This Document Contains Chapters 15 to 16 Chapter 15 Nonrenewable Energy Summary 1. Nonrenewable energy sources are obtained from the earth’s crust and primarily from carbon-containing fossil fuels. They are non-renewable because they have finite lifetimes, but the different forms of non-renewable fuels (e.g., oil, coal, uranium) have highly variable lifetimes. 2. The advantages of oil include low cost, high net energy yield, easy transportation, low land use, well-developed technology, and efficient system of distribution. Disadvantages include need for a substitute discovery; low price encourages waste, air pollution, and water pollution. Oil supplies are estimated to be approximately 80% depleted between 2050 and 2100. 3. The advantages of natural gas include plentiful supplies, high net energy yield, low cost, less air pollution than oil, moderate environment impact, and easy transport. Disadvantages include the fact that it is a nonrenewable resource, comparative high cost, release of carbon dioxide when burned (although lower than other fossil fuels such as coal), leaks, and requirement for pipeline infrastructure for transport. 4. The advantages of coal include plentiful supplies, high net energy yield, low cost, well-developed technology, and air pollution can be partially managed with appropriate technology. Disadvantages include very high environmental impact, land disturbance, air and water pollution, threat to human health, high carbon dioxide emissions, and release of radioactive particles and mercury. 5. The advantages of nuclear power include large fuel supply, low environmental impact, low carbon dioxide emissions (none from energy generation), moderate land disruption and use, and low risk of accidents. Disadvantages include high cost, low net energy yield, high environmental impact in case of accident, catastrophic accidents, long-term storage of radioactive waste, and potential for nuclear proliferation. Key Questions and Concepts 15-1 What Is Net Energy and Why Is It Important? CORE CASE STUDY: Fossil fuels are an example of non-renewable resources. At the time of the Industrial Revolution, wood was our primary energy source. Coal soon replaced wood, and later petroleum came into play. By 1900 40% of our energy came from oil, and today we live in a fossil fuel era. A. Net energy is the usable amount of high-quality energy available from a given quantity of an energy resource. 1. Currently, oil has a high net energy ratio because it comes from large concentrated deposits. As these reserves dwindle, the net energy ratio declines. 2. Any energy source with low or negative net energy yield cannot compete in the marketplace. 3. About 84% of commercial energy is wasted in the United States 15-2 What Are the Advantages and Disadvantages of Using Oil? A. Oil supplies 1/3 of the world’s commercial energy and 40% for the US. B. Crude oil is a thick liquid containing hydrocarbons. C. Peak production occurs when the pressure in a well drops and production starts to decline. 1. Global peak production is the point at which the world meets maximum production. D. After extraction, oil is refined. E. Petrochemicals are used as raw materials chemicals, plastics and many other products. F. Proven oil reserves are deposits from which oil can be extracted profitably under current conditions. Unproven reserves consist of probably reserves (50% chance of recovery) and possible reserves (10-40% chance of recovery). G. The OPEC countries—most of them in the Middle East—have 2/3 of the world’s proven oil reserves and most of the world’s unproven reserves. Oil is the most widely used resource in the world. H. The United States produces about 9% of the world’s crude oil and uses about 23% of crude oil extracted worldwide each year. I. Burning oil produces air pollution and releases the greenhouse gas carbon dioxide into the atmosphere. CASE STUDY: Northeastern Alberta, Canada, has about three-quarters of the world’s oil sand reserves. Accounting for these unconventional oil reserves, Canada has the second largest reserves after Saudi Arabia. The drawback of extracting this resource is the enormous environmental cost. In 2008, the US imported 19% of its oil from Canada, about half of which was produced from tar sands. J. Oil shales are rocks that are a potential supply of heavy oil 1. 72% of these reserves are in the US states of Colorado, Wyoming and Utah, primarily located on public land. 2. It takes considerable energy and money to convert this to shale oil. Net energy is low. 15-3 What Are the Advantages and Disadvantages of Using Natural Gas? A. Natural gas consists mostly of methane and is often found above reservoirs of crude oil. Natural gas also contains small amounts of heavier hydrocarbons and a small amount of hydrogen sulfide. 1. Russia has about 25% of the world’s supply. The United States has about 3.4 %. 2. Burning natural gas releases less CO2 per unit of energy than burning oil, oil sand, or coal. B. Coal bed methane gas is found in coal beds across parts of the United States and Canada. These resources are now actively used but have large potential impacts on air quality and water quality. C. Methane hydrate deposits are another source of unconventional natural gas found in the arctic permafrost and deep beneath the ocean bottom. Extraction techniques are too expensive at present. 15-4 What Are the Advantages and Disadvantages of Using Coal? A. Coal is a solid fossil fuel formed from land plants that lived 300–400 million years ago. It is an abundant energy resource that is burned mostly to produce electricity and steel. 1. Supplies could last from 214 to 1125 years depending on use. 2. The United States has 28% of the world’s proven reserves. 3. It is mostly carbon with small amounts of sulfur. Burning coal releases SO2 and fine particle pollution. 4. Coal burning plants are among the largest emitters of carbon dioxide. 5. Burning coal emits trace amounts of mercury and radioactive materials. 6. The use of coal is growing, especially in China. CASE STUDY: Burning coal and removing pollutants from the resulting emissions produces an ash that contains toxic chemicals such as arsenic, cadmium, chromium, lead, mercury, and radioactive radium. In the United States 57% of this waste is buried or made into slurry to be stored in holding ponds. Toxic metals in coal ash waste ponds have contaminated ground water used by 63 communities in 26 states. The Environmental Integrity Project suggest that they inspect, monitor and regulate coal ash storage sites, and that they phase out all wet storage of coal ash and classify it as a hazardous waste. Coal and electric utility companies have successfully opposed these regulations. B. Beginning in 2008, the coal industry and related companies began funding a clean coal publicity campaign. Critics argue that there is no such thing as clean coal. C. Coal can be converted to gaseous and liquid fuels that burn cleaner than coal, but the costs are high and burning them releases more carbon dioxide than burning coal. Coal can be converted into synthetic natural gas (SNG or syngas) by coal gasification or into liquid fuel by coal liquefaction. These procedures require 50% more coal be mined and will add 50% more CO2 emissions to the atmosphere. 15-5 What Are the Advantages and Disadvantages of Using Nuclear Energy? A. Nuclear power is complex and costly, relying on a controlled nuclear fission reaction that takes place in a reactor. Light water reactors produce 85% of the world’s nuclear generated electricity. 1. LWR’s lose about 75% of energy as waste heat. 2. The entire fuel cycle has a low to negative net energy yield when accounting for mining and upgrading uranium fuel as well as storing wastes and dismantling old plants. 3. Enriched uranium 235 is processed into small pellets which are packed into fuel rods and grouped into fuel assemblies. 4. Control rods are moved in and out of the reactor core to absorb neutrons and regulate the amount of energy produced. 5. A coolant, usually water, cycles through the core to remove heat. 6. A containment shell surrounds the reactor core. B. Proponents of nuclear power tend to focus on low emissions. However, the entire nuclear fuel cycle includes the mining and enrichment of uranium, and the safe storage of wastes. C. 436 nuclear reactors in 31 countries produce 6% of the world’s commercial energy, and 14% of its electricity. D. The government has provided subsidies, tax breaks and loan guarantees to the nuclear power industry. E. An obstacle to nuclear power development has been safety concerns. Built-in safety features make the risk of exposure to radioactivity in more developed countries extremely low. CASE STUDY: The world’s worst nuclear power plant accident occurred in 1986 in Ukraine. On April 26, 1986, a series of explosions at the Chernobyl nuclear plant blew the roof off a reactor building, the reactor partially melted down, and its graphite moderator caught fire and burned for 10 days. The disaster was caused by poor reactor design and human error. After the accident, 350,000 people had to abandon their homes because of contamination. F. Spent fuel rods are removed and stored outside the reactor in water-filled pools. After years of cooling, they can be transferred to dry casks where they need to be stored safely for thousands of years. CASE STUDY: In 1987, the DOE announced plans to store nuclear wastes in the Yucca Mountain desert region. After spending more than $10 billion, concerns about the safety of storing wastes in the earthquake prone region led to a presidential request that Congress cut funding to the project. G. There are three ways to retire worn out nuclear power plants. 1. Dismantle and store the radioactive parts in a secure place. 2. Install a physical barrier and monitor it securely for 30-100 years. 3. Entomb the plant in concrete. H. Nuclear power may not be able to lessen our dependence on foreign oil, as only 2% of our electricity comes from oil burning plants. 1. 95% of uranium used in US power plants is imported, primarily from Russia. I. Nuclear fusion involves nuclear change in which two isotopes of a light element are forced together until they fuse, releasing energy in the process. This technology is still in the laboratory stage. Teaching Tips: Large Lecture Classes: Poll the class on whether we should open offshore sites and ANWR to drilling. Poll again after covering the oil section and discussing the distribution of oil reserves globally. Discuss any differences in perspectives before and after the presentation of the oil section. Carry out a similar poll for nuclear energy after discussing the positive aspects of nuclear energy and again after the negative aspects. Smaller Lecture Classes: Break the class up into teams of four students and ask them to develop a consensus statement about whether or not the U.S. should invest more heavily in nuclear energy and/or oil shale development. In the event that the group cannot agree on a recommendation, ask the group to have a vote and record the results. Have a representative from each group read the statement to the class and report on the vote. Use the results (and conflict) to highlight the difficulty in these particular decisions and discuss the problems in coming to a consensus statement. Key Terms coal crude oil liquefied natural gas (LPG) liquefied petroleum gas (LPG) natural gas net energy nuclear fusion oil sand peak production petrochemicals petroleum proven oil reserves shale oil synthetic natural gas (SNG) tar sand unproven reserves Term Paper Research Topics 1. Oil and natural gas: oil prices and economic development in developing countries; enhanced oil-recovery techniques; shale oil extraction; petrochemicals; heavy oils from Athabascan tar sands; Alaska's Prudhoe Bay gas deposits. 2. Coal: low-sulfur coal reserves in the United States; geographic distribution of coal-burning power plants in the United States; fluidized-bed combustion; the U.S. Synthetic Fuels Corporation. 3. Nuclear fission: centralized energy planning in France; genetic damage to A-bomb survivors; Three Mile Island; Chernobyl; how nuclear fuel assemblies are made; radioactive tailings as a health hazard; geologic repositories for high-level radioactive wastes; commercial low-level nuclear waste dump sites; storing high-level liquid wastes; geographic distribution of nuclear power plants in the United States; keeping weapons-grade nuclear materials "out of the wrong hands"; nuclear reprocessing plants. 4. Breeder nuclear fission versus conventional nuclear fusion; pros and cons. 5. Nuclear regulation in the U.S.: who should be involved in decision making about the development of nuclear energy? 6. What are the trade-offs of coal and unconventional fossil fuel development (e.g., oil shales)? Evaluate these resources from a national security perspective and from an environmental perspective. How do these differ? 7. Examine the legal and societal implications of the Mining Law of 1872; The Atomic Energy Commission (1946–1975); the Nuclear Regulatory Commission; the Energy Research and Development Administration (ERDA); the Nuclear Safety Analysis Center; the Institute of Nuclear Power Operations; the Price-Anderson Act. 8. What is the relationship between the United States and countries with large supplies of critical and strategic energy sources? What should it be? 9. What is clean coal? Does it offer real promise and should it be developed in the U.S.? 10. Evaluate all U.S. oil reserves and estimate the potential supply in these reserves. Is that supply sufficient to justify extraction? Discussion topics 1. U.S. dependence on imported oil. Answer: The U.S. has historically relied on imported oil to meet its energy needs, leading to concerns about energy security and economic vulnerability. Dependence on foreign oil can expose the nation to supply disruptions and price volatility, affecting national security and economic stability. Efforts to diversify energy sources and increase domestic production have aimed to reduce this dependence. 2. Strategic and environmental implications of oil versus coal distributions globally. Would the world be different if coal was the major fossil fuel used? Answer: Globally, oil is a crucial energy source for transportation, while coal is mainly used for electricity generation. If coal were the primary fossil fuel, there might be less emphasis on oil-rich regions, potentially altering geopolitical dynamics. However, coal's higher carbon emissions could exacerbate climate change and environmental degradation, leading to greater global warming concerns and health impacts from air pollution. 3. Fossil fuels and the greenhouse effect. How do you balance use of fossil fuels against the risks of climate change? Answer: Fossil fuels contribute significantly to greenhouse gas emissions, driving climate change. Balancing their use involves transitioning to cleaner energy sources, improving energy efficiency, and investing in carbon capture technologies. Policymakers must weigh economic growth and energy needs against environmental protection and the long-term consequences of climate change. 4. Environmental versus economic tradeoffs of domestic oil drilling. Answer: Domestic oil drilling can boost economic growth, create jobs, and enhance energy security. However, it also poses environmental risks, including habitat destruction, oil spills, and pollution. The tradeoff requires careful consideration of immediate economic benefits against potential long-term environmental costs and the impact on ecosystems and public health. 5. Oil and gas exploration on public lands. How much development should occur in sensitive ecological settings? Answer: Exploration on public lands can provide economic benefits and energy resources but must be balanced against preserving sensitive ecological settings. Limiting development in these areas can protect biodiversity, water resources, and cultural sites. The extent of development should consider environmental impact assessments and prioritize conservation where possible. 6. What will happen when oil runs out? Answer: As oil reserves deplete, the world will face energy shortages, economic challenges, and potential geopolitical tensions. Transitioning to alternative energy sources, such as renewables and nuclear power, is crucial to mitigate these impacts. Investment in energy efficiency and innovation in sustainable technologies will also play a key role in preparing for a post-oil future. 7. Should the U.S. mandate higher energy efficiency? Answer: Mandating higher energy efficiency can reduce energy consumption, lower greenhouse gas emissions, and decrease reliance on fossil fuels. It can also lead to cost savings for consumers and businesses. Implementing stricter efficiency standards and incentivizing energy-efficient technologies can help the U.S. meet its environmental and economic goals while promoting sustainable energy practices. Activities and Projects 1. Arrange a class excursion to a coal-burning power plant in your vicinity. Have a company spokesperson explain the electricity-generating process and the design and operating features of equipment and systems that control air pollution emissions and reduce thermal water pollution. 2. Schedule a guided tour to a nuclear power plant for your class. 3. If there is a nuclear power plant operating in your vicinity, invite a spokesperson from your local emergency disaster preparedness agency to present a guest lecture explaining the emergency evacuation plan for this facility. 4. Survey the cost of gasoline in your city and compare to the national average. Have students research where the profits from gasoline sales go. 5. Give the students an assignment of living a low carbon life for one day. Have them record a diary of their activities and then carry out an analysis of their carbon emissions for that day. 6. Have students perform a carbon footprint analysis online. 7. A new power plant must be built in your community, but it remains to be decided whether it will be a fossil-fuel or nuclear plant. As a class exercise, set up a mock public hearing to present the arguments for both sides. Make specific role assignments so that prepared statements will accurately reflect varying points of view such as those of contractors, environmentalists, project engineers, state energy officials, and concerned citizens. 8. As a class exercise, assign appropriate roles and research assignments to students (or teams of students) and stage mock negotiations among several less-developed nations seeking to establish a cartel for controlling the supply and price of the vitally important industrial commodity X. Assume that the cartel is successful, and stage additional mock negotiations between the cartel and more-developed nations whose economies are suffering grievously for want of affordable supplies of commodity X. Attitudes and Values 1. Do you favor requiring all cars to get at least 21 kilometers per liter (50 miles per gallon) and vans and light trucks to get at least 15 kilometers per liter (35 miles per gallon) of gasoline within the next 10 years? Who would benefit and who would be harmed by these regulations? Answer: Requiring higher fuel efficiency standards would reduce fuel consumption and emissions, benefiting the environment and consumers through lower fuel costs. However, automotive manufacturers might face increased production costs to develop more efficient vehicles, potentially passing costs onto consumers. Oil companies could see reduced demand for gasoline, impacting their revenues. 2. Would you favor much stricter, twice-a-year inspections of air pollution control equipment on motor vehicles and tough fines for not keeping these systems in good working order? Answer: Stricter inspections and fines would ensure vehicles maintain optimal emissions control, improving air quality and public health. While beneficial for the environment, this could impose additional costs and inconvenience on vehicle owners, particularly those with older cars, as they may need to invest in repairs or upgrades to comply with regulations. 3. Would you favor a $2 tax on a gallon of gasoline and heating oil to help reduce wasteful consumption, extend oil supplies, reduce air pollution, delay projected global warming, and stimulate improvements in energy efficiency and the use of less harmful energy sources? What would this tax due to lower-income citizens? Answer: A $2 tax could incentivize energy conservation and investment in cleaner technologies, reducing environmental impacts. However, it would disproportionately affect lower-income citizens, who may already struggle with energy costs. To mitigate this, revenue from the tax could fund subsidies or rebates for energy-efficient upgrades and public transportation. 4. Is there an obligation to save fossil fuel resources for future generations? Answer: There is a moral obligation to conserve fossil fuel resources, as they are finite and vital for future generations' energy needs. Sustainable practices, such as developing renewable energy sources and improving energy efficiency, can ensure that future generations have access to necessary resources and a stable climate. 5. Would you support laws requiring that all new homes and buildings meet high energy-efficiency standards for insulation, air infiltration, and heating and cooling systems? Answer: Supporting such laws would reduce energy consumption, lower utility costs, and decrease greenhouse gas emissions. While initial construction costs might increase, long-term savings and environmental benefits outweigh the costs. These standards would also promote the use of sustainable materials and technologies in the construction industry. 6. Would you favor such a law for existing homes and buildings? Answer: Implementing high energy-efficiency standards for existing homes and buildings would significantly reduce energy waste and emissions. Although retrofitting can be costly, government incentives and subsidies could ease the financial burden. Such a law would ultimately improve energy efficiency, lower utility costs, and contribute to environmental conservation. News Videos Does Clean Coal Exist? The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Additional Video Resources American Experience: Alaskan Pipeline (PBS documentary series) How was the Alaskan Pipeline built and what is its impact? http://www.pbs.org/wgbh/amex/pipeline/ American Experience: Meltdown at Three Mile Island (PBS documentary series) America’s worst nuclear disaster, the causes and the aftermath. http://www.pbs.org/wgbh/amex/three/sfeature/index.html Crude (Documentary, 2009) http://www.crudethemovie.com/ A Crude Awakening (Documentary, 2007) http://www.oilcrashmovie.com/index2.html The End of Suburbia: Oil Depletion and the Collapse of The American Dream (Documentary, 2004) http://www.endofsuburbia.com/ An Inconvenient Truth (Documentary, 2006) A documentary on Al Gore's campaign to make the issue of global warming a recognized problem worldwide. http://www.climatecrisis.net/ NOVA: World in the Balance—The People Paradox China segment on fossil fuel use. Main Website: http://www.pbs.org/wgbh/nova/worldbalance/ Teacher’s Guide: http://www.pbs.org/wgbh/nova/teachers/programs/3108_worldbal.html Oil on Ice (Documentary, 2004) Arctic National Wildlife Refuge and drilling for oil. http://www.oilonice.org/ Web Resources U.S. Department of Energy World energy overview. http://www.eia.doe.gov/iea/overview.html U.S. Department of Energy U.S. Oil Shale resources. http://www.fossil.energy.gov/programs/reserves/npr/Oil_Shale_Resource_Fact_Sheet.pdf U.S. Department of Energy U.S. energy source page. http://www.energy.gov/energysources/index.htm International Energy Agency Oil Market Report. http://omrpublic.iea.org/ Suggested Answers to End of Chapter Review Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 371. Describe our history of energy use over the last three hundred years. What is net energy and why is it important for evaluating energy resources? Explain why the nuclear fuel cycle has a low net energy yield and thus must be subsidized to compete in the open marketplace. Answer: • About 275 years ago, we invented the steam engine used to power engines and machinery. Firewood provided about 91% of the energy used for heating and for running steam engines. By 1900, coal provided 73% of our energy. In the mid-1800s, we started pumping oil from the ground and converting it to fuels such as gasoline and heating oil. By 1900, we got 40% of our energy from oil, 38% from coal, and 18% from natural gas. In the 1950s, we learned how to split the nuclei of certain types of uranium atoms and to use this energy to produce electricity. Today, 82% of our energy comes from nonrenewable oil, natural gas, and coal resources. • Net energy is the amount of high-quality energy available from a resource minus the amount of energy needed to make it available. It is calculated by estimating the total amount of energy available from the resource over its lifetime and then subtracting the amount of energy used in finding, processing, and transporting the useful energy to users. • Electricity produced by the nuclear power fuel cycle has a low net energy ratio because large amounts of energy are needed for each step in the cycle: to extract and process uranium ore, convert it into nuclear fuel, build and operate nuclear power plants, store the highly radioactive wastes they produce for thousands of years, dismantle the highly radioactive plants after their 15– 60 years of useful life, and store the radioactive parts. A rule of thumb is that any energy resource with a low net energy will need government subsidies to compete in the marketplace with high net energy resources. 2. What is crude oil (petroleum) and how is it extracted from the earth and refined? What percentages of the commercial energy use in the world and in the United States are provided by crude oil? What is the peak production for an oil well and for the world? What is a petrochemical and why are such chemicals important? What are proven oil reserves? Describe two types of unproven reserves. Discuss the question of how long global and U. S. supplies of conventional crude oil might last. What are the major advantages and disadvantages of using conventional oil as an energy resource? Answer: • Petroleum, or crude oil, is oil as it comes out of the ground. This black, gooey liquid consists of hundreds of different combustible hydrocarbons along with small amounts of sulfur, oxygen, and nitrogen impurities. To extract the oil, a well is drilled vertically or horizontally into the deposit beneath the ground. Then oil, drawn by gravity out of the rock pores flows into the bottom of the well and is pumped to the surface. In the process of refining, it is heated to separate it into components with different boiling points. • oil is the most widely use form of commercial energy and about 79% of the energy used in the world and 85% of the energy used the United States) comes from burning nonrenewable fossil fuels. • Peak production for an oil well is when the pressure in a well drops and its rate of conventional crude oil production starts to decline. Peak production for the world is the point when we reach the global maximum overall rate of conventional crude oil production. • Some of the products of crude oil distillation, called petrochemicals, are used as raw materials in industrial organic chemicals, cleaning fluids, pesticides, plastics, synthetic fibers, paints, medicines, and many other products. • Proven oil reserves are identified deposits from which conventional crude oil can be extracted profitably at current prices with current technology. • Two types of unproven reserves include probable reserves (with a 50% or better chance of recovery), and possible reserves (with a 10-40% chance of recovery). • It is predicted global reserves of conventional crude oil will be 80% depleted sometime between 2050 and 2100, depending on consumption rates. The United States has only about 1.5% of the world’s proven crude oil reserves. • See Figure 15-6 for the advantages and disadvantages of using crude oil as an energy resource. The extraction, processing, and burning of nonrenewable oil and other fossil fuels have severe environmental impacts, including land disruption, air pollution, greenhouse gas emissions, water pollution, and loss of biodiversity. 3. What is tar sand, or oil sand, and how is it extracted and converted to heavy oil? What are some environmental problems related to the use of this resource? What is shale oil and how is it produced? What are the major advantages and disadvantages of using heavy oils produced from tar sand and shale oil as energy resources? Answer: • Tar sand, or oil sand, is a mixture of clay, sand, water, and a combustible organic material called bitumen—a thick, sticky, tar-like heavy oil with a high sulfur content. If tar sand is close enough to the surface it can be strip-mined. First the overlying surface is clear-cut, next the overburden is stripped away, and then the tar sand is dug up and taken to an upgrading plant. There the oil sand is mixed with hot water and steam to extract the bitumen, which is converted into a low-sulfur, synthetic, crude oil suitable for refining. • Some environmental problems include large amounts of water needed for processing, severe land disruption, severe water pollution, air pollution and CO2 emissions when produced and burned. • Oily rocks are another potential supply of heavy oil. Such rocks, called oil shales contain a solid combustible mixture of hydrocarbons called kerogen. It can be extracted from crushed oil shales by heating them in a large container, a process that yields a distillate called shale oil. Before the thick shale oil can be sent by pipeline to a refinery, it must be heated to increase its flow rate and processed to remove sulfur, nitrogen, and other impurities. • Advantages of using heavy oils from tar sand and oil shale as energy resources include: a moderate cost (tar sand); large potential supplies, especially tar sands in Canada; easy transportation within and between countries; efficient distribution system in place; and technology well-developed (tar sand). Disadvantages include: high cost (oil shale), low net energy yield, and environmental costs not included in market price. 4. Define natural gas, liquefied petroleum gas (LPG), and liquefied natural gas (LNG)? What three countries have most of the world’s natural gas reserves? What are the major advantages and disadvantages of using conventional natural gas as an energy resource? What are three sources of unconventional natural gas and what major problems are related to the use of these resources? Answer: • Natural gas is a mixture of gases of which 50–90% is methane (CH4). Conventional natural gas lies above most reservoirs of crude oil. • When a natural gas field is tapped, propane and butane gases are liquefied and removed as liquefied petroleum gas (LPG). • So that it can be transported across oceans, natural gas is converted to liquefied natural gas (LNG) at a very low temperature and high pressure. This highly flammable liquid is then put aboard refrigerated tanker ships. After arriving at its destination, it is heated and converted back to the gaseous state at regasification plants before it is distributed by pipeline. • Russia, Iran and Qatar have most of the world’s natural gas reserves. • Advantages and of using conventional natural gas as an energy resource include: ample supplies, high net energy yield, low cost, less air pollution than other fossil fuels, lower CO2 emissions than other fossil fuels, easily transported by pipeline, low land use, and good fuel for fuel cells, gas turbines, and motor vehicles. Disadvantages include nonrenewable resource, releases CO2 when burned, government subsidies, environmental costs not included in market price, methane (a greenhouse gas) can leak from pipelines, difficult to transfer from one country to another, and can be shipped across oceans only as highly explosive LNG. • Three sources of unconventional natural gas are coal bed methane gas, natural gas found in underground shale beds, and methane hydrate trapped in permafrost. The problems with producing natural gas from the first two sources include scarring of land, large water use, and potential pollution of drinking water from aquifers. So far, it costs too much to get natural gas from methane hydrates, and the release of methane to the atmosphere during removal and processing would have detrimental effects. 5. What is coal and how is it formed? How does a coal-burning power plant work? What three countries have the largest proven reserves of coal? Describe the use of coal in China. Describe the problem of coal ash waste. Explain why there is no such thing as clean coal. What are the major advantages and disadvantages of using coal as an energy resource? Answer: • Coal, a fossil fuel, is a rock that burns and was formed in several stages out of the remains of land plants that were buried 300–400 million years ago and exposed to intense heat and pressure over millions of years. • Power is generated by burning pulverized coal to boil water and produce steam that then spins a turbine. • The United States, Russia and China have the largest reserves of coal. • China burns more coal than any other nation and this has helped fuel its rapid economic growth. In 2009, China was building the equivalent of one large coal-fired power plant per week. Most of them lacked modern air pollution control. China has become the world’s leading emitter of CO2 and of sulfur dioxide. • Burning coal and removing pollutants from the emissions produces an ash containing highly toxic chemicals such as arsenic, cadmium, chromium, lead, mercury, and radioactive radium. Much of this is then stored in holding ponds. • Coal can be burned more cleanly, but there is no coal that does not pollute. • Advantages of using coal as an energy resource include: ample supplies (214–1125 years), high net energy yield, low cost, well-developed technology, and air pollution can be reduced with improved technology. Disadvantages include air and water pollution, severe threat to human health when burned, environmental costs not included in market price, large government subsidies, high CO2 emissions when produced and burned, and radioactive particle and toxic mercury emissions. 6. What is synthetic natural gas (SNG)? What are the major advantages and disadvantages of using liquid and gaseous synfuels produced from coal? Answer: • Solid coal can be converted into synthetic natural gas (SNG) by a process called coal gasification, which removes sulfur and most other impurities from coal. It is also converted into liquid fuels such as methanol and synthetic gasoline through a process called coal liquefaction. These fuels, called synfuels, are often referred to as cleaner versions of coal. • Advantages and disadvantages of using synthetic natural gas (SNG) and liquid synfuels produced from coal include: large potential supply, vehicle fuel, moderate cost, and lower air pollution than coal when burned. Disadvantages include low to moderate net energy yield, higher cost than coal, requires mining 50% more coal, environmental costs not included in market price, high environmental impact, large government subsidies, high water use, and higher CO2 emissions than coal. 7. How does a nuclear fission reactor work and what are its major safety features? Describe the nuclear fuel cycle. Describe some of the consequences of the Chernobyl nuclear power plant accident. What are the major advantages and disadvantages of relying on the nuclear fuel cycle as a way to produce electricity? Compare the advantages and disadvantages of using the nuclear fuel cycle and coal to produce electricity. Answer: • A nuclear power plant is a highly complex and costly system designed to perform a relatively simple task: to boil water to produce steam that spins a turbine and generates electricity. What makes it complex is the use of a controlled nuclear fission reaction to provide the heat. The fission reaction takes place in a reactor. The most common reactors are called light-water reactors (LWRs). • The overlapping and multiple safety features of a modern nuclear reactor (emergency core cooling system and containment shell with thick steel-reinforced, concrete walls surrounds the reactor core) make it very expensive to build and maintain. • The nuclear fuel cycle includes the nuclear power plant, the mining of uranium, processing and enriching the uranium to make fuel, using it in a reactor, and safely storing the resulting highly radioactive wastes for thousands of years until their radioactivity falls to safe levels. • On April 26, 1986, two simultaneous explosions in one of the reactors in a nuclear power plant in Chernobyl, Ukraine (then part of the Soviet Union) blew the massive roof off a reactor building. The reactor partially melted down and its graphite moderator caught fire and burned for 10 days. The initial explosion and the prolonged fires released a huge radioactive cloud that spread over much of Belarus, Russia, Ukraine, and Europe and eventually encircled the planet. In 2008, after 22 years, areas of the Ukraine and northern Europe are still dangerously contaminated with radioactive materials. • The nuclear power fuel cycle has a low environmental impact and a very low accident risk, but its use has been limited because of high costs, a low net energy yield, long-lived radioactive wastes, vulnerability to sabotage, and the potential for spreading nuclear weapons technology. • Both approaches to power generation yield dangerous byproducts (nuclear waste and coal ash). In contrast, however, nuclear power generation produces no emissions, while coal contributes greatly to climate change. 8. How do nuclear power plant operators store highly radioactive spent fuel rods? Why are spent fuel rods vulnerable to terrorist acts? What is the connection between commercial nuclear power plants and the spread of nuclear weapons? How can we deal with the highly radioactive wastes produced by the nuclear fuel cycle? What can we do with worn out nuclear power plants? Discuss whether using nuclear power can reduce U.S. dependence on imported oil. What role is nuclear power likely to play in slowing projected global climate disruption caused in part by emissions of carbon dioxide? What role might new-generation nuclear power plants play? Answer: • Radioactive wastes must be stored safely for at least 10,000 years and possibly up to 240,000 years. Secure and safe disposal methods are being developed such as deep burial; most scientists and engineers agree in principle that deep burial is the safest and cheapest way to store high-level radioactive waste. • Radioactive waste storage pools and dry casks are usually located outside of reactor buildings and thus are not protected as well as the reactor core is from acts of terrorism. • Nuclear reactors and uranium fuel enrichment and purification technology have been available in the international marketplace for decades. This equipment can be used to produce bomb-grade material for use in nuclear weapons. • Long-term disposal of nuclear waste is very problematic. It is generally thought that deep burial in an underground repository is the best option. Spent fuel rods can also be processed to reduce their storage time, but this is costly. • Old nuclear power plants can be dismantled and its radioactive parts stored in a secure repository, which no country has built so far—a physical barrier installed around the plant and set up with full-time security for 30–100 years, until the plant can be dismantled after its radioactivity has reached safer levels; or enclose the entire plant in a concrete and steel tomb. • Some proponents of nuclear power in the United States claim it will reduce the country’s dependence on imported oil. Other analysts disagree, pointing out that only 2– 3% of the electricity in the United States is generated by burning oil. • Nuclear power advocates say that increased use of nuclear power will reduce the threat of global warming by greatly reducing or eliminating emissions of CO2. However, scientists say that when the entire nuclear fuel cycle is considered, nuclear power plants do emit CO2. MIT researchers concluded that some 1,000 to 1,500 new reactors would have to be built worldwide by 2025 in order to put a serious dent in projected global warming. • Partly to address economic and safety concerns, the U. S. nuclear industry plans to build hundreds of smaller, second-generation plants. These advanced light- water reactors have built-in safety features designed to make meltdowns, explosions, and the release of radioactive emissions almost impossible. However, safety concerns remain. 9. What is nuclear fusion and what is its potential as an energy resource? Describe what happened to conventional nuclear power and its possible role in the future. Answer: • Nuclear fusion is a nuclear change in which two isotopes of light elements, such as hydrogen, are forced together at extremely high temperatures until they fuse to form a heavier nucleus, releasing energy in the process. Some scientists hope that controlled nuclear fusion will provide an almost limitless source of heat and electricity, but this technology is not available yet. • Conventional nuclear power has been largely subsidized. Proponents of nuclear power argue that governments should continue funding research, development, and pilot-plant testing of potentially safer and cheaper conventional fission reactor designs, along with nuclear fusion. Others would support expansion of nuclear power only when certain safety, financial and energy criteria are met. Some analysts call for phasing out all or most government subsidies, tax breaks, and insurance and loan guarantees for nuclear power. 10. What are this chapter’s three big ideas? Describe how the three principles of sustainability could be applied to our future energy resource choices. Answer: • The three big ideas are: ○ A key factor to consider in evaluating the usefulness of any energy resource is its net energy yield. ○ Conventional oil, natural gas, and coal are plentiful and have moderate to high net energy yields, but using any fossil fuel, especially coal, has a high environmental impact. ○ Nuclear power has a low environmental impact and a very low accident risk, but high costs, a low net energy yield, long-lived radioactive wastes, and the potential for spreading nuclear weapons technology have limited its use. • The principles of sustainability would dictate that no habitat be destroyed in the process of generating energy, that all energy be ultimately derived from the sun, and that we do not overload the chemical cycles (with too much carbon, for example). Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. In the past, we have made shifts in our reliance on energy resources (Core Case Study). Do you believe that over the next 50 years, we need to shift to a new mix of more sustainable and less environmentally harmful renewable energy resources, or continue depending mostly on nonrenewable fossil fuels and nuclear power? Explain. How might such a shift affect your lifestyle and that of any children and grandchildren that you might have? Answer: It is imperative that we shift to more sustainable sources of energy in order to diminish and ameliorate the negative environmental effects that fossil fuel consumption have had on our environment. This shift may mean that future generation may have to be more efficient in their use of energy, but ultimately, they will live in an environment that is less polluted. 2. Should governments give a high priority to considering net energy yields when deciding what energy resources to support? What are other factors that should be considered? Explain your thinking. Answer: Net yield should definitely be considered. If it is not, it is ultimately the populace that will need to support or subsidize the industry. True efficiency is in the best interest of the people from both an economic and environmental standpoint. Other factors that should be considered are the environmental implications of using a given source, beginning with extraction of the resource to waste disposal. 3. To continue using oil at the current rate, we must discover and add to global oil reserves the equivalent of two new Saudi Arabian supplies every 10 years. Do you think this is possible? If not, what effects might the failure to find such supplies have on your life and on the lives of any children or grandchildren that you might have. Answer: Most oil geologists believe finding and adding substantial global oil reserves is highly unlikely. Especially since the international community would need to discover an oil reserve equivalent to two new Saudi Arabian supplies every ten years. To me, this seems almost impossible. There are many types of oil, like petroleum and oil sand or shale, but at the rate the global community is using these supplies we will be out of resources in my lifetime. This will definitely affect my children and grand-children. If we don’t take action quickly by reducing oil use and finding alternative power sources then my children and grand-children will be faced with the problem of lack of energy that my generation caused. 4. List three actions you can take to reduce your dependence on oil and gasoline in order to slow depletion of the world’s oil. Which of these things do you already do or plan to do? Answer: Three actions I can take to reduce dependence on oil and gas: (1) Drive less, walk and bike more—It’s hard to give up a car and walk to school or work instead of driving, especially since our community is so centered on cars for work, play, and general mobility, and the distances involved are so great. Carpooling is an option that I use with my friends and I do use my bike in the neighborhood. So, it’s a good goal to have but it may be hard to accomplish all the time. (2) Buy a hybrid car—When shopping for a new car, I would definitely look at hybrids and try to buy one of those rather than another car. Even if I didn’t buy a hybrid car I could try and buy a car that gets better gas mileage rather than a gas-guzzling SUV. (3) Limit my use electricity—If everyone in the world turned everything off that they were not using instead of leaving it plugged in, we could save so much power and energy. Even if we didn’t turn everything off but reduced our use of electronic and powered products we could help reduce our use of energy. Even unplugging things when they are not in use saves electricity. 5. Explain why you are for or against increasing oil imports to the United States or to the country in which you live. If you favor reducing dependence on oil imports, what do you think are the three best ways to do this? Answer: In 2009 the United States imported about 60 percent of its oil. We are not producing enough of our own oil to supply our needs and we continue to import it from OPEC (Organization of Petroleum Exporting Countries) nations and the Middle East. If we continue to import from the Middle East and other countries that support or condone terrorism, then we are fighting and funding a war on terrorism while supporting the enemy by spending large amounts of money on imported oil. I favor reducing our oil imports by promoting energy efficiency and conservation programs, levying taxes on high-consumers, and providing tax breaks to others for using less energy. 6. Some people in China point out that the United States and European nations fueled their economic growth during the industrial revolution by burning coal, with little effort to control the resulting air pollution. They then sought cleaner energy sources later when they became more affluent. China says it is being asked to clean up from the effects of coal burning before it becomes affluent enough to do so, without greatly slowing its economic growth. How would you deal with this dilemma? Since China’s outdoor air pollution has implications for the entire world, what role, if any, should the more-developed nations play in helping China to reduce its dependence on coal and to burn coal and to rely more on sustainable energy resources? Answer: There may be a range of answers to this question depending on personal perspectives. One potential solution is for the developed world to transfer pollution control or energy production technologies at a limited cost or for free to aid in the reduction of pollution. More aggressive policies might include sanctions or tariffs but these would require ignoring the ethical issues described in this question. 7. Explain why you agree or disagree with the following proposals made by various energy analysts as ways to solve U.S. energy problems: (a) find and develop more domestic supplies of crude oil; (b) place a heavy federal tax on gasoline and imported oil to help reduce the waste and consumption of crude oil resources and to encourage use of other alternatives; (c) increase dependence on coal; (d) phase out use of coal by 2050; (e) increase dependence on nuclear power; (f) phase out all nuclear power plants by 2025. Answer: Agree or Disagree? Note—the answers below are possible answers but the complexity of these questions means that multiple solutions and responses are possible. a. Place a heavy tax on gas and imported oil to help reduce the waste of oil resources. AGREE: major environmental problems are being caused by our overuse of oil and wasting some of the oil we use in inefficient process in general. b. Build several more liquefied natural gas processing plants to facilitate greatly increased importing of this resource. AGREE: if we could switch to the cleaner burning natural gas and process it ourselves rather than import as much natural gas, we could cut down on the energy that is used in the importation process in transportation, etc. Also, we could use the flared gas that is wasted at oil refineries. c. Increase dependence on coal. DISAGREE: although our coal supplies could last us anywhere from 214 to 1,125 years, coal burning causes major air pollution and has a severe environmental impact on our land, water, and air. It is the single biggest polluter in many major, well-developed countries. All of these reasons, as well as many others, are explanation enough for why we should not increase our dependence on coal. Some people would argue that we should do this by using clean coal technologies and sequestering carbon emissions. d. Phase out use of coal by 2050. AGREE: Relying on coal has extremely detrimental effects on the climate and on human health. Of course, in phasing out coal, we would be shifting our dependence to something else. The objective should be to replace this dirty energy source with clean renewable alternatives and to increase efficiency dramatically by 2050. e. Increase dependence on nuclear power. DISAGREE: a lot of the public distrusts nuclear power and is afraid of it, and of the government’s upkeep of the plants and oversight of the facilities by the NRC. There have been several cases in the past few years of leaks and other problems with nuclear materials. Also, with nuclear matter there is always a chance of explosion or meltdown as well as the chance of exposure to radioactive material. Until these problems have been addressed we should not consider nuclear power, even though it is a far cleaner energy source than coal in terms of emissions. f. Phase out all nuclear power plants by 2025. AGREE: nuclear power is too costly and too risky. Nuclear power plants are also spreading the knowledge needed to make nuclear weapons. Currently 60 countries in the world have nuclear weapons or the knowledge and ability to make them. As a young person growing up in the unstable world of today this is a frightening thought. 8. Explain why you agree or disagree with each of the following proposals made by the U.S. nuclear power industry: (a) provide up to $350 billion in government subsidies and loan guarantees to build a large number of better-designed nuclear fission power plants, in order to reduce dependence on imported oil and slow projected climate change, (b) prevent the public from participating in hearings on licensing of new nuclear power plants and on safety issues at the nation’s nuclear reactors, (c) allow electric utility companies to begin charging consumers for some of the costs of proposed new nuclear power plants before they are built; (d) greatly increase federal subsidies for developing nuclear fusion. Agree or Disagree? Some possible answers are below. Answer: a. AGREE: it would reduce our country’s dependence on oil as well as help us come up with better-designed plants and reduce global warming. b. DISAGREE: the public should know what’s going on in the nation. Especially if it is going on in their community and includes the licensing of new nuclear power plants. Safety issues would be of paramount importance for everyone to be informed about. c. DISAGREE: this would have the same effect of subsidizing the development of a nuclear power infrastructure. Consumers should be offered the option of funding new projects, but the projects should be based on a model of sustainability. d. AGREE: nuclear fusion has potential to produce a lot of energy and be the fuel of the future. It could destroy toxic wastes, supply electricity for home and business use, as well as electrolyze water to produce hydrogen gas in large enough quantities to run a hydrogen economy. Although we have already spent 50 years on research, it is possible that nuclear fusion could be amazing for our country and the global community as a whole. At present the whole concept seems to be a scientist’s pipe dream. 9. Congratulations! You are in charge of the world. What roles would nonrenewable fossil fuels, the nuclear fuel cycle, and nuclear fusion plan in your energy policy? Explain. Answer: The first two options would be gradually phased out, with a moratorium placed on the development of any new infrastructure, in favor of renewable alternatives. I would continue to support the academic pursuit of research on nuclear fusion (as I would for any other scientific pursuit), but would not include it in my energy policy. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: 1. Cultural differences affect brand perception and strategy adaptation. 2. Balancing global identity with local customization and diverse consumer behaviors. Ecological Footprint Analysis In 2008, the average fleet-wide fuel economy of new cars, light trucks, and SUVs in the United States was 11.4 kilometers per liter (kpl) or 26.6 miles per gallon (mpg), and the average motor vehicle in the United States was driven 19,300 kilometers (12,000 miles). There were about 250 million motor vehicles in the United States in 2008. The U.S. Environmental Protection Agency estimates that 2.3 kilograms of CO2 are released when 1 liter of gasoline is burned (19.4 pounds CO2 are released when 1 gallon is burned). Use these data to calculate the gasoline consumption and carbon footprints of individual motor vehicles with different fuel efficiencies and for all of the motor vehicles in the United States by answering the following questions. 1. Suppose a car has an average fuel efficiency of 8.5 kpl (20 mpg) and is driven 19,300 kilometers (12,000 miles) a year. (a) How many liters and gallons of gasoline does this vehicle consume in a year? (b) If gasoline costs $0.80 per liter ($3.00 per gallon), how much will the owner spend on fuel in a year? (c) How many liters (and gallons) and of gasoline would be consumed by a U.S. fleet of 250 million such vehicles in a year? (1 liter = 0.265 gallons and 1 kilometer = 0.621 miles) 2. Recalculate the values in Question 1, assuming that a car has an average fuel efficiency of 19.6 kpl (46 mpg). 3. Determine the number of metric tons of CO2 emitted annually by (a) the car described in Question 1 with a low fuel efficiency, (b) a fleet of 250 million vehicles with this same fuel efficiency, (c) the car described in Question 2 with a high fuel efficiency, and (d) a fleet of 250 million vehicles with this same high fuel efficiency. These calculations provide a rough estimate of the CO2 footprints for individual cars and for the entire U.S. fleet with low and high efficiency cars. (1 kilogram = 2.20 pounds; 1 metric ton = 1,000 kilograms = 2,200 pounds = 1.1 tons; 1 ton = 2,000 pounds). 4. If the average fuel efficiency of the U.S. fleet increased from 8.5 kpl (20 mpg) to 19.6 kpl (46 mpg), by what percentage would this reduce the CO2 emissions from the entire fleet per year? You can think of this as the percentage reduction in the carbon footprint of U.S. motor vehicle fleet. Answers: Chapter 16 Energy Efficiency and Renewable Energy Summary 1. The advantages of improving energy efficiency include benefits to the environment, people, and the economy through prolonged fossil fuel supplies, reduced oil imports, very high net energy yield, low cost reduction of pollution, and improved local economies. 2. The advantages of solar energy include reduction of air pollution, reduction of dependence on oil, and low land use. Disadvantages include production of photocells results in release of toxic chemicals, life of systems is short, need backup systems, and high cost. 3. The advantages of hydropower include high net energy yield, low cost electricity, long life span, no carbon dioxide emissions during operation, flood control below dam, water for irrigation, and reservoir development. Disadvantages include high construction cost, high environmental impact, high carbon dioxide emissions from biomass decay, flooding of natural areas, conversion of land habitats to lake habitats, danger of dam collapsing, people relocation, limits fish populations below dam, and decrease flow of silt. 4. The advantages of wind power include high net energy yield and efficiency, low cost and environmental impact, no carbon dioxide emissions, and quick construction. Disadvantages include need for winds and backup systems, high land use, visual and noise pollution, interfering with bird migrations. 5. The advantages of biomass include large potential supplies, moderate costs, no net carbon increase, and use of agricultural, timber, and urban wastes. Disadvantages include nonrenewable resource if not harvested sustainably, moderate to high environmental impact, low photosynthetic efficiency, soil erosion, water pollution, and loss of wildlife. 6. The advantages of geothermal energy include very high efficiency, low carbon dioxide emissions, low cost and land use, low land disturbance, and moderate environmental impact. Disadvantages include scarcity of suitable sites, potential depletion, moderate to high air pollution, noise and odor, and high cost. 7. The advantages of hydrogen gas include the fact that it can be produced from water, the low environmental impact, no carbon dioxide emission, competitive price, ease of storage, safety, and high efficiency. Disadvantages include energy needed to produce the fuel, negative energy yield, nonrenewable, high cost, and no fuel distribution system exists. 8. The advantages of using smaller, decentralized micropower sources include size, fast production and installation, high energy efficiency, low or no CO2 emissions, low air pollution, easy repair, reliable, increased national security, and easily financed. 9. We can improve energy efficiency by increasing fuel efficiency standards, large tax credits for purchasing energy efficient cars, houses, and appliances, encouraging independent energy production, and increasing research and development. Key Questions and Concepts 16-1 Why Is Energy Efficiency an Important Energy Resource? CORE CASE STUDY: Amory Lovins founded the Rocky Mountain Institute to consult on issues of energy and resource efficiency. The headquarters is located in an ultra-efficient building in Snowmass, Colorado that requires very little energy beyond what is derived from the sun. Lovins is a leader in the transition to a more energy efficient world. A. Energy saved through efficiency reduces the need for the production of energy from another source. Energy efficiency is a measure of the useful energy produced compared to the energy that is converted to low-quality heat energy. About 84% of all commercial energy used in the U.S. is wasted. About 41% is wasted because of the degradation of energy quality imposed by the second law of thermodynamics. About 43% of the energy used in the United States is unnecessarily wasted by such things as motor vehicles, furnaces, and living and working in leaky, poorly designed buildings. Since the 1980s the U.S. has reduced the amount of energy used per person, but unnecessary energy waste still costs the U.S. about $570,000 per minute. B. Much energy is wasted because of widespread reliance on incandescent light bulbs, internal combustion engines, nuclear power plants, and coal-fired power plants. . 16-2 How Can We Cut Energy Waste? A. Industry accounts for 30% of global energy consumption. B. Ways to save money and energy in industry include: 1. Cogeneration using a combined heat and power system. 2. Replacing energy wasting electric motors. 3. Recycling materials 4. Replacing low-efficiency incandescent lighting. CASE STUDY: A smart grid is an energy efficient, high-voltage power grid with very efficient transmission lines that is responsive to changes in supply and demand. China is investing heavily in the technology and may become the leader. Energy experts place high priority of converting outdated grids to smart grids. C. Transportation accounts for 28% of energy consumption in the United States. 1. Between 1973 and 1985, fuel efficiency increased because of government-mandated corporate average fuel economy standards. Since 1985 fuel economy has gone down. 2. Ways to save energy in transportation include offering incentives to purchase more efficient vehicles, shifting to electric rail systems, and encouraging bicycle use. D. More energy efficient vehicles are now being produced and more are planned. 1. These include hybrids, plug-in hybrids, energy efficient diesels, fuel cell technology, and vehicles made of ultra-light and ultra-strong composite materials. SCIENCE FOCUS: Lithium-ion batteries, commonly found in cell phones and laptops, are the most promising for electric vehicles. However, there are drawbacks, such as possible risk of fire, and cost. Modern research is bringing about promising alternatives. E. We can save energy in buildings by getting heat from the sun, super insulating them, and using plant-covered green roofs. We can save energy in existing buildings by insulating them, plugging leaks, and using energy-efficient heating and cooling systems, appliances, and lighting. F. There are three reasons renewable energy is not more widespread: 1. Since 1950, tax breaks, subsidies, and research funding have been much lower for renewable energy than for fossil fuels. 2. Subsidies and tax breaks are virtually guaranteed for fossil fuels and nuclear power, but must be renewed by Congress every few years for renewable energy. 3. The prices we pay for fossil fuels do not include their detrimental effects on the environment. 16-3 What Are the Advantages and Disadvantages of Using Solar Energy? A. Solar has two forms for heating, passive and active. We can heat buildings by orienting them toward the sun (passive solar heating) or by pumping a liquid such as water through rooftop collectors (active solar heating). Tradeoffs are listed in figure 16-14. B. Indirect solar energy (wind) and other natural services can be used to help cool buildings. C. Large arrays of solar collectors in sunny deserts can produce high-temperature heat to spin turbines and produce electricity, but costs are high. Solar thermal systems can collect and transform radiant energy to high-temperature thermal energy (heat), which can be used directly or converted to electricity. D. Solar can be used to provide electricity. Solar cells convert sunlight to electricity. The primary barrier to use is the high initial cost (though rapidly falling). Photovoltaic (PV) cells/solar cells convert solar energy directly into electrical energy. The solar cell is a transparent wafer that is energized by sunlight, which causes electrons in the semiconductor to flow, creating an electrical current. 16-4 What Are the Advantages and Disadvantages of Using Hydropower? A. Water flowing in rivers and streams can be trapped in reservoirs behind dams and released as needed to spin turbines and produce electricity. Hydropower is an indirect form of renewable solar energy. Hydropower supplied 20% of the world’s electricity in 2007. B. Pros and cons are given in Figure 16-22. Some expect that the use of large-scale dams will fall over the next several decades as reservoirs fill with silt and concerns over methane emissions grow. Small-scale projects eliminate most of the harmful environmental effects of large-scale projects. C. Ocean tides and waves can also be used to generate electricity. However, the costs are high and there are few favorable locations for this technology. 16-5 What Are the Advantages and Disadvantages of Using Wind Power? A. Wind power is an indirect form of solar energy. 1. Wind farms are large groups of wind turbines clustered together. 2. Wind is the world’s second fastest growing source of energy, behind solar cells. 3. The world’s largest wind producers are China, USA, Germany, Spain and India. 4. Winds are stronger and steadier over water than land, making offshore wind farms a promising option. 5. Wind power is widely distributed, inexhaustible, carbon-free and pollution-free. 6. Some drawbacks include the remoteness of some of the best wind sites, winds can die down and necessitate a backup supply of power, and many people complain that wind farms are unsightly and noisy. CASE STUDY: The DOE estimates that the Great Plains states could generate the electricity needs of the lower 48 states with wind power. Offshore wind farms could also supply all of the nation’s electricity. With expanded and sustained subsidies, wind farms could replace all of the coal-fired plants in the US. 16-6 What Are the Advantages and Disadvantages of Using Biomass as an Energy Source? A. Plant materials and animal wastes can be burned to provide heat or electricity, or can be converted into gaseous or liquid biofuels. Most biomass is burned directly for heating and cooking and this comprises up to 95% of the energy used in the poorest developing countries. The general advantages and disadvantages of burning solid biomass are listed in figure 16-26. B. Motor vehicles can run on ethanol, biodiesel, and methanol produced from plants and plant wastes. The biggest producers (Brazil, the U.S., the European Union, and China) plan to double their production of biofuels by 2020. Biofuels have advantages over gasoline and diesel fuel. Crops that are used to produce biofuels can be grown almost anywhere. The plants must be produced and harvested sustainably, resulting in no net increase in carbon dioxide. Biofuels are available now and are easy to store and transport. Rapid expansion of biofuels may (or may already) reduce the food available for consumption resulting in higher prices. Extensive use of biofuels could have dramatic impacts on the use of agricultural land. CASE STUDY: Biodiesel is produced from vegetable oils. Production is growing rapidly in the United States. Some drawbacks include the large areas of land required to grow the crops, loss of topsoil, runoff, and the large energy requirements which reduce the overall net energy yield. CASE STUDY: Ethanol can be made from crops as well as wastes from agriculture, forestry, and municipalities. Brazil and the United States are the largest producers of ethanol. Brazil produces enough to power 45% of its motor vehicles. Drawbacks to ethanol production include habitat destruction, high energy input requirements, soil erosion, runoff, and stresses on water supplies. Ethanol demand is also tied to food prices. An alternative is cellulosic ethanol, made from inedible parts of plants. Switchgrass is one promising plant for cellulosic ethanol production. However, it is difficult and costly to break down cellulose. CASE STUDY: Scientists are attempting to use existing or genetically engineered oil-rich algae to produce biofuels. This requires much less land, water and other resources than other biofuel production methods. Research is ongoing. 16-7 What Are the Advantages and Disadvantages of Using Geothermal Energy? A. We can use geothermal energy stored in the earth’s mantle to heat and cool buildings and to produce electricity. Geothermal heat pumps use a pipe and duct system to bring heat stored in underground rocks and fluids. The earth is used as a heat source in winter and a heat sink in summer. A closed loop of buried pipes filled with fluid to move heat in or out of the ground for heating/cooling needs. The EPA declared this the most energy-efficient, cost-effective, and environmentally clean way to heat or cool a building. B. Hydrothermal reservoirs can be tapped into to extract steam or hot water. C. The US is the world’s largest producer of geothermal energy. D. Hot, dry rock found about 3 miles underground can also be used to generate electricity. 1. Digging into the earth’s crust is costly, and may trigger small earthquakes. 16-8 What Are the Advantages and Disadvantages of Using Hydrogen as an Energy Resource? A. Hydrogen gas can be produced from water and organic molecules and produces nonpolluting water vapor when burned. Widespread use of hydrogen as a fuel would eliminate most of the air pollution problems we face today, but it takes energy and money to produce hydrogen from water and organic compounds. It is not a source of energy; it is a fuel produced by using energy. B. Current versions of fuel cells are expensive, but are the best way to use hydrogen to produce electricity. Whether a hydrogen-based energy system produces less carbon dioxide than a fossil fuel depends on how the hydrogen is produced. H fuel could be produced by electricity from coal-burning power plants, from coal itself, or strip it from organic compounds, but this could add more carbon dioxide to the atmosphere. 16-9 How Can We Make the Transition to a More Sustainable Energy Future? A. Decisions about energy futures require consideration of long periods of time (decades) and considerable investment in infrastructure. B. There are three general conclusions about energy transformations. 1. There will a gradual shift from large, centralized micropower systems to smaller, decentralized micropower systems. 2. The best alternatives combine improved energy efficiency and the use of natural gas and sustainably produced biofuels to make the transition to a diverse mix of locally available renewable-energy resources. 3. Because of their abundance and price, fossil fuels will continue to be used in large quantities, which means there will remain a need to find ways to reduce the environmental impacts of these fuels. C. Governments can use a combination of subsidies, tax breaks, rebates, taxes, and public education to promote or discourage use of various energy alternatives. Economics and politics are the basic strategies to help stimulate or dampen the short-term and long-term use of a particular energy resource. Key Terms active solar heating system cogeneration combined heat and power systems (CHP) energy efficiency geothermal energy passive solar heating system photovoltaic (PV) cells solar cells Teaching Tips: Large Lecture Courses: Start the lecture with a chart showing the price of oil over the last decade and a comparison of total miles driven in the U.S. First drop since 1979 occurred in 2008. Compare this graph to graphs of the use of wind power, solar power, and biofuel use. All these graphs will show dramatic recent changes. Now contrast these graphs with a map of fossil fuel reserves and particularly unconventional and coal reserves in the U.S. This contrast can be used to set up the basic decision faced by the U.S. in particular in the coming years—to develop national fossil fuel supplies or to follow a renewable path. Smaller Lecture Courses: Have students read a selection of articles from the NY Times series on Chinese growth and pollution (http://www.nytimes.com/interactive/2007/08/26/world/asia/choking_on_growth.html). Structure a class around a discussion of the choices China is facing today compared to the history of U.S. development. Ask questions about the tradeoffs between economic development and environmental protection (and human health). Term Paper Research Topics 1. Improving energy efficiency: energy-efficient office buildings; earth-sheltered houses; retrofitting energy-wasting houses; superinsulation; earth tubes; evaporative coolers; energy-efficient appliances; compact fluorescent light bulbs; "smart" windows; super insulated windows; roof-attachable solar cell rolls; the Albers Technologies air conditioner. 2. Solar technologies: the solar power tower; the Odeillo furnace; solar power satellites; photovoltaics; active solar systems; passive solar heating; microprocessors to control house temperatures. 3. Biomass: modern wood stoves; bagasse as a biomass fuel; biomass use in the developing countries; gasohol; methanol; Cellulosic ethanol. 4. Wind: wind farming in California; wind turbine designs. 5. Water power: large-scale hydropower projects in developing countries; rehabilitating small-scale hydroelectric plants in New England; wave power devices—a comparison of various approaches; ocean thermal energy conversion; the Bay of Fundy tidal power project. 6. Hydrogen gas: a versatile fuel of the future. 7. Balancing environment and clean energy generation in hydroelectric installations. 8. The role of a decentralized energy supply in the future. 9. Regulation as a tool for energy efficiency. How much should federal, state, and local governments do? 10. Renewable energy potential in the U.S.—what are the limitations to full scale use of renewable energy? 11. Nuclear energy—pros and cons. Discussion Topics 1. What to do with high level nuclear waste. Answer: High-level nuclear waste requires secure, long-term storage due to its radioactivity. Options include deep geological repositories, where waste can be isolated safely for thousands of years, and reprocessing, which recycles usable materials. Governments must carefully manage these solutions, ensuring environmental and public safety while addressing public concerns and regulatory requirements. 2. Restricting energy use in the developing world versus the developed world. What is fair? Answer: Balancing energy restrictions between developing and developed countries requires equity and justice. Developed nations, having historically contributed more to environmental degradation, should lead in reducing consumption and emissions. Developing nations, focusing on growth and poverty alleviation, should be supported with technology transfers and financial aid to pursue sustainable energy solutions without hindering their development. 3. Who should pay for the use of cleaner energy technologies? Answer: Funding for cleaner energy technologies should be a shared responsibility among governments, private sector stakeholders, and consumers. Governments can offer incentives and subsidies, while businesses invest in innovation and infrastructure. Consumers may bear some costs through higher prices, but targeted subsidies and rebates can ease the financial burden, especially for low-income households. 4. Should energy decisions in the U.S. be made at the local, state, or federal level? Answer: Energy decisions should involve collaboration across local, state, and federal levels, each addressing unique challenges and opportunities. Local governments can tailor solutions to community needs, states can implement region-specific policies, and the federal government can provide overarching regulations and support for national infrastructure projects. This multi-level approach ensures comprehensive and effective energy management. 5. Should inefficient cars and trucks be banned? Answer: Banning inefficient vehicles could accelerate the transition to more fuel-efficient and environmentally friendly alternatives, reducing emissions and fuel consumption. However, it should be implemented gradually, with provisions for those economically impacted, such as offering subsidies for new, efficient vehicle purchases or retrofitting existing ones to meet efficiency standards. 6. LEED building certification—what’s involved and how much does it cost? Answer: LEED (Leadership in Energy and Environmental Design) certification involves adhering to sustainable building practices in areas like energy efficiency, water usage, and indoor air quality. The cost varies based on project size, scope, and certification level, ranging from a few thousand to several hundred thousand dollars. However, LEED buildings often yield long-term savings through reduced energy and operating costs. 7. Should we invest in infrastructure for a hydrogen-based economy? Answer: Investing in hydrogen infrastructure could support a cleaner energy future, as hydrogen is a versatile, zero-emission fuel. However, significant investment is needed in production, storage, and distribution technologies. This investment could be justified if paired with renewable energy sources, as it would reduce dependence on fossil fuels, enhance energy security, and mitigate climate change. Activities and Projects 1. Ask an architect or contractor with experience in decentralized use of perpetual and renewable resources to visit the class and discuss the practical aspects of designing, financing, and installing small-scale solar, wind, and biogas systems for individual residences, farms, businesses, or factories. 2. Find out if representatives from your local electrical utility offer customers energy audits of their homes. If so, ask them to come to your class and tell what they look for in homes and what seem to be the most common ways customers can increase their energy efficiency. 3. Have your students find out if your institution's electrical utility has a conservation program. Does it have policies that encourage customers to purchase energy-efficient appliances and use energy-efficient light bulbs? 4. Organize a class field trip featuring guided tours of homes and/or other buildings that have solar heating systems. If possible, include examples of both passive and active systems and an earth-sheltered house. 5. See if there are LEED certified buildings on campus. Have students survey a LEED certified building and compare it to an older, more inefficient building. 6. Have a class debate on fossil fuel versus renewable sources of future energy. 7. Have a class debate/vote on the use of nuclear power (with a power plant located a thousand miles away and one located five miles away). 8. Ask students to survey newspapers for one week for articles on energy use and report back to the class about what they read. 9. Have your students audit energy use and waste on your campus and in activities (such as commuting) associated with the operation of your campus. Are opportunities to conserve significant amounts of energy going unrecognized or ignored? 10. As a class project, conduct a survey of students at your school to determine what beliefs and attitudes they have regarding sustainable-earth energy alternatives that entail a loss of convenience or additional expenditures of time and money on the part of energy users. Are young people today willing to significantly alter their lifestyles to use and waste less energy? News Videos End for Selling Traditional Bulbs; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Finding Alternatives to Oil; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Miles Per Gallon, Requirements for Automakers; Environmental Science in the Headlines, 2007; DVD; ISBN 0495385433 Philadelphia Eagles Playing for Planet’s Victory; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Planet Earth 2007; Environmental Science in the Headlines, 2007; DVD; ISBN 0495385433 Additional Video Resources Conservation & Energy Alternatives (Documentary, 2001) Trouble in the Middle East and growing concerns over global warming cause concern about how America is going to get powering the future. E2 Energy (Documentary, 2007) This PBS series includes 30-minute segments on the people, places and innovations relevant to our energy future. The End of Suburbia: Oil Depletion and the Collapse of The American Dream (Documentary, 2004) http://www.endofsuburbia.com/ NOVA: Saved by the Sun (Online) Main Website: http://www.pbs.org/wgbh/nova/solar/program.html Teacher’s Guide: http://www.pbs.org/wgbh/nova/teachers/programs/3406_solar.html Oil on Ice (Documentary, 2004) Arctic National Wildlife Refuge and drilling for oil. http://www.oilonice.org/ Who Killed The Electric Car (Documentary, 2006) Documentary that investigates the birth and death of the electric car, as well as the role of renewable energy and sustainable living in the future. http://www.whokilledtheelectriccar.com/ Attitudes and Values 1. What obligation do you have to use renewable, sustainable energy? Why? Answer: Individuals and societies have a moral obligation to use renewable, sustainable energy to mitigate environmental degradation, combat climate change, and ensure a healthy planet for future generations. Utilizing renewable resources reduces reliance on finite fossil fuels, decreases greenhouse gas emissions, and fosters long-term energy security, benefiting both the environment and human health. 2. Is energy a right for all people? Should it be available to only those who can pay? Answer: Access to energy is a fundamental need and should be considered a right, as it is essential for basic living standards, economic development, and well-being. Energy should not be restricted solely to those who can afford it; policies should ensure equitable access, particularly for marginalized communities, by providing affordable and reliable energy solutions. 3. How should we balance cost and environmental impact in choosing energy sources? Answer: Balancing cost and environmental impact requires prioritizing long-term sustainability over short-term savings. While cleaner energy may have higher upfront costs, it often leads to long-term economic and environmental benefits, such as reduced health care costs and climate mitigation. Policymakers and businesses should consider total lifecycle costs, including externalities like pollution, when choosing energy sources. 4. Who should bear the cost of cleaner energy, the developed or developing world? Does it matter who uses the most energy now? Answer: The developed world, historically responsible for higher emissions and with greater financial resources, should lead in bearing the costs of cleaner energy. This includes providing technology transfer and financial support to developing nations. It matters who uses the most energy now, as current high-energy consumers should contribute more to the transition, recognizing their larger environmental impact. 5. How much would you personally pay for cleaner energy? Answer: The willingness to pay for cleaner energy varies based on individual financial circumstances, environmental awareness, and values. Many are willing to pay a premium for cleaner energy to support sustainability and reduce their carbon footprint. However, the amount can depend on the perceived benefits, availability of subsidies, and the overall cost difference compared to conventional energy sources. Web Resources Energy Information Administration Energy statistics from the US government. http://www.eia.doe.gov/ Fuel Cells 2000 Fuel cell information from multiple sources. http://www.fuelcells.org/ National Renewable Energy Laboratory in Golden Colorado Links to information on multiple forms of renewable energy. http://www.nrel.gov/ American Wind Energy Association Trade group for wind power providers. http://www.awea.org/ Suggested Responses to End of Chapter Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 398. Describe the work of Amory Lovins at the Rocky Mountain Institute. Answer: • Amory Lovins established a non-partisan, nonprofit group that does research and consulting on energy and efficiency. He and the staff at the Rocky Mountain Institute have consulted for more than 80 corporations and 50 countries to help save energy and money. 2. What is energy efficiency? Explain why we can think of energy efficiency as an energy resource. What percentage of the energy used in the United States is unnecessarily wasted? List four widely used energy-wasting technologies. What are the major advantages of reducing energy waste? List three reasons why this source of energy has been neglected? Answer: • The best way to conserve energy is to improve energy efficiency— the measure of how much work we can get from each unit of energy we use. • To most energy analysts, reducing energy waste is the quickest, cleanest, and usually the cheapest, way to provide for our energy future. • Forty three percent of all commercial energy used in the United States is wasted unnecessarily, mostly due to the inefficiency of incandescent lights, furnaces, industrial motors, coal and nuclear power plants, most motor vehicles, and other devices. • Four energy-wasting technologies: • Incandescent light bulbs • Internal combustion engines • Nuclear power-plants • Coal-fired power plants • Major advantages of reducing energy waste include prolonging fossil fuel supplies, reducing oil imports and energy security, getting a very high net energy yield, low cost, reducing pollution and environmental degradation, buying time to phase in renewable energy, and creating local jobs. • One reason improving energy efficiency is neglected is a glut of relatively low- cost fossil fuels. As long as energy remains artificially cheap, people are more likely to waste it and less likely to invest in improving energy efficiency. Another reason is that there are few large and long-lasting governmental tax breaks, rebates, low- interest, long- term loans, and other economic incentives for consumers and businesses to invest in improving energy efficiency. Also, the U. S. federal government has done a poor job of encouraging fuel efficiency in motor. 3. Describe three ways to save energy and money in (a) industry, (b) transportation, (c) new buildings and (d) existing buildings. What is cogeneration (combined heat and power or CHP)? How could we encourage electric utility companies to reduce their energy waste? What is a smart grid and why is it important? Answer: • Ways to save energy and money include: ○ In industry: cogeneration, replace energy-wasting electric motors and recycle materials. ○ In transportation: increase public transportation, increase mileage standards and more energy-efficient vehicles. ○ In new buildings: orient the structure toward the sun, using living roofs and super insulating. ○ In existing buildings: improve insulation, use energy efficient appliances, and use energy efficient windows. • In cogeneration, two useful forms of energy (such as steam and electricity) are produced from the same fuel source. • Utility companies could reduce their energy waste by requiring that industries use cogeneration, replace energy-wasting electric motors, recycling materials, and switch from incandescent lighting. • A smart grid is an energy-efficient, digitally controlled, ultra-high-voltage grid with superefficient transmission lines that is responsive to local and regional changes in demand and supply. It is important because it can help to conserve vast amounts of energy. 4. Describe the trends in fuel efficiency in the United States since the 1970s. Explain why the price of gasoline is much higher than what consumers pay at the pump. What is a feebate? Distinguish among hybrid, plug-in hybrid, and fuel- cell motor vehicles. Describe the possible connection between wind farms and plug-in hybrid cars. Summarize the search for better batteries and describe two promising new developments. What is a living roof? What is the importance of a white or light-colored roof? What is a super insulated house? Compare the efficiency of incandescent, compact fluorescent, and LED light bulbs. Explain how using compact fluorescent light bulbs can reduce overall air pollution from toxic mercury. What are green buildings and why are they important? List six ways you can save energy where you live. Give three reasons why we waste so much energy. Answer: • The price of gasoline does not include hidden costs such as government subsidies and tax breaks for oil companies, car manufacturers and road builders; costs of pollution control and cleanup; costs of military protection of oil supplies in the Middle East (not including the two Iraq wars); time wasted in traffic jams; and costs of illness from air and water pollution in the form of higher medical bills and health insurance premiums. • The price of gasoline does not include hidden costs such as government subsidies and tax breaks for oil companies, car manufacturers and road builders; costs of pollution control and cleanup; costs of military protection of oil supplies in the Middle East (not including the two Iraq wars); time wasted in traffic jams; and costs of illness from air and water pollution in the form of higher medical bills and health insurance premiums. • Feebate is a combination of a fee and a rebate, such as a program in which buyers of fuel-inefficient vehicles pay a high fee, and the resulting revenues are given to buyers of efficient vehicles as rebates. • Hybrids use more than one form of power. A plug-in hybrid electric vehicle is a hybrid with a second and more powerful battery that can be plugged into a conventional electrical outlet and recharged. • Fuel-cell motor vehicles use hydrogen gas as fuel to produce electricity. • Wind can be used to generate electricity for charging plug-in hybrids, thus generating a carbon neutral, zero-emissions form of transportation. • The major obstacle standing in the way of mass-market, plug-in, hybrid electric vehicles is the difficulty in making an affordable battery that can store enough energy to power a vehicle over long distances without overheating. Two promising developments are new type of lithium battery that charges more rapidly, is less likely to heat up to dangerous levels, and is cheaper than the batteries used to power today’s hybrid vehicles; and using nanotechnology to make electrodes out of a nano phosphate material that will lengthen battery life and will not heat up and release flammable oxygen. • Living roofs are covered with soil and vegetation. • Light colored roofs help reduce cooling costs by reflecting incoming solar radiation especially in hotter climates. • Superinsulation allows a house to be so heavily insulated and airtight that heat from direct sunlight, appliances, and human bodies can warm it with little or no need for a backup heating system, even in extremely cold climates. • A compact fluorescent bulb uses one-fourth as much electricity as an incandescent bulb. LEDs use about one-seventh of the electricity required by an incandescent bulb. • The total amount of mercury in all of the country’s CFLs is a tiny fraction of the amount of mercury released every year by coal-fired power plants that produce the electricity that lights many energy-wasting incandescent bulbs. • Green buildings incorporate many energy-efficient and money-saving designs, make use of natural lighting, passive solar heating, solar cells, solar hot water heaters, recycled wastewater, and energy-efficient appliances and lighting. They are important in increasing our overall energy efficiency. • Six ways to save energy are: ○ Plant trees to block summer sun. ○ Use compact fluorescent light bulbs. ○ Turn off lights and electronics when not in use, ○ Use high-efficiency windows. ○ Weather strip and caulk doors. ○ Use fans instead of air conditioning. • Three reasons we waste energy are: ○ Fossil fuels and nuclear power are artificially cheap. ○ There are few government incentives to invest in energy efficiency. ○ People tend to resist change. 5. List five advantages of relying more on a variety of renewable energy sources and describe two factors holding back such a transition. Distinguish between a passive solar heating system and an active solar heating system and discuss the major advantages and disadvantages of such systems for heating buildings. What are three ways to cool houses naturally? Discuss the major advantages and disadvantages of concentrating solar energy to generate high-temperature heat and electricity. What is a solar cell (photovoltaic or PV cell) and what are the major advantages and disadvantages of using such devices to produce electricity? Answer: • Making a major shift toward a variety of locally available renewable energy resources over the next few decades would ○ Result in a more decentralized and efficient energy economy that is less vulnerable to supply cutoffs from terrorist attacks and natural disasters such as hurricanes. ○ Improve national security for many countries by reducing their need to import oil from the Middle East. ○ Reduce trade deficits that grow when a country imports oil. ○ Greatly reduce emissions of climate-changing greenhouse gases and other air pollutants. ○ Create large numbers of jobs, including high- paying jobs for skilled workers. ○ Save consumers money. • A passive solar heating system absorbs and stores heat from the sun directly within a well-insulated structure without the need for pumps or fans to distribute the heat. An active solar heating system uses energy from the sun by pumping a heat-absorbing fluid through special collectors usually mounted on a roof or on special racks to face the sun. • Advantages of heating a house with passive or active solar energy include: energy is free, net energy is moderate (active) to high (passive), quick installation, and no CO2 emissions. Disadvantages include: need access to sun 60% of time, sun can be blocked by trees and other structures, environmental costs not included in market price, need heat storage system, high cost (active), active system needs maintenance and repair, active collectors unattractive, very low air and water pollution, very low land disturbance (built into roof or windows), and moderate cost (passive). • Three ways to keep cool: ○ Block the high summer sun with window overhangs or awnings. ○ Use a light-colored roof to reflect as much as 80% of the sun’s heat (compared to only 8% for a dark colored roof). ○ Use geothermal heat pumps for cooling (and heating in winter). • Advantages of using solar energy to generate high-temperature heat and electricity include: moderate environmental impact, no CO2 emissions, fast construction (1–2 years), and costs reduced with natural gas turbine backup. Disadvantages include: low efficiency, low net energy, high costs, environmental costs not included in market price, needs backup or storage system, needs access to sun most of the time, and may disturb desert areas. • Solar energy can be converted directly into electrical energy by photovoltaic (PV) cells, commonly called solar cells. Most solar cells are thin wafers of purified silicon with trace amounts of metals that allow them to function as semiconductors to produce electricity. • Advantages of using solar cells to produce electricity include: fairly high net energy yield, work on cloudy days, quick installation, easily expanded or moved, no CO2 emissions, low environmental impact, last 20–40 years, low land use (if on roof or built into walls or windows), and reduces dependence on fossil fuels. Disadvantages include: need access to sun, low efficiency, need electricity storage system or backup, environmental costs not included in market price, high costs (but should be competitive in 5–15 years), high land use (solar-cell power plants) could disrupt desert areas, and DC current must be converted to AC. 6. What are the major advantages and disadvantages of using hydropower? What is the potential for using tides and waves to produce electricity? Answer: • Advantages of using large dams and reservoirs to produce electricity include: moderate to high net energy, high efficiency (80%), large untapped potential, low-cost electricity, long life span, no CO2 emissions during operation in temperate areas, can provide flood control below dam, provides irrigation water, and reservoir useful for fishing and recreation. Disadvantages include: high construction costs, high environmental impact from flooding land to form a reservoir, environmental costs not included in market price, high CH4 emissions from rapid biomass decay in shallow tropical reservoirs, danger of collapse, uproots people, decreases fish harvest below dam, and decreases flow of natural fertilizer (silt) to land below dam. • In some coastal bays and estuaries, water levels can rise or fall by 6 meters or more between daily high and low tides. Dams have been built across the mouths of some bays and estuaries to capture the energy in these flows for hydropower. However, globally, sites with large enough daily tidal flows are limited. • One way to produce electricity is by tapping wave energy along seacoasts where there are almost continuous waves. Off the coast of Portugal, large chains of floating steel tubes move up and down with the wave action and generate electricity. However, most analysts expect tidal and wave power sources to make only a small contribution to world electricity supplies, primarily because there are few suitable sites, the costs are high, and the equipment is vulnerable to corrosion and storm damage. Improved technology could greatly increase the production of electricity from waves sometime during this century. 7. What is a wind turbine? What is a wind farm? What are the major advantages and disadvantages of using wind to produce electricity? Explain why the United States is the “Saudi Arabia of wind energy.” What are the major advantages and disadvantages of burning wood to provide heat and electricity? What are biofuels and what are the major advantages and disadvantages of using biodiesel and ethanol to power motor vehicles? Evaluate the use of corn, sugarcane, and cellulose plants to produce ethanol Answer: l. Describe the potential for using algae and bacteria to produce gasoline and diesel fuel. 2. A wind turbine is driven by flows of air, or wind, and converts wind energy into electrical energy. Wind farms have interconnected arrays of ten to hundreds of turbines. • Advantages of wind power include: moderate to high net energy yield, high efficiency, moderate capital cost, low electricity cost, very low environmental impact, no CO2 emissions, quick construction, easily expanded, can be located at sea, and land below turbines can be used to grow crops or graze livestock. Disadvantages include: steady winds needed, backup systems needed when winds are low, plastic components produced from oil, environmental costs not included in market price, high land use for wind farm, visual pollution, noise when located near populated areas, and can kill birds and interfere with flights of migratory birds if not sited properly. • Wind farms in the Great Plains states have the potential to generate more than enough power for the lower 48 states, and have been dubbed the Saudi Arabia of wind energy. • Using wood to provide heat and electricity has advantages that include: potentially renewable forest and can be local, and disadvantages that include increased deforestation, not enough, and air pollution. • Plant materials and animal wastes can be converted into gaseous or liquid biofuels. • Advantages of using biodiesel as a vehicle fuel include: reduced CO emissions, reduced CO2 emissions (78%), high net energy yield for oil palm crops, moderate net energy yield for grape seed crops, reduced hydrocarbon emissions, better gas mileage (40%), and potentially renewable. Disadvantages include: increased NOx emissions and more smog, higher cost than regular diesel, environmental costs not included in market price, low net energy yield for soybean crops, may compete with growing food on cropland and raise food prices, loss and degradation of biodiversity from crop plantations, and can make engines hard to start in cold weather. • Advantages of using ethanol as a vehicle fuel include: high octane, some reduction in CO2 emissions (sugarcane bagasse), high net energy yield (bagasse and switchgrass), can be sold as a mixture of gasoline and ethanol or as pure ethanol, and potentially renewable. Disadvantages include: lower driving range, low net energy yield (corn), higher CO2 emissions (corn), much higher cost, environmental costs not included in market price, may compete with growing food and raise food prices, higher NOx emissions and more smog, and corrosives can make engines hard to start in cold weather. • Ethanol can be made through the fermentation and distillation of sugars in plants such as sugarcane, corn, and switchgrass. Running motor vehicles run on ethanol or ethanol- gasoline mixtures can save huge amounts of money in imported oil costs. Brazil and the United States are the largest ethanol producers. In Brazil, ethanol production has created about 1 million rural jobs. Brazil plans to greatly expand its production of sugarcane to produce ethanol and to grow more soybeans to produce biodiesel. However, this could threaten some of the country’s biodiversity. In the United States, most ethanol is made from corn. A growing number of analysts warn that producing ethanol from corn will not significantly reduce the country’s oil imports or help to slow global warming. • Biofuels can potentially be made from various types of existing or genetically engineered oil-rich algae and bacteria. However, there is much research still to be done in this area. 8. What is geothermal energy and what are three sources of such energy? What are the major advantages and disadvantages of using geothermal energy as a source of heat and to produce electricity? What are the major advantages and disadvantages of using hydrogen as a fuel and to produce electricity and to power motor vehicles? Answer: • Geothermal energy is heat stored in soil, underground rocks, and fluids in the earth’s mantle that can be tapped into to store energy to heat and cool buildings and to produce electricity. • Advantages of geothermal energy for space heating and for producing electricity or high-temperature heat for industrial processes include: very high efficiency, moderate net energy at accessible sites, lower CO2 emissions than fossil fuels, low cost at favorable sites, low land use and disturbance, and moderate environmental impact. Disadvantages include: scarcity of suitable sites, can be depleted if used too rapidly, environmental costs not included in market price, CO2 emissions, moderate to high local air pollution, noise and odor (H2S), and high cost except at the most concentrated and accessible sources. • Advantages of hydrogen: ○ Can be produced from plentiful water. ○ Low environmental impact. ○ Renewable if produced from renewable energy resources. ○ No CO2 emissions if produced from water. ○ Good substitute for oil. ○ Competitive price if environmental and social costs are included in cost comparisons. ○ Easier to store than electricity. ○ Safer than gasoline and natural gas. ○ Nontoxic. ○ High efficiency (45–65%) in fuel cells. • Disadvantages of hydrogen: ○ Not found as H2 in nature. ○ Energy is needed to produce fuel. ○ Negative net energy. ○ CO2 emissions if produced from carbon-containing compounds. ○ Environmental costs not included in market price. ○ Nonrenewable if generated by fossil fuels or nuclear power. ○ High costs (that may eventually come down). ○ Will take 25 to 50 years to phase in. ○ Short driving range for current fuel-cell cars. ○ No fuel distribution system in place. ○ Excessive H2 leaks may deplete ozone in the atmosphere. 9. List three general conclusions of energy experts about possible future energy paths for the world. List five major strategies for making the transition to a more sustainable energy future. Describe three roles that governments play in determining which energy resources we use. Answer: • There will be a gradual shift from large, centralized macro power systems to smaller, decentralized micropower systems such as wind turbines, household solar-cell panels, rooftop solar water heaters, small natural gas turbines, and fuel cells for cars, houses, and commercial buildings. • A combination of greatly improved energy efficiency and the temporary use of a natural gas will best help us to make the transition to a diverse mix of locally available renewable energy resources over the next several decades. • Because of their supplies and artificially low prices, fossil fuels will continue to be used in large quantities. • See Figure 16-33 for major strategies for making the transition to a more sustainable energy future. • Three roles government plays: ○ Keeps the prices of selected energy resources artificially low to encourage use of those resources. ○ Keeps the prices of selected energy resources artificially high to discourage their use. ○ Emphasizes consumer education. 10. What are this chapter’s three big ideas? Describe how the Rocky Mountain Institute applies the three principles of sustainability to evaluating and using energy resources. Answer: • This chapter’s big ideas are: ○ We should evaluate energy resources on the basis of their potential supplies, how much net useful energy they provide, and the environmental impacts of using them. ○ Using a mix of renewable energy sources—especially solar, wind, flowing water, sustainable biofuels, and geothermal energy—can drastically reduce pollution, greenhouse gas emissions, and biodiversity losses. ○ Making the transition to a more sustainable energy future will require sharply reducing energy waste, using a mix of environmentally friendly renewable energy resources, and including the harmful environmental costs of energy resources in their market prices. • The Rocky Mountain Institute seeks solutions that maximize solar energy use, are live sustaining, and non-polluting. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. Imagine that you live in the Rocky Mountain Institute’s building (Figure 16-1), powered mostly by the sun (Core Case Study). Do you think that you would have to give up any of the conveniences you now enjoy? If so, what are they? Describe any adjustments you might have to make in your way of living. Answer: Student responses may vary. The designs advocated by the Rocky Mountain Institute do not necessarily prohibit modern conveniences, but rather focus on efficiency, which may require certain behavioral modifications. Living in the Rocky Mountain Institute’s building, powered mostly by solar energy, would likely involve some adjustments to current conveniences. You might need to: 1. Reduce Energy Use: Be more conscious of electricity consumption, possibly limiting the use of high-energy appliances. 2. Adjust Habits: Shift daily routines to align with solar energy availability, such as running appliances during daylight hours. 3. Embrace Efficiency: Opt for energy-efficient devices and lighting to minimize usage. Overall, while some conveniences might be adjusted, the focus would be on sustainability rather than eliminating comfort. 2. List five ways in which you unnecessarily waste energy during a typical day, and explain how these actions violate any of the four scientific principles of sustainability (see back cover). Answer: People unnecessarily waste energy by having too many lights on in the home at night. Also, people use air conditioners when it is not absolutely necessary; try opening a window! This applies in the winter, too. People should wear more clothes instead of wasting energy by having their heaters turned on high. People should not leave computers on at night when they go to bed and are not using them. When using a dish washer you should make sure it has a full load in it. These are examples of things that I used to do, but after realizing that I am going against the principles of sustainability, I no longer do them, particularly not relying on the sun for energy. 3. Congratulations! You have won $500,000 to build a more sustainable house of your choice. With the goal of maximizing energy efficiency, what type of house would you build? How large would it be? Where would you locate it? What types of materials would you use? What types of materials would you not use? How would you heat and cool the house? How would you heat water? What types of lighting, stove, refrigerator, washer, and dryer would you use? Which, if any, of these appliances could you do without? Answer: Student answers will vary but $500,000 would allow considerable innovation in home design. Student answers may include alternative energy supplies including geothermal, solar (active or passive). Locations will vary with student choices. Materials could include reclaimed building materials, sustainably harvested materials or renewable materials such as strawbales. Heavy use of metals and non-sustainably produced woods would be discouraged. Lighting, heating and appliances can be highly energy efficient (e.g. CFL or LED lighting). Options for doing without will vary by student. Build a 1,500-2,000 sq ft passive solar home using bamboo, recycled steel, and low-impact insulation. Locate it for optimal solar gain. Heat and cool with geothermal systems and passive design. Use solar water heaters. Opt for LED lighting and energy-efficient appliances. Consider line drying to eliminate the dryer. 4. A homebuilder installs electric baseboard heat and claims, “It is the cheapest and cleanest way to go.” Apply your understanding of the second law of thermodynamics (see Chapter 2, p. 47) and net energy (see Figure 15-3) to evaluate this claim. Answer: The second law of thermodynamics states that when energy changes from one form to another, some of the useful energy is always degraded to lower-quality, more dispersed, less useful energy. If the electricity came from a nuclear plant then it could be argued that this is cleaner than generating it from coal. However, the net energy efficiency in either case is very low (@14%) when compared to other methods, such as passive solar that has a much higher net energy efficiency (@90%). His claim is very flawed. 5. Should buyers of energy-efficient motor vehicles receive large rebates funded by fees levied on gas-guzzlers? Explain. Answer: An argument in favor of this proposal is that buyers of energy efficient vehicles are helping the environment and should be rewarded in some way. If this is a monetary reward then the funds could be raised by taxing those less-responsible people that drive the gas-guzzlers. We need to introduce more incentives for purchasing hybrids and more disincentives for buying low-mpg vehicles. 6. Explain why you agree or disagree with the following proposals made by various energy analysts: (a) We should eliminate government subsidies for all energy alternatives so that all energy providers can compete in a true free-market system. (b) We should phase out all government tax breaks and other subsidies for conventional fossil fuels (oil, natural gas, and coal), synthetic natural gas and oil, and nuclear power (fission and fusion). We should replace them with subsidies and tax breaks for improving energy efficiency and developing solar, wind, geothermal, hydrogen, and biomass energy alternatives. (c) We should leave development of solar, wind, and hydrogen energy to private enterprise and it should receive little or no help from the federal government, but nuclear energy and fossil fuels should continue to receive large federal government subsidies. Answer: (a) I agree that government subsidies for all energy alternatives should be eliminated so all energy choices can compete in a true free-market system. A counter argument is that government should try to steer energy development toward renewable technologies and this may require subsides. (b) I agree that all government subsidies or tax breaks for conventional fuels should be replaced with subsidies and tax breaks for improving energy efficiency and developing solar, wind, geothermal, hydrogen, and biomass energy alternatives. (c) The government should not leave development of alternative energies in the hands of the private sector so long as other energy sources receive large government subsidies. 7. Imagine that you are in charge of the U.S. Department of Energy (or the energy agency in the country where you live). What percentages of your research and development budget will you devote to fossil fuels, nuclear power, renewable energy, and improving energy efficiency? How would you distribute your funds among the various types of renewable energy? Explain your thinking. Answer: I would devote 15 percent of the R&D budget to fossil fuels. This would be in order to develop cleaner coal burning technology and methods to reduce carbon dioxide and nitrogen oxide emissions. Fifteen percent of the budget would go to nuclear, which would be focused on dealing with the radioactive waste that is produced so it can be transformed into less dangerous forms. We will still need to rely on these “old” methods to supply our energy needs until we can replace them with other forms of “newer” energy sources. That is why I would allocate 50 percent toward R&D in the arena of renewable/alternative energy sources. These cannot be developed overnight, and it will take time to get the ones that work out the best into widespread use. We can also reduce the amount of energy right now by being more energy efficient and improving energy conservation in all areas of our energy use, which is why I would set aside 20 percent of the budget for R&D in this area. 8. China is investing 10 times as much as the United States is spending (as a percentage of its gross domestic product) in new, cleaner energy technologies such as electric cars, wind power, and solar energy. Chinese leaders understand that these technologies represent one of the biggest money-making opportunities of this century, and they plan to sell these technologies to the world. Energy analysts and economists call for the United States to launch a massive research and development program to join China in becoming a technological and economic leader in the area of clean energy. Do you agree with this proposal? Explain. Answer: Absolutely. The United States has a wonderful opportunity to contribute to the development of new technologies and to bolster its economy by positioning itself as a global leader in the clean energy movement. 9. Congratulations! You are in charge of the world. List the five most important features of your energy policy. Answer: Five important features of my energy policy would be: promote energy conservation and efficiency; phase-out the use of wasteful energy appliances in the home; improve the mpg of all vehicles on the road and encourage more people to drive hybrids and/or similar fuel efficient cars; ensure that all new construction meets sustainable energy standards or are LEED certified, and promote zero population growth strategies immediately. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: 1. What are the most effective strategies for integrating renewable energy sources into residential designs? 2. How can the choice of building materials impact long-term energy efficiency and sustainability? Ecological Footprint Question Make calculations to fill in the missing data in this table. Show all calculations. (1 liter = 0.265 gallon; 1 kilogram = 2.20 pounds; 1 hectare = 10,000 square meters = 2.47 acres) EPA Size Class Model Combined highway and city fuel efficiency in kpl (mpg) Liters (gallons) of gasoline consumed per year, assuming an average mileage of 19,300 kilometers (12,000 miles) Kilograms (pounds) of CO2 produced per year, assuming that the combustion of gasoline releases 2.3 kilograms per liter (19 pounds per gallon) Hectares (acres) of tropical rain forest needed to uptake the CO2 produced per year, assuming that the uptake of an undisturbed forest is 0.5 kilograms of CO2 per square meter Compact Honda Civic Hybrid 17.8 (42.0) Midsize Car Toyota Camry Hybrid 14.4 (34.0) Sports Utility Vehicle (SUV) Hummer H3 6.40 (15.0) Source : : www.fueleconomy.gov/feg/findacar.htm ANSWERS EPA Size Class Model Combined highway and city fuel efficiency in kpl (mpg) Liters (gallons) of gasoline consumed per year, assuming an average mileage of 19,300 kilometers (12,000 miles) Kilograms (pounds) of CO2 produced per year, assuming that the combustion of gasoline releases 2.4 kilograms per liter (19.6 pounds per gallon) Hectares (acres) of tropical rain forest needed to uptake the CO2 produced per year, assuming that the uptake of an undisturbed forest is 0.5 kilograms of CO2 per square meter Compact Honda Civic Hybrid 17.8 (42.0) 1,084 (286) 2,602 (5,606) 0.5 (1.2) Midsize Car Toyota Camry Hybrid 14.4 (34.0) 1,340 (353) 3,216 (6,919) 0.64 (1.6) Sports Utility Vehicle (SUV) Hummer H3 6.40 (15.0) 3,016 (800) 7,238 (15,680) 1.4 (3.6) 1. About how many times as much CO2 per year is produced by the SUV as is produced by the compact car? 2. About how many times as much CO2 per year is produced by the SUV as is produced by the midsize car? 3. How many hectares (acres) of tropical rain forest are needed to take up the CO2 produced annually by 1 million SUVs? 4. How many hectares (acres) of tropical rain forest are needed to take up the CO2 produced annually by 1 million midsize cars? 5. How many hectares (acres) of tropical rain forest are needed to take up the CO2 produced annually by 1 million compact cars? Calculations: Gasoline consumed per year: Compact: 19,300 kilometers per year/17.8 kilometers per year = 1,084 liters 12,000 miles per year/42.0 miles per gallon = 286 gallons Midsize: 19,300 kilometers per year/14.4 kilometers per year = 1,340 liters 12,000 miles per year/34.0 miles per gallon = 353 gallons SUV: 19,300 kilometers per year/6.40 kilometers per year = 3,016 liters 12,000 miles per year/15.0 miles per gallon = 800 gallons CO2 produced per year Compact: 1,084 liters gasoline x 2.4 kilograms CO2 per liter = 2,602 kilograms of CO2 per year 286 gallons gasoline x 19.6 pounds CO2 per liter = 5,606 pounds of CO2 per year Midsize: 1,340 liters gasoline x 2.4 kilograms CO2 per liter = 3,216 kilograms of CO2 per year 353 gallons gasoline x 19.6 pounds CO2 per liter = 6,919 pounds of CO2 per year SUV: 3,016 liters gasoline x 2.4 kilograms CO2 per liter = 7,238 kilograms of CO2 per year 800 gallons gasoline x 19.6 pounds CO2 per liter = 15,680 pounds of CO2 per year Tropical forest needed to remove CO2 output per year Compact: 2,602 kilograms CO2 x 1 square meter forest/0.5 kilograms CO2 x 1 hectare/10,000 square meters = 0.5 hectares of forest 0.5 hectares x 2.47 acres/hectare = 1.2 acres of forest Midsize: 3,216 kilograms CO2 x 1 square meter forest/0.50 kilograms CO2 x 1 hectare/10,000 square meters = 0.64 hectares of forest 0.62 hectares x 2.47 acres/hectare = 1.6 acres of forest SUV: 7,238 kilograms CO2 x 1 square meter forest/0.50 kilograms CO2 x 1 hectare/10,000 square meters = 1.4 hectares of forest 1.4 hectares x 2.47 acres/hectare = 3.6 acres of forest 1. Answer: 15,680 pounds of CO2 per year/5,606 pounds of CO2 per year = 2.8 times 2. Answer: 15,680 pounds of CO2 per year/6,919 pounds of CO2 per year = 2.3 times 3. Answer: 3.6 acres of forest x 1 million = 3.6 million acres 4. Answer: 1.6 acres of forest x 1 million = 1.6 million acres 5. Answer: 1.2 acres of forest x 1 million = 1.2 million acres Solution Manual for Living in the Environment: Principles, Connections, and Solutions G. Tyler Miller, Scott Spoolman 9780538735346
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