity components may need more spinning reserve (plants operating at less than full load). Pumped-storage hydroelectricity or other forms of grid energy storage can store energy developed by high-wind periods and release it when needed. Stored energy increases the economic value of wind energy since it can be shifted to displace higher cost generation during peak demand periods. The potential revenue from this arbitrage can offset the cost and losses of storage; the cost of storage may add 25% to the cost of any wind energy stored, but it is not envisaged that this would apply to a large proportion of wind energy generated. The 2 GW Dinorwig pumped storage plant in Wales evens out electrical demand peaks, and allows base-load suppliers to run their plant more efficiently. Although pumped storage power systems are only about 75% efficient, and have high installation costs, their low running costs and ability to reduce the required electrical base-load can save both fuel and total electrical generation costs. In particular geographic regions, peak wind speeds may not coincide with peak demand for electrical power. In the US states of California and Texas, for example, hot days in summer may have low wind speed and high electrical demand due to air conditioning. Some utilities subsidize the purchase of geothermal heat pumps by their customers, to reduce electricity demand during the summer months by making air conditioning up to 70% more efficient; widespread adoption of this technology would better match electricity demand to wind availability in areas with hot summers and low summer winds. Another option is to interconnect widely dispersed geographic areas with an HVDC "Super grid". In the USA it is estimated that to upgrade the transmission system to take in planned or potential renewables would cost at least $60 billion. In the UK, demand for electricity is higher in winter than in summer, and so are wind speeds. Solar power tends to be complementary to wind. On daily to weekly timescales, high pressure areas tend to bring clear skies and low surface winds, whereas low pressure areas tend to be windier and cloudier. On seasonal timescales, solar energy typically peaks in summer, whereas in many areas wind energy is lower in summer and higher in winter. Thus the intermittencies of wind and solar power tend to cancel each other somewhat. A demonstration project at the Massachusetts Maritime Academy shows the effect. The Institute for Solar Energy Supply Technology of the University of Kassel pilot-tested a combined power plant linking solar, wind, biogas and hydrostorage to provide load-following power around the clock, entirely from renewable sources. A report on Denmark's wind power noted that their wind power network provided less than 1% of average demand 54 days during the year 2002. Wind power advocates argue that these periods of low wind can be dealt with by simply restarting existing power stations that have been held in readiness or interlinking with HVDC. Electrical grids with

slow-responding thermal power plants and without ties to networks with hydroelectric generation may have to limit the use of wind power. Three reports on the wind variability in the UK issued in 2009, generally agree that variability of wind needs to be taken into account, but it does not make the grid unmanageable; and the additional costs, which are modest, can be quantified. A 2006 International Energy Agency forum presented costs for managing intermittency as a function of wind-energy's share of total capacity for several countries, as shown: Increase in system operation costs, Euros per MW·h, for 10% and 20% wind share 10% 20% Germany 2.5 3.2 Denmark 0.4 0.8 Finland 0.3 1.5 Norway 0.1 0.3 Sweden 0.3 0.7

Capacity credit and fuel saving Many commentators concentrate on whether or not wind has any "capacity credit" without defining what they mean by this and its relevance. Wind does have a capacity credit, using a widely accepted and meaningful definition, equal to about 20% of its rated output (but this figure varies depending on actual circumstances). This means that reserve capacity on a system equal in MW to 20% of added wind could be retired when such wind is added without affecting system security or robustness. But the precise value is irrelevant since the main value of wind (in the UK, worth 5 times the capacity credit value) is its fuel and CO2 savings. According to a 2007 Stanford University study published in the Journal of Applied Meteorology and Climatology, interconnecting ten or more wind farms can allow an average of 33% of the total energy produced to be used as reliable, baseload electric power, as long as minimum criteria are met for wind speed and turbine height.

Installation placement Good selection of a wind turbine site is critical to economic development of wind power. Aside from the availability of wind itself, other factors include the availability of transmission lines, value of energy to be produced, cost of land acquisition, land use considerations, and environmental impact of construction and operations. Off-shore locations may offset their higher construction cost with higher annual load factors, thereby reducing cost of energy produced. Wind farm designers use specialized wind

energy software applications to evaluate the impact of these issues on a given wind farm design. Wind power density (WPD) is a calculation of the effective power of the wind at a particular location. A map showing the distribution of wind power density is a first step in identifying possible locations for wind turbines. In the United States, the National Renewable Energy Laboratory classifies wind power density into ascending classes. The larger the WPD at a location, the higher it is rated by class. Wind power classes 3 (300– 400 W/m2 at 50 m altitude) to 7 (800–2000 W/m2 at 50 m altitude) are generally considered suitable for wind power development. There are 625,000 km2 in the contiguous United States that have class 3 or higher wind resources and which are within 10 km of electric transmission lines. If this area is fully utilized for wind power, it would produce power at the average continuous equivalent rate of 734 GWe. For comparison, in 2007 the US consumed electricity at an average rate of 474 GW, from a total generating capacity of 1,088 GW.

Wind power usage # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Installed windpower capacity (MW) Nation 2005 2006 2007 2008 40,722 48,122 56,614 65,255 European Union United States 9,149 11,603 16,819 25,170 Germany 18,428 20,622 22,247 23,903 1,266 2,599 5,912 12,210 China 10,028 11,630 15,145 16,740 Spain 4,430 6,270 7,850 9,587 India 1,718 2,123 2,726 3,537 Italy 779 1,589 2,477 3,426 France United Kingdom 1,353 1,963 2,389 3,288 1,022 1,716 2,130 2,862 Portugal 3,132 3,140 3,129 3,164 Denmark Canada 683 1,460 1,846 2,369 1,236 1,571 1,759 2,237 Netherlands 1,040 1,309 1,528 1,880 Japan Australia 579 817 817 1,494 Sweden 509 571 831 1,067 Ireland 495 746 805 1,245 573 758 873 990 Greece 819 965 982 995 Austria 20 65 207 433 Turkey

2009 74,767 35,159 25,777 25,104 19,149 10,925 4,850 4,410 4,070 3,535 3,465 3,319 2,229 2,056 1,712 1,560 1,260 1,087 995 801

20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

Poland 83 153 276 472 725 29 237 247 339 606 Brazil 167 194 287 384 563 Belgium Mexico 2 84 85 85 520 New Zealand 168 171 322 325 497 104 188 280 358 436 Taiwan 268 325 333 428 431 Norway 145 230 310 390 430 Egypt 119 176 192 278 348 South Korea 64 64 125 125 253 Morocco Hungary 18 61 65 127 201 30 57 116 150 192 Czech Republic Bulgaria 14 36 57 158 177 ? ? ? 20 168 Chile Finland 82 86 110 143 147 Estonia ? ? 59 78 142 Costa Rica ? ? ? 74 123 77 86 89 90 94 Ukraine Iran 32 47 67 82 91 Lithuania 7 56 50 54 91 Other Europe (non EU27) 391 494 601 1022 1385 Rest of Americas 155 159 184 210 175 Rest of Africa 52 52 51 56 91 & Middle East Rest of Asia 27 27 27 36 51 & Oceania World total (MW) 59,024 74,151 93,927 121,188 157,899

There are now many thousands of wind turbines operating, with a total nameplate capacity of 157,899 MW of which wind power in Europe accounts for 48% (2009). World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years. 81% of wind power installations are in the US and Europe. The share of the top five countries in terms of new installations fell from 71% in 2004 to 62% in 2006, but climbed to 73% by 2008 as those countries — the United States, Germany, Spain, China, and India — have seen substantial capacity growth in the past two years (see chart). The World Wind Energy Association forecast that, by 2010, over 200 GW of capacity would have been installed worldwide, up from 73.9 GW at the end of 2006, implying an anticipated net growth rate of more than 28% per year.

Wind accounts for nearly one-fifth of electricity generated in Denmark — the highest percentage of any country — and it is tenth in the world in total wind power generation. Denmark is prominent in the manufacturing and use of wind turbines, with a commitment made in the 1970s to eventually produce half of the country's power by wind. In recent years, the US has added substantial amounts of wind power generation capacity, growing from just over 6 GW at the end of 2004 to over 35 GW at the end of 2009. The U.S. is currently the world's leader in wind power generation capacity. The country as a whole generates just 2.4% of its electrical power from wind, but several states generate substantial amounts of wind power. Texas is the state with the largest amount of generation capacity with 9,410 MW installed. This would have ranked sixth in the world, were Texas a separate country. Iowa is the state with the highest percentage of wind generation, at 14.2% in 2009. California was one of the incubators of the modern wind power industry, and led the U.S. in installed capacity for many years. As of mid-2010, fourteen U..S. states had wind power generation capacities in excess of 1000 MW. U.S. Department of Energy studies have concluded that wind from the Great Plains states of Texas, Kansas, and North Dakota could provide enough electricity to power the entire nation, and that offshore wind farms could do the same job. China had originally set a generating target of 30,000 MW by 2020 from renewable energy sources, but reached 22,500 MW by end of 2009 and could easily surpass 30,000 MW by end of 2010. Indigenous wind power could generate up to 253,000 MW. A Chinese renewable energy law was adopted in November 2004, following the World Wind Energy Conference organized by the Chinese and the World Wind Energy Association. By 2008, wind power was growing faster in China than the government had planned, and indeed faster in percentage terms than in any other large country, having more than doubled each year since 2005. Policymakers doubled their wind power prediction for 2010, after the wind industry reached the original goal of 5 GW three years ahead of schedule. Current trends suggest an actual installed capacity near 20 GW by 2010, with China shortly thereafter pursuing the United States for the world wind power lead. India ranks 5th in the world with a total wind power capacity of 10,925 MW in 2009, or 3% of all electricity produced in India. The World Wind Energy Conference in New Delhi in November 2006 has given additional impetus to the Indian wind industry. Muppandal village in Tamil Nadu state, India, has several wind turbine farms in its vicinity, and is one of the major wind energy harnessing centres in India led by majors like Suzlon, Vestas, Micon among others. Mexico recently opened La Venta II wind power project as a step toward reducing Mexico's consumption of fossil fuels. The 88 MW project is the first of its kind in Mexico, and will provide 13 percent of the electricity needs of the state of Oaxaca. By 2012 the project will have a capacity of 3,500 MW. In May 2010, Sempra Energy announced it would build a wind farm in Baja California, with a capacity of at least 1,000 MW, at a cost of $5.5 billion.

Another growing market is Brazil, with a wind potential of 143 GW. South Africa has a proposed station situated on the West Coast north of the Olifants River mouth near the town of Koekenaap, east of Vredendal in the Western Cape province. The station is proposed to have a total output of 100 MW although there are negotiations to double this capacity. The plant could be operational by 2010. France has announced a target of 12,500 MW installed by 2010, though their installation trends over the past few years suggest they'll fall well short of their goal. Canada experienced rapid growth of wind capacity between 2000 and 2006, with total installed capacity increasing from 137 MW to 1,451 MW, and showing an annual growth rate of 38%. Particularly rapid growth was seen in 2006, with total capacity doubling from the 684 MW at end-2005. This growth was fed by measures including installation targets, economic incentives and political support. For example, the Ontario government announced that it will introduce a feed-in tariff for wind power, referred to as 'Standard Offer Contracts', which may boost the wind industry across the province. In Quebec, the provincially owned electric utility plans to purchase an additional 2000 MW by 2013. By 2025, Canada will reach its capacity of 55,000 MW of wind energy, or 20% of the country's energy needs.

Small-scale wind power

This wind turbine charges a 12 V battery to run 12 V appliances. Small-scale wind power is the name given to wind generation systems with the capacity to produce up to 50 kW of electrical power. Isolated communities, that may otherwise rely on diesel generators may use wind turbines to displace diesel fuel consumption. Individuals may purchase these systems to reduce or eliminate their dependence on grid electricity for economic or other reasons, or to reduce their carbon footprint. Wind turbines have been used for household electricity generation in conjunction with battery storage over many decades in remote areas. Grid-connected wind turbines may use grid energy storage, displacing purchased energy with local production when available. Off-grid system users can either adapt to intermittent power or use batteries, photovoltaic or diesel systems to supplement the wind turbine. Equipment such as parking meters or wireless Internet gateways may be powered

by a wind turbine that charges a small battery, replacing the need for a connection to the power grid. In locations near or around a group of high-rise buildings, wind shear generates areas of intense turbulence, especially at street-level. The risks associated with mechanical or catastrophic failure have thus plagued urban wind development in densely populated areas, rendering the costs of insuring urban wind systems prohibitive. Moreover, quantifying the amount of wind in urban areas has been difficult, as little is known about the actual wind resources of towns and cities. A new Carbon Trust study into the potential of small-scale wind energy has found that small wind turbines could provide up to 1.5 terawatt hours (TW·h) per year of electricity (0.4% of total UK electricity consumption), saving 0.6 million tonnes of carbon dioxide (Mt CO2) emission savings. This is based on the assumption that 10% of households would install turbines at costs competitive with grid electricity, around 12 pence (US 19 cents) a kW·h. Distributed generation from renewable resources is increasing as a consequence of the increased awareness of climate change. The electronic interfaces required to connect renewable generation units with the utility system can include additional functions, such as the active filtering to enhance the power quality.

Economics and feasibility

5 kilowatt Vertical axis wind turbine

Windmill with rotating sails

Relative cost of electricity by generation source Growth and cost trends Wind power has negligible fuel costs, but a high capital cost. The estimated average cost per unit incorporates the cost of construction of the turbine and transmission facilities, borrowed funds, return to investors (including cost of risk), estimated annual production, and other components, averaged over the projected useful life of the equipment, which may be in excess of twenty years. Energy cost estimates are highly dependent on these assumptions so published cost figures can differ substantially. A British Wind Energy Association report gives an average generation cost of onshore wind power of around 3.2

pence (between US 5 and 6 cents) per kW·h (2005). Cost per unit of energy produced was estimated in 2006 to be comparable to the cost of new generating capacity in the US for coal and natural gas: wind cost was estimated at $55.80 per MW·h, coal at $53.10/MW·h and natural gas at $52.50. Other sources in various studies have estimated wind to be more expensive than other sources. A 2009 study on wind power in Spain by the Universidad Rey Juan Carlos concluded that each installed MW of wind power destroyed 4.27 jobs, by raising energy costs and driving away electricity-intensive businesses. However, the presence of wind energy, even when subsidised, can reduce costs for consumers (€5 billion/yr in Germany) by reducing the marginal price by minimising the use of expensive 'peaker plants'. In 2004, wind energy cost a fifth of what it did in the 1980s, and some expected that downward trend to continue as larger multi-megawatt turbines were mass-produced. However, installed cost averaged €1,300 a kW in 2007, compared to €1,100 a kW in 2005. Not as many facilities can produce large modern turbines and their towers and foundations, so constraints develop in the supply of turbines resulting in higher costs. Global Wind Energy Council (GWEC) figures show that 2007 recorded an increase of installed capacity of 20 GW, taking the total installed wind energy capacity to 94 GW, up from 74 GW in 2006. Despite constraints facing supply chains for wind turbines, the annual market for wind continued to increase at an estimated rate of 37%, following 32% growth in 2006. In terms of economic value, the wind energy sector has become one of the important players in the energy markets, with the total value of new generating equipment installed in 2007 reaching €25 billion, or US$36 billion. Although the wind power industry will be impacted by the global financial crisis in 2009 and 2010, a BTM Consult five year forecast up to 2013 projects substantial growth. Over the past five years the average growth in new installations has been 27.6 percent each year. In the forecast to 2013 the expected average annual growth rate is 15.7 percent. More than 200 GW of new wind power capacity could come on line before the end of 2013. Wind power market penetration is expected to reach 3.35 percent by 2013 and 8 percent by 2018. Existing generation capacity represents sunk costs, and the decision to continue production will depend on marginal costs going forward, not estimated average costs at project inception. For example, the estimated cost of new wind power capacity may be lower than that for "new coal" (estimated average costs for new generation capacity) but higher than for "old coal" (marginal cost of production for existing capacity). Therefore, the choice to increase wind capacity will depend on factors including the profile of existing generation capacity.

Theoretical potential - World

Map of available wind power for the United States. Color codes indicate wind power density class. Wind power available in the atmosphere is much greater than current world energy consumption. The most comprehensive study as of 2005 found the potential of wind power on land and near-shore to be 72 TW, equivalent to 54,000 MToE (million tons of oil equivalent) per year, or over five times the world's current energy use in all forms. The potential takes into account only locations with mean annual wind speeds ≥ 6.9 m/s at 80 m. The study assumes six 1.5 megawatt, 77 m diameter turbines per square kilometer on roughly 13% of the total global land area (though that land would also be available for other compatible uses such as farming). The authors acknowledge that many practical barriers would need to be overcome to reach this theoretical capacity. The practical limit to exploitation of wind power will be set by economic and environmental factors, since the resource available is far larger than any practical means to develop it.

Theoretical potential - UK A recent estimate gives the total potential average output for UK for various depth and distance from the coast. The maximum case considered was beyond 200 km from shore and in depths of 100 – 700 m (necessitating floating wind turbines) and this gave an

average resource of 2,000 GWe which is to be compared with the average UK demand of about 40 GWe.

Direct costs Many potential sites for wind farms are far from demand centres, requiring substantially more money to construct new transmission lines and substations. In some regions this is partly because frequent strong winds themselves have discouraged dense human settlement in especially windy areas. The wind which was historically a nuisance is now becoming a valuable resource, but it may be far from large populations which developed in areas more sheltered from wind. Since the primary cost of producing wind energy is construction and there are no fuel costs, the average cost of wind energy per unit of production depends on a few key assumptions, such as the cost of capital and years of assumed service. The marginal cost of wind energy once a plant is constructed is usually less than 1 cent per kW·h. Since the cost of capital plays a large part in projected cost, risk (as perceived by investors) will affect projected costs per unit of electricity. The commercial viability of wind power also depends on the price paid to power producers. Electricity prices are highly regulated worldwide, and in many locations may not reflect the full cost of production, let alone indirect subsidies or negative externalities. Customers may enter into long-term pricing contracts for wind to reduce the risk of future pricing changes, thereby ensuring more stable returns for projects at the development stage. These may take the form of standard offer contracts, whereby the system operator undertakes to purchase power from wind at a fixed price for a certain period (perhaps up to a limit); these prices may be different than purchase prices from other sources, and even incorporate an implicit subsidy. Where the price for electricity is based on market mechanisms, revenue for all producers per unit is higher when their production coincides with periods of higher prices. The profitability of wind farms will therefore be higher if their production schedule coincides with these periods. If wind represents a significant portion of supply, average revenue per unit of production may be lower as more expensive and less-efficient forms of generation, which typically set revenue levels, are displaced from economic dispatch. This may be of particular concern if the output of many wind plants in a market have strong temporal correlation. In economic terms, the marginal revenue of the wind sector as penetration increases may diminish.

External costs Most forms of energy production create some form of negative externality: costs that are not paid by the producer or consumer of the good. For electric production, the most significant externality is pollution, which imposes social costs in increased health expenses, reduced agricultural productivity, and other problems. In addition, carbon dioxide, a greenhouse gas produced when fossil fuels are burned, may impose even

greater costs in the form of global warming. Few mechanisms currently exist to internalise these costs, and the total cost is highly uncertain. Other significant externalities can include military expenditures to ensure access to fossil fuels, remediation of polluted sites, destruction of wild habitat, loss of scenery/tourism, etc. If the external costs are taken into account, wind energy can be competitive in more cases, as costs have generally decreased because of technology development and scale enlargement. Supporters argue that, once external costs and subsidies to other forms of electrical production are accounted for, wind energy is amongst the least costly forms of electrical production. Critics argue that the level of required subsidies, the small amount of energy needs met, the expense of transmission lines to connect the wind farms to population centers, and the uncertain financial returns to wind projects make it inferior to other energy sources. Intermittency and other characteristics of wind energy also have costs that may rise with higher levels of penetration, and may change the cost-benefit ratio.

Incentives

Some of the over 6,000 wind turbines at Altamont Pass, in California, United States. Developed during a period of tax incentives in the 1980s, this wind farm has more turbines than any other in the United States.

Wind energy in many jurisdictions receives some financial or other support to encourage its development. Wind energy benefits from subsidies in many jurisdictions, either to increase its attractiveness, or to compensate for subsidies received by other forms of production which have significant negative externalities. In the United States, wind power receives a tax credit for each kW·h produced; at 1.9 cents per kW·h in 2006, the credit has a yearly inflationary adjustment. Another tax benefit is accelerated depreciation. Many American states also provide incentives, such as exemption from property tax, mandated purchases, and additional markets for "green credits". Countries such as Canada and Germany also provide incentives for wind turbine construction, such as tax credits or minimum purchase prices for wind generation, with assured grid access (sometimes referred to as feed-in tariffs). These feed-in tariffs are typically set well above average electricity prices. The Energy Improvement and Extension Act of 2008 contains extensions of credits for wind, including microturbines. Secondary market forces also provide incentives for businesses to use wind-generated power, even if there is a premium price for the electricity. For example, socially responsible manufacturers pay utility companies a premium that goes to subsidize and build new wind power infrastructure. Companies use wind-generated power, and in return they can claim that they are making a powerful "green" effort. In the USA the organization Green-e monitors business compliance with these renewable energy credits.

Full costs and lobbying Commenting on the EU's 2020 renewable energy target, Helm (2009) is critical of how the costs of wind power are citied by lobbyists: For those with an economic interest in capturing as much of the climate-change pork barrel as possible, there are two ways of presenting the costs [of wind power] in a favourable light: first, define the cost base as narrowly as possible; and, second, assume that the costs will fall over time with R&D and large-scale deployment. And, for good measure, when considering the alternatives, go for a wider cost base (for example, focusing on the full fuel-cycle costs of nuclear and coal-mining for coal generation) and assume that these technologies are mature, and even that costs might rise (for example, invoking the peak oil hypothesis). A House of Lords Select Committee report (2008) on renewable energy in the UK says: We have a particular concern over the prospective role of wind generated and other intermittent sources of electricity in the UK, in the absence of a break-through in electricity storage technology or the integration of the UK grid with that of continental Europe. Wind generation offers the most readily available short-term enhancement in renewable electricity and its base cost is relatively cheap. Yet the evidence presented to us implies that the full costs of wind generation (allowing for intermittency, back-up conventional plant and grid connection), although declining over time, remain significantly higher than those of conventional or nuclear generation (even before

allowing for support costs and the environmental impacts of wind farms). Furthermore, the evidence suggests that the capacity credit of wind power (its probable power output at the time of need) is very low; so it cannot be relied upon to meet peak demand. Thus wind generation needs to be viewed largely as additional capacity to that which will need to be provided, in any event, by more reliable means Helm (2009) says that wind's problem of intermittent supply will probably lead to another dash-for-gas or dash-for-coal in Europe, possibly with a negative impact on energy security. In the United States, the wind power industry has recently increased its lobbying efforts considerably, spending about $5 million in 2009 after years of relative obscurity in Washington.

Environmental effects

Livestock ignore wind turbines, and continue to graze as they did before wind turbines were installed. Compared to the environmental effects of traditional energy sources, the environmental effects of wind power are relatively minor. Wind power consumes no fuel, and emits no

air pollution, unlike fossil fuel power sources. The energy consumed to manufacture and transport the materials used to build a wind power plant is equal to the new energy produced by the plant within a few months of operation. Garrett Gross, a scientist from UMKC in Kansas City, Missouri states, "The impact made on the environment is very little when compared to what is gained." The initial carbon dioxide emission from energy used in the installation is "paid back" within about 2.5 years of operation for offshore turbines. Danger to birds and bats has been a concern in some locations. American Bird Conservancy cites studies that indicate that about 10,000 - 40,000 birds die each year from collisions with wind turbines in the U.S. and say that number may rise substantially as wind capacity increases in the absence of mandatory guidelines. However, studies show that the number of birds killed by wind turbines is very low compared to the number of those that die as a result of certain other ways of generating electricity and especially of the environmental impacts of using non-clean power sources. Fossil fuel generation kills around twenty times as many birds per unit of energy produced than wind-farms. Bat species appear to be at risk during key movement periods. Almost nothing is known about current populations of these species and the impact on bat numbers as a result of mortality at windpower locations. Offshore wind sites 10 km or more from shore do not interact with bat populations. While a wind farm may cover a large area of land, many land uses such as agriculture are compatible, with only small areas of turbine foundations and infrastructure made unavailable for use. Aesthetics have also been an issue. In the USA, the Massachusetts Cape Wind project was delayed for years mainly because of aesthetic concerns. In the UK, repeated opinion surveys have shown that more than 70% of people either like, or do not mind, the visual impact. According to a town councillor in Ardrossan, Scotland, the overwhelming majority of locals believe that the Ardrossan Wind Farm has enhanced the area, saying that the turbines are impressive looking and bring a calming effect to the town. Noise has also been an issue. In the United States, law suits and complaints have been filed in several states, citing noise, vibrations and resulting lost property values in homes and businesses located close to industrial wind turbines. With careful implanting of the wind turbines, along with use of noise reducing-modifications for the wind turbines however, these issues can be addressed.

Chapter- 4

Nuclear Power

The Ikata Nuclear Power Plant, a pressurized water reactor that cools by secondary coolant exchange with the ocean.

The Susquehanna Steam Electric Station, a boiling water reactor. The reactors are located inside the rectangular containment buildings towards the front of the cooling towers.

Three nuclear powered ships, (top to bottom) nuclear cruisers USS Bainbridge and USS Long Beach with USS Enterprise the first nuclear powered aircraft carrier in 1964. Crew members are spelling out Einstein's mass-energy equivalence formula E = mc2 on the flight deck. Nuclear power is produced by controlled (i.e., non-explosive) nuclear reactions. Commercial and utility plants currently use nuclear fission reactions to heat water to produce steam, which is then used to generate electricity. In 2009, 13–14% of the world's electricity came from nuclear power. Also, more than 150 naval vessels using nuclear propulsion have been built.

Use

Historical and projected world energy use by energy source, 1980-2030, Source: International Energy Outlook 2007, EIA.

Nuclear power installed capacity and generation, 1980 to 2007 (EIA).

The status of nuclear power globally.

The CANDU Bruce Nuclear Generating Station is the second largest nuclear power plant in the world. As of 2005, nuclear power provided 6.3% of the world's energy and 15% of the world's electricity, with the U.S., France, and Japan together accounting for 56.5% of nuclear generated electricity. In 2007, the IAEA reported there were 439 nuclear power reactors in operation in the world, operating in 31 countries. As of December 2009, the world had 436 reactors. Since commercial nuclear energy began in the mid 1950s, 2008 was the first year that no new nuclear power plant was connected to the grid, although two were connected in 2009. Annual generation of nuclear power has been on a slight downward trend since 2007, decreasing 1.8% in 2009 to 2558 TWh with nuclear power meeting 13–14% of the world's electricity demand. One factor in the nuclear power percentage decrease since 2007 has been the prolonged shutdown of large reactors at the Kashiwazaki-Kariwa Nuclear Power Plant in Japan following the Niigata-Chuetsu-Oki earthquake. The United States produces the most nuclear energy, with nuclear power providing 19% of the electricity it consumes, while France produces the highest percentage of its electrical energy from nuclear reactors—80% as of 2006. In the European Union as a whole, nuclear energy provides 30% of the electricity. Nuclear energy policy differs between European Union countries, and some, such as Austria, Estonia, and Ireland, have no active nuclear power stations. In comparison, France has a large number of these plants, with 16 multi-unit stations in current use.

In the US, while the coal and gas electricity industry is projected to be worth $85 billion by 2013, nuclear power generators are forecast to be worth $18 billion. Many military and some civilian (such as some icebreaker) ships use nuclear marine propulsion, a form of nuclear propulsion. A few space vehicles have been launched using full-fledged nuclear reactors: the Soviet RORSAT series and the American SNAP-10A. International research is continuing into safety improvements such as passively safe plants, the use of nuclear fusion, and additional uses of process heat such as hydrogen production (in support of a hydrogen economy), for desalinating sea water, and for use in district heating systems.

Nuclear fusion Nuclear fusion reactions have the potential to be safer and generate less radioactive waste than fission. These reactions appear potentially viable, though technically quite difficult and have yet to be created on a scale that could be used in a functional power plant. Fusion power has been under intense theoretical and experimental investigation since the 1950s.

Use in space Both fission and fusion appear promising for space propulsion applications, generating higher mission velocities with less reaction mass. This is due to the much higher energy density of nuclear reactions: some 7 orders of magnitude (10,000,000 times) more energetic than the chemical reactions which power the current generation of rockets. Radioactive decay has been used on a relatively small (few kW) scale, mostly to power space missions and experiments by using radioisotope thermoelectric generators such as those developed at Idaho National Laboratory.

History Origins The pursuit of nuclear energy for electricity generation began soon after the discovery in the early 20th century that radioactive elements, such as radium, released immense amounts of energy, according to the principle of mass–energy equivalence. However, means of harnessing such energy was impractical, because intensely radioactive elements were, by their very nature, short-lived (high energy release is correlated with short halflives). However, the dream of harnessing "atomic energy" was quite strong, even it was dismissed by such fathers of nuclear physics like Ernest Rutherford as "moonshine." This situation, however, changed in the late 1930s, with the discovery of nuclear fission.

In 1932, James Chadwick discovered the neutron, which was immediately recognized as a potential tool for nuclear experimentation because of its lack of an electric charge. Experimentation with bombardment of materials with neutrons led Frédéric and Irène Joliot-Curie to discover induced radioactivity in 1934, which allowed the creation of radium-like elements at much less the price of natural radium. Further work by Enrico Fermi in the 1930s focused on using slow neutrons to increase the effectiveness of induced radioactivity. Experiments bombarding uranium with neutrons led Fermi to believe he had created a new, transuranic element, which he dubbed hesperium. But in 1938, German chemists Otto Hahn and Fritz Strassmann, along with Austrian physicist Lise Meitner and Meitner's nephew, Otto Robert Frisch, conducted experiments with the products of neutron-bombarded uranium, as a means of further investigating Fermi's claims. They determined that the relatively tiny neutron split the nucleus of the massive uranium atoms into two roughly equal pieces, contradicting Fermi. This was an extremely surprising result: all other forms of nuclear decay involved only small changes to the mass of the nucleus, whereas this process—dubbed "fission" as a reference to biology—involved a complete rupture of the nucleus. Numerous scientists, including Leo Szilard, who was one of the first, recognized that if fission reactions released additional neutrons, a self-sustaining nuclear chain reaction could result. Once this was experimentally confirmed and announced by Frédéric Joliot-Curie in 1939, scientists in many countries (including the United States, the United Kingdom, France, Germany, and the Soviet Union) petitioned their governments for support of nuclear fission research, just on the cusp of World War II.

Constructing the core of B-Reactor at Hanford Site during the Manhattan Project. In the United States, where Fermi and Szilard had both emigrated, this led to the creation of the first man-made reactor, known as Chicago Pile-1, which achieved criticality on December 2, 1942. This work became part of the Manhattan Project, which built large reactors at the Hanford Site (formerly the town of Hanford, Washington) to breed plutonium for use in the first nuclear weapons, which were used on the cities of Hiroshima and Nagasaki. A parallel uranium enrichment effort also was pursued. After World War II, the prospects of using "atomic energy" for good, rather than simply for war, were greatly advocated as a reason not to keep all nuclear research controlled by military organizations. However, most scientists agreed that civilian nuclear power would take at least a decade to master, and the fact that nuclear reactors also produced weaponsusable plutonium created a situation in which most national governments (such as those in the United States, the United Kingdom, Canada, and the USSR) attempted to keep reactor research under strict government control and classification. In the United States, reactor research was conducted by the U.S. Atomic Energy Commission, primarily at Oak Ridge, Tennessee, Hanford Site, and Argonne National Laboratory.

The first light bulbs ever lit by electricity generated by nuclear power at EBR-1 at what is now Idaho National Laboratory. Work in the United States, United Kingdom, Canada, and USSR proceeded over the course of the late 1940s and early 1950s. Electricity was generated for the first time by a nuclear reactor on December 20, 1951, at the EBR-I experimental station near Arco, Idaho, which initially produced about 100 kW. Work was also strongly researched in the US on nuclear marine propulsion, with a test reactor being developed by 1953. (Eventually, the USS Nautilus, the first nuclear-powered submarine, would launch in 1955.) In 1953, US President Dwight Eisenhower gave his "Atoms for Peace" speech at the United Nations, emphasizing the need to develop "peaceful" uses of nuclear power quickly. This was followed by the 1954 Amendments to the Atomic Energy Act which allowed rapid declassification of U.S. reactor technology and encouraged development by the private sector.

Early years

Calder Hall nuclear power station in the United Kingdom was the world's first nuclear power station to produce electricity in commercial quantities.

The Shippingport Atomic Power Station in Shippingport, Pennsylvania was the first commercial reactor in the USA and was opened in 1957. On June 27, 1954, the USSR's Obninsk Nuclear Power Plant became the world's first nuclear power plant to generate electricity for a power grid, and produced around 5 megawatts of electric power. Later in 1954, Lewis Strauss, then chairman of the United States Atomic Energy Commission (U.S. AEC, forerunner of the U.S. Nuclear Regulatory Commission and the United States Department of Energy) spoke of electricity in the future being "too cheap to meter". Strauss was referring to hydrogen fusion- which was secretly being developed as part of Project Sherwood at the time - but Strauss's statement was interpreted as a promise of very cheap energy from nuclear fission. The U.S. AEC itself had issued far more conservative testimony regarding nuclear fission to the U.S. Congress only months before, projecting that "costs can be brought down... [to]... about the same as the cost of electricity from conventional sources..." Significant disappointment would develop later on, when the new nuclear plants did not provide energy "too cheap to meter." In 1955 the United Nations' "First Geneva Conference", then the world's largest gathering of scientists and engineers, met to explore the technology. In 1957 EURATOM was launched alongside the European Economic Community (the latter is now the European

Union). The same year also saw the launch of the International Atomic Energy Agency (IAEA). The world's first commercial nuclear power station, Calder Hall in Sellafield, England was opened in 1956 with an initial capacity of 50 MW (later 200 MW). The first commercial nuclear generator to become operational in the United States was the Shippingport Reactor (Pennsylvania, December 1957). One of the first organizations to develop nuclear power was the U.S. Navy, for the purpose of propelling submarines and aircraft carriers. It has an unblemished record in nuclear safety, perhaps because of the stringent demands of Admiral Hyman G. Rickover, who was the driving force behind nuclear marine propulsion as well as the Shippingport Reactor (Alvin Radkowsky was chief scientist at the U.S. Navy nuclear propulsion division, and was involved with the latter). The U.S. Navy has operated more nuclear reactors than any other entity, including the Soviet Navy, with no publicly known major incidents. The first nuclear-powered submarine, USS Nautilus (SSN-571), was put to sea in December 1954. Two U.S. nuclear submarines, USS Scorpion and USS Thresher, have been lost at sea. These vessels were both lost due to malfunctions in systems not related to the reactor plants. The sites are monitored and no known leakage has occurred from the onboard reactors. The United States Army also had a nuclear power program, beginning in 1954. The SM-1 Nuclear Power Plant, at Ft. Belvoir, Virginia, was the first power reactor in the US to supply electrical energy to a commercial grid (VEPCO), in April 1957, before Shippingport.

Development

History of the use of nuclear power (top) and the number of active nuclear power plants (bottom). Installed nuclear capacity initially rose relatively quickly, rising from less than 1 gigawatt (GW) in 1960 to 100 GW in the late 1970s, and 300 GW in the late 1980s. Since the late 1980s worldwide capacity has risen much more slowly, reaching 366 GW in 2005. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 70s and early 80s) — in 2005, around 25 GW of new capacity was planned. More than two-thirds of all nuclear plants ordered after January 1970 were eventually cancelled. A total of 63 nuclear units were canceled in the USA between 1975 and 1980.

Washington Public Power Supply System Nuclear Power Plants 3 and 5 were never completed. During the 1970s and 1980s rising economic costs (related to extended construction times largely due to regulatory changes and pressure-group litigation) and falling fossil fuel prices made nuclear power plants then under construction less attractive. In the 1980s (U.S.) and 1990s (Europe), flat load growth and electricity liberalization also made the addition of large new baseload capacity unattractive. The 1973 oil crisis had a significant effect on countries, such as France and Japan, which had relied more heavily on oil for electric generation (39% and 73% respectively) to invest in nuclear power. Today, nuclear power supplies about 80% and 30% of the electricity in those countries, respectively. A general movement against nuclear power arose during the last third of the 20th century, based on the fear of a possible nuclear accident as well as the history of accidents, fears of radiation as well as the history of radiation of the public, nuclear proliferation, and on the opposition to nuclear waste production, transport and lack of any final storage plans. Protest movements against nuclear power first emerged in the USA in the late 1970s and spread quickly to Europe and the rest of the world. Anti-nuclear power groups emerged in every country that has had a nuclear power programme. Some of these anti-nuclear power organisations are reported to have developed considerable expertise on nuclear

power and energy issues. In 1992, the chairman of the Nuclear Regulatory Commission said that "his agency had been pushed in the right direction on safety issues because of the pleas and protests of nuclear watchdog groups". Health and safety concerns, the 1979 accident at Three Mile Island, and the 1986 Chernobyl disaster played a part in stopping new plant construction in many countries, although the public policy organization Brookings Institution suggests that new nuclear units have not been ordered in the U.S. because of soft demand for electricity, and cost overruns on nuclear plants due to regulatory issues and construction delays. Unlike the Three Mile Island accident, the much more serious Chernobyl accident did not increase regulations affecting Western reactors since the Chernobyl reactors were of the problematic RBMK design only used in the Soviet Union, for example lacking "robust" containment buildings. Many of these reactors are still in use today. However, changes were made in both the reactors themselves (use of low enriched uranium) and in the control system (prevention of disabling safety systems) to reduce the possibility of a duplicate accident. An international organization to promote safety awareness and professional development on operators in nuclear facilities was created: WANO; World Association of Nuclear Operators. Opposition in Ireland and Poland prevented nuclear programs there, while Austria (1978), Sweden (1980) and Italy (1987) (influenced by Chernobyl) voted in referendums to oppose or phase out nuclear power. In July 2009, the Italian Parliament passed a law that canceled the results of an earlier referendum and allowed the immediate start of the Italian nuclear program. One Italian minister even called the nuclear phase-out a "terrible mistake".

Nuclear reactor technology

Cattenom Nuclear Power Plant

Just as many conventional thermal power stations generate electricity by harnessing the thermal energy released from burning fossil fuels, nuclear power plants convert the energy released from the nucleus of an atom, typically via nuclear fission. When a relatively large fissile atomic nucleus (usually uranium-235 or plutonium-239) absorbs a neutron, a fission of the atom often results. Fission splits the atom into two or more smaller nuclei with kinetic energy (known as fission products) and also releases gamma radiation and free neutrons. A portion of these neutrons may later be absorbed by other fissile atoms and create more fissions, which release more neutrons, and so on. This nuclear chain reaction can be controlled by using neutron poisons and neutron moderators to change the portion of neutrons that will go on to cause more fissions. Nuclear reactors generally have automatic and manual systems to shut the fission reaction down if unsafe conditions are detected. A cooling system removes heat from the reactor core and transports it to another area of the plant, where the thermal energy can be harnessed to produce electricity or to do other useful work. Typically the hot coolant will be used as a heat source for a boiler, and the pressurized steam from that boiler will power one or more steam turbine driven electrical generators. There are many different reactor designs, utilizing different fuels and coolants and incorporating different control schemes. Some of these designs have been engineered to meet a specific need. Reactors for nuclear submarines and large naval ships, for example, commonly use highly enriched uranium as a fuel. This fuel choice increases the reactor's power density and extends the usable life of the nuclear fuel load, but is more expensive and a greater risk to nuclear proliferation than some of the other nuclear fuels. A number of new designs for nuclear power generation, collectively known as the Generation IV reactors, are the subject of active research and may be used for practical power generation in the future. Many of these new designs specifically attempt to make fission reactors cleaner, safer and/or less of a risk to the proliferation of nuclear weapons. Passively safe plants (such as the ESBWR) are available to be built and other designs that are believed to be nearly fool-proof are being pursued. Fusion reactors, which may be viable in the future, diminish or eliminate many of the risks associated with nuclear fission.

Flexibility of nuclear power plants It is often claimed that nuclear stations are inflexible in their output, implying that other forms of energy would be required to meet peak demand. While that is true for certain reactors, this is no longer true of at least some modern designs. Nuclear plants are routinely used in load following mode on a large scale in France.

Boiling water reactors normally have load-following capability, implemented by varying the recirculation water flow.

Life cycle

The nuclear fuel cycle begins when uranium is mined, enriched, and manufactured into nuclear fuel, (1) which is delivered to a nuclear power plant. After usage in the power plant, the spent fuel is delivered to a reprocessing plant (2) or to a final repository (3) for geological disposition. In reprocessing 95% of spent fuel can be recycled to be returned to usage in a power plant (4). A nuclear reactor is only part of the life-cycle for nuclear power. The process starts with mining. Uranium mines are underground, open-pit, or in-situ leach mines. In any case, the uranium ore is extracted, usually converted into a stable and compact form such as

yellowcake, and then transported to a processing facility. Here, the yellowcake is converted to uranium hexafluoride, which is then enriched using various techniques. At this point, the enriched uranium, containing more than the natural 0.7% U-235, is used to make rods of the proper composition and geometry for the particular reactor that the fuel is destined for. The fuel rods will spend about 3 operational cycles (typically 6 years total now) inside the reactor, generally until about 3% of their uranium has been fissioned, then they will be moved to a spent fuel pool where the short lived isotopes generated by fission can decay away. After about 5 years in a cooling pond, the spent fuel is radioactively and thermally cool enough to handle, and it can be moved to dry storage casks or reprocessed.

Conventional fuel resources Uranium is a fairly common element in the Earth's crust. Uranium is approximately as common as tin or germanium in Earth's crust, and is about 40 times more common than silver. Uranium is a constituent of most rocks, dirt, and of the oceans. The fact that uranium is so spread out is a problem because mining uranium is only economically feasible where there is a large concentration. Still, the world's present measured resources of uranium, economically recoverable at a price of 130 USD/kg, are enough to last for "at least a century" at current consumption rates. This represents a higher level of assured resources than is normal for most minerals. On the basis of analogies with other metallic minerals, a doubling of price from present levels could be expected to create about a tenfold increase in measured resources, over time. However, the cost of nuclear power lies for the most part in the construction of the power station. Therefore the fuel's contribution to the overall cost of the electricity produced is relatively small, so even a large fuel price escalation will have relatively little effect on final price. For instance, typically a doubling of the uranium market price would increase the fuel cost for a light water reactor by 26% and the electricity cost about 7%, whereas doubling the price of natural gas would typically add 70% to the price of electricity from that source. At high enough prices, eventually extraction from sources such as granite and seawater become economically feasible. Current light water reactors make relatively inefficient use of nuclear fuel, fissioning only the very rare uranium-235 isotope. Nuclear reprocessing can make this waste reusable and more efficient reactor designs allow better use of the available resources. Breeding As opposed to current light water reactors which use uranium-235 (0.7% of all natural uranium), fast breeder reactors use uranium-238 (99.3% of all natural uranium). It has been estimated that there is up to five billion years’ worth of uranium-238 for use in these power plants. Breeder technology has been used in several reactors, but the high cost of reprocessing fuel safely requires uranium prices of more than 200 USD/kg before becoming justified economically. As of December 2005, the only breeder reactor producing power is BN-

600 in Beloyarsk, Russia. The electricity output of BN-600 is 600 MW — Russia has planned to build another unit, BN-800, at Beloyarsk nuclear power plant. Also, Japan's Monju reactor is planned for restart (having been shut down since 1995), and both China and India intend to build breeder reactors. Another alternative would be to use uranium-233 bred from thorium as fission fuel in the thorium fuel cycle. Thorium is about 3.5 times as common as uranium in the Earth's crust, and has different geographic characteristics. This would extend the total practical fissionable resource base by 450%. Unlike the breeding of U-238 into plutonium, fast breeder reactors are not necessary — it can be performed satisfactorily in more conventional plants. India has looked into this technology, as it has abundant thorium reserves but little uranium. Fusion Fusion power advocates commonly propose the use of deuterium, or tritium, both isotopes of hydrogen, as fuel and in many current designs also lithium and boron. Assuming a fusion energy output equal to the current global output and that this does not increase in the future, then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years. Although this process has yet to be realized, many experts and civilians alike believe fusion to be a promising future energy source due to the short lived radioactivity of the produced waste, its low carbon emissions, and its prospective power output.

Solid waste The most important waste stream from nuclear power plants is spent nuclear fuel. It is primarily composed of unconverted uranium as well as significant quantities of transuranic actinides (plutonium and curium, mostly). In addition, about 3% of it is fission products from nuclear reactions. The actinides (uranium, plutonium, and curium) are responsible for the bulk of the long-term radioactivity, whereas the fission products are responsible for the bulk of the short-term radioactivity. High-level radioactive waste After about 5 percent of a nuclear fuel rod has reacted inside a nuclear reactor that rod is no longer able to be used as fuel (due to the build-up of fission products). Today, scientists are experimenting on how to recycle these rods so as to reduce waste and use the remaining actinides as fuel (large-scale reprocessing is being used in a number of countries). A typical 1000-MWe nuclear reactor produces approximately 20 cubic meters (about 27 tonnes) of spent nuclear fuel each year (but only 3 cubic meters of vitrified volume if reprocessed). All the spent fuel produced to date by all commercial nuclear power plants in the US would cover a football field to the depth of about one meter.

Spent nuclear fuel is initially very highly radioactive and so must be handled with great care and forethought. However, it becomes significantly less radioactive over the course of thousands of years of time. After 40 years, the radiation flux is 99.9% lower than it was the moment the spent fuel was removed from operation, although the spent fuel is still dangerously radioactive at that time. After 10,000 years of radioactive decay, according to United States Environmental Protection Agency standards, the spent nuclear fuel will no longer pose a threat to public health and safety. When first extracted, spent fuel rods are stored in shielded basins of water (spent fuel pools), usually located on-site. The water provides both cooling for the still-decaying fission products, and shielding from the continuing radioactivity. After a period of time (generally five years for US plants), the now cooler, less radioactive fuel is typically moved to a dry-storage facility or dry cask storage, where the fuel is stored in steel and concrete containers. Most U.S. waste is currently stored at the nuclear site where it is generated, while suitable permanent disposal methods are discussed. As of 2007, the United States had accumulated more than 50,000 metric tons of spent nuclear fuel from nuclear reactors. Permanent storage underground in U.S. had been proposed at the Yucca Mountain nuclear waste repository, but that project has now been effectively cancelled - the permanent disposal of the U.S.'s high-level waste is an as-yet unresolved political problem. The amount of high-level waste can be reduced in several ways, particularly nuclear reprocessing. Even so, the remaining waste will be substantially radioactive for at least 300 years even if the actinides are removed, and for up to thousands of years if the actinides are left in. Even with separation of all actinides, and using fast breeder reactors to destroy by transmutation some of the longer-lived non-actinides as well, the waste must be segregated from the environment for one to a few hundred years, and therefore this is properly categorized as a long-term problem. Subcritical reactors or fusion reactors could also reduce the time the waste has to be stored. It has been argued that the best solution for the nuclear waste is above ground temporary storage since technology is rapidly changing. Some people believe that current waste might become a valuable resource in the future. According to a 2007 story broadcast on 60 Minutes, nuclear power gives France the cleanest air of any industrialized country, and the cheapest electricity in all of Europe. France reprocesses its nuclear waste to reduce its mass and make more energy. However, the article continues, "Today we stock containers of waste because currently scientists don't know how to reduce or eliminate the toxicity, but maybe in 100 years perhaps scientists will... Nuclear waste is an enormously difficult political problem which to date no country has solved. It is, in a sense, the Achilles heel of the nuclear industry... If France is unable to solve this issue, says Mandil, then 'I do not see how we can continue our nuclear program.'" Further, reprocessing itself has its critics, such as the Union of Concerned Scientists. Low-level radioactive waste

The nuclear industry also produces a huge volume of low-level radioactive waste in the form of contaminated items like clothing, hand tools, water purifier resins, and (upon decommissioning) the materials of which the reactor itself is built. In the United States, the Nuclear Regulatory Commission has repeatedly attempted to allow low-level materials to be handled as normal waste: landfilled, recycled into consumer items, et cetera. Most low-level waste releases very low levels of radioactivity and is only considered radioactive waste because of its history. Comparing radioactive waste to industrial toxic waste In countries with nuclear power, radioactive wastes comprise less than 1% of total industrial toxic wastes, much of which remains hazardous indefinitely. Overall, nuclear power produces far less waste material by volume than fossil-fuel based power plants. Coal-burning plants are particularly noted for producing large amounts of toxic and mildly radioactive ash due to concentrating naturally occurring metals and mildly radioactive material from the coal. A recent report from Oak Ridge National Laboratory concludes that coal power actually results in more radioactivity being released into the environment than nuclear power operation, and that the population effective dose equivalent from radiation from coal plants is 100 times as much as from ideal operation of nuclear plants. Indeed, coal ash is much less radioactive than nuclear waste, but ash is released directly into the environment, whereas nuclear plants use shielding to protect the environment from the irradiated reactor vessel, fuel rods, and any radioactive waste on site.

Reprocessing Reprocessing can potentially recover up to 95% of the remaining uranium and plutonium in spent nuclear fuel, putting it into new mixed oxide fuel. This produces a reduction in long term radioactivity within the remaining waste, since this is largely short-lived fission products, and reduces its volume by over 90%. Reprocessing of civilian fuel from power reactors is currently done on large scale in Britain, France and (formerly) Russia, soon will be done in China and perhaps India, and is being done on an expanding scale in Japan. The full potential of reprocessing has not been achieved because it requires breeder reactors, which are not yet commercially available. France is generally cited as the most successful reprocessor, but it presently only recycles 28% (by mass) of the yearly fuel use, 7% within France and another 21% in Russia. Unlike other countries, the US stopped civilian reprocessing from 1976 to 1981 as one part of US non-proliferation policy, since reprocessed material such as plutonium could be used in nuclear weapons: however, reprocessing is not allowed in the U.S. In the U.S., spent nuclear fuel is currently all treated as waste. In February, 2006, a new U.S. initiative, the Global Nuclear Energy Partnership was announced. It is an international effort aimed to reprocess fuel in a manner making nuclear proliferation unfeasible, while making nuclear power available to developing countries.

Depleted uranium Uranium enrichment produces many tons of depleted uranium (DU) which consists of U238 with most of the easily fissile U-235 isotope removed. U-238 is a tough metal with several commercial uses—for example, aircraft production, radiation shielding, and armor—as it has a higher density than lead. Depleted uranium is also controversially used in munitions; DU penetrators (bullets or APFSDS tips) "self sharpen", due to uranium's tendency to fracture along shear bands.

Economics The economics of nuclear power plants are primarily influenced by the high initial investment necessary to construct a plant. In 2009, estimates for the cost of a new plant in the U.S. ranged from $6 to $10 billion. It is therefore usually more economical to run them as long as possible, or construct additional reactor blocks in existing facilities. In 2008, new nuclear power plant construction costs were rising faster than the costs of other types of power plants. A prestigious panel assembled for a 2003 MIT study of the industry found the following: In deregulated markets, nuclear power is not now cost competitive with coal and natural gas. However, plausible reductions by industry in capital cost, operation and maintenance costs, and construction time could reduce the gap. Carbon emission credits, if enacted by government, can give nuclear power a cost advantage. —The Future of Nuclear Power Life-extending nuclear power plants beyond their original design lives, by replacing major components and other equipment modernisation, is often economic. Generation II reactors built in the 1960s to 1980s generally had an original design life of 30 to 40 years, and many are being life-extended to 50 or 60 years. In the U.S. every operating nuclear power plant has had a life extension, or is intending to have or apply for an extension, as of 2010. A second life-extension to 80 years may also be economic in many cases.

Chapter- 5

Tidal Power

Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power. The first large-scale tidal power plant (the Rance Tidal Power Station) started operation in 1966. Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Among sources of renewable energy, tidal power has traditionally suffered from relatively high cost and limited availability of sites with sufficiently high tidal ranges or flow velocities, thus constricting its total availability. However, many recent technological developments and improvements, both in design (e.g. dynamic tidal power, tidal lagoons) and turbine technology (e.g. new axial turbines, crossflow turbines), indicate that the total availability of tidal power may be much higher than previously assumed, and that economic and environmental costs may be brought down to competitive levels. Historically, tide mills have been used, both in Europe and on the Atlantic coast of North America. The earliest occurrences date from the Middle Ages, or even from Roman times.

Generation of tidal energy

Variation of tides over a day Tidal power is the only form of energy which derives directly from the relative motions of the Earth–Moon system, and to a lesser extent from the Earth–Sun system. Tidal forces produced by the Moon and Sun, in combination with Earth's rotation, are responsible for the generation of the tides. Other sources of energy originate directly or indirectly from the Sun, including fossil fuels, conventional hydroelectric, wind, biofuels, wave power and solar. Nuclear energy makes use of Earth's mineral deposits of fissile elements, while geothermal power uses the Earth's internal heat which comes from a combination of residual heat from planetary accretion (about 20%) and heat produced through radioactive decay (80%).

Tidal energy is extracted from the relative motion of large bodies of water. Periodic changes of water levels, and associated tidal currents, are due to the gravitational attraction of the Sun and Moon. Magnitude of the tide at a location is the result of the changing positions of the Moon and Sun relative to the Earth, the effects of Earth rotation, and the local geography of the sea floor and coastlines. Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource. A tidal generator uses this phenomenon to generate electricity. Greater tidal variation or tidal current velocities can dramatically increase the potential for tidal electricity generation. The movement of the tides causes a continual loss of mechanical energy in the Earth– Moon system due to pumping of water through the natural restrictions around coastlines, and consequent viscous dissipation at the seabed and in turbulence. This loss of energy has caused the rotation of the Earth to slow in the 4.5 billion years since formation. During the last 620 million years the period of rotation has increased from 21.9 hours to the 24 hours we see now; in this period the Earth has lost 17% of its rotational energy. While tidal power may take additional energy from the system, increasing the rate of slowdown, the effect would be noticeable over millions of years only, thus being negligible.

Generating methods

The world's first commercial-scale and grid-connected tidal stream generator – SeaGen – in Strangford Lough. The strong wake shows the power in the tidal current.

Top-down view of a DTP dam. Blue and dark red colors indicate low and high tides, respectively. Tidal power can be classified into three generating methods:

Tidal stream generator Tidal stream generators (or TSGs) make use of the kinetic energy of moving water to power turbines, in a similar way to wind turbines that use moving air. This method is gaining in popularity because of the lower cost and lower ecological impact compared to tidal barrages.

Tidal barrage Tidal barrages make use of the potential energy in the difference in height (or head) between high and low tides. Barrages are essentially dams across the full width of a tidal estuary, and suffer from very high civil infrastructure costs, a worldwide shortage of viable sites and environmental issues.

Dynamic tidal power Dynamic tidal power (or DTP) exploits an interaction between potential and kinetic energies in tidal flows. It proposes that (for example: 30–50 km length) dams be built from coasts straight out into the sea or ocean, without enclosing an area. Tidal phase

differences are introduced by the presence and dimensions of the dam, which is not negligible in size compared to the local tidal wavelength. This leads to hydraulic head differences across the dam. Turbines in the dam are used to convert power (6–15 GW per dam). In shallow coastal seas featuring strong coast-parallel oscillating tidal currents such as found in the UK, China and Korea, a significant water level differential (of at least 2–3 meters) would appear across the dam.

Current and future tidal power schemes • •

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The first tidal power station was the Rance tidal power plant built over a period of 6 years from 1960 to 1966 at La Rance, France. It has 240 MW installed capacity. The first tidal power site in North America is the Annapolis Royal Generating Station, Annapolis Royal, Nova Scotia, which opened in 1984 on an inlet of the Bay of Fundy. It has 20 MW installed capacity. The first in-stream tidal current generator in North America (Race Rocks Tidal Power Demonstration Project) was installed at Race Rocks on southern Vancouver Island in September 2006. The next phase in the development of this tidal current generator will be in Nova Scotia. A small project was built by the Soviet Union at Kislaya Guba on the Barents Sea. It has 0.4 MW installed capacity. In 2006 it was upgraded with a 1.2MW experimental advanced orthogonal turbine. Jindo Uldolmok Tidal Power Plant in South Korea is a tidal stream generation scheme planned to be expanded progressively to 90 MW of capacity by 2013. The first 1 MW was installed in May 2009. A 1.2 MW SeaGen system became operational in late 2008 on Strangford Lough in Northern Ireland. The Jiangxia Tidal Power Station near the mouth of the Yalu River in China is operational, with current installed capacity of 3.2 MW. It may be expanded. 254 MW Sihwa Lake Tidal Power Plant in South Korea is under construction and planned to be completed by the end of 2010. The contract for an 812 MW tidal barrage near Ganghwa Island north-west of Incheon has been signed by Daewoo. Completion is planned for 2015.

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A 1,320 MW barrage built around islands west of Incheon is proposed by the Korean government, with projected construction start in 2017.

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Other South Korean projects include barrages planned for Garorim Bay, Ansanman, and Swaseongho, and tidal generation associated with the Saemangeum reclamation project. The barrages are all in the multiple-hundred megawatts range.

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Estimates for new tidal barrages in England give the potential generation at 5.6GW mean power.

Country

Place

Mean tidal range (m)

Area of basin Maximum capacity (MW) (km²)

United Kingdom

River Severn

7.8

450

8,640

Russia

Penzhinskaya Bay

6.0

20,500

87,000