ENV330
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15 -Chapter Introduction
Core Case Study
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Using Hydrofracking to Produce Oil and Natural Gas
15.1
Energy Resources
15.1a
Where Does the Energy We Use Come From?
15.1b
Net Energy: It Takes Energy to Get Energy
15.1c
Some Energy Resources Need Subsidies
15.2
Oil
15.2a
We Depend Heavily On Oil
15.2b
Are We Running Out of Crude Oil?
15.2c
Environmental Impact of Heavy Oil
15.3
Natural Gas
15.3a
What Is Natural Gas?
15.3b
Natural Gas and Climate
15.4
Coal
15.4a
Coal: A Plentiful but Dirty Fuel
15.4b
The Full Cost of Using Coal
15.4c
The Future of Coal
15.4d
Converting Coal into Gaseous and Liquid Fuels
15.5
Nuclear Power
15.5a
How Does a Nuclear Fission Reactor Work?
15.5b
The Nuclear Fuel Cycle
15.5c
Radioactive Nuclear Wastes
15.5d
Nuclear Power and Climate Change
15.5e
Nuclear Power’s Uncertain Future
15.5f
Nuclear Fusion
Tying It All Together
Fracking, Nonrenewable Energy, and Sustainability
Chapter Review
Critical Thinking
Doing Environmental Science
Data Analysis15.1aWhere Does the Energy We Use Come From?
Some 99% of the energy that heats the earth and makes it livable comes from the sun—in keeping with the solar energy principle of sustainability. Without this free and essentially inexhaustible input of solar energy, the earth’s average temperature would be and life as we know it would not exist.
To supplement the sun’s life-sustaining energy, we use commercial energy—energy produced from a variety of nonrenewable and renewable resources and sold in the marketplace. Nonrenewable energy resources, include fossil fuels (oil, natural gas, coal) formed from the remains of plants and animals that lived long ago and in the nuclei of certain atoms (nuclear energy). We discuss these resources in this chapter. Renewable energy resources that are replenished by natural processes include energy from the sun, wind, flowing water (hydropower), biomass (energy stored in plants), and heat in the earth’s interior (geothermal energy). They are discussed in Chapter 16 .
85%
Percentage of the world’s commercial energy that comes from nonrenewable energy (mostly fossil fuels)
In 2017, 85% of the world’s commercial energy and 80% of U.S. commercial energy came from nonrenewable resources (mostly oil, natural gas, and coal), while the rest came from renewable resources ( Figure 15.2 )
Figure 15.2
Energy use by source throughout the world (left) and in the United States (right) in 2017.
(Compiled by the authors using data from British Petroleum, U.S. Energy Information Administration (EIA), and International Energy Agency (IEA)
15.1bNet Energy: It Takes Energy to Get Energy
Producing high-quality energy from any energy resource requires an input of high-quality energy. For example, before oil can be used, it must be located, pumped from beneath the ground or ocean floor, transferred to a refinery, converted to gasoline and other fuels, and delivered to consumers. Each of these steps uses high-quality energy, obtained mostly by burning fossil fuels, especially gasoline and diesel fuel produced from oil. Because of the second law of thermodynamics (Chapter 2), some of the high-quality energy used in each step is degraded to lower quality energy that typically flows into the environment as heat.
Net energy is the amount of high-quality energy available from a given quantity of an energy resource, minus the high-quality energy needed to make the energy available.
This information can also be expressed as a net energy ratio (NER) , also known as the energy returned on investment (EROI).
Net energy values are rough estimates depending on the items included and the availability of data. For this reason, Figure 15.3 shows generalized net energies for major energy resources and systems. It is based on several sources of scientific data and classifies estimated net energy as high, medium, low, or negative (negative being a net energy loss).
Figure 15.3
Generalized net energies for various energy resources and systems.
Critical Thinking:
1. Based only on these data, which two resources in each category will give the greatest return on the investment?
(Compiled by the authors using data from the U.S. Department of Energy; U.S. Department of Agriculture; Colorado Energy Research Institute, Net Energy Analysis, 1976; Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981, and Charles A. S. Hall and Kent A. Klitgaard, Energy and the Wealth of Nations, New York: Springer, 2012.) Top left: racorn/ Shutterstock.com. Bottom left: Donald Aitken/National Renewable Energy Laboratory. Top right: Serdar Tibet/ Shutterstock.com. Bottom right: Michel Stevelmans/ Shutterstock.com.
15.1cSome Energy Resources Need Subsidies
Resources with low net energies are costly to bring to the market. This makes it difficult for such energy resources to compete in the marketplace against energy resources with higher net energies unless they receive subsidies and tax breaks from the government (taxpayers) or other outside sources.
For example, electricity produced by nuclear power has a low net energy. This is because large amounts of high-quality energy are needed for each step in the nuclear power fuel cycle: to extract and process uranium ore, upgrade it to nuclear fuel, build and operate nuclear power plants, dismantle each radioactive nuclear plant after its useful life (typically 40-60 years) and safely store for thousands of years the highly radioactive wastes created in operating and dismantling each plant.
The low net energy and the resulting high cost of the entire nuclear fuel cycle (discussed later in this chapter) is one reason why governments (taxpayers) throughout the world heavily subsidize nuclear-generated electricity to make it available to consumers at an affordable price. However, such subsidies hide the true costs of nuclear power and thus violate the full-cost pricing principle of sustainability.
Another factor that can affect the usefulness of an energy resource is its energy density , the amount of energy available per kilogram of the resource. The two energy resources with the highest densities are uranium-235 fuel, used to produce electricity in nuclear power plants, and compressed hydrogen gas , which when burned does not emit climate-changing gases or other air pollutants. However, energy density can be misleading because it does not take into account the high-quality energy needed to make the energy resource available for use. For example, the entire nuclear power process of using uranium-235 to produce electricity has a low net energy as described above, and producing hydrogen gas results in a net energy loss.
17.4fImplementing Pollution Prevention
Pollution prevention programs by 3M and other companies are leading the way but there are major challenges in applying the precautionary principle more widely in the United States. A key to pollution prevention is banning the use of harmful chemicals or regulating their use.
At U.S. Congressional hearings in 2009, experts testified that the current regulatory system in the United States makes it virtually impossible for the government to limit or ban the use of toxic chemicals. Under this system, by 2009 the EPA has required testing for only 200 of the more than 85,000 chemicals registered for use in the United States and had issued regulations to control fewer than 12 of those chemicals.
However, there has been some progress. In 2011, after a 35-year delay promoted by politically powerful coal companies and utilities that burn coal to produce electricity, the EPA took a step toward pollution prevention by issuing a rule to control emissions of mercury ( Core Case Study ) and harmful fine-particle pollution from older coal-burning plants in 28 states.
Many eastern states suffer from deposition of mercury and harmful particles produced by older coal-burning power and electric plants in the Midwest and blown eastward by prevailing winds ( Figure 17.20 ). The new proposed air pollution standards could prevent as many as 11,000 premature deaths, 200,000 non-fatal heart attacks, and 2.5 million asthma attacks, according to the EPA. In 2014, the U.S. Supreme Court upheld these new EPA regulations but there have been growing efforts in Congress and pressure from coal companies to roll back or eliminate this standard.
Atmospheric wet deposition of mercury in the lower 48 states in 2010. Since then some progress has been made in reducing mercury levels in the eastern half of the 48 states.
Critical Thinking:
1. Why do the highest levels occur mainly in the eastern half of the United States?
(Compiled by the authors using data from the Environmental Protection Agency and the National Atmospheric Deposition Program)
In 2018, under pressure from coal industry the head of the EPA, who for 10 years served as the top attorney for the chief executive of a major coal company, was reviewing the 2011 and 2015 mercury air pollution standards, which the American Lung Association estimated would prevent 11,000 premature deaths per year and has dramatically reduced mercury pollution. The EPA head hoped to see how the standards could be greatly weakened, along with other air and water pollution standards for potentially toxic chemicals, because of the high costs to the coal industry. The goal is to set lower, more coal industry-friendly standards and possibly set the stage for full repeal of the EPA mercury standards.
Pollution prevention is happening on an international scale. The Stockholm Convention of 2000 is an international agreement to ban or phase out the use of 12 of the most notorious persistent organic pollutants (POPs), also called the dirty dozen. These highly toxic chemicals have been shown to produce numerous harmful effects, including cancers, birth defects, compromised immune systems, and declining sperm counts and sperm quality in men in a number of countries. The list includes DDT and eight other pesticides, PCBs, and dioxins. In 2009, nine more POPs were added, some of which are widely used in pesticides and in flame-retardants added to clothing, furniture, and other consumer goods. The treaty went into effect in 2004 but has not been formally approved or implemented by the United States.
Representatives from many nations developed a United Nations treaty known as the Minamata Convention which seeks to curb most human-related inputs of mercury into the environment ( Core Case Study ). The overall goal is to reduce global mercury emissions by 15% to 35% in the next several decades. In August 2017, the treaty went into effect after 50 countries (including the United States) had ratified or signed it. The treaty requires countries to implement the best-available mercury emission-control technologies within five years. It also restricts the use of mercury in common household products, thermometers and other measuring devices, light bulbs, batteries, and some cosmetics. However, there are no penalties for not meeting these requirements.
17.5aThe Greatest Health Risks Come from Poverty, Gender, and Lifestyle Choices
Risk analysis involves identifying hazards and evaluating their associated risks (risk assessment; Figure 17.2 , left), ranking risks (comparative risk analysis), determining options and making decisions about reducing or eliminating risks (risk management; Figure 17.2 , right), and informing decision makers and the public about risks (risk communication).
Statistical probabilities based on experience, animal testing, and other assessments are used to estimate risks from older technologies and chemicals. To evaluate new technologies and products, risk evaluators use more uncertain statistical probabilities, based on models rather than on actual experience and testing.
In terms of the number of deaths per year ( Figure 17.21 , left), the greatest risk by far is poverty, followed by air pollution and tobacco use. Many deaths due to poverty are caused by malnutrition, increased susceptibility to normally nonfatal infectious diseases, and often-fatal infectious diseases transmitted by unsafe drinking water.
Figure 17.21
Estimated numbers of deaths per year in the world from various causes. Numbers in parentheses represent these death tolls in terms of numbers of fully loaded 200-passenger jet airplanes crashing every day of the year with no survivors.
Critical Thinking:
1. Which three of these causes are the most threatening to you?
(Compiled by the authors using data from the World Health Organization, Environmental Protection Agency, and U.S. Centers for Disease Control and Prevention)
Studies show that the four greatest risks in terms of shortened life spans are living in poverty, being born male, smoking (see the Case Study that follows), and being obese. Some of the greatest risks of premature death are illnesses that result primarily from lifestyle choices that people make ( Figure 17.22 ).
Figure 17.22
Leading causes of death in the United States. Some result from lifestyle choices and are preventable.
Data Analysis:
1. The number of deaths from tobacco use is how many times the number of deaths from alcohol?
(Compiled by the authors using data from the U.S. Centers for Disease Control and Prevention.)
Case Study
Cigarettes and E-Cigarettes
Cigarette smoking is the world’s most preventable and largest cause of premature death among adults. The WHO estimates that smoking contributed to the deaths of 100 million people during the 20th century and could kill 1 billion people during this century unless governments and individuals act to dramatically reduce smoking.
The WHO and a report by the U.S. Surgeon General estimated that each year, globally tobacco contributes to the premature deaths of about 6 million people resulting from 25 illnesses, including heart disease, stroke, type 2 diabetes, lung and other cancers, memory impairment, bronchitis, and emphysema ( Figure 17.23 ). This amounts to an average of more than 16,400 deaths every day.
Figure 17.23
The difference between normal human lungs (left) and the lungs of a person who died of emphysema (right). The major causes of emphysema are prolonged smoking and exposure to air pollutants.
Arthur Glauberman/Science Source
In a study led by Rachel A. Whitmer, researchers tracked the health of 21,123 individuals for 30 years. They found that people between the ages of 50 and 60 who had smoked one to two packs of cigarettes daily had a 44% higher chance of getting Alzheimer’s disease or vascular dementia (which reduces blood flow to the brain and can erode memory) by age 72.
The projected annual death toll by 2030 from smoking-related diseases is 8 million—an average of 21,900 preventable deaths per day—according to the CDC and the WHO. About 80% of these deaths are expected to occur in less-developed countries, especially China, with 350 million smokers. The annual death toll from smoking in China is about 1.2 million, an average of about 137 deaths every hour. By 2050, the annual death toll from smoking in China could reach 3 million. There is little effort to reduce smoking in China, partly because cigarette taxes provide up to 10% of the central government’s total annual revenues. A study by Zhengming Chen and a team of other researchers, projected that smoking could lead to 3 million deaths per year in China by 2050.
According to the CDC, smoking is the leading cause of preventable death in the United States, killing about 492,000 Americans per year—an average of 1,348 deaths per day, or nearly one every minute ( Figure 17.22 ). This death toll is roughly equivalent to almost 7 fully loaded 200-passenger jet planes crashing every day of the year with no survivors. Smoking kills far more Americans each year than car crashes, alcohol, legal and illegal drugs, suicides, and murders combined. Smoking also causes about 8.6 million illnesses every year in the United States. The overwhelming scientific consensus is that the nicotine inhaled in tobacco smoke or in e-cigarettes is highly addictive, with the addictive power of heroin and cocaine. A British government study showed that adolescents who smoke more than one cigarette have an 85% chance of becoming long-term smokers.
Studies indicate that cigarette smokers die, on average, 10 years earlier than nonsmokers, but that kicking the habit—even at 50 years of age—can cut such a risk in half. If people quit smoking by age 30, they can avoid nearly all the risk of dying prematurely. However, it is difficult for smokers to quit because of the strong addictive power of nicotine.
Secondhand smoke—smoke inhaled by people living with or working around smokers—is also a hazard. Children who grow up living with smokers are more likely to develop allergies and asthma. Among adults, nonsmoking spouses of smokers have a 30% higher risk of both heart attack and lung cancer than spouses of nonsmokers have. A study by British researchers found that, globally, exposure to secondhand smoke contributes to about 600,000 deaths per year. According to the CDC, daily exposure to secondhand smoke is responsible for nearly 42,000 deaths per year in the United States.
A growing number of people are using various forms of electronic cigarettes or e-cigarettes, battery-operated nicotine inhalers ( Figure 17.24 , left). The nicotine is extracted from tobacco and mixed with chemicals such as propylene glycol and flavorings such as menthol, mint, and diacetyl and 2,3-pentanedione (which provide a buttery taste). A lithium-ion battery heats the nicotine solution and converts it to a vapor that contains nicotine and other chemicals (mostly flavorings) that is inhaled and then exhaled ( Figure 17.24 , right). Smoking e-cigarettes is called vaping.
Figure 17.24
An e-cigarette that can be refilled with a solution of nicotine (e-juice), left photo. A battery converts the liquid to a vapor that is exhaled (right photo).
jps/ Shutterstock.com; deineka/ Shutterstock.com
Are e-cigarettes safe? No one knows, because they have not been around long enough to be thoroughly evaluated. E-cigarettes reduce or eliminate the inhalation of tar and numerous other harmful chemicals found in regular cigarette smoke. However, they expose users to highly addictive nicotine, which is categorized as a poison ( Table 17.1 ), sometimes at levels of up to 5 times as high (10% nicotine) as that found in regular cigarettes (2% nicotine). There are claims that e-cigarettes may help smokers quit by discouraging e-cigarette users from smoking conventional cigarettes. However, evidence on these claims is controversial and will take years of research to evaluate. In 2015, a new type of very high-nicotine e-cigarette was released. Most commonly called a Juul and resembling a USB drive, it exposes users to an amount of nicotine equivalent to 200 puffs, or a pack of cigarettes.
There is pressure on the FDA to ban some of the flavorings, especially menthol and mint, which make it easier for teenagers to smoke e-cigarettes. However, such a ban will take years to implement and is opposed by the major tobacco companies.
Some scientists warn that we are hooking a new generation of young people on nicotine with potentially unknown risks. The same thing happened to the generation of young people who became addicted to cigarette smoking in the 1950s and 1960s.
The European Union (EU) has banned the advertising and sales of e-cigarettes and tobacco products to minors, as well as internet sales of these products. EU regulations also limit the concentration of nicotine in e-cigarettes to 2% and require the disclosure of e-cigarette ingredients. They require that these products have childproof and tamper-proof packaging that carries graphic warnings on the harmful health effects of nicotine. In 2016, the FDA issued a set of rules that banned the sale of e-cigarettes to anyone under the age of 18. The rules also require package warning labels and make all existing and new e-cigarette products subject to FDA approval.
Currently the United States is suffering from an opioid drug overdose epidemic that kills 49,000 people per year, an average of 134 deaths a day. Many people are addicted to, and many die from, fentanyl and other opioids. Since 2017, the number of deaths from overdoses of synthetic opioids sold illegally exceeded those from opioids sold legally as prescription painkillers.
17.5bEstimating Risks from Technologies
The more complex a technological system, and the higher the number people required to design and run it, the more difficult it is to estimate the risks of using the system. The overall reliability of such a system—the probability (expressed as a percentage) that the system will complete a task without failing—is the product of two factors:
With careful design, quality control, maintenance, and monitoring, a highly complex system such as a nuclear power plant or a deep-sea oil-drilling rig can achieve a high degree of technological reliability. However, human reliability usually is much lower than technological reliability and is almost impossible to predict.
Suppose the estimated technological reliability of a nuclear power plant is 95% (0.95) and human reliability is 75% (0.75). Then the overall system reliability is . Even if we could make the technology 100% reliable (1.0), the overall system reliability would still be only .
We can make a system safer by moving more of the potentially fallible elements from the human side to the technological side. However, chance events such as a lightning strike can knock out an automatic control system, and no machine or computer program can completely replace human judgment. In addition, the parts in any automated control system are manufactured, assembled, tested, certified, inspected, and maintained by fallible human beings. Computer software programs used to monitor and control complex systems can also be flawed because of human design error or can be deliberately sabotaged to cause them to malfunction.
Learning from Nature
Locusts have highly evolved eyes that allow them to see in several directions simultaneously, which helps them to avoid colliding with each other when flying in swarms. Engineers are studying this in their quest to develop anti-collision devices for cars and airplanes.
17.5cMost People Do a Poor Job of Evaluating Risks
Most of us are not good at assessing the relative risks from the hazards that we encounter. Many people deny or shrug off the high-risk chances of death or injury from the voluntary activities they enjoy. These include risks of death by smoking (1 in 250 by age 70 for a pack-a-day smoker), motorcycling (1 in 1,000), hang gliding (1 in 1,250), and driving (1 in 3,300 without a seatbelt and 1 in 6,070 with a seatbelt).
Indeed, the most dangerous thing that many people do each day is to drive or ride in a car. Yet some of these same people may be terrified about their chances of being killed by getting pneumonia from the flu (a 1 in 130,000 chance), a nuclear power plant accident (1 in 200,000), West Nile virus (1 in 1 million), a lightning strike (1 in 3 million), Ebola virus (1 in 4 million), a commercial airplane crash (1 in 9 million), snakebite (1 in 36 million), or shark attack (1 in 281 million).
Five factors can cause people to see a technology or a product as being more or less risky than experts judge it to be. The first factor is fear. Research shows that fear causes people to overestimate risks and to worry more about catastrophic risks than they do about common, everyday risks. Studies show that people tend to overestimate numbers of deaths caused by tornadoes, floods, fires, homicides, cancer, and terrorist attacks, and to underestimate death tolls from flu, diabetes, asthma, heart attack, stroke, and automobile accidents.
The second factor clouding risk evaluation is the degree of control individuals have in a given situation. Many people have a greater fear of things over which they do not have personal control. For example, some individuals feel safer driving their own car for long distances than traveling the same distance on a plane, but look at the numbers. The risk of dying in a car accident in the United States while using a seatbelt is 1 in 6,070, whereas the risk of dying in a U.S. commercial airliner crash is about 1 in 9 million.
The third factor influencing risk evaluation is whether a risk is catastrophic or chronic. People usually are more frightened by news of catastrophic accidents such as a plane crash than of a cause of death such as smoking, which has a much higher death toll spread out over time.
Fourth, some people have optimism bias, the belief that risks that apply to other people do not apply to them. For example, they may be upset when they see others driving erratically while talking on a cell phone or texting but believe they can do so without impairing their own driving ability.
A fifth factor affecting risk analysis is that many of the risky things we do are highly pleasurable and give instant gratification, while the potential harm from such activities comes later. Examples are smoking cigarettes and eating too much food.
17.5dGuidelines for Evaluating and Reducing Risk
Here are four guidelines for better evaluating and reducing risk and making better lifestyle choices:
· Compare risks. In evaluating a risk, the key question is not “Is it safe?” but rather “How risky is it compared to other risks?”
· Determine how much risk you are willing to accept. For most people, a 1 in 100,000 chance of dying or suffering serious harm from exposure to an environmental hazard is a threshold for changing their behavior. However, in establishing standards and reducing risk, the EPA generally assumes that a 1 in 1 million chance of dying from an environmental hazard is acceptable.
· Evaluate the actual risk involved. The news media usually exaggerate the daily risks we face in order to capture our interest and attract more readers, listeners, or television viewers. As a result, most people who are exposed to a daily diet of such exaggerated reports believe that the world is much more dangerous and risk-filled than it really is.
· Concentrate on evaluating and carefully making important lifestyle choices. When evaluating risk, it is important to ask, “Do I have any control over this?” There is no point worrying about risks over which we have little or no control.
Big Ideas
· We face significant hazards from infectious diseases such as flu, AIDS, tuberculosis, diarrheal diseases, and malaria, and from exposure to chemicals that can cause cancers and birth defects, as well as chemicals that can disrupt the human immune, nervous, and endocrine systems.
· Because of the difficulty of evaluating the harm caused by exposure to chemicals, many health scientists call for much greater emphasis on pollution prevention.
· By becoming informed, thinking critically about risks, and making careful choices, we can reduce the major risks we face.
· In the Core Case Study that opens this chapter, we saw that mercury (Hg) and its compounds that occur regularly in the environment can permanently damage the human nervous system, kidneys, and lungs and harm fetuses and cause birth defects. In this chapter, we also learned of many other chemical hazards, as well as biological, physical, cultural, and lifestyle hazards, in the environment. In addition, we saw how difficult it is to evaluate the nature and severity of threats from these various hazards.
· One of the important facts discussed in this chapter is that on a global basis, the greatest threat to human health is poverty (often leading to malnutrition and disease), followed air pollution, smoking, alcohol, and work-related injury and disease.
· There are some threats that we can do little to avoid, but we can reduce other threats, partly by applying the three scientific principles of sustainability. For example, we can greatly reduce our exposure to mercury and other pollutants by shifting from the use of nonrenewable fossil fuels (especially coal) to wider use of a diversity of renewable energy resources, including solar and wind energy. We can reduce our exposure to harmful chemicals used in the manufacturing of various goods by cutting resource use and waste and by reusing and recycling material resources. We can also mimic biodiversity by using diverse strategies for solving environmental and health problems, and for reducing poverty and controlling population growth. In doing this, we also help to preserve the earth’s biodiversity and increase our beneficial environmental impact.
· In the Core Case Study that opens this chapter, we saw that mercury (Hg) and its compounds that occur regularly in the environment can permanently damage the human nervous system, kidneys, and lungs and harm fetuses and cause birth defects. In this chapter, we also learned of many other chemical hazards, as well as biological, physical, cultural, and lifestyle hazards, in the environment. In addition, we saw how difficult it is to evaluate the nature and severity of threats from these various hazards.
· One of the important facts discussed in this chapter is that on a global basis, the greatest threat to human health is poverty (often leading to malnutrition and disease), followed air pollution, smoking, alcohol, and work-related injury and disease.
· There are some threats that we can do little to avoid, but we can reduce other threats, partly by applying the three scientific principles of sustainability. For example, we can greatly reduce our exposure to mercury and other pollutants by shifting from the use of nonrenewable fossil fuels (especially coal) to wider use of a diversity of renewable energy resources, including solar and wind energy. We can reduce our exposure to harmful chemicals used in the manufacturing of various goods by cutting resource use and waste and by reusing and recycling material resources. We can also mimic biodiversity by using diverse strategies for solving environmental and health problems, and for reducing poverty and controlling population growth. In doing this, we also help to preserve the earth’s biodiversity and increase our beneficial environmental impact.
15
–
Chapter Introduction
Core Case Study
Using Hydrofracking to Produce Oil and Natural Gas
15.1
Energy Resources
15.1a
Where Does the Energy We Use Come From?
15.1b
Net Energy: It Takes Energy to Get Energy
15.1c
Some Energy Resources Need
Subsidies
15.2
Oil
15.2a
We Depend Heavily On Oil
15.2b
Are We Running Out of Crude Oil?
15.2c
Environmental Impact of Heavy Oil
15.3
Natural Gas
15.3a
What Is Natural Gas?
15.3b
Natural Gas and Climate
15.4
Coal
15.4a
Coal: A Plentiful but Dirty Fuel
15 -Chapter Introduction
Core Case Study
Using Hydrofracking to Produce Oil and Natural Gas
15.1
Energy Resources
15.1a
Where Does the Energy We Use Come From?
15.1b
Net Energy: It Takes Energy to Get Energy
15.1c
Some Energy Resources Need Subsidies
15.2
Oil
15.2a
We Depend Heavily On Oil
15.2b
Are We Running Out of Crude Oil?
15.2c
Environmental Impact of Heavy Oil
15.3
Natural Gas
15.3a
What Is Natural Gas?
15.3b
Natural Gas and Climate
15.4
Coal
15.4a
Coal: A Plentiful but Dirty Fuel
,
Chapter 16
·
·
· Core Case Study Saving Energy and Money
· 16.1 A New Energy Transition
· 16.1a Establishing New Energy Priorities
· 16.2 Reducing Energy Waste
· 16.2a We Waste a Lot of Energy and Money
· 16.2b Improving Energy Efficiency in Industries and Utilities
· 16.2c Building a Smarter and More Energy-Efficient Electrical Grid
· 16.2d Making Transportation More Energy-Efficient
· 16.2e Switching to Energy-Efficient Vehicles
· 16.2f Buildings That Save Energy and Money
· 16.2g Air Conditioning and Climate Change
· 16.h Saving Energy and Money in Existing Buildings
· 16.2i Why Are We Wasting So Much Energy and Money?
· 16.2j Relying More on Renewable Energy
· 16.3 Solar Energy
· 16.3a Heating Buildings and Water with Solar Energy
· 16.3b Cooling Buildings Naturally
· 16.3c Concentrating Sunlight to Produce High-Temperature Heat and Electricity
· 16.3d Using Solar Cells to Produce Electricity
· 16.4 Wind Energy
· 16.4a Using Wind to Produce Electricity
· 16.5 Geothermal Energy
· 16.5a Tapping into the Earth’s Internal Heat
· 16.6 Biomass Energy
· 16.6a Producing Energy by Burning Solid Biomass
· 16.6b Using Liquid Biofuels to Power Vehicles
· 16.7 Hydropower
· 16.7a Producing Electricity from Falling and Flowing Water
· 16.8 Hydrogen
· 16.8a Will Hydrogen Save Us?
· 16.9 A More Sustainable Energy Future
· 16.9a Shifting to a New Energy Economy
· Tying It All Together Saving Energy and Money and Reducing Our Environmental Impact
16.1aEstablishing New Energy Priorities
Shifting to new energy resources is not new. The world has shifted from primary dependence on wood to coal, then from coal to oil, and then to our current dependence on a mixture of oil, natural gas, and coal as new technologies made these three energy resources more available and affordable. Each of these shifts in key energy resources took about 50 to 60 years. Making an energy shift involves making an enormous investment in scientific research, engineering, research, technology, and infrastructure to develop and spread the use of new energy resources.
Currently, the world gets 85% of its commercial energy, and the United States gets 80% of its commercial energy from three carbon-containing fossil fuels—oil, coal, and natural gas ( Figure 15.2 ). These energy resources have supported tremendous economic growth and improved the lives of many people.
However, many people are awakening to the fact that burning fossil fuels, especially coal, plays an important role in three of the world’s most serious environmental problems: air pollution, climate change, and ocean acidification. Fossil fuels are affordable because their market prices do not include these and other harmful health and environmental effects. In addition, they have been receiving government (taxpayer) subsides for decades, even though they are well-established and profitable businesses.
According to many scientists, energy experts, and energy economists, over the next 50 to 60 years and beyond, we need to and can make a new energy transition by
1. improving energy efficiency and reducing energy waste;
2. decreasing our dependence on nonrenewable fossil fuels;
3. relying more on a mix of renewable energy from the sun, wind, the earth’s interior heat (geothermal energy), and hydropower to produce most of the world’s electricity;
4. developing modern smart electrical grids to distribute electricity produced from renewable and nonrenewable energy resources; and
5. shifting to much greater dependence on electric cars, buses, scooters, and other vehicles with batteries that are recharged by electricity produced by solar cells and wind turbines.
Energy researchers and analysts point out that it is both technologically and economically feasible to make a transition toward getting most of our electricity from the sun and wind over the next 50-60 years. It would also be a way to implement the solar energy principle of sustainability globally.
This restructuring of the global energy system and economy over the next 50 to 60 years and beyond will save money, create profitable business and investment opportunities, and provide jobs. For example, building and installing solar cells and wind turbines (on land and at sea) will create thousands of jobs. It will also save lives by sharply reducing air pollution and by helping keep climate change and ocean acidification from spiraling out of control and creating ecological and economic chaos. Finally, it will increase our positive environmental impact, and pass the world on to future generations in better shape than we found it, in keeping with the ethical principle of sustainability.
This energy shift is being driven by the availability of perpetual supplies of clean and increasingly cheaper solar and wind energy throughout the world. Advances in solar cell and wind turbine technology have been steadily reducing the cost of using wind and solar energy to produce electricity. This is in contrast to fossil fuels, which are dependent on finite supplies that are not widely distributed, are controlled by a few countries, and are subject to fluctuating prices based on supply and demand.
In this new technology-driven energy economy, an increasing percentage of the world’s electricity will be produced locally from available sun and wind and regionally from solar cell power plants and wind farms. It will be transmitted to consumers through modern, interactive, smart electrical grids. Homeowners and businesses with solar panels on their land or their roofs (or roof coverings that contain solar cells) will be able to heat and cool their homes and businesses, run electrical devices, charge hybrid or electric cars, and sell the excess electricity they produce. The United States will benefit economically, because making such a market-based shift will set off an explosion of innovations in energy efficiency, renewable energy, and battery technology that will create millions of jobs. Old energy technologies would be replaced by cleaner and cheaper new energy technologies. According to economists, this is how creative capitalism works.
Like any major societal change, this shift will not be easy. However, to many analysts the current and long-term harmful environmental, health, and economic benefits of making this shift far outweigh any temporary harmful effects this shift might cause.
This shift is underway and gaining momentum as the cost of electricity produced from the sun and wind continues its rapid fall and investors see a way to make money on two of the world’s fastest growing businesses. Germany, Sweden, and Denmark have made significant progress in this energy resource transition.
Costa Rica is a global leader in this transition, as well as in reforestation ( Chapter 10 Core Case Study ). It gets none of its electricity from burning coal and more than 90% of its electricity from renewable resources—hydropower, geothermal energy, and wind and solar power. Costa Rica’s National Decarbonization Plan calls for having electric passenger trains in service by 2022 and having nearly a third of its buses running on electricity by 2035. It also envisions nearly all of its cars and buses running on electricity by 2050, supported by battery recharging stations throughout the country. If this ambitious plan succeeds, it will show the world how a small country can make a transition to a new and more sustainable energy system.
The United States has yet to commit to making the new energy shift. The reasons are complex, but this is partly because of more than four decades of opposition by politically and economically powerful fossil fuel and electric utility companies. The only question is whether we have the political and ethical will to make this vitally important economic and environmental transition.
16.2aWe Waste a Lot of Energy and Money
Improving energy efficiency and wasting less energy are key strategies in using energy more sustainability. Energy efficiency is a measure of how much useful work we can get from each unit of energy. Improving energy efficiency means using less energy to provide the same amount of work. We can do this by using more energy-efficient cars, heating and cooling systems, light bulbs (such as LED bulbs), appliances, computers, and industrial processes.
43%
Percentage of energy used in the United States that is unnecessarily wasted.
No energy-using device operates at 100% efficiency because some energy is always lost to the environment as low-quality heat, as required by the second law of thermodynamics (see Chapter 2 ). About 84% of all commercial energy used in the United States is wasted ( Figure 16.2 ). About 41% of this energy unavoidably ends up as low-quality waste heat in the environment because of the degradation of energy quality imposed by the second law of thermodynamics. The other 43% is wasted unnecessarily, mostly due to the inefficiency of industrial motors, motor vehicles, power plants, light bulbs, and numerous other devices. This wasted energy is the country’s largest untapped source of energy. Reducing this huge waste of energy would save consumers money and reduce our harmful environmental impact from energy use. According to energy experts, the United States has more potential for improving energy efficiency than any other country.
Figure 16.2
Flow of commercial energy through the U.S. economy. Only 16% of the country’s high-quality energy ends up performing useful tasks.
Critical Thinking:
1. What are two examples of unnecessary energy waste?
(Compiled by the authors using data from U.S. Department of Energy.)
Another reason for our costly and wasteful use of energy is that many people live and work in poorly insulated, leaky houses and buildings that require excessive heating during cold weather and excessive cooling during hot weather (see Figure 16.1 ). In addition, about 75% of Americans who commute to work do this mostly alone in energy-inefficient vehicles, and only 5% rely on more energy-efficient mass transit.
A major way in which we waste energy and money is through heavy reliance on widely used energy-inefficient technologies. One example is data centers, which process all online information (such as data on social media sites) and provide cloud-based data storage for users. These data centers–some of them as big as two football fields–require huge amounts of energy to operate and to cool because of the massive heat thrown off by their rows and rows of servers. Typically, these centers use only 10% of the electrical energy they consume. The other 90% is lost as waste heat. These data centers run 24 hours a day at their maximum capacities, regardless of the demand. Some data companies are reducing their environmental impact by getting the electricity they use mostly or totally from solar and wind energy.
Another example of energy waste is internal combustion engine, which propels most motor vehicles. It wastes about 75% of the high-quality energy in its gasoline fuel. Thus, only about 25% of the money people spend on gasoline provides them with transportation. The other 75% pays for waste heat released into the atmosphere.
We could cut much of this energy waste by changing our behavior. Energy conservation means reducing or eliminating the unnecessary waste of energy. If you ride your bicycle to school or work rather than driving a car, you are practicing energy conservation. Another way to waste less energy and money is to turn off lights and electronic devices when you are finished using them.
Improving energy efficiency and conserving energy have numerous economic, health, and environmental benefits ( Figure 16.3 ). To most energy analysts, they are the quickest, cleanest, and usually the cheapest ways to provide more energy, reduce pollution and environmental degradation, and slow climate change and ocean acidification.
Figure 16.3
Improving energy efficiency and conserving energy can have important benefits.
Critical Thinking:
1. Which two of these benefits do you think are the most important? Why?
Top: Dmitry Raikin/ Shutterstock.com. Center: V. J. Matthew/ Shutterstock.com. Bottom: andrea lehmkuhl/ Shutterstock.com.
However, improving energy efficiency and conserving energy are not always an option for people who cannot afford to invest in them. As a result, these people are unable to reduce their energy bills. There is a growing network of public and private programs designed to upgrade energy efficiency in public housing units, provide affordable tax credits for energy efficiency upgrades, and assist individual homeowners in improving energy efficiency. Many are calling for increasing such efforts.
16.2bImproving Energy Efficiency in Industries and Utilities
Industry accounts for about 36% of the world’s energy consumption and 33% of U.S. energy consumption. Industries that use the most energy are those that produce petroleum, chemicals, cement, steel, aluminum, and paper and wood products.
Utility companies and industries can save energy by using cogeneration to produce two useful forms of energy from the same fuel source. For example, the steam used for generating electricity in a power or industrial plant can be captured and used again to heat the plant or other nearby buildings. The energy efficiency of cogeneration systems is 60–80%, compared to 25–35% for coal-fired and nuclear power plants. Denmark uses cogeneration to produce 38% of its electricity compared to 12% in the United States.
Inefficient motors account for 60% of the electricity used in U.S. industry. Industries can save energy and money by using more energy-efficient variable-speed electric motors that run at the minimum speed needed for each job. In contrast, standard electric motors run at full speed with their output throttled to match the task. This is somewhat like using one foot to push the gas pedal to the floorboard of your car and putting your other foot on the brake pedal to control its speed.
A growing number of major corporations are saving money by improving energy efficiency. For example, between 1990 and 2015, Dow Chemical Company, which operates 165 manufacturing plants in 37 countries, saved $27 billion in a comprehensive program to improve energy efficiency, and these efforts continue. Ford Motor Company saves $1 million a year by turning off computers that are not in use.
16.2cBuilding a Smarter and More Energy-Efficient Electrical Grid
In the United States, electricity is delivered to consumers through an electrical grid. The U.S. electrical grid system, designed more than 100 years ago, is inefficient and outdated. According to former U.S. energy secretary Bill Richardson, “We’re a major superpower with a third-world electrical grid system.”
There is increasing pressure to convert and expand the outdated U.S. electrical grid system into a smart grid. This new grid would be a digitally controlled, ultra-high-voltage (UHV), and high-capacity system with superefficient transmission lines. It would be less vulnerable to power outages because it could quickly adjust for a major power loss in one part of the country by automatically rerouting available electricity from other parts of the country. A national network of wind farms and solar power connected to a smart grid would make the sun and wind reliable sources of electricity around the clock without having expensive backup systems. Without such a grid, the contribution of wind and solar energy is unlikely to expand as projected.
According to the U.S. Department of Energy (DOE), building such a grid would cost the United States up to $800 billion over the next 20 years. However, it would save the U.S. economy $2 trillion during that period. So far, the U.S. Congress has not authorized significant funding for this vital component of the country’s energy and economic future. Meanwhile, China is investing in establishing a smart national electrical grid system.
The two fastest growing energy resources in the world and in the United States are solar and wind energy used to produce electricity. However, this growth will be limited unless wind farms and solar cell power plants built in sparsely populated areas or at sea can be connected to a smart grid. A national network of wind farms and solar cell power plants in the United States would make the sun and wind reliable sources of electricity around the clock. Without such a grid, the United States will not reap the environmental and economic advantages of relying on the sun and wind to produce most of its electricity. 16.2dMaking Transportation More Energy-Efficient
In 1975, the U.S. Congress established Corporate Average Fuel Economy (CAFE) standards to improve the average fuel economy of new cars and light trucks, vans, and sport utility vehicles (SUVs) in the United States. Between 1973 and 2015, these standards increased the average fuel economy for such vehicles in the United States from 5 kilometers per liter, or kpl (11.9 miles per gallon, or mpg) to 10.6 kpl (24.9 mpg). The government fuel-economy goal has been 23.3 kpl (54.5 mpg) by 2025 (South Korea, the European Union, and Canada have even higher goals). According to the U.S. Environmental Protection Agency (EPA), this would provide $100 billion of benefits from reduced air pollution while lowering carbon dioxide emissions and reducing oil imports because of more efficient transportation.
However, in 2018, the EPA and the U.S. Department of Transportation, under pressure from some automakers, proposed reducing the fuel-economy goal to 12 kpl (29 mpg) and prohibiting California and 13 other states from car emission standards higher than those set by the federal government, a privilege granted under the 1970 Clean Air Act.
Critics of these government proposals point out that since the mid-1970s motor vehicle air pollution, including emissions of climate-changing per kilometer of travel has dropped sharply and motor vehicle fatalities have dropped 65% as average fuel economy has increased. They also point out that not promoting a shift to much higher fuel economy standards would reduce efforts to slow climate change.
Energy experts project that by 2040, all new cars and light trucks sold in the United States could get more than 43 kpl (100 mpg) using available technology. Part of this is due to new and more efficient internal combustion engines. Achieving this level of fuel efficiency is an important way to reduce energy waste, save consumers money, cut air pollution, and slow climate change and ocean acidification.
However, many consumers buy energy-inefficient sport-utility vehicles (SUVs) and pickup trucks, which are more profitable for automakers and accounted for 60% of new vehicles sales in the United States in 2018. One reason for this is that most consumers are unaware that gasoline costs them much more than the price they pay at the pump. A number of hidden gasoline costs not included in the price of gasoline include government subsidies and tax breaks for oil companies, car manufacturers, and road builders. Hidden costs also include costs related to pollution control and cleanup and higher medical bills and health insurance premiums resulting from illnesses caused by air and water pollution related to the production and use of motor vehicles. The International Center for Technology Assessment estimated that the hidden costs of gasoline for U.S. consumers amount to $3.18 per liter ($12.00 per gallon).
One way to include more of these hidden costs in the market price is through higher gasoline taxes—an application of the full-cost pricing principle of sustainability. However, higher gas taxes are politically unpopular, especially in the United States. Some analysts call for increasing U.S. gasoline taxes and reducing payroll and income taxes to offset any additional financial burden to consumers. Another way for governments to encourage higher energy efficiency in transportation is to give consumers significant tax breaks or other economic incentives to encourage them to buy more fuel-efficient vehicles.
Other ways to save energy and money in transportation include building or expanding mass transit systems within cities, constructing high-speed rail lines between cities (as is done in Japan, much of Europe, and China), and carrying more freight by rail instead of in heavy trucks. Another approach is to encourage bicycle use by building bike lanes along highways and city streets
16.hSaving Energy and Money in Existing Buildings
Here are ways to reduce energy use in existing buildings and to cut energy waste and save money on electricity, heating, and cooling bills (see Core Case Study ):
· Conduct an energy audit to detect air leaks ( Figure 16.1 ).
· Insulate the building and plug air leaks.
· Use energy-efficient (double- or triple-pane) windows.
· Seal leaky heating and cooling ducts in attics and unheated basements.
· Heat water more efficiently. One option is a roof-mounted solar hot water heater. Another option is a tankless instant water heater. It uses natural gas or liquefied petroleum gas (but not an electric heater, which is inefficient) to deliver hot water only when it is needed rather than keeping water in a large tank hot all the time.
· Use energy-efficient appliances. A refrigerator with its freezer in a drawer on the bottom uses about half as much energy as one with the freezer on the top or on the side, which allows dense cold air to flow out quickly when the door is opened. Microwave ovens use less electricity than electric stoves do for cooking and 66% less energy than conventional ovens. Front-loading clothes washers use 55% less energy and 30% less water than top-loading models use and cut operating costs in half.
· Use energy-efficient computers. According to the EPA, if all computers sold in the United States met its Energy Star requirements, consumers would save $1.8 billion a year in energy costs and reduce greenhouse gas emissions by an amount equal to that of taking about 2 million cars off the road.
· Use energy-efficient lighting. The DOE estimates that by switching to energy-efficient LED bulbs over the next 20 years, U.S. consumers could save money and reduce the demand for electricity by an amount equal to the output of 40 new power plants. In recent years, the cost of LED bulbs has fallen by 90%. They last 25 times longer than traditional incandescent bulbs (which waste 95% of their energy) and 2.5 times longer than compact fluorescent bulbs.
· Stop using the standby mode. Consumers can reduce their energy use and their monthly power bills by plugging their standby electronic devices into smart power strips that cut off power to a device when it detects that the device has been turned off.
Figure 16.8 lists ways in which individuals can cut energy use and save money in their homes.
Figure 16.8
Individuals matter: People can save energy and money where they live and reduce their harmful environmental impact.
16.2iWhy Are We Wasting So Much Energy and Money?
Considering its impressive array of economic and environmental benefits (Figure 16.3), why is there so little emphasis on reducing energy waste by improving energy efficiency and conserving energy? One reason is that energy resources such as fossil fuels and nuclear power are artificially cheap. This is primarily because of the government subsidies and tax breaks they receive and because their market prices do not include the harmful environmental and health costs of producing and using them. This distortion of the energy marketplace violates the full-cost pricing principle of sustainability.
Another reason for continuing energy waste is that governments do not provide significant government tax breaks, rebates, low-interest and long-term loans, and other economic incentives for individuals and businesses to invest in improving energy efficiency. A third reason is that most governments and utility companies have not put a high priority on educating the public about the environmental and economic advantages of improving energy efficiency and conserving energy.
Some critics say an emphasis on improving energy efficiency does not work because of the rebound effect in which some people tend to use more energy when they buy energy-efficient devices. For example, some people who buy a more efficient car tend to drive more, which offsets some of their energy and money savings and their reduced environmental impact.
Instead of downplaying efforts to improve energy efficiency, energy experts call for a major program to educate people about the rebound effect and its waste of money and long-lasting harmful health and environmental effects.
16.2jRelying More on Renewable Energy
In addition to reducing energy waste, we can make greater use of renewable energy from the sun, wind, flowing water, biomass, and heat from the earth’s interior (geothermal energy). The lesson from one of nature’s three scientific principles of sustainability is to rely mostly on solar energy. Most forms of renewable energy can be traced to the sun, because wind, flowing water, and biomass would not exist, were it not for solar energy. Another form of renewable energy is geothermal energy, or heat from the earth’s interior. All of these sources of renewable energy are constantly replenished at no cost to us.
In 2018, California, the world’s fifth largest economy, got 36% of its electricity from renewable energy resources. That year, California’s legislature passed a law requiring the state to get 60% of electricity from renewable energy resources by 2030 and 100% by 2045. In 2018, the legislature also passed a law requiring solar panels on all new homes built after 2020.
According to the IEA, solar and wind are the world’s fastest-growing energy resources and nuclear energy is the slowest (Figure 15.24). China has the world’s largest installed capacity for electricity from wind power and solar cells. It plans to become the largest user and seller of wind turbines and solar cells, which are projected to be two of the world’s fastest growing businesses over the next few decades. China’s goal is to greatly expand its production of electricity from renewable wind, sun, and flowing water (hydropower) to help reduce its use of coal and the resulting outdoor air pollution that kills about 1.2 million of its citizens each year.
If renewable energy is so great, why does it provide only 11% of the world’s energy (Figure 15.2, left) and 12% of the energy used in the United States (Figure 15.2, right)? There are several reasons.
Second, since 1950, government tax breaks, subsidies, and funding for research and development of renewable energy resources have been much lower than those for fossil fuels and nuclear power. According to the IEA, global subsidies for fossil fuels are nearly 10 times more than global subsidies for renewable energy.
Third, U.S. government subsidies and tax breaks for renewable energy have been increasing, but Congress must renew them every few years, which hinders investments in renewable energy. In contrast, billions of dollars of annual subsidies for fossil fuels and nuclear power have essentially been guaranteed for many decades thanks in large part to political pressure from these industries.
Fourth, the prices for nonrenewable fossil fuels and nuclear power do not include most of the harmful environmental and human health costs of producing and using them. As a result, they are partially shielded from free-market competition with cleaner renewable sources of energy.
Fifth, history shows that it typically takes 50 to 60 years to make a shift from one set of key energy resources to another. Renewable wind and solar energy are the world’s fastest growing sources of energy, but it will likely take several decades for them to supply 25% or more of the world’s electricity.
16.3bCooling Buildings Naturally
Direct solar energy works against us when we want to keep a building cool. However, we can use indirect solar energy (mainly wind) to help cool buildings. We can open windows to take advantage of breezes and use fans to keep the air moving. When there is no breeze, superinsulation and high-efficiency windows keep hot air outside.
Other ways to keep buildings cool include:
1. blocking the sun with shade trees, broad overhanging eaves, window awnings, or shades;
2. using a light-colored roof to reflect up to 90% of the sun’s heat (compared to only 10–15% for a dark-colored roof), or using a living or green roof; and
3. using geothermal heat pumps to pump cool air from underground into a building during summer.
Learning from Nature
Some species of African termites stay cool in a hot climate by building giant mounds that allow air to circulate through them. Engineers have used this design lesson from nature to cool buildings naturally, reduce energy use, and save money.
16.3cConcentrating Sunlight to Produce High-Temperature Heat and Electricity
One of the problems with direct solar energy is that it is dispersed. Solar thermal systems , also known as concentrated solar power (CSP), use different methods to collect and concentrate solar energy to boil water and produce steam for generating electricity. These systems can be used in deserts and other open areas with ample sunlight.
One such system uses rows of curved mirrors, called parabolic troughs, to collect and concentrate sunlight. Each trough focuses incoming sunlight on a pipe that runs through its center and is filled with synthetic oil (Figure 16.13). Solar energy heats this oil to a temperature high enough to boil water and produce steam that spins a turbine to generate electricity.
Figure 16.13
Solar thermal power: This solar power plant in California’s Mojave Desert uses curved (parabolic) solar collectors to concentrate solar energy for producing electricity.
National Renewable Energy Laboratory
Another solar thermal system (Figure 16.14) uses an array of computer-controlled mirrors to track the sun and focus its energy on a central power tower. The concentrated heat is used to boil water and produce steam that drives turbines to produce electricity. The heat produced by either of these systems can also be used to melt a type of salt stored in a large insulated container. The heat stored in this molten salt backup system can be released as needed to produce electricity at night or on cloudy days.
Figure 16.14
Solar thermal power: In this system in California an array of mirrors tracks the sun and focuses reflected sunlight on a central receiver to boil the water for producing electricity.
Sandia National Laboratories/National Renewable Energy Laboratory
Some analysts see solar thermal power as a growing and important source of the world’s electricity. However, because solar thermal systems have a low net energy, they require large government subsidies or tax breaks to be competitive in the marketplace. These systems also require large volumes of cooling water for condensing the steam back to water and for washing the surfaces of the mirrors and parabolic troughs. However, they are usually built in sunny, arid desert areas where water is scarce. Figure 16.15 summarizes the major advantages and disadvantages of using these solar thermal systems.
Figure 16.15
Using solar energy to generate high-temperature heat and electricity has advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
Top: Sandia National Laboratories/National Renewable Energy Laboratory. Bottom: National Renewable Energy Laboratory.
We can also use concentrated solar energy on a smaller scale. In some sunny areas, people use inexpensive solar cookers to focus and concentrate sunlight for boiling and sterilizing water (Figure 16.16, left) and cooking food (Figure 16.16, right). Solar cookers can replace wood and charcoal fires and reduce indoor air pollution, a major health hazard in less-developed nations. They also help reduce deforestation by decreasing the need for firewood and charcoal made from firewood.
Figure 16.16
Solutions: Solar cooker (left) in Costa Rica and simple solar oven (right).
chriss73/ Shutterstock.com; M. Cornelius/ Shutterstock.com
16.3dUsing Solar Cells to Produce Electricity
In 1931, Thomas Edison (inventor of the electric light bulb) told Henry Ford, “I’d put my money on the sun and solar energy. … I hope we don’t have to wait until oil and coal run out before we tackle that.” Edison’s dream is now a reality.
We can convert solar energy directly into electrical energy using photovoltaic (PV) cells , commonly called solar cells . Most solar cells are thin transparent wafers of purified silicon (Si) or polycrystalline silicon with trace amounts of metals that allow them to produce electricity when sunlight strikes them. Solar cells are wired together in a panel and many panels can be connected to produce electricity for a house or a large solar power plant (Figure 16.17). Such systems can be connected to electrical grids or to batteries that store the electrical energy until it is needed. Large solar-cell power plants are operating in Germany, Spain, Portugal, South Korea, China, and the southeastern United States. In 2017, factories in China produced more than two-thirds of the world’s solar cell panels.
Figure 16.17
Solar cell power plant: Huge arrays of solar cells can be connected to produce electricity.
Arrays of solar cells can be mounted on rooftops or incorporated into almost any type of roofing material. Nanotechnology and other emerging technologies will likely allow the manufacturing of solar cells in paper-thin, rigid or flexible sheets that can be printed like newspapers and attached to or embedded in other surfaces such as outdoor walls, windows, drapes, and clothing (to recharge batteries in mobile phones and other personal electronic devices). Figure 16.18 shows a solar cell village in Germany. Solar power providers in several countries are putting floating arrays of solar cell panels on the surfaces of lakes, reservoirs, ponds, and canals. In 2017, China developed the world’s largest floating solar farm on a lake. Engineers are developing dirt and water-repellent coatings to keep solar panels and collectors clean without having to use water. GREEN CAREER: Solar-cell technology
Figure 16.18
Solar cell village in Germany.
iStock.com/schmidt-z
Nearly 1.3 billion people, most of them in rural villages in less developed countries are not connected to an electrical grid. A growing number of these people are using rooftop solar panels (Figure 16.19) to power energy-efficient LED lamps that can replace costly and inefficient kerosene lamps that pollute indoor air. Expanding off-grid solar-cell systems to additional rural villages will help hundreds of millions of people lift themselves out of poverty and reduce their exposure to deadly indoor air pollution.
Figure 16.19
Solutions: A solar cell panel provides electricity for lighting this hut in rural West Bengal, India. In 2017, solar cells produced 6.3% of India’s electricity.
Jim Welc/National Renewable Energy Laboratory
India has more than 300 million mostly rural poor people who are not connected to an electrical grid. Private entrepreneurs in India and Africa are setting up stand-alone solar-powered microgrids where a centralized group of solar cell panels are connected by cable to a few dozen homes and local businesses. Customers use cell phones to connect to village smart meters and purchase a certain amount of electricity. The smart meters cut off the power when a user’s payment runs out.
Solar cells have no moving parts, need no water for cooling, and operate safely and quietly. They do not emit greenhouse gases or other air pollutants, but they are not a carbon-free option because fossil fuels are used to produce and transport the panels. However, the emissions per unit of electricity produced are much smaller than those generated by using fossil fuels and nuclear power to produce electricity. Conventional solar cells also contain toxic materials that must be recovered when the cells wear out after 20–25 years of use, or when they are replaced by new systems.
One problem with current solar cells is their low energy efficiency. They typically convert only about 20% of the incoming solar energy into electricity, although their efficiency is rapidly improving. In 2014, researchers at Germany’s Fraunhofer Institute for Solar Energy Systems developed a solar cell with an efficiency of 45%—compared to an efficiency of 35% for fossil fuel and nuclear electric power plants. They are working to scale up this prototype cell for commercial use. Figure 16.20 lists the major advantages and disadvantages of using solar cells to produce electricity.
Figure 16.20
Using solar cells to produce electricity has advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
Top: Martin D. Vonka/ Shutterstock.com. Bottom: pedrosala/ Shutterstock.com.
Some businesses and homeowners are spreading the cost of rooftop solar power systems over decades by including them in their mortgages. Others are leasing solar-cell systems from companies that install and maintain them.
Some communities and neighborhoods are using community solar or shared solar systems to provide electricity for individuals who rent or live in condominiums, or whose access to sunlight is blocked by buildings or trees. Customers buy the power from a centrally located small solar cell power plant. The power is delivered by the local utility and customers share deductions on their monthly bills for any excess power the project sells back to the grid.
Use of solar cells is the world’s fastest growing way of producing electricity. Between 2001 and 2018, the cost per watt of electricity produced by solar cells fell by 80%. Producing electricity from solar cells is expected to grow because solar energy is unlimited and available throughout the world. It is also a technology, not a fuel such as coal or natural gas, the prices of which are controlled by available supplies. Prices for solar cell systems are likely to continue dropping because of technological advances, mass production, and decreased installation costs. In 2018, California had half of the country’s rooftop solar cell installations and a quarter of U.S. solar-energy jobs.
Solar cells cannot produce electricity at night, and storing energy in large batteries for use at night and on cloudy days is expensive. However, researchers at Ohio State University have developed a solar cell panel with a built-in battery that is 25% less expensive and 20% more efficient than conventional batteries. If it can be mass-produced, this invention could revolutionize the use of solar energy to produce electricity. GREEN CAREER: Solar-cell technology
Learning from Nature
A rainforest butterfly species called the glasswing, with its transparent wings, provided the inspiration for a cost-effective coating for solar panels that allows the panels to absorb more light and generate electricity more efficiently.
If pushed hard and supported by government subsidies equivalent to or greater than fossil fuel subsidies, solar energy could supply as much as 23% of U.S. electricity by 2050, according to projections by the NREL. After 2050, solar electricity is likely to become one of the top sources of electricity for the United States and much of the world. If this happens, it will represent a global application of the solar energy principle of sustainability.
16.3dUsing Solar Cells to Produce Electricity
In 1931, Thomas Edison (inventor of the electric light bulb) told Henry Ford, “I’d put my money on the sun and solar energy. … I hope we don’t have to wait until oil and coal run out before we tackle that.” Edison’s dream is now a reality.
We can convert solar energy directly into electrical energy using photovoltaic (PV) cells , commonly called solar cells . Most solar cells are thin transparent wafers of purified silicon (Si) or polycrystalline silicon with trace amounts of metals that allow them to produce electricity when sunlight strikes them. Solar cells are wired together in a panel and many panels can be connected to produce electricity for a house or a large solar power plant (Figure 16.17). Such systems can be connected to electrical grids or to batteries that store the electrical energy until it is needed. Large solar-cell power plants are operating in Germany, Spain, Portugal, South Korea, China, and the southeastern United States. In 2017, factories in China produced more than two-thirds of the world’s solar cell panels.
Figure 16.17
Solar cell power plant: Huge arrays of solar cells can be connected to produce electricity.
Ollyy/ Shutterstock.com
Arrays of solar cells can be mounted on rooftops or incorporated into almost any type of roofing material. Nanotechnology and other emerging technologies will likely allow the manufacturing of solar cells in paper-thin, rigid or flexible sheets that can be printed like newspapers and attached to or embedded in other surfaces such as outdoor walls, windows, drapes, and clothing (to recharge batteries in mobile phones and other personal electronic devices). Figure 16.18 shows a solar cell village in Germany. Solar power providers in several countries are putting floating arrays of solar cell panels on the surfaces of lakes, reservoirs, ponds, and canals. In 2017, China developed the world’s largest floating solar farm on a lake. Engineers are developing dirt and water-repellent coatings to keep solar panels and collectors clean without having to use water. GREEN CAREER: Solar-cell technology
Figure 16.18
Solar cell village in Germany.
iStock.com/schmidt-z
Nearly 1.3 billion people, most of them in rural villages in less developed countries are not connected to an electrical grid. A growing number of these people are using rooftop solar panels (Figure 16.19) to power energy-efficient LED lamps that can replace costly and inefficient kerosene lamps that pollute indoor air. Expanding off-grid solar-cell systems to additional rural villages will help hundreds of millions of people lift themselves out of poverty and reduce their exposure to deadly indoor air pollution.
Figure 16.19
Solutions: A solar cell panel provides electricity for lighting this hut in rural West Bengal, India. In 2017, solar cells produced 6.3% of India’s electricity.
Jim Welc/National Renewable Energy Laboratory
India has more than 300 million mostly rural poor people who are not connected to an electrical grid. Private entrepreneurs in India and Africa are setting up stand-alone solar-powered microgrids where a centralized group of solar cell panels are connected by cable to a few dozen homes and local businesses. Customers use cell phones to connect to village smart meters and purchase a certain amount of electricity. The smart meters cut off the power when a user’s payment runs out.
Solar cells have no moving parts, need no water for cooling, and operate safely and quietly. They do not emit greenhouse gases or other air pollutants, but they are not a carbon-free option because fossil fuels are used to produce and transport the panels. However, the emissions per unit of electricity produced are much smaller than those generated by using fossil fuels and nuclear power to produce electricity. Conventional solar cells also contain toxic materials that must be recovered when the cells wear out after 20–25 years of use, or when they are replaced by new systems.
One problem with current solar cells is their low energy efficiency. They typically convert only about 20% of the incoming solar energy into electricity, although their efficiency is rapidly improving. In 2014, researchers at Germany’s Fraunhofer Institute for Solar Energy Systems developed a solar cell with an efficiency of 45%—compared to an efficiency of 35% for fossil fuel and nuclear electric power plants. They are working to scale up this prototype cell for commercial use. Figure 16.20 lists the major advantages and disadvantages of using solar cells to produce electricity.
Figure 16.20
Using solar cells to produce electricity has advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
Top: Martin D. Vonka/ Shutterstock.com. Bottom: pedrosala/ Shutterstock.com.
Some businesses and homeowners are spreading the cost of rooftop solar power systems over decades by including them in their mortgages. Others are leasing solar-cell systems from companies that install and maintain them.
Some communities and neighborhoods are using community solar or shared solar systems to provide electricity for individuals who rent or live in condominiums, or whose access to sunlight is blocked by buildings or trees. Customers buy the power from a centrally located small solar cell power plant. The power is delivered by the local utility and customers share deductions on their monthly bills for any excess power the project sells back to the grid.
Use of solar cells is the world’s fastest growing way of producing electricity. Between 2001 and 2018, the cost per watt of electricity produced by solar cells fell by 80%. Producing electricity from solar cells is expected to grow because solar energy is unlimited and available throughout the world. It is also a technology, not a fuel such as coal or natural gas, the prices of which are controlled by available supplies. Prices for solar cell systems are likely to continue dropping because of technological advances, mass production, and decreased installation costs. In 2018, California had half of the country’s rooftop solar cell installations and a quarter of U.S. solar-energy jobs.
Solar cells cannot produce electricity at night, and storing energy in large batteries for use at night and on cloudy days is expensive. However, researchers at Ohio State University have developed a solar cell panel with a built-in battery that is 25% less expensive and 20% more efficient than conventional batteries. If it can be mass-produced, this invention could revolutionize the use of solar energy to produce electricity. GREEN CAREER: Solar-cell technology
Learning from Nature
A rainforest butterfly species called the glasswing, with its transparent wings, provided the inspiration for a cost-effective coating for solar panels that allows the panels to absorb more light and generate electricity more efficiently.
If pushed hard and supported by government subsidies equivalent to or greater than fossil fuel subsidies, solar energy could supply as much as 23% of U.S. electricity by 2050, according to projections by the NREL. After 2050, solar electricity is likely to become one of the top sources of electricity for the United States and much of the world. If this happens, it will represent a global application of the solar energy principle of sustainability.
16.5aTapping into the Earth’s Internal Heat
Geothermal energy is heat stored in soil, underground rocks, and fluids in the earth’s mantle. It is used to heat and cool buildings and to heat water to produce electricity. Geothermal energy is available around the clock but is practical only at sites with high enough concentrations of underground heat.
A geothermal heat pump system (Figure 16.24) can heat and cool a house almost anywhere in the world. This system makes use of the temperature difference between the earth’s surface and underground at a depth of 3–6 meters (10–20 feet), where the temperature typically is year-round. In winter, a closed loop of buried pipes circulates a fluid, which extracts heat from the ground and carries it to a heat pump, which transfers the heat to a home’s heat distribution system. In summer, this system works in reverse, removing heat from a home’s interior and storing it below ground.
Figure 16.24
Natural capital: A geothermal heat pump system can heat or cool a house almost anywhere.
According to the EPA, a geothermal heat pump system is the most energy-efficient, reliable, environmentally clean, and cost-effective way to heat or cool a space. Installation costs can be high but are recouped within 3 to 5 years, after which these systems save energy and money for their owners. Initial costs can be added to a home mortgage to spread the financial burden over two or more decades.
Engineers have also learned how to tap into deeper, more concentrated hydrothermal reservoirs of geothermal energy (Figure 16.25). Wells are drilled into the reservoirs to extract their dry steam (with a low water content), wet steam (with a high water content), or hot water. The steam or hot water can be used to heat homes and buildings, provide hot water, grow vegetables in greenhouses, raise fish in aquaculture ponds, and spin turbines to produce electricity.
Figure 16.25
Power plants can produce electricity from heat extracted from underground geothermal reservoirs. The photo shows a geothermal power plant in Iceland that produces electricity and heats a nearby spa called the Blue Lagoon.
Richard Nowitz/National Geographic Image Collection
Drilling geothermal wells, like drilling oil and natural gas wells, is expensive and requires a major investment. It is also a risky investment because drilling projects do not always succeed in tapping into concentrated deposits of geothermal energy. Once a successful deposit is found, it can supply geothermal energy for heat or to produce electricity around the clock, as long as heat is not removed from the deposit faster than the earth replaces it—usually at a slow rate. When this happens, geothermal energy becomes a nonrenewable resource.
Geothermal energy generates electricity in 24 countries and provides heat in 70 countries. The United States is the world’s largest producer of geothermal electricity from hydrothermal reservoirs, most of it in California, Nevada, Utah, and Hawaii. Figure 16.26 is a map of the best geothermal energy sites in the continental United States. The U.S. Geothermal Energy Association (GEO) estimates that 90% of the available geothermal energy for producing electricity in the United States and 60% of the potential supply in California has not been tapped.
Figure 16.26
Potential geothermal energy resources in the continental United States.
(Compiled by the authors using data from U.S. Department of Energy and U.S. Geological Survey)
Iceland gets almost all of its electricity from renewable hydroelectric (72%) and geothermal (25%) power plants (Figure 16.25, photo) and about 90% of its demand for heat and hot water from geothermal energy. In Peru, a National Geographic Explorer is carrying out research to develop that country’s geothermal resources (Individuals Matter 16.1).
Individuals Matter 16.1
Andrés Ruzo—Geothermal Energy Sleuth and National Geographic Explorer
Courtesy of Andrés Ruzo
Andrés Ruzo is a geophysicist with a passion to learn about geothermal energy and to show how this renewable and clean energy source can help us solve some of the world’s energy problems. As a boy, he spent summers on the family farm in Nicaragua. Because the farm rests on top of the Casita Volcano, he was able to experience firsthand the power of the earth’s heat.
As an undergraduate student at Southern Methodist University (SMU) in Dallas, Texas (USA), because of his boyhood experience, he took a course in volcanology. The course awakened his passion for geology along with a desire to learn more about the earth’s heat as a source of energy. This led him to pursue a PhD in geophysics at SMU’s Geothermal Laboratory.
Beginning in 2009, he has been gathering data across Peru to develop the country’s first detailed heat flow map—which will help identify areas of geothermal energy potential. His fieldwork involves lowering temperature-measuring equipment down into oil, gas, mining, or water wells. Much of this work was done in the Talara Desert in northwestern Peru, where surface temperatures can exceed . These data illustrate how thermal energy flows through the upper crust of the earth, and highlights areas where earth’s heat can potentially be tapped as a source of energy.
Ruzo believes that geothermal energy is a “sleeping giant” that, if properly harnessed, can be an important renewable source of heat and electricity. He says that his goal in life is “to be a force of positive change in the world.”
Figure 16.27 lists the major advantages and disadvantages of using geothermal energy. The biggest factors limiting the widespread use of geothermal energy are the lack of hydrothermal sites with concentrations of heat high enough to make it affordable and the high cost of drilling the wells and building the plants.
Figure 16.27
Using geothermal energy for space heating and for producing electricity or high-temperature heat for industrial processes has advantages and disadvantages.
Critical Thinking:
1. Do you think the advantages outweigh the disadvantages? Why or why not?
Photo: N. Minton/ Shutterstock.com
16.6aProducing Energy by Burning Solid Biomass
Energy can be produced by burning biomass, the organic matter found in plants, plant and animal wastes, and plant products such as scrap lumber. Examples of biomass fuels include wood, wood pellets, wood wastes, charcoal made from wood, and agricultural wastes such as sugarcane stalks, rice husks, and corncobs.
Most solid biomass is burned for heating and cooking. It can also be used to provide heat for industrial processes and to generate electricity. Biomass used for heating and cooking supply 10% of the world’s energy, 35% of the energy used in less-developed countries, and 95% of the energy used in the poorest countries.
Wood is a renewable resource only if it is not harvested faster than it is replenished. The problem is that about 2.7 billion people in 77 less-developed countries face a fuelwood crisis. To survive, they often meet their fuel needs by harvesting trees faster than new ones can replace them.
One solution is to plant fast-growing trees, shrubs, or perennial grasses in biomass plantations. However, repeated cycles of growing and harvesting these plantations can deplete the soil of key nutrients. It can also allow for the spread of nonnative tree species that become invasive species.
Clearing forests and grasslands to provide fuel also causes problems. It reduces biodiversity and the amount of vegetation that would otherwise capture climate-changing .
In the southeastern and northwestern United States, virgin and second-growth hardwood forests are being cleared to make wood pellets for fuel. They are mostly exported to European Union countries for use in heating factories and producing electricity. Critics call this an unsustainable practice. The pellet industry denies that they are removing whole trees and says they are using only tree branches and other wood wastes to make the pellets. However, as the volume of wood pellet production has increased, observers are seeing the destruction of large forested areas.
There is also controversy over burning forestry and crop wastes to provide heat and electricity. The supply of such wastes is not as large as some have estimated, and collecting and transporting these widely dispersed wastes to factories and utilities is difficult and expensive. In addition, crop wastes left on fields are valuable soil nutrients, and scientists argue they should be used as such.
In addition, burning wood and other forms of biomass produces and other pollutants such as fine particulates in smoke. Figure 16.28 lists the major advantages and disadvantages of burning solid biomass as a fuel.
Figure 16.28
Burning solid biomass as a fuel has advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
Top: Fir4ik/ Shutterstock.com. Bottom: Eppic/ Dreamstime.com.
16.6bUsing Liquid Biofuels to Power Vehicles
Biomass can also be converted into liquid biofuels for use in motor vehicles. The two most common liquid biofuels are ethanol (ethyl alcohol produced from plants and plant wastes) and biodiesel (produced from vegetable oils). The three biggest biofuel producers are, in order, the United States (producing ethanol from corn), Brazil (producing ethanol from sugarcane residues), and the European Union (producing biodiesel from vegetable oils).
Biofuels have three major advantages over gasoline and diesel fuel produced from oil. First, biofuel crops can be grown throughout much of the world, which can help more countries reduce their dependence on imported oil. Second, if growing new biofuel crops keeps pace with harvesting them, there is no net increase in emissions, unless existing grasslands or forests are cleared to plant biofuel crops. Third, biofuels are easy to store and transport through existing fuel networks and can be used in motor vehicles at little additional cost.
Since 1975, global ethanol production has increased rapidly, especially in the United States and Brazil. Brazil makes ethanol from bagasse, a residue produced when sugarcane is crushed. This sugarcane ethanol has a medium net energy that is 8 times higher than that of ethanol produced from corn. About 70% of Brazil’s motor vehicles run on ethanol or ethanol–gasoline mixtures produced from sugarcane grown on only 1% of the country’s arable land. This has greatly reduced Brazil’s dependence on imported oil. However, one drawback is that some forests are being cleared to grow more sugar cane to produce ethanol.
In 2017, just over 30% of the corn produced in the United States was used to make ethanol, which is mixed with gasoline to fuel cars. Studies indicate that corn-based ethanol has a low net energy because of the large-scale use of fossil fuels to produce fertilizers, grow the corn, and convert it to ethanol. This means that corn-based ethanol needs U.S. government subsidies to compete in the marketplace.
According to a study by the Environmental Working Group (EWG), producing and burning corn-based ethanol adds at least 20% more greenhouse gases to the atmosphere per unit of energy than does producing and burning gasoline. Growing corn also requires a great deal of water, and ethanol distilleries produce large volumes of wastewater.
According to another study by the Environmental Working Group (EWG), the heavily government-subsidized corn-based ethanol program in the United States has taken more than 2 million hectares (5 million acres) of land out of the soil conservation reserve, an important topsoil preservation program. Growing corn also requires large amounts of water and land—resources that are in short supply in some areas.
Furthermore, scientists warn that large-scale biofuel farming could reduce biodiversity, degrade soil quality, and increase erosion. As a result, a number of scientists and energy economists call for withdrawing government subsidies for corn-based ethanol production and reducing the current limit of no more than 10% ethanol in U.S. gasoline as mandated by the Energy Independence and Security Act of 2007. In contrast, corn-growers and ethanol distiller have proposed allowing up to 30% ethanol in gasoline. They claim that the harmful environmental effects of corn-based ethanol are overblown and that it has many environmental and economic benefits. In 2018, the U.S. Congress supported using 15% ethanol in gasoline.
An alternative to corn-based ethanol is cellulosic ethanol, which is produced from the inedible cellulose that makes up most of the biomass of plants in the form of leaves, stalks, and wood chips. Cellulosic ethanol can be produced from tall and rapidly growing grasses such as switchgrass and miscanthus that do not require nitrogen fertilizers and pesticides. They also do not have to be replanted because they are perennial plants, and they can be grown on degraded and abandoned farmlands.
Ecologist David Tilman ( Individuals Matter 12.1 ) estimates that the net energy of cellulosic ethanol is about five times that of corn-based ethanol. However, producing cellulosic ethanol is not yet affordable, and growing switchgrass or miscanthus requires even more land than does growing corn. More research is also needed to determine possible environmental impacts.
In Malaysia and Indonesia, large areas of tropical rain forests are being cleared and replaced with plantations of oil palm trees ( Figure 10.4 ), which produce a fruit that contains palm oil. After the oil is extracted, about a third of it is exported to Europe to make biodiesel fuel and the rest goes into processed food and cosmetics. The clearing and burning of tropical forests to make space for these palm oil plantations eliminates the vital biodiversity of the forests. It also adds to the atmosphere, and the resulting plantations remove far less than do the forests they replace.
Another possible alternative to corn-based ethanol involves using algae to produce biofuels. As a crop, algae can grow year-round in various aquatic environments. Algae store energy as natural oils in their cells. This oil can be extracted and refined to make a product very much like gasoline or biodiesel. Currently, extracting and refining the oil from algae is too costly. More research is needed to evaluate the potential for this possible biofuel option.
Figure 16.29 compares the advantages and disadvantages of using biodiesel and ethanol liquid biofuels.
Figure 16.29
Ethanol and biodiesel biofuels have advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
16.7aProducing Electricity from Falling and Flowing Water
Hydropower is any technology that uses the kinetic energy of flowing and falling water to produce electricity. This renewable energy resource is an indirect form of solar energy because it depends on heat from the sun evaporating surface water as part of the earth’s solar-powered water cycle (Figure 3.19).
The most common way to harness hydropower is to build a high dam across a large river to create a reservoir (see Chapter 13 opening photo). Some of the water stored in the reservoir is allowed to flow through large pipes at controlled rates, turning blades on a turbine that produces electricity (see Figure 13.15), which is distributed by the electrical grid.
Hydropower is the world’s most widely used renewable energy resource. In 2017, it produced about 17% of the world’s electricity according to the IEA. In 2017, the world’s top four producers and consumers of hydropower were, in order, China, Canada, Brazil, and the United States. In 2017, hydropower supplied about 7.5% of the electricity used in the United States and about half of the electricity used on the West Coast, mostly in Washington and California.
According to the United Nations, only 13% of the world’s potential for hydropower has been developed. Countries with the greatest potential include China, India, and several countries in South America and Central Africa. China, with the world’s largest hydropower output, plans to more than double its output during the next decade and is building or funding more than 200 hydropower dams around the world.
Hydropower is the least expensive renewable energy resource. Once a dam is up and running, its source of energy—flowing water—is free and is annually renewed by snow and rainfall unless climate change reduces the water flow in some areas with existing hydropower plants. Despite their potential, some analysts expect that the use of large-scale hydropower plants will fall slowly over the next several decades, as many existing reservoirs fill with silt and become useless faster than new systems are built.
There is also growing concern over emissions of methane, a potent greenhouse gas, from the decomposition of submerged vegetation in hydropower plant reservoirs, especially in warm climates. Scientists at Brazil’s National Institute for Space Research estimate that the world’s largest dams altogether are the single largest human-caused source of climate-changing methane. The electricity output of hydropower plants may also drop if atmospheric temperatures continue to rise and melt mountain glaciers that are a primary source of water for these plants.
It is unlikely that large new hydroelectric dams will be built in the United States because most of the best sites already have dams and because of the high cost of building new dams. In addition, there is growing controversy over the harmful effects of interrupting river flows. However, the turbines at many existing U.S. hydropower dams could be modernized and upgraded to increase their output of electricity. Figure 16.30 lists the major advantages and disadvantages of using large-scale hydropower plants to produce electricity.
Figure 16.30
Using large dam and reservoir systems to produce electricity has advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
Photo: Andrew Zarivny/ Shutterstock.com
Another way to produce electricity from flowing water is to tap into tidal energy, the energy from ocean tides and waves. In some coastal bays and estuaries, water levels can rise or fall by 6 meters (20 feet) or more between daily high and low tides. Dams can be built across the mouths of such bays and estuaries to capture the energy in these flows for hydropower. The only three large tidal energy dams currently operating are in France, Nova Scotia, and South Korea. According to energy experts, tidal power will make only a minor contribution to the world’s electricity production because sites with large tidal flows are rare.
For decades, scientists and engineers have been trying to produce electricity by tapping wave energy along seacoasts where there are almost continuous waves. However, production of electricity from tidal and wave systems is limited because of a lack of suitable sites, citizen opposition at some sites, high costs, and equipment damage from saltwater corrosion and storms.
China is building a pilot plant to evaluate the feasibility of producing electricity by using the difference in temperature between warm surface water and cold deep water in parts of the world’s tropical oceans to generate a flow of electrons. The United States experimented with this approach, called ocean thermal-energy conversion (OTEC), in the 1980s, but abandoned it because of its high cost.
16.8aWill Hydrogen Save Us?
Some scientists say that the fuel of the future is hydrogen gas . Most of their research has been focused on using fuel cells ( Figure 16.31 ) that combine and oxygen gas to produce electricity while emitting nonpolluting water vapor into the atmosphere.
Figure 16.31
A fuel cell takes in hydrogen gas and separates the hydrogen atoms’ electrons from their protons. The electrons flow through wires to provide electricity, while the protons pass through a membrane and combine with oxygen gas to form water vapor. Note that this process is the reverse of electrolysis, the process of passing electricity through water to produce hydrogen fuel.
Widespread use of hydrogen as a fuel for running motor vehicles, heating buildings, and producing electricity would eliminate most of the outdoor air pollution that comes from burning fossil fuels. It would also greatly reduce climate change and ocean acidification, because its use does not increase emissions as long as the is not produced with the use of fossil fuels or nuclear power.
Third, although fuel cells are the best way to use , current versions of fuel cells are expensive. However, progress in the development of nanotechnology (see Science Focus 14.1 ) and mass production could lead to less expensive fuel cells.
Fourth, whether or not a hydrogen-based energy system produces less and outdoor air pollution than a fossil fuel system depends on how the fuel is produced. Electricity from coal-burning and nuclear power plants can be used to decompose water into and . However, this approach does not avoid the harmful environmental effects associated with using coal and the nuclear fuel cycle. Research indicates that making from coal or stripping it from methane or gasoline adds much more to the atmosphere per unit of heat generated than does burning the coal or methane directly.
Hydrogen’s negative net energy is a serious limitation. It means that this fuel will have to be heavily subsidized in order for it to compete in the open marketplace. However, this could change. Chemist Daniel Nocera has been learning from nature by studying how a leaf uses photosynthesis to produce the chemical energy used by plants and he has developed an “artificial leaf.” This credit-card-sized silicon wafer produces and when placed in a glass of tap water and exposed to sunlight. The hydrogen can be extracted and used to power fuel cells. Scaling up this or similar processes to produce large amounts of at an affordable price with an acceptable net energy over the next several decades could represent a tipping point for use of solar energy and hydrogen fuel. Doing so would help implement the solar energy principle of sustainability on a global scale.
Figure 16.32 lists the major advantages and disadvantages of using hydrogen as an energy resource. GREEN CAREER: Fuel cell technology
Figure 16.32
Using hydrogen as a fuel for vehicles and for providing heat and electricity has advantages and disadvantages.
Critical Thinking:
1. Do the advantages outweigh the disadvantages? Why or why not?
Photo: LovelaceMedia/ Shutterstock.com
16.9aShifting to a New Energy Economy
According to its proponents, a major shift to a new set of energy resources over the next 50 to 60 years (see Section 16.1) would have numerous environmental, health, and economic benefits.
China (which uses 20% of the world’s energy) and the United States (which uses 19% of the world’s energy) are the key players in making this shift. China has a long way to go in reducing its heavy dependence on coal and leads the world in climate-changing emissions. However, it has launched efforts to make its economy more energy efficient, build a modern smart electrical grid, and install solar hot water heaters on a large scale. China is also building wind farms and solar power plants, supporting research on better batteries and solar and wind technologies, and building and selling all-electric cars. It is also making money by producing and selling more wind turbines and solar cell panels than any other country.
The United States is also making efforts to shift to a new energy economy. However, it is falling behind China’s efforts and those of countries such as Germany, Sweden, and Denmark. This is mostly because of more than 40 years of successful efforts by powerful fossil fuel and electric utility companies to stop or slow down this energy shift because it threatens their profits.
· Use full-cost pricing to include the harmful health and environmental costs of using fossil fuels and all other energy resources in their market prices.
· Tax carbon emissions. This is supported by most economists and many business leaders, and is now done in 40 countries. Use the revenue to reduce taxes on income and wealth and to promote investments and research in new energy-efficient and renewable energy technologies.
· Sharply decrease and eventually eliminate government subsidies for fossil fuel industries, which are well-established and profitable businesses.
· Mandate that a certain percentage (typically 20–40%) of the electricity generated by utility companies be from renewable resources (as is done in 24 countries and in 29 U.S. states).
· Increase government fuel efficiency (CAFE) standards for new vehicles to 43 kilometers per liter (100 miles per gallon) by 2040.
We have the creativity, wealth, and most of the technology to make the transition to a safer, more energy-efficient, and cleaner energy economy within your lifetime. With such a shift, we would greatly increase our beneficial environmental impact. Figure 16.33 lists ways in which you can take part in the transition toward such a future.
Figure 16.33
Individuals matter: You can make a shift in your own life toward using energy more sustainably.
Critical Thinking:
1. Which three of these measures do you think are the most important ones to take? Why? Which of these steps have you already taken and which do you plan to take?
Big Ideas
· To make our economies more sustainable, we need to reduce our use of fossil fuels, especially coal, and greatly increase energy efficiency, reduce energy waste, and use a mix of renewable energy resources, especially the sun and wind.
· Making this energy shift will have important economic and environmental benefits.
· Making the transition to a more sustainable energy future will require including the harmful environmental and health costs of all energy resources in their market prices, taxing carbon emissions, and greatly increasing government subsidies and research and development for improving energy efficiency and developing renewable energy resources.
· Tying It All TogetherSaving Energy and Money and Reducing Our Environmental Impact
·
· In the Core Case Study, we learned that by wasting energy, we waste money and increase our harmful environmental impact. The world and the United States waste so much energy that reducing this waste by increasing energy efficiency and saving energy is the quickest, cleanest, and usually the cheapest way to provide more energy. In doing so, we would also reduce pollution and environmental degradation and slow climate change and ocean acidification.
· Over the next 50 to 60 years, we could choose to rely less on fossil fuels, especially coal, and more on increasing energy efficiency and using a mix of solar, wind, and other renewable energy resources. Making this energy shift would have enormous economic, environmental, and health benefits.
· Relying more on energy from the sun and wind helps us to implement the solar energy principle of sustainability. It also follows the chemical cycling principle of sustainability by reducing our excess inputs of into the atmosphere, which disrupt the earth’s carbon cycle and cause ocean acidification when the ocean removes some of this excess from the atmosphere. This energy shift also mimics the earth’s biodiversity principle of sustainability by reducing the environmental degradation that degrades biodiversity.
· Making this shift will require implementing the full-cost pricing principle of sustainability by including the harmful health and environmental costs of energy resources in their market prices. It will also require compromise and trade-offs in the political arena, in keeping with the win-win principle of sustainability. By making this energy shift, we would also be implementing the ethical principle of sustainability, which calls for us to leave the earth’s life support system in as good as or better than it is now.
· Tying It All TogetherSaving Energy and Money and Reducing Our Environmental Impact
·
· LianeM/ Shutterstock.com
· In the Core Case Study, we learned that by wasting energy, we waste money and increase our harmful environmental impact. The world and the United States waste so much energy that reducing this waste by increasing energy efficiency and saving energy is the quickest, cleanest, and usually the cheapest way to provide more energy. In doing so, we would also reduce pollution and environmental degradation and slow climate change and ocean acidification.
· Over the next 50 to 60 years, we could choose to rely less on fossil fuels, especially coal, and more on increasing energy efficiency and using a mix of solar, wind, and other renewable energy resources. Making this energy shift would have enormous economic, environmental, and health benefits.
· Relying more on energy from the sun and wind helps us to implement the solar energy principle of sustainability. It also follows the chemical cycling principle of sustainability by reducing our excess inputs of into the atmosphere, which disrupt the earth’s carbon cycle and cause ocean acidification when the ocean removes some of this excess from the atmosphere. This energy shift also mimics the earth’s biodiversity principle of sustainability by reducing the environmental degradation that degrades biodiversity.
· Making this shift will require implementing the full-cost pricing principle of sustainability by including the harmful health and environmental costs of energy resources in their market prices. It will also require compromise and trade-offs in the political arena, in keeping with the win-win principle of sustainability. By making this energy shift, we would also be implementing the ethical principle of sustainability, which calls for us to leave the earth’s life support system in as good as or better than it is now.
· Data Analysis
· Study the table below and then answer the questions that follow it by filling in the blank columns in the table.
|
Combined City/Highway Fuel Efficiency for 2017 Models |
||||
|
Model |
Miles per Gallon (mpg) |
Kilometers per Liter (kpl) |
Annual Liters (Gallons) of Gasoline |
Annual Emissions |
|
Chevrolet All-Electric Volt |
106 |
|||
|
Nissan All-Electric Leaf |
112 |
|||
|
Toyota Prius Prime Plug-in Hybrid |
54 |
|||
|
Toyota Prius—Hybrid |
52 |
|||
|
Chevrolet Cruze |
34 |
|||
|
Honda Accord |
29 |
|||
|
Jeep Patriot 4WD |
24 |
|||
|
Ford F150 Pickup |
22 |
|||
|
Chevrolet Camaro 8 cyl |
20 |
|||
|
Ferrari F12 |
12 |
|||
|
Compiled by the authors using data from the U.S. Environmental Protection Agency Fuel Economy Report. |
C
hapter
16
·
·
·
Core Case Study
Saving Energy and Money
·
16.1
A New Energy Transition
·
16.1a
Establishing New Energy Priorities
·
16.2
Reducing Energy Waste
·
16.2a
We Waste a Lot of Energy and Money
·
16.2b
Improving Energy Efficiency in Industries and Utilities
·
16.2c
Building a Smarter and More Energy
–
Efficient Electrical Grid
·
16.2d
Making Transportation More Energy
–
Efficient
·
16.2e
Switching to Energy
–
Efficient Vehicles
·
16.2f
Buildings That Save Energy and Money
·
16.2g
Air Conditioning and Climate Change
·
16.h
Saving Energy and Money in Existing Buil
dings
·
16.2i
Why Are We Wasting So Much Energy and Money?
·
16.2j
Relying More on Renewable Energy
·
16.3
Solar Energy
·
16.3a
Heating Buildings an
d Water with Solar Energy
·
16.3b
Cooling Buildings Naturally
·
16.3c
Concentrating Sunlight to Produce High
–
Temperature Heat and
Electricity
·
16.3d
Using Solar Cells to Produce Electricity
·
16.4
Wind Energy
·
16.4a
Using Wind to Produce Electricity
·
16.5
Geothermal Energy
·
16.5a
Tapping into
the Earth’s Internal Heat
·
16.6
Biomass Energy
·
16.6a
Producing Energy by Burning Solid Biomass
Chapter 16
Core Case StudySaving Energy and Money
16.1A New Energy Transition
16.1aEstablishing New Energy Priorities
16.2Reducing Energy Waste
16.2aWe Waste a Lot of Energy and Money
16.2bImproving Energy Efficiency in Industries and Utilities
16.2cBuilding a Smarter and More Energy-Efficient Electrical Grid
16.2dMaking Transportation More Energy-Efficient
16.2eSwitching to Energy-Efficient Vehicles
16.2fBuildings That Save Energy and Money
16.2gAir Conditioning and Climate Change
16.hSaving Energy and Money in Existing Buildings
16.2iWhy Are We Wasting So Much Energy and Money?
16.2jRelying More on Renewable Energy
16.3Solar Energy
16.3aHeating Buildings and Water with Solar Energy
16.3bCooling Buildings Naturally
16.3cConcentrating Sunlight to Produce High-Temperature Heat and
Electricity
16.3dUsing Solar Cells to Produce Electricity
16.4Wind Energy
16.4aUsing Wind to Produce Electricity
16.5Geothermal Energy
16.5aTapping into the Earth’s Internal Heat
16.6Biomass Energy
16.6aProducing Energy by Burning Solid Biomass
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ENV330 Module 5a AVP Transcript Title Slide Narrator: Our current energy path is unsustainable, as illustrated by the BP Deepwater Gulf of Mexico disaster, perhaps the single largest degradation of natural capital in history. Our ever increasing population, each with an exponentially increasing energy demand has caused us to take larger and larger environmental risks to try to satisfy our insatiable appetite for ever increasing amounts of energy. With every additional 1000 barrels of oil or 1000 lbs. of coal burned, we add hundreds of tons of CO2 to the atmosphere, causing ever accelerating Global Climate Change. We are clearly on a dangerously unsustainable path. We must transition to sustainable energy sources, and increase the efficiency of all energy using activities. There is no other viable option. Slide 2 Title: Energy Consumption Slide content: [image of a big city at night from the air] Narrator: The total annual energy use in the US has almost tripled in the last 60 years, although per capita US consumption has begun to level off in the last 20 years. In the last 25 years unsustainable US coal and oil consumption has increased dramatically and is projected to continue increasing dramatically for the next few decades. Per capita energy consumption in the US, Scandinavia, Saudi Arabia and Australia far exceed per capita energy use anywhere else in the world – with a few minor exceptions. Global use of renewable, sustainable energy is almost three times as great as in the US, where only about 7% of energy is sustainably produced. The global use of Geothermal, Solar and Wind power is 2 ½ times greater in other countries than in the US. Why do you think the world as a whole relies more on renewable energy than the United States does? Slide 3 Title: Our Unsustainable Approach to Meeting Our Energy Needs Slide Content: [image of a body of water with sludge covering the watergrass] Narrator: The recent BP Gulf of Mexico oil spill is an ongoing environmental tragedy which illustrates the folly of our unsustainable approach to meeting our energy needs. This environmental catastrophe will have ecological and economic ramifications for decades. Perhaps it will stimulate public and governmental change towards a sustainable, green, renewable energy future – if we are wise enough to make the change. Slide 4 Title: Political Response to BP Oil Spill in Gulf Slide Content: [image of President and Michelle Obama and Secretary of the Navy Ray Mabus standing on a dock]
Narrator: President Barack Obama stated, in response to the BP Oil spill: “the time has come, once and for all, for this nation to embrace a clean energy future”. He also stated that the nation “must acknowledge that there are inherent risks to drilling four miles beneath the surface of the Earth, risks that are bound to increase the harder oil extraction becomes.” Additionally he stated “if we refuse to take into account the full cost of our fossil fuel addiction – if we don’t factor in the environmental costs and national security costs and the true economic costs – we will have missed our best chance.” He went on to discuss the need to create more energy efficient cars and homes, more nuclear power plants, and rolling back the tax breaks given to oil companies. These are hopeful signs that perhaps the US government will finally act to push us into a sustainable energy future! Slide 5 Title: Net Energy Ratios Slide Content: [image of an electric heater] Narrator: In considering which energy sources are sustainable, we must consider their net energy ratios for particular tasks. The net energy ratio calculation takes into account all the energy used to discover, mine, transport and use the energy source. A useful rule of thumb is that any energies with low net ratios, like nuclear energy, usually have to be heavily subsidized by the taxpayer to keep its price artificially low so that it can compete in the marketplace with high net energy sources such as solar and ethanol. In other words, subsidies and tax breaks must be used to level the playing field for inefficient, low net energy power sources. Question: Are you OK with government using your tax dollars in this way? Can you think of a more sustainable way that government could use your tax dollars to encourage renewable energy development and production? Let’s compare the net energy efficiency for heating a building using nuclear generated electricity to run an electric resistance heater. Compare it with using passive solar to heat the building. Passive solar energy is using free sunlight energy and intelligent architectural design of buildings to maximize this “free” source of energy. Net energy efficiency is calculated by multiplying the efficiencies at each step of the process from the source to the end usage. Using nuclear power to heat the space is only 14% efficient, whereas using passive solar heating is 90% efficient! And, if the entire nuclear fuel cycle efficiencies are considered – the storage and production of long-term nuclear waste — the nuclear option is only about 8% efficient, that is, there is a 92% WASTE of energy compared with only an 8% waste of energy using passive solar. So, for heating buildings, using passive solar, and using natural gas have the highest net energy ratios, whereas electric heating using nuclear generated electricity, has the worst. Question: What is the source of energy you use in your home? In your office? How are they heated? Although coal has the highest net energy ratio for high-temperature industrial heat generation, it has a very low net energy ratio for heating buildings. To be an Earth sustaining society we must learn to use the appropriate energy for each task so as not to further degrade natural capital. For transportation, ethanol from sugarcane residues or rapidly growing switch grass, makes the most sense whereas corn ethanol, oil shale and coal liquefaction the least sense. Using gasoline for
transportation has only half the net energy benefits of using ethanol from sugarcane residue, as has been done in Brazil for decades. Question: Why do you think we continue to use inefficient ecologically destructive energies with low net energy ratios that require government tax subsidies? It makes no scientific or economic sense! Slide 6 Title: The Nuclear Fuel Cycle Slide Content: [image of a large nuclear power plant] Narrator: Let’s consider the Nuclear Fuel Cycle. In order to account for the REAL costs of nuclear power, one must include the entire life cycle, and all the costs of nuclear energy. This includes not only the mining, processing, transportation, power plant production, and transmission of electric energy I just mentioned. To truly compare the real costs of nuclear power generation we must ALSO consider the long-term storage of radioactive wastes – and I DO MEAN LONG TERM – 1000’s to 10’s of thousands of years – from mining to the operation of the nuclear power plant (the whole plant becomes a radioactive disposal issue eventually), to the cost of protection of the facilities from terrorists, and the protection of the radioactive wastes from terrorists who could use it to create nuclear weapons, and to the cost of safely transporting all the radioactive wastes to a permanent storage facility that must be maintained and protected for thousands of years! By the way, NO SAFE PERMANENT STORAGE FACILITY HAS BEEN FOUND YET, after 50 years of searching. No wonder the nuclear power industry must receive such huge subsidies from the government in order to be profitable! Questions:
Do you think that the market price of nuclear-generated electricity should include all the costs of the fuel cycle?
Would sustainable, renewable energies like solar and wind be cheaper in comparison to nuclear if we had to pay the whole cost of nuclear power in our electric bills, or if it was included in the price of goods or services using those energies?
What would happen if we had to pay the cost of Global Climate change caused by the burning of fossil fuels like coal and oil in our electric bills?
Why isn’t this the way electricity is priced? End of Presentation
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FUNDING FOR THIS PROGRAM IS PROVIDED BY… [ HORN HONKS ] Narrator: AIR POLLUTION — WE CAN'T ALWAYS SEE IT, BUT ITS EFFECTS CAN BE DEADLY. TO FIND WAYS TO REDUCE ITS IMPACT WE NEED TO KNOW EXACTLY WHAT POLLUTANTS ARE EMITTED AND HOW THEY CHANGE AS THEY TRAVEL THROUGH THE ATMOSPHERE. AT THIS POINT, WE PRIMARILY HAVE SULFATE PARTICLES. USING CUTTING-EDGE INSTRUMENTS AERODYNE RESEARCH CAN DETECT TINY CONCENTRATIONS OF POLLUTANTS IN REAL TIME TRACKING THEM BACK TO THEIR SOURCES AND SHOWING HOW THEY EVOLVE HOUR BY HOUR UNDER THE EFFECTS OF SUNLIGHT AND WEATHER.
IN MEXICO CITY LUISA MOLINA IS LEADING A GROUP OF OVER 450 SCIENTISTS IN THE MOST COMPREHENSIVE STUDY EVER CONDUCTED OF ONE CITY'S AIR EMISSIONS. SAMPLING ITS PLUME OF POLLUTANTS FROM CRADLE TO GRAVE THE TEAM HOPES TO LEARN HOW THE CITY'S POLLUTION AFFECTS THE SURROUNDING REGIONS AND EVEN THE GLOBAL CLIMATE. TODAY, THE RAPID INCREASE OF POPULATION AND INDUSTRIALIZATION IS CAUSING INCREASING CONCERNS ABOUT AIR POLLUTION. BOTH RESEARCHERS HOPE TO DISCOVER WHAT'S CAUSING THE MOST DAMAGE AND FIND WAYS TO REDUCE THE HUMAN AND GLOBAL IMPACT. [ HORN HONKS ] Kolb: ONE OF THE REAL FACTS THAT WE ALL HAVE TO DEAL WITH IS THAT PEOPLE MAKE POLLUTION
AND AS THE POPULATION OF THE EARTH GROWS UNLESS WE'RE VERY CLEVER AND WORK VERY HARD THE LEVELS OF POLLUTION WE ALL HAVE TO LIVE WITH WILL GROW ALONG WITH IT. WE HAVE TO UNDERSTAND WHICH POLLUTANTS ARE THE ONES THAT WEMUSTCONTROL AND WE HAVE TO COME UP WITH EITHER CHANGES IN OUR TECHNOLOGY OR CHANGES IN OUR LIFESTYLES WHICH REDUCE THE HEAVY POLLUTION BURDENS THAT WE EMIT INTO THE ATMOSPHERE. Narrator: CHARLES KOLB IS PRESIDENT OF AERODYNE RESEARCH A COMPANY THAT SPECIALIZES IN STUDYING AIR POLLUTION AND DESIGNING INSTRUMENTS TO HELP MEASURE IT. A NEW AEROSOL MASSSPEC BODY. Kolb: OUR AIR-POLLUTION RESEARCH FOCUSES ON WHAT'S EMITTED BY VARIOUS POLLUTION SOURCES — CARS, TRUCKS, PLANES,
FACTORIES, AND MANY OTHER SOURCES — AND TO UNDERSTAND HOW THEY CHANGE THE ATMOSPHERE AND HOW THAT CHANGED ATMOSPHERE TURNS AROUND AND IMPACTS PEOPLE AND THE CLIMATE AND THE ECOSYSTEMS THAT WE WANT TO PRESERVE. Narrator: AIR POLLUTANTS EXIST AS HARMFUL GASES OR AS AEROSOLS. AEROSOLS ARE MICROSCOPIC SOLID OR LIQUID PARTICLES SUSPENDED IN THE AIR AND THESE POLLUTANTS CAN HAVE DEADLY EFFECTS. Kolb: MOST OF US CAN ONLY SURVIVE A MINUTE OR SO WITHOUT A FRESH BREATH OF AIR AND IF THE AIR CONTAINS SUBSTANCES WHICH ARE GOING TO REALLY HURT YOUR HEALTH YOU'D HATE TO THINK THAT YOU'RE SHORTENING YOUR LIFE WITH EVERY BREATH OF AIR YOU TAKE. Narrator: THE WORST
AIR-POLLUTION DISASTER ON RECORD OCCURRED IN LONDON IN DECEMBER OF 1952. AT THIS TIME, LONDONERS STILL CONSUMED LOTS OF COAL WHICH LED TO LARGE AMOUNTS OF POLLUTANTS IN THE AIR INCLUDING BLACK CARBON, OR SOOT PARTICLES AND SULFUR DIOXIDE. AND THIS TOXIC MIX TURNED FATAL. Kolb: THE PARTICLE LOADING GOT SO HEAVY DURING ONE EPISODE THAT THE SO-CALLED KILLER FOGS ACTUALLY KILLED MANY THOUSANDS OF PEOPLE OVER ABOUT A WEEK AND A HALF. Narrator: THANKS TO REGULATIONS TO REDUCE THESE POLLUTANTS EVENTS LIKE THIS ARE RARE TODAY. HOWEVER, PUBLIC HEALTH OFFICIAL SESTIMATE THAT 70,000 AMERICANS DIE PREMATURELY EACH YEAR
DUE TO AIR POLLUTION. IN ORDER TO MONITOR THESE POLLUTANTS KOLB AND HIS TEAM AT AERODYNE RESEARCH DEVELOPED A SERIES OF REVOLUTIONARY LABORATORY-GRADE INSTRUMENTS THAT COULD BE DEPLOYED FROM A MOBILE VAN. Kolb: WE'VE DEVELOPED SOME VERY CAPABLE AND VERY FAST RESEARCH INSTRUMENTS THAT CAN BE DEPLOYED IN THE ATMOSPHERE AND MEASURE RIGHT AWAY WHAT'S THERE. Narrator: TRADITIONALLY SAMPLES HAD TO BE BROUGHT BACK TO THE LAB TO BE ANALYZED BUT WITH THE MOBILE VAN, MEASUREMENTS ARE INSTANTANEOUS. THE BENEFIT OF USING REAL-TIME INSTRUMENTATION IS THAT IT MAXIMIZES THE SCIENTIFIC IMPACT
THAT WE'RE ABLE TO HAVE WHEN WE'RE OUT IN THE FIELD. IT LOOKS LIKE WE'RE PICKING UP A GOOD SULFATE PLUME. Kolb: THE MOBILE LAB IS EQUIPPED WITH INSTRUMENTS THAT CAN MEASURE EVERY SECOND OR SO. IF YOU'RE CHARACTERIZING AN EMISSIONS SOURCE AND ITS EMISSIONS ARE CHANGING SECOND BY SECOND AS A VEHICLE MIGHT AS IT STOPS AND STARTS OR ACCELERATES OR GOES UP A HILL THEN IF YOU DON'T MEASURE SECOND BY SECOND YOU WON'T GET THE RIGHT ANSWER. NITRATES? YEAH, I SEE SOME NITRATES. Narrator: ONE KEY INSTRUMENT IS AERODYNE'S AEROSOL MASS SPECTROMETER WHICH MEASURES THE TINY SUSPENDED PARTICLES IN THE ATMOSPHERE. WHAT'S REALLY SPECIAL ABOUT IT IS THAT USUALLY WHEN YOU'RE LOOKING AT PARTICLES
YOU JUST KNOW SORT OF HOW MANY PARTICLES ARE IN YOUR SAMPLE. BUT WHAT THE AMS IS CAPABLE OF DOING IS TELLING YOU WHAT THE CHEMICAL SPECIES OF EACH OF THOSE PARTICLES IS. YOU CAN SAY, "OH, YOU KNOW, THERE'S 1,000 PARTICLES IN THIS CUBIC CENTIMETER OF AIR," ROUGHLY THIS BIG, BUT YOU CAN ALSO SAY "OH, A CERTAIN FRACTION OF THEM ARE SULFATE "A CERTAIN FRACTION OF THEM ARE SOME SORT OF ORGANIC A CERTAIN FRACTION OF THEM ARE NITRATE," ET CETERA, ET CETERA. AND SO THAT GIVES YOU A MUCH STRONGER CAPABILITY BECAUSE IT TURNS OUT THAT THE WAY THESE PARTICLES INTERACT WITH THE ENVIRONMENT, FOR INSTANCE HOW THEY MIGHT OR MIGHT NOT AFFECT GLOBAL WARMING DEPENDS UPON THEIR COMPOSITION. AND HOW THEY MIGHT AFFECT OR
MIGHT NOT AFFECT HUMAN HEALTH DEPENDS ON THEIR COMPOSITION AS WELL AS THEIR SIZE. Herndon: IF YOU'RE CONCERNED ABOUT THE HEALTH IMPACTS YOU'RE MOST CONCERNED ABOUT THE SIZE OF PARTICLES THAT ARE SUFFICIENTLY SMALL SO THAT THEY GO INTO YOUR LUNGS DEEP INTO YOUR LUNGS, ALONG WITH THE GAS FLOW. AND IN THAT CASE YOU COULD ACTUALLY BE INTRODUCING SOME THINGS INTO YOUR BODY, INTO YOUR BLOODSTREAM, QUICKLY THAT HAVE NO BUSINESS BEING THERE. Narrator: PARTICLES LESS THAN 10 MICROMETERS IN DIAMETER JUST A FRACTION OF THE WIDTH OF A HUMAN HAIR CAN LODGE DEEP INTO THE LUNGS. THOSE SMALLER THAN 2.5 MICROMETERS CLASSIFIED AS "FINE PARTICLES,"
HAVE BEEN LINKED TO THE MOST SERIOUS HEALTH PROBLEMS. Kolb: IT CAN LEAD TO A NUMBER OF MEDICAL COMPLICATIONS INCLUDING NOT JUST LUNG DISEASE — EMPHYSEMA, ASTHMA, POSSIBLY LUNG CANCER — BUT CAN ALSO PUT A VERY HIGH STRAIN ON YOUR HEART AND CAN LEAD TO HEART ATTACKS. Narrator: AERODYNE MEASURES BOTH THE HAZARDOUS PARTICLES AND THE POLLUTANT GASES BEING EMITTED FROM VARIOUS SOURCES. YOU'D THINK YOU'D SEE SOME SULFATE, BUT I DON'T KNOW. Kolb: WE WANT TO USE OUR MOBILE LABORATORY TO UNDERSTAND POLLUTANTS THAT ARE DIRECTLY EMITTED INTO THE ATMOSPHERE. WE CALL THOSE "PRIMARY POLLUTANTS." WITH A MOBILE LABORATORY YOU CAN ACTUALLY MAP OUT THE DISTRIBUTION OF THE AIR POLLUTANTS
SO THAT YOU HAVE A MUCH BETTER PICTURE OF HOW THE POLLUTANTS ARE DISPERSED AROUND, SAY, A CITY, OR AROUND A FACTORY COMPLEX. IN ADDITION, YOU CAN LOCATE SOURCES OF POLLUTANTS BECAUSE YOU CAN SEE A CONCENTRATION IN A PLUME AND YOU CAN THEN USE THE MOBILE LABORATORY TO ACTUALLY FOLLOW THE PLUME BACK TO THE SOURCE. Narrator: VEHICLE EMISSIONS ARE ONE OF THE SOURCES OF PRIMARY POLLUTANTS TRACKED BY AERODYNE. WHILE THE EMISSIONS FROM AN INDIVIDUAL CAR ARE RELATIVELY LOW COMPARED WITH FACTORIES IN MANY CITIES, THE MILLIONS OF VEHICLES ON THE ROAD ADD UP TO BE THE MOST SERIOUS THREAT TO CLEAN AIR. VEHICLE EXHAUST POLLUTANTS INCLUDE AEROSOLS AND THESE GASES…
USING THEIR TRACE-GAS DETECTOR THE AERODYNE TEAM CAN MONITOR THESE POLLUTANT GASES EVEN AT VERY LOW LEVELS. BUT THESE POLLUTANTS, BY THEMSELVES ARE NOT THE ONLY CONCERN. SOME PRIMARY POLLUTANTS, SUCH AS NOx BECOME EVEN MORE DANGEROUS WHEN THEY BEGIN A COMPLEX CHEMICAL REACTION AFTER BEING EXPOSED TO SUNLIGHT. SECOND BIG JOB WITH THE MOBILE LAB IS TO GO OUT AND ACTUALLY THEN SEE WHAT HAPPENS TO THOSE PRIMARY POLLUTANTS AS THEY COOK IN THE ATMOSPHERE. THIS CHEMISTRY CAN CREATE WHAT WE CALL "SECONDARY POLLUTANTS." IT CAN CHEMICALLY CHANGE THE POLLUTANTS THAT WERE EMITTED INTO THE ATMOSPHERE
INTO DIFFERENT AND SOMETIMES MORE DANGEROUS CHEMICALS. Narrator: ONE SECONDARY POLLUTANT THAT CONCERNS SCIENTISTS IS OZONE. OZONE IS A GAS MADE UP OF 3 OXYGEN MOLECULES AND IT CAN HAVE BOTH GOOD AND BAD EFFECTS DEPENDING ON WHERE IT'S LOCATED. THE STRATOSPHERIC OZONE LAYER PROTECTS THE EARTH FROM HARMFUL ULTRAVIOLET RAYS BUT GROUND-LEVEL OZONE, IN THE TROPOSPHERE IS HIGHLY REACTIVE AND CAN CAUSE IRRITATION OF THE RESPIRATORY SYSTEM PERMANENTLY SCARRING LUNG TISSUE. Kolb: OZONE IS A VERY POWERFUL OXIDANT. IT CAN KIND OF BLEACH THE CELLS IN YOUR BODY AND CAN CREATE A LOT OF SERIOUS PROBLEMS BOTH TO PEOPLE, TO OTHER ANIMALS, AND TO PLANTS.
Narrator: THE MAIN PRECURSORS IN CREATING OZONE ARE NITROGEN OXIDES EMITTED FROM VEHICLES AND OTHER COMBUSTION SOURCES AND HYDROCARBONS, THE RESULT OF COMBUSTION OTHER INDUSTRIAL PROCESSES, AND VEGETATION. WHEN THESE POLLUTANTS INTERACT IN THE PRESENCE OF SUNLIGHT THEY PRODUCE GROUND-LEVEL OZONE. SUNLIGHT CAUSES NITROGEN DIOXIDE, NO2 TO SEPARATE INTO NITRIC OXIDE, "NO," AND AN OXYGEN ATOM. THE OXYGEN ATOM ADDS TO NATURALLY OCCURRING MOLECULAR OXYGEN, OR O2 TO CREATE OZONE. BUT THIS IS JUST THE FIRST STEP IN A CHAIN REACTION OF OZONE PRODUCTION. THE REMAINING NITRIC OXIDE REACTS WITH UNSTABLE MOLECULES THAT ARE PRODUCTS OF HYDROCARBONS OXIDIZING IN THE ATMOSPHERE RECREATING NITROGEN DIOXIDE
CAUSING A VICIOUS CYCLE OF OZONE PRODUCTION. Kolb: SO OZONE GETS FORMED AS A SECONDARY POLLUTANT. IT'S NOT EMITTED DIRECTLY AND IT'S IMPORTANT TO UNDERSTAND NOT ONLY HOW MUCH OZONE IS IN THE ATMOSPHERE BUT HOW MUCH OF ITS PRECURSOR CHEMICALS ARE THERE SO WE CAN PREDICT WHAT THE OZONE WILL LOOK LIKE AS THE WIND BLOWS THAT CHEMICAL MIXTURE ACROSS THE COUNTRYSIDE. Narrator: AERODYNE'S VAN HAS BEEN DEPLOYED ALL OVER NORTH AMERICA TO HELP ENGINEERS AND PLANNERS IDENTIFY THE BEST STRATEGIES TO REDUCE POLLUTANTS FROM INDUSTRIES AND TRANSPORTATION SYSTEMS. Kolb: WE'VE WORKED WITH THE METROPOLITAN TRANSIT AUTHORITY IN NEW YORK CITY THAT RUNS ABOUT A THIRD OF
THE CITY'S BUSES TO DETERMINE WHICH TYPES OF BUSES EMIT WHAT KINDS OF POLLUTANTS. SO ONE CAN TAKE THE MOBILE LAB AND FOLLOW THE BUSES AS THEY GO ABOUT THEIR ROUTES IN THE CITY. AND AS THEY STOP AND START, TAKE ON PASSENGERS ACCELERATE, SLOW DOWN ONE CAN SEE HOW BOTH THE PARTICLE POLLUTANTS AND THE GASEOUS POLLUTANTS THEY EMIT CHANGE. THEN YOU CAN TAKE THE SAME TYPE OF BUS AND PUT SOME EMISSION-CONTROL TECHNOLOGY ON IT — MAYBE A TRAP THAT TRAPS AND BURNS THE PARTICLES — AND YOU CAN SEE WHAT EFFECT THAT HAS ON THE PARTICLE EMISSIONS AND ALSO WHAT EFFECT IT HAS ON THE GASEOUS EMISSIONS. Narrator: WHEN KOLB'S TEAM TESTED THESE BUSES THEY FOUND SOME UNEXPECTED
RESULTS. Kolb: THE DIESEL BUSES WITH PARTICLE TRAPS DID, INDEED, EMIT ONLY ABOUT A QUARTER OF THE PARTICLES THAT NORMAL DIESEL BUSES EMITTED BUT THEY DID EMIT A LARGE AMOUNT OF NITROGEN DIOXIDE WHICH IS, AGAIN, A GAS THAT IS A TOXIC AIR POLLUTANT. SO YOU HAVE TO BE CAREFUL WHEN YOU'RE TRYING TO SOLVE ONE POLLUTION PROBLEM THAT YOU DON'T CREATE A SECOND POLLUTION PROBLEM WHICH MAY BE AS SERIOUS AS THE FIRST ONE. Narrator: IN EUROPE AND THE UNITED STATES POLICIES HAVE BEEN PUT IN PLACE TO REDUCE AIR POLLUTION. THE CLEAN AIR ACT OF 1970, WHICH SET LIMITS ON CONCENTRATIONS OF CERTAIN POLLUTANTS ALONG WITH SUBSEQUENT PROGRAMS HAS SIGNIFICANTLY IMPROVED AIR QUALITY.
Kolb: SINCE 1970, WE'VE HAD FAIRLY STRICT LAWS WHICH HAVE HELPED STOP THE INCREASE IN BAD AIR-POLLUTION EPISODES AND, IN FACT, IN MOST CITIES HAVE DECREASED THEM. BUT IN CITIES WITH RAPID GROWTH AND WITH CHALLENGING CLIMATES — CLIMATES THAT CAN LEAD TO A LOT OF CHEMISTRY IN THE AIR AND A LOT OF SECONDARY POLLUTION FORMATION THERE ARE CERTAINLY STILL BIG CHALLENGES LEFT. Narrator: DEVELOPING INNOVATIVE WAYS TO MEASURE PRIMARY AND SECONDARY POLLUTANTS IS A NECESSARY FIRST STEP IN CREATING EFFECTIVE STRATEGIES FOR PROTECTING HUMAN HEALTH. BUT MEASURING THE LOCAL AIR POLLUTION FROM CARS AND FACTORIES IS JUST ONE PIECE OF THE PUZZLE. ATMOSPHERIC CIRCULATION
CARRIES POLLUTANT STREAMS FAR BEYOND THE METROPOLITAN AREAS WHERE THEY ARE CREATED CAUSING REGIONAL AND EVEN GLOBAL EFFECTS. AND SO THE POLLUTIONS THAT ARE CREATED IN THE LARGE MEGACITIES IN CHINA CAN DELIVER VERY HIGH LEVELS OF POLLUTANTS ALL ACROSS THE UNITED STATES JUST AS THE POLLUTION THAT'S CREATED IN THE MIDWEST AND THE EASTERN PART OF THE UNITED STATES REACHES ALL THE WAY TO EUROPE. IT ONLY TAKES ABOUT TWO WEEKS FOR AIR TO GO ALL THE WAY AROUND THE WORLD. Narrator: AND SOME POLLUTANTS SUCH AS AEROSOLS AND GREENHOUSE GASES LIKE CARBON DIOXIDE AND OZONE EVEN AFFECT THE GLOBAL CLIMATE. SO WE DON'T HAVE THE LUXURY OF THINKING
THAT IT'S OTHER PEOPLE'S AIR-POLLUTION PROBLEMS OTHER PEOPLE'S CLIMATE PROBLEMS. IF THEY'RE HAVING PROBLEMS WE'RE GOING TO HAVE PROBLEMS, TOO. Narrator: AND ONE OF THE BIGGEST EMERGING THREATS TO THE GLOBAL ENVIRONMENT IS INCREASED AIR POLLUTION FROM MEGACITIES. A MEGACITY IS DEFINED AS HAVING 10 MILLION OR MORE INHABITANTS. CURRENTLY, THERE ARE OVER 20 MEGACITIES WORLDWIDE AND THAT NUMBER CONTINUES TO GROW AT AN ALARMING RATE. HUNDREDS OF MILLIONS OF PEOPLE CURRENTLY LIVE IN THESE CITIES AND IT IS PROJECTED THAT BY THE MIDDLE OF THE CENTURY THIS NUMBER WILL BE MULTIPLIED MANY TIMES OVER WITH 60% OF THE WORLD'S POPULATION LIVING IN URBAN AREAS. THIS RAPID GROWTH
MEANS AN EVER-RISING TOLL TO HUMAN HEALTH UNLESS WE GAIN A BETTER UNDERSTANDING OF THE LIFE CYCLE OF AIR POLLUTANTS. AND THAT'S EXACTLY WHAT'S BEING DONE IN MEXICO CITY FOR THE MILAGRO PROJECT THE LARGEST COORDINATED STUDY EVER CONDUCTED OF MEGACITY AIR POLLUTION. 1, 2, 3. LUISA MOLINA IS THE PROJECT COORDINATOR AND ONE OF THE LEAD SCIENTISTS ON THIS EFFORT. Molina: "MILAGRO" STANDS FOR "MEGACITY INITIATIVE LOCAL AND GLOBAL RESEARCH OBSERVATIONS." AND WE WERE VERY, VERY PLEASED THAT WE WERE ABLE TO FIND AN ACRONYM, MILAGRO THAT NOT ONLY FIT THE THEMES OF OUR MEASUREMENT CAMPAIGN BUT IT ALSO MEANS "MIRACLE" IN SPANISH.
Narrator: IN MARCH 2006 MOLINA GATHERED AN INTERNATIONAL TEAM OF MORE THAN 450 SCIENTISTS TO INVESTIGATE THE EFFECTS OF LOCAL POLLUTION IN MEXICO CITY ON THE SURROUNDING REGIONS AND THE GLOBAL ATMOSPHERE. THE SCIENTISTS REPRESENT OVER 50 ACADEMIC AND RESEARCH INSTITUTIONS FROM MEXICO, EUROPE, AND THE UNITED STATES INCLUDING NASA, THE DEPARTMENT OF ENERGY AND THE NATIONAL SCIENCE FOUNDATION. MEXICO CITY IS AN IDEAL LOCATION FOR MILAGRO'S MEGACITY RESEARCH. SURROUNDED ON THREE SIDES BY MOUNTAINS POLLUTANTS BECOME TRAPPED WITHIN THE CITY. Molina: THERE ARE MANY REASONS FOR SELECTING MEXICO CITY. FIRST OF ALL, MEXICO CITY IS ONE OF THE LARGEST
MEGACITIES. IT HAS ABOUT 20 MILLION PEOPLE. IT IS IN A TROPICAL LATITUDE SO IT'S REPRESENTATIVE OF MANY OF THE FUTURE MEGACITIES WHICH WILL BE IN ASIA, IN AFRICA. MEXICO CITY IS AT A HIGH ALTITUDE AND THE SOLAR RADIATION IS VERY STRONG AND THE PHOTOCHEMISTRY, IT IS VERY REACTIVE. AND OF COURSE, WHAT WE HOPE IS THAT WHAT WE LEARN FROM MEXICO CITY IT WILL PROVIDE INSIGHT FOR US SO THAT WE CAN USE THAT INSIGHT AND UNDERSTANDING AND APPLY IT TO OTHER FUTURE MEGACITIES. Narrator: WHILE MANY PREVIOUS STUDIES REVEALED A GREAT DEAL ABOUT POLLUTION WITHIN MEXICO CITY WHAT HAPPENED TO THE POLLUTION AFTER IT LEFT THE CITY AND WHAT ITS EFFECTS WERE ON THE REGION AND THE GLOBE HAD NEVER BEEN
SYSTEMATICALLY STUDIED UNTIL MILAGRO. SO YOU HAVE ALL THIS POLLUTION COMING OUT FROM BURNING OF FOSSIL FUELS, FROM CARS, FROM INDUSTRY. AND SO THE POLLUTANTS THAT EMITTED LOCALLY THE LOCAL EFFECTS WOULD BE ON THE HEALTH OF THE POPULATION AND ON THE AIR QUALITY. BUT THEN THEY COULD ALSO — THE REGIONAL IMPACT WHICH WOULD AFFECT THE ECOSYSTEM. AND THEN, ALSO, THERE'S THE GLOBAL IMPACT THAT WOULD AFFECT THE CLIMATE. SO THIS IS VERY SERIOUS. Narrator: 24 HOURS A DAY FOR 30 DAYS THE MILAGRO TEAM COLLECTED DATA USING AIRPLANES, RADARS, WEATHER BALLOONS AND DOZENS OF SCIENTIFIC INSTRUMENTS. I BROUGHT HERE TO MEXICO CITY AN INSTRUMENT WHICH I CALL
THE DIFFERENTIAL SUPERSATURATION SEPARATOR. OUR INSTRUMENT IS CALLED A LONG-PATH DIFFERENTIAL OPTICAL ABSORPTION SPECTROMETER. PHOTOELECTRIC AEROSOL SENSOR. A PROTON TRANSFER MASS SPECTROMETER. THIS IS WHAT WE CALL A CAPS PROBE, WHICH STANDS FOR "CLOUD AEROSOL AND PRECIPITATION SPECTRA" PROBE. WHAT IT MEASURES IS AEROSOL PARTICLES WHICH ARE THE VERY FINE PARTICLES IN THE AIR. AS WE FLY, IT'S IN FRONT OF THE PLANE BECAUSE THERE WOULD BE ENGINE EXHAUST IF IT WAS FURTHER BACK SO IT SEES THE AIR FIRST. AEROSOL AIR COMES THROUGH THIS PROBE AND WHAT IS DETECTED IS THE SIZE OF THE PARTICLES. BY SIMULTANEOUSLY AND COLLABORATIVELY GATHERING THEIR DATA
THE SCIENTISTS WILL HAVE BETTER INFORMATION TO CREATE NEW MODELS FOR PREDICTING THE TRANSPORT OF POLLUTION OVER WIDE GEOGRAPHIC AREAS. Molina: THE OBJECTIVE OF THIS STUDY, OF MILAGRO IS TO FOLLOW THE PLUMES AND FIND OUT WHERE AND HOWAND WHEN THE PLUMES ARE TRANSPORTED TO OTHER REGIONS. AND SO IT IS VERY IMPORTANT FOR US NOT ONLY JUST TO LOOK AT ONE SITE BUT TO LOOK AT VARIOUS SITES. Narrator: TO STUDY THE MOVEMENT OF PLUMES THE RESEARCHERS HAVE THREE MAIN FIXED GROUND SITES — "T0," LOCATED IN THE CENTER OF THE CITY AND T1 AND T2, TWO POINTS NORTH OF THE CITY WHERE THE PREVAILING WINDS ARE EXPECTED TO CARRY THE PLUMES. AT THESE SITES, RESEARCH
TEAMS MEASURE TRACE GASES AEROSOL CONCENTRATIONS, AND SOLAR-RADIATION LEVELS AS WELL AS METEOROLOGICAL DATA. Molina: WE HAVE TO MEASURE THE PRESSURE WE MEASURE THE TEMPERATURE WE MEASURE THE RELATIVE HUMIDITY AND THE WIND SPEED — THE WIND DIRECTION. THESE ALL AFFECT THE TRANSPORT OF THE POLLUTANTS. Narrator: THE AERODYNE TEAM TRAVELED TO MEXICO CITY AS PART OF THE MILAGRO CAMPAIGN. TO HELP MONITOR THE PLUME THEY SET UP THEIR MOBILE LAB IN A UNIQUE, ELEVATED LOCATION BETWEEN T0 AND T1, CALLED PICO DE TRES PADRES. WE'RE ABOUT A THOUSAND METERS ABOVE EACH OF THESE TWO SITES. SO WE HAVE AN OPPORTUNITY AT THIS LOCATION TO ACTUALLY LOOK AT THE LOFTED PLUME THAT'S COMING TO US.
Narrator: IN THE MORNING THIS LOCATION HAS RELATIVELY CLEAN AIR SINCE IT IS ABOVE THE BOUNDARY LAYER A LAYER NEAR THE GROUND THAT DOES NOT MIX WELL WITH THE ATMOSPHERE ABOVE. THIS LAYER TRAPS THE POLLUTION BELOW IN THE BASIN OF MEXICO CITY. BUT AS THE SUN HEATS THE EARTH, THE BOUNDARY LAYER RISES. Herndon: BUT WHAT WE'RE OBSERVING RIGHT NOW — WE'RE ABOVE THE MIXING HEIGHT. ALL OF THE POLLUTION AND EMISSIONS THAT ARE TAKING PLACE ARE NOT ABLE TO MIX UP AND COME UP TO THIS LOCATION. WHAT HAPPENS IS THAT THE SUN COMES UP AND BEGINS TO HEAT THE SURFACE OF THE EARTH. AND JUST LIKE PUTTING A PAN OF BOILING WATER ONTO THE STOVE IT BEGINS TO MIX AND BOIL, MOVING THE AIR UPWARD,
UPWARD. AND SO IT MIXES UP AND UP AND UP. AND WE'RE LOCATED UP HERE AT THIS LOCATION AND SUDDENLY WE BEGIN TO SEE MUCH OF THE CITY POLLUTION AND EMISSIONS COMING TO US BUT IT'S A BIT LATER THAN WHEN THE SUN COMES UP. WE'RE SEEING INCREASES IN CARBON MONOXIDE CARBON DIOXIDE, AND NOx. Narrator: AS THE SUN PEAKS AND CONTINUES THROUGH THE AFTERNOON THE POLLUTANTS CHEMICALLY CHANGE AS THEY REACT IN THE ATMOSPHERE. Herndon: WHAT WE OBSERVED AT T0 WE SAW A MIXTURE OF PRIMARY AND SECONDARY POLLUTANT SPECIES. UP HERE, THE CHARACTER OF JUST ABOUT EVERYTHING WE HAVE SEEN INDICATES THAT IT'S VERY SECONDARY, VERY PROCESSED. SO, FROM THAT POINT OF VIEW WE HAVE AN OPPORTUNITY TO
LOOK AT THE FIRST STEPS AS THE PLUME IS MOVING DOWNWIND AS TO WHAT IS HAPPENING WHAT CHANGES ARE TAKING PLACE IN THE COMPOSITION OF THOSE EMISSIONS. Narrator: IN ADDITION TO GROUND SITES RESEARCHERS ALSO MEASURED POLLUTANTS FROM AIRPLANES AND SATELLITES TO CORROBORATE THEIR DATA AND TO HELP TRACK THE PLUME. Molina: IT IS VERY IMPORTANT FOR US TO DO AN INTEGRATED MEASUREMENT. IN ORDER FOR YOU TO LOOK AT THE OUTFLOW NOT ONLY DO YOU NEED A GROUND BASE BUT YOU ALSO NEED TO HAVE A LARGER COVERAGE SO THE AIRPLANE IS VERY ESSENTIAL. AND THEN THE SATELLITE OBSERVATION PROVIDE EVEN LARGER INTO SPACE.
WE WANTED TO USE DIFFERENT TECHNIQUES THAT COMPLEMENT EACH OTHER SO IT'S VERY IMPORTANT FOR US TO HAVE COMPLIMENTARY MEASUREMENTS. IT'S IMPORTANT FOR US TO HAVE INTERCOMPARISON. IN FACT, SOME OF THE MEASUREMENTS DURING THE CAMPAIGN WERE DESIGNED EXACTLY FOR THAT PURPOSE. Narrator: LONG-TERM, MILAGRO WILL LEAD TO BETTER MODELS OF HOW EMISSIONS ARE TRANSPORTED AND TRANSFORMED HELPING COUNTRIES MANAGE AND IMPROVE AIR QUALITY. PRELIMINARY DATA SHOW THAT THE AEROSOL PLUME FROM MEXICO CITY TRAVELS OUTSIDE THE CITY AND RISES HIGH INTO THE TROPOSPHERE. HERE, THE PREVAILING HIGH-ALTITUDE WINDS CAN POTENTIALLY TRANSPORT THE POLLUTANTS LONG
DISTANCES EVEN ACROSS CONTINENTS. BUT IT WILL BE MANY YEARS BEFORE MOLINA AND HER TEAM HAVE DEFINITIVE RESULTS. Molina: MILAGRO — RIGHT NOW WE ONLY FINISH THE FIRST PHASE ONE THE MEASUREMENT, THE OBSERVATION STAGE. AND THEN THE NEXT PHASE IS NOW WE ARE IN THE PROCESS OF DOING THE DATA ANALYSIS SO WE HAVE ALL OF THIS TONS AND TONS OF DATA. THEN ALL THIS INFORMATION ARE NOW FIT INTO MODELS. THEN WE ARE GOING TO PRESENT THE RESULTS TO THE MEXICAN GOVERNMENT. Narrator: WHILE THE MEXICAN GOVERNMENT HAS RECENTLY MADE STRIDES IN REDUCING EMISSIONS WITH STRICTER REGULATION POLICIES AND CLEANER FUEL MEXICO CITY IS JUST ONE OF A GROWING NUMBER OF MEGACITIES. Molina: WE HOPE THAT BY
STUDYING MEXICO CITY USE THIS AS A CASE STUDY THEN WE CAN FIND OUT HOW WOULD THE FUTURE MEGACITIES THAT ARE COMING UP HOW WOULD THEY INFLUENCE THE ATMOSPHERIC COMPOSITIONS ON A LARGE RREGIONAL-GLOBAL SCALE. Kolb: IF WE DON'T CONTROL THE CHANGES WE MAKE TO THE ATMOSPHERE THE ATMOSPHERE MAY BEGIN TO CONTROL HOW MANY OF US ARE LEFT ON THE PLANET. SO IT'S VITAL THAT WE UNDERSTAND WHAT HAPPENS TO THE POLLUTANTS WE EMIT AND WE UNDERSTAND HOW TO BETTER CONTROL THEM SO THE PLANET CAN CONTINUE TO BE A HABITABLE PLACE FOR BOTH PEOPLE AND THE REST OF THE CREATURES WE SHARE IT WITH.
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FUNDING FOR THIS PROGRAM IS PROVIDED BY ANNENBERG MEDIA. Narrator: THE WORLD NEEDS ENERGY. AND NEARLY 80% OF IT COMES FROM BURNING FOSSIL FUELS — OIL, NATURAL GAS, AND COAL. BUT BURNING THESE FUELS EMITS CARBON DIOXIDE A GREENHOUSE GAS THAT CONTRIBUTES TO CLIMATE CHANGE. HOW CAN WE CONTINUE TO SUPPL YOUR EVER-GROWING NEED FOR POWER WITHOUT DAMAGING THE ENVIRONMENT? ONE POSSIBILITY IS TO PUT THE CARBON DIOXIDE BACK WHERE IT CAME FROM — IN UNDERGROUND ROCK FORMATIONS. THE MIDWEST REGIONAL CARBON SEQUESTRATION PARTNERSHIP IS INVESTIGATING THIS STRATEGY WHICH WILL HELP MITIGATE THE EFFECTS OF THE CONTINUED USE OF FOSSIL FUELS FOR ENERGY. RENEWABLE ENERGY SOURCES
ARE ANOTHER OPTION. AND IN GOLDEN, COLORADO THE NATURAL RENEWABLE ENERGY LABORATORY IS TRYING TO SCALE UP PROCESSES FOR CREATING BIOFUELS FROM THE PRODUCTS OF AMERICAN FARMS THEIR GOAL IS TO SUPPLY UP TO A THIRD OF THE COUNTRY'S GASOLINE NEEDS WITHIN 25 YEARS. BOTH PROJECTS ARE PUSHING THE LIMITS OF MODERN SCIENCE IN HOPES OF LEADING THE WAY TO A MORE SUSTAINABLE ENERGY FUTURE. 40% OF THE WORLD'S ELECTRICITY COMES FROM COAL. COAL IS THE FOSSILIZED REMAINS OF ANCIENT VEGETATION. AND WITH GLOBAL RESERVES THAT COULD LAST OVER 250 YEARS IT IS THE CHEAPEST AND MOST ABUNDANT NON-RENEWABLE ENERGY SOURCE AVAILABLE. BUT BURNING COAL PRODUCES
EXHAUST PRODUCTS INCLUDING NOT JUST WATER VAPOR WHICH IS MOST OF WHAT WE SEE COMING OUT OF SMOKESTACKS BUT ALSO CARBON DIOXIDE AN INVISIBLE GREENHOUSE GAS THAT CONTRIBUTES TO CLIMATE CHANGE. AS THE NEED FOR ENERGY AROUND THE WORLD CONTINUES TO GROW NEW COAL-FIRED POWER PLANTS THAT WILL LAST 50 YEARS OR MORE COME ONLINE EVERY WEEK. COAL WILL POWER THE WORLD FOR DECADES. HOW CAN WE CONTINUE TO USE THIS INEXPENSIVE AND PLENTIFUL RESOURCE WITHOUT FURTHER DAMAGING THE ENVIRONMENT? Dr. Gupta: THE WAY TO TAKE CARE OF REDUCING CARBON DIOXIDE IS YOU HAVE MULTIPLE OPTIONS. DEFINITELY YOU NEED TO INCREASE THE EFFICIENCY OF YOUR ENERGY USE. YOU ALSO NEED TO LOOK AT RENEWABLE ENERGY SOURCES
LIKE SOLAR ENERGY, WIND ENERGY. BUT IT IS CLEARLY RECOGNIZED BY THE RESEARCH COMMUNITY THAT YOU NEED A THIRD SET OF TECHNOLOGIES THAT CAN PROVIDE A MEANS TO KEEP USING FOSSIL FUELS ESPECIALLY COAL, WHICH IS OUR MOST ABUNDANT FOSSIL FUEL IN AN ENVIRONMENTALLY SOUND MANNER. Narrator: NEERAJ GUPTA IS A GEOLOGIST WITH BATTELLE MEMORIAL INSTITUTE A SCIENCE AND TECHNOLOGY ENTERPRISE THAT IS RESEARCHING THE FEASIBILITY AND COST OF CAPTURING CARBON DIOXIDE FROM POWER PLANTS AND INJECTING IT INTO UNDERGROUND ROCK FORMATIONS A PROCESS CALLED CARBON CAPTURE AND SEQUESTRATION. Dr. Gupta: WE CALL IT CCS. YOU ARE PUTTING THE CO2 BACK INTO THE GROUND. SO JUST LIKE YOU PRODUCE FOSSIL FUELS
LIKE COAL AND OIL AND GAS FROM THE DEEP GEOLOGIC FORMATIONS FROM THE SEDIMENTARY LAYERS YOU'RE USING THE SAME TYPE OF LAYERS AND PUTTING CO2 BACK INTO THE GROUND WHERE IT CAME FROM. Narrator: IN BELMONT COUNTY, OHIO BATTELLE IS COLLABORATING WITH FirstEnergy CORP. WHO IS HOSTING THE PROJECT AT THEIR R.E. BURGER COAL-FIRED POWER PLANT. STEPS AWAY FROM THE PLANT, CREWS WORK AROUND THE CLOCK DRILLING A 2 1/2-KILOMETER, OR 8,000-FOOT, HOLE SEARCHING FOR RESERVOIRS DEEP UNDERGROUND THAT CAN HOLD THE PLANT'S CARBON DIOXIDE. THIS IS ONE OF BATTELLE MEMORIAL INSTITUTE'S RESEARCH SITES THAT ARE A PART OF THE MIDWEST REGIONAL CARBON SEQUESTRATION PARTNERSHIP
ONE OF SEVEN U.S. DEPARTMENT OF ENERGY PROGRAMS BEING CONDUCTED ACROSS THE UNITED STATES THAT ARE STUDYING CARBON CAPTURE AND SEQUESTRATION AS ONE OPTION FOR MITIGATING CLIMATE CHANGE. CO2 IS ROUTINELY SEPARATED AND CAPTURED AS A BY PRODUCT FROM INDUSTRIAL PROCESSES. BUT THESE CAPTURE TECHNOLOGIES ARE NOT COST-EFFECTIVE ON THIS SCALE AND ARE BEING FURTHER DEVELOPED. THE OBSTACLE FOR SEQUESTRATION, HOWEVER, IS NOT COST. FOR YEARS, CARBON DIOXIDE HAS BEEN PUMPED INTO THE GROUND TO ENHANCE OIL RECOVERY. THE CHALLENGE NOW IS TO TEST THIS TECHNOLOGY FOR LONG-TERM STORAGE. PHIL JAGUCKI IS A GEOLOGIST ON THE PROJECT. Jagucki: CARBON DIOXIDE IS
INJECTED INTO THE GROUND EVERY DAY. BUT WE WANT TO PUT IT IN AND KEEP IT DOWN THERE AND WE NEED TO FIND WAYS TO MONITOR IT SO THAT WE CAN VERIFY THAT IT'S STAYING UNDERGROUND THAT IT'S BEHAVING AS WE INTENDED OR AS WE HAD PLANNED. AND SO THAT'S THE KNOWLEDGE GAP THAT WE HAVE TO FILL. WHEN IS THE LAST SURVEY? IF YOU THINK OF THE ANALOGY OF THE OIL AND GAS FIELDS THAT MATERIAL HAS BEEN DOWN THERE FOR MILLIONS OF YEARS. WHEN WE PUT CO2 IN IT SHOULD REMAIN THERE FOR MILLIONS OF YEARS. Narrator: THE FIRST REQUIREMENT FOR A GOOD POTENTIAL ROCK RESERVOIR IS POROSITY. THE TARGET ROCK MUST HAVE ENOUGH TINY SPACES BETWEEN ROCK GRAINS TO ABSORB THE CO2. Dr. Gupta: YOU CAN IMAGINE, FOR EXAMPLE MAYBE A SPONGE.
AND IF YOU PUT A DROP OF WATER ON SOME PIECES OF ROCK THAT WATER IS IMMEDIATELY ABSORBED. Narrator: NEAR THE SURFACE POROUS ROCKS LIKE THESE ACT AS AQUIFERS FOR DRINKING WATER. BUT AS YOU GET DEEPER, THIS IS NOT THE CASE. LAYERS OF POROUS ROCK CAN CONTAIN OIL, GAS OR IN THIS CASE, BRINE, OR SALTY WATER. Dr. Gupta: YOU WANT TO MAKE SURE THAT THE CO2 THAT YOU INJECT IS DEEPER THAN ANY FRESHWATER SOURCES OF GROUNDWATER. SO AS YOU GO DEEPER THAT HIGH-SALINITY WATER IS NOT USEABLE NOW OR IN THE FORESEEABLE FUTURE FOR ANY OTHER USES. THAT'S WHY IT CAN BE USED FOR INJECTION. Narrator: THESE BRINE, OR SALTY RESERVOIRS CAN BE AN IDEAL LOCATION FOR
CARBON SEQUESTRATION. BUT JUST AS CRITICAL AS THEIR POROSITY IS THEIR PERMEABILITY ALLOWING THE CARBON DIOXIDE TO MOVE THROUGH THE ROCK'S PORES. BUT PERMEABILITY CAN ENABLE THE CO2 TO MOVE UPWARDS AND ESCAPE TO THE SURFACE MAKING A NONPOROUS IMPERMEABLE LAYER ABOVE THE RESERVOIR KNOWN AS CAP ROCK ANOTHER IMPORTANT, NECESSARY CHARACTERISTIC. Dr. Gupta: IT WOULD BE LIKE A PIECE OF SHALE-TYPE ROCK WHERE YOU PUT A DROP OF WATER AND IT DOESN'T GET ABSORBED VERY QUICKLY OR NOT AT ALL. THAT'S A CAP ROCK, AND THAT PREVENTS THE LEAKAGE OF CO2. Narrator: WHEN SANDSTONE AND SHALE SAMPLES ARE BOTH INJECTED WITH BLUE DYE AND VIEWEDUNDER THE SAME MAGNIFICATION
YOU CAN SEE THE DIFFERENCE BETWEEN AN IMPERMEABLE, NONPOROUS ROCK AND ONE WHICH IS POROUS AND PERMEABLE. THE FIRST STEP IN LOOKING FOR POTENTIAL GEOLOGICAL STORAGE SITES WITH THESE CRITICAL CHARACTERISTICS IS A SEISMIC SURVEY OF THE POTENTIAL AREA. Jagucki: THE SEISMIC SURVEY ALLOWS US TO COVER A LARGER AREA WITHOUT HAVING TO DRILL WELLS EVERYWHERE. WE CAME OUT HERE WITH TRUCKS THAT ARE EQUIPPED TO VIBRATE THE GROUND. A LOT OF PEOPLE CALL THEM THUMPER TRUCKS. WE HAVE A SERIES OF MICROPHONES STUCK INTO THE GROUND TO MEASURE THAT SOUND AS IT PASSES DOWN AND THEN COMES BACK UP. AND WE RAN ABOUT FIVE MILES NORTH TO SOUTH
AND ABOUT FIVE MILES EAST TO WEST SO THAT COVERS A FAIRLY LARGE AREA. Narrator: THE PRELIMINARY IMAGES TRANSLATED FROM THE VIBRATIONS SUGGESTED THAT THE BELMONT COUNTY SITE WAS AN OPTIMAL, NON-FAULTED GEOLOGIC LOCATION FOR CARBON SEQUESTRATION SHOWING LAYERS OF POROUS SANDSTONE CAPPED BY EVEN THICKER LAYERS OF IMPERMEABLE ROCK. THE TWO LAYERS THEY ARE INTERESTED IN AS POTENTIAL INJECTION ZONES ARE THE ORISKANY LAYER WHICH IS AROUND 1,800 METERS, OR 6,000 FEET BELOW THE SURFACE, AND THE CLINTON LAYER ANOTHER 600 METERS, OR 2,000 FEET, LOWER. THE NEXT STEP IS TO DRILL A WELL OVER 2,400 METERS, OR 8,000 FEET, DEEP TO CONFIRM THESE FINDINGS.
TO REACH THIS DEPTH CREWS OF FOUR WORK 24 HOURS A DAY DRILLING AT A RATE OF ABOUT TWO MINUTES PER FOOT BY ADDING 30-FOOT SECTIONS OF DRILL PIPE ONE AT A TIME. Meggyesy: BASICALLY, THEY'RE GONNA PICK THOSE UP AND THEY ARE GOING TO PUT IT DOWN IN THE HOLE AND PICK UP ANOTHER ONE. EVERY TIME THEY WANT TO DO SOMETHING WITH A BIT THEY HAVE TO PULL ALL OF THAT PIPE BACK OUT AND THEY HAVE TO PUT IT ALL BACK IN AGAIN. Narrator: AS THEY DRILL THE HOLE THEY CONTINUOUSLY TAKE ROCK SAMPLES TO DETERMINE IF THE LAYERS THEY SAW ON THE SEISMIC SURVEY ARE ACTUALLY THERE. Meggyesy: WE HAVE A BUNCH OF VERY LARGE AIR COMPRESSORS BIGGER THAN A PICKUP TRUCK, THAT ARE BLOWING COMPRESSED AIR DOWN THROUGH THE DRILL PIPE, OUT THE BIT
AND IS PICKING UP THE DEBRIS AS WE'RE DRILLING. IT'S LIFTING IT ALL THE WAY BACK UP OUT THE HOLE AND IT BLOWS IT OUTAT THE BLOW PITS. Jagucki: AS THAT FLUID COMES OUT WE CAN LITERALLY HOLD A BUCKET UNDER THE END OF IT AND WE GET SOME WATER AND CUTTINGS IN IT. AND THEN WE GIVE THAT SAMPLE TO OUR MUD LOGGER AND THE MUD LOGGER LOOKS AT THE CUTTINGS. HE CAN TELL WHAT TYPE OF ROCK WE'RE IN. Narrator: AT APPROXIMATELY 1.8 KILOMETERS OR 5,800 FEET, DOWN THE TEAM EXPECTS TO FIND THE SANDSTONE THAT IS PART OF THE ORISKANY ROCK LAYER ONE OF THE POTENTIAL INJECTION ZONES. BUT SO FAR, THERE IS NO SIGN OF THAT LAYER. Jagucki: WE LOGGED ANOTHER WELL
ABOUT 30 MILES NORTH OF HERE, AND THAT SANDSTONE WAS PRESENT. SOME OF OUR OTHER REGIONAL DATA TELLS US THAT IT'S HERE. BUT IT'S AT THIS PARTICULAR LOCATION. THAT'S WHY IT'S SO IMPORTANT TO GET SITE-SPECIFIC INFORMATION BECAUSE NO MATTER HOW GOOD YOUR REGIONAL INFORMATION IS UNTIL YOU VERIFY IT ON-SITE, YOU JUST DON'T KNOW. Narrator: AT ABOUT 5,900 FEET THE SAND GRAINS FROM THE ORISKANY LAYER START TO APPEAR. Jagucki: WE WERE GLAD WHEN WE FOUND THE ORISKANY SANDSTONE. THAT PROVIDES A GOOD POTENTIAL TARGET FOR US TO DO OUR EXPERIMENT. AND IT'S DEEP BELOW GROUND SURFACE. IT'S OVER A MILE DOWN. IT'S WELL CONTAINED. IT'S GOT THOUSANDS OF FEET OF SHALE ABOVE IT THAT FORM A VERY GOOD CONTAINMENT LAYER.
Narrator: ADDITIONAL TESTS ARE DONE. WELL LOGGING MEASURES FLUID LEVELS THAT ACT AS A PROXY OF POROSITY IN THE ROCK INDICATING LAYERS OF POROUS SANDSTONE AND NONPOROUS SHALE. AND CORE SAMPLES ARE COMPARED TO PREVIOUS EXAMPLES TAKEN OVER DECADES FROM OHIO GEOLOGICAL SURVEYS LAB. THIS DATA WILL PROVIDE THE EXACT DEPTH AND CHARACTERISTICS OF THE ROCK LAYERS. ONCE THESE EVALUATIONS ARE COMPLETE THE ROCK WILL BE TESTED BY INJECTING ABOUT TWO DAYS' WORTH OF PLANT CO2 EMISSIONS AND MONITORING WHETHER ANY OF IT IS LEAKING UP TO THE SURFACE. IF THIS TECHNOLOGY PROVES FEASIBLE AND ECONOMICALLY VIABLE
THEN CARBON SEQUESTRATION HOLDS GREAT PROMISE AS BEING PART OF THE SOLUTION TO CONTINUE TO PROVIDE AFFORDABLE ENERGY WITHOUT CONTRIBUTING TO CLIMATE CHANGE. Dr. Gupta: WE HAVE TO CLEARLY RECOGNIZE THAT THIS IS ONE OF SEVERAL OPTIONS THAT WE HAVE TO DEPLOY. IT IS NOT THE ONLY OPTION. BUT THIS OPTION, IF IT CAN BE USED LIKE WE ARE TRYING TO SHOW WITH OUR RESEARCH WOULD BE A SIGNIFICANT PART OF THE PORTFOLIO OF TECHNOLOGIES FOR REDUCING CO2 EMISSIONS. Narrator: CARBON CAPTURE AND SEQUESTRATION IS JUST ONE PART OF THE EFFORT IN PROVIDING A SUSTAINABLE ENERGY FUTURE. RENEWABLE FORMS OF ENERGY, SUCH AS SOLAR AND WIND ALONG WITH ENERGY EFFICIENCY
ARE ALSO VITAL COMPONENTS TO THIS STRATEGY HOLDING PROMISE THAT WE WILL BE ABLE TO MEET THE CHALLENGE OF POWERING OUR HOMES AND OUR BUSINESSES IN A LESS DAMAGING WAY. BUT WE STILL NEED TO GET AROUND. 350 MILLION GALLONS OF PETROLEUM IS BURNED EVERY DAY IN THE UNITED STATES MOST OF IT FOR TRANSPORTATION EMITTING APPROXIMATELY 700 MILLION METRIC TONS OF CARBON DIOXIDE A YEAR. AND THE WORLDWIDE DEMAND FOR FUEL IS ONLY GOING UP CREATING A PRESSING NEED FOR NEW RENEWABLE FUELS. Douglas: THE URGENCY TO FIND RENEWABLE TRANSPORTATION FUELS IS AT LEAST TWOFOLD. ONE IS ENERGY SECURITY. OUR NATION IS ALMOST WHOLLY DEPENDENT FOR TRANSPORTATION FUELS ON PETROLEUM PRODUCTS.
AND MOST OF THAT PETROLEUM COMES FROM OVERSEAS. AND IT IS BECOMING MORE AND MORE SCARCE AND HARDER AND HARDER TO FIND. IN ADDITION TO THAT BURNING OF PETROLEUM IN CARS, BUSES, PLANES HAS BEEN IDENTIFIED AS A PRIMARY CONTRIBUTOR TO THE AMOUNT OF CARBON DIOXIDE THAT'S GOING INTO THE ATMOSPHERE WHICH COULD CONTRIBUTE TO CLIMATE CHANGE. AND SO THERE'S AN ENVIRONMENTAL BENEFIT TO FINDING A RENEWABLE RESOURCE. Narrator: AT THE NATIONAL RENEWABLE ENERGY LABORATORY OR NREL, IN GOLDEN, COLORADO SCIENTISTS AND ENGINEERS WORKING FOR NREL's BIOMASS PROGRAM ARE DEVELOPING NEW WAYS TO GET FUEL FROM PLANTS.
THEIR GOAL IS TO REPLACE A THIRD OF THE UNITED STATES' GASOLINE CONSUMPTION WITH PLANT-BASED BIOFUELS, OR ETHANOL, BY THE YEAR 2030. Douglas: WHEN YOU BURN FOSSIL FUELS YOU'RE RELEASING CARBON DIOXIDE THAT WAS FIXED IN THE EARTH MILLIONS OF YEARS AGO WHEN THOSE ANCIENT PLANTS DIED. BUT WHEN YOU'RE USING A BIO-BASED FUEL LIKE ETHANOL YOU'RE ACTUALLY ONLY RELEASING CARBON DIOXIDE THAT WAS ONLY RECENTLY FIXED BY THE PLANTS AND THEN THE PLANTS THAT YOU'RE GROWING FOR NEXT YEAR'S CROP WILL THEN FIX THAT CARBON BACK AGAIN. SO THE CARBON CYCLE IS NEARLY 100% COMPLETE. Narrator: TODAY, MOST OF THE ETHANOL PRODUCED IN THE UNITED STATES COMES FROM CORN. THE PROCESS IS NOT MUCH
DIFFERENT FROM THAT OF MAKING WINE OR BREWING BEER. IN LARGE-SCALE PLANTS ALL OVER THE MIDWEST THE STARCH IN CORN KERNELS IS CONVERTED TO SUGARS WHICH ARE THEN FERMENTED WITH YEAST. THE END PRODUCT OF THIS FERMENTATION IS THEN DISTILLED TO SEPARATE THE ETHANOL. BUT THERE ARE LIMITATIONS TO INCREASING THE PRODUCTION OF CORN ETHANOL. CORN IS ALREADY A VALUABLE COMMODITY. IT IS AN INGREDIENT IN MANY OF THE FOODS WE EAT AND ALSO USED AS FEED FOR LIVESTOCK. Douglas: WE THINK WE CAN GO TO ABOUT 15 BILLION GALLONS OF ETHANOL A YEAR FROM CORN KERNELS. BUT ANYTHING BEYOND THAT THE COMPETITION BETWEEN FUEL AND FOOD STARTS TO TAKE PLACE. AND SO TO GET MORE
THAN 15 BILLION GALLONS OF ETHANOL A YEAR WE NEED TO GO TO OTHER METHODS. AND THAT'S WHY WE'RE INTERESTED IN TRYING TO LEARN HOW TO ECONOMICALLY MAKE ETHANOL FROM THE CELLULOSIC MATERIALS — THAT IS, THE STALKS, STEMS, LEAVES — THE NONEDIBLE PARTS OF THE PLANT. Narrator: CELLULOSIC MATERIAL, OR BIOMASS IS BASICALLY THE FIBROUS, WOODY AND GENERALLY INEDIBLE PORTIONS OF PLANTS. AND IT IS THE MOST PLENTIFUL BIOLOGICAL MATERIAL ON EARTH. THE CHALLENGE FOR NREL SCIENTISTS AND ENGINEERS LIKE ANDY ADEN IS TO DESIGN COST-EFFECTIVE CONVERSION PLANTS THAT CAN CREATE FUEL FROM MANY DIFFERENT TYPES OF BIOMASS. Aden: THERE ARE LOTS OF DIFFERENT TYPES OF BIOMASS. THERE ARE AGRICULTURAL
RESIDUES, LIKE CORN STOVER OR WHEAT STRAW THINGS THAT ARE CURRENTLY LEFT IN THE FIELD AFTER THE GRAIN HAS BEEN HARVESTED. THERE ARE WOOD TYPES OF FEED STOCKS THAT ARE BIOMASS — WOOD CHIPS LIKE POPLAR, FOR EXAMPLE. IT'S A VERY FAST-GROWING TREE AND YOU CAN POTENTIALLY HAVE PLANTATIONS OF THIS MATERIAL THAT CAN PRODUCE LARGE AMOUNTS OF BIOMASS FOR FUEL ALL THE WAY EVEN TO A PRAIRIE GRASS LIKE SWITCH GRASS. THE BENEFITS OF THIS MATERIAL IS IT'S VERY DROUGHT-TOLERANT AND YOU CAN GET A LOT MORE TONNAGE OF THIS MATERIAL OFF OF AN ACRE OF LAND. SO THERE ARE A LOT OF REASONS AND A LOT OF ADDITIONAL BENEFITS FOR USING BIOMASS AS A SOURCE OF ETHANOL AS OPPOSED TO JUST CORN GRAIN ONE OF WHICH IS THERE'S A LOT MORE OF IT OUT THERE
THE SECOND OF WHICH IS YOU AVOID THE FOOD-VERSUS-FUEL ISSUES. THE THIRD POTENTIAL BENEFIT IS TO FARMERS IN RURAL AMERICA BECAUSE IT ADDS ADDITIONAL MARKETS FOR THEM TO SELL MATERIALS INTO. Narrator: BUT THERE ARE MANY OBSTACLES IN CREATING ETHANOL FROM CELLULOSIC MATERIAL. THROUGH PHOTOSYNTHESIS PLANTS MAKE SUGARS THAT THEY USE FOR ENERGY TO GROW. SOME OF THOSE SUGARS ARE BONDED TOGETHER AND STORED CREATING STARCHES, LIKE THE STARCH IN A CORN KERNEL THAT CAN BE USED LATER FOR ENERGY. THESE STARCHES ARE EASILY BROKEN DOWN MAKING THEM AN ATTRACTIVE SOURCE FOR ETHANOL CONVERSION. BUT SOME SUGARS ARE BONDED DIFFERENTLY, INTO LONG CHAINS LIKE STEEL GIRDERS WITHIN
PLANT CELL WALLS. SPECIFICALLY, THERE ARE THREE PRIMARY COMPONENTS OF BIOMASS — CELLULOSE, HEMICELLULOSE, AND THE POLYMER LIGNIN WHICH FILLS THE REMAINING SPACES IN THE PLANT CELL WALL. PLANTS EVOLVED SO THAT THESE MATERIALS WOULD LAST A LONG TIME AND BE CHEMICALLY DIFFICULT TO BREAK DOWN MAKING THE BIOMASS CONVERSION PROCESS CHALLENGING. NREL HAS CREATED A PILOT PLANT TO TEST WAYSTO IMPROVE THE PROCESS OF BREAKING DOWN THE CELLULOSIC MATERIAL AND MAKE THE SUGARS AVAILABLE FOR FERMENTATION. THE FIRST STEP IN THE PROCESSIS PRETREATMENT. Aden: NATURE HAS REALLY MADE THESE MATERIALS TO BE RESISTANT TO BEING BROKEN DOWN. SO THAT'S WHY WE HAVE TO DO SOME PREPROCESSING
TO BREAK APART THE CELLULOSE AND THE HEMICELLULOSE FROM THE LIGNIN. AND THAT'S WHAT HAPPENS IN THE PRETREATMENT PART OF THE PROCESS. WE START TO USE ACID AS A CHEMICAL HYDROLYSIS AGENT — HYDROLYSIS REALLY MEANS ADDING WATER TO A REACTION — TO BEGIN TO BREAK DOWN THE BIOMASS INTO ITS INDIVIDUAL PIECES AND GET SOME OF THE THOSE SUGARS INTO SOLUTION. Narrator: THIS PRETREATMENT PROCESS RELEASES THE SUGARS IN THE HEMICELLULOSE. BUT THE CELLULOSE REMAINS SOMEWHAT INTACT LEADING TO THE NEXT STEP IN BREAKING DOWN THE CELLULOSIC MATERIAL. Aden: ONCE WE'VE PRETREATED THE BIOMASS WE BRING THAT PRETREATED BIOMASS, IN A SLURRY OR A PASTE INTO OUR FERMENTERS HERE. AND THIS IS WHERE WE ADD OUR CELLULASE ENZYME
INTO THE PROCESS. CELLULASE ENZYME IS SIMPLY A NATURAL PROTEIN THAT ACTS AS A CATALYST TO BREAK DOWN THE CELLULOSE INTO ITS INDIVIDUAL SUGAR UNITS. ONCE WE HAVE THAT MIXTURE OF SUGARS THAT HAS COME FROM THE PRETREATMENT AND FROM USING THE ENZYMES WE CAN FERMENT THAT MIXTURE OF SUGARS THEN INTO FUEL ETHANOL. Narrator: THE ENZYMES USED TO BREAK DOWN THE CELLULOSIC MATERIAL ARE AN EXPENSIVE PART OF THIS PROCESS. NREL's EXTENSIVE BIOCHEMICAL LABORATORIES ALONG WITH INDUSTRY PARTNERS, HAVE BROUGHT THE COST DOWN FROM $5 PER GALLON OF ETHANOL PRODUCED TO ABOUT 20 CENTS PER GALLON. BUT THIS COST HAS TO BE REDUCED EVEN FURTHER TO COMPETE WITH CORN
ETHANOL AND TRADITIONAL PETROLEUM. BILL ADNEY IS RESEARCHING NEW WAYS TO IMPROVE THESE ENZYMES USING BIOTECHNOLOGY. Dr. Adney: ENZYMES ARE IMPORTANT IN NATURE IN THE BREAKDOWN OF BIOMASS. THEY'RE FOUND ALL OVER THE PLACE, WHEN YOU THINK ABOUT IT. COMPOST PILES WOULD BE ONE EXAMPLE OF A PLACE WHERE YOU WOULD FIND CELLULOSE-DEGRADING ENZYMES. AND WE'VE LOOKED ALL SORTS OF PLACES. Narrator: ONE PLACE THEY LOOKED WAS YELLOWSTONE NATIONAL PARK. Dr. Adney: WE WERE LOOKING FOR ENZYMES THAT COULD SURVIVE AT HIGH TEMPERATURE. SO WE LOOKED AT SOME OF THE BIOMASS THAT'S DECAYING IN THE HOT SPRINGS. Narrator: WHAT THEY FOUND WAS A BACTERIUM
THAT FEEDS ON THE ORGANIC DEBRIST HAT FALLS INTO HOT SPRINGS. THE ENZYME THEY ISOLATED FROM THE BACTERIUM ATTACHES ITSELF TO THE CHAIN OF SUGARS IN CELLULOSE AND BREAKS IT APART. Dr. Adney: THIS PARTICULAR ENZYME WE'VE DONE SOME ENGINEERING ON AND HAVE BEEN ABLE TO IMPROVE THE ACTIVITY BY ABOUT 12% TO 15%. Narrator: WHILE THIS ENZYME BREAKS THE CHAIN IT DOES NOT RELEASE THE SUGARS. THAT IS THE JOB OF ANOTHER ENZYME ONE THAT WAS DISCOVERED NEARLY 50 YEARS AGO. Dr. Adney: IN THE LATE '50s, EARLY '60s IT WAS AN ISSUE WITH THE ARMY UNIFORMS IN THE TROPIC AREAS. THEY FOUND THAT THEY WERE DEGRADING RAPIDLY. SO THE ARMY BEGAN TO INVESTIGATE WHY THIS WAS
OCCURRING. AND ONE OF THE FIRST THINGS THEY ISOLATED WAS A FUNGUS THAT PRODUCED ENZYMES THAT BROKE DOWN THE COTTON MATERIAL FOUND IN THE SOLDERS' UNIFORMS. THESE ENZYMES ARE VERY UNIQUE. THEY ARE TERMED PROCESSIVE ENZYMES. SO ONCE THEY ATTACH TO A CHAIN, THEY MOVE PROCESSIVELY DOWN RELEASING THE SUGAR AS THEY MOVE ALONG. THIS PARTICULAR ENZYME IS PROBABLY THE SINGLE MOST IMPORTANT ENZYME IN BIOMASS CONVERSION AT THIS TIME. YET WE DON'T KNOW HOW IT REALLY WORKS. Narrator: BY GAINING A BETTER UNDERSTANDING OF HOW THESE ENZYMES WORK AND ENGINEERING THEM TO FUNCTION MORE EFFECTIVELY RESEARCHERS AT NREL WILL IMPROVE THE BIOMASS-CONVERSION PROCESS
EVEN FURTHER. ONCE THE ENZYMES HAVE BROKEN DOWN THE SUGAR CHAINS FERMENTATION ORGANISMS ARE ADDED TO TURN THOSE SUGARS INTO ETHANOL. IN THIS PART OF THE PROCESS, TOO, PROGRESS NEEDS TO BE MADE. Aden: IN THE CURRENT CORN-ETHANOL INDUSTRY THE YEAST THEY USE TO FERMENT THE GLUCOSE INTO ETHANOL IS VERY GOOD AT WHAT IT DOES. IN THIS PROCESS, WE HAVE A MIXTURE OF SUGARS — GLUCOSE, XYLOSE, MANNOSE, AND OTHER SUGARS. WE HAVE ORGANISMS ENGINEERED TO BE ABLE TO FERMENT SOME OF THOSE SUGARS PRIMARILY GLUCOSE AND XYLOSE, AT THE SAME TIME BUT THEY DON'T DO IT AS EFFICIENTLY AS THEY NEED TO AND WE'D LIKE TO ENGINEER THEM TO DO OTHER SUGARS AS
WELL TO MAKE THIS A MORE EFFICIENT PROCESS AND GET MORE ETHANOL FOR EVERY POUND OF BIOMASS THAT WE BRING IN. Narrator: AT NREL THEY ARE CONTINUALLY ENGINEERING THESE ORGANISMS TO BECOME MORE EFFICIENT IN HOPES OF ONE DAY PRODUCING A SINGLE FERMENTING ORGANISM THAT CAN TOLERATE HIGH CONCENTRATIONS OF ETHANOL AND WORK ON ALL SUGARS AT ONCE. BUT ALL OF THESE PROCESSES TAKE A LOT OF ENERGY. AND HERE IN THE PILOT PLANT THEY ARE WORKING ON A SOLUTION TO THAT AS WELL BY USING THE LAST REMAINING PIECE OF THE CELLULOSIC MATERIAL, THE LIGNIN. Aden: THAT LIGNIN PLAYS A VERY IMPORTANT PART IN THE ENERGY PICTURE OF THIS PROCESS. BECAUSE CELLULOSIC BIOMASS
HAS THIS LIGNIN COMPONENT THAT CAN BE USED FOR A FUEL,YOU DON'T HAVE TO BUY COAL. YOU DON'T HAVE TO BUY NATURAL GAS. YOU CAN BE A SELF-SUSTAINING ENERGY PLANT LIKE THIS BY BURNING THIS LIGNIN RESIDUE. YOU COULD NOT ONLY PROVIDE ALL OF THE ENERGY NEEDS FOR A PROCESSING PLANT SUCH AS THIS YOU COULD ALSO POTENTIALLY SELL A GREEN ENERGY BYPRODUCT TO THE LOCAL POWER GRID. Narrator: BY MAXIMIZING THE ENERGY POTENTIAL OF CELLULOSIC MATERIAL NREL's BIOMASS PROGRAMIS HELPING TO PAVE THE WAY TO A NEW ENERGY FUTURE. Douglas: WITH ADDED EFFICIENCIES WE THINK WE COULD VERY EASILY GET TO THE POINT WHERE HALF OR MORE OF THE LIQUID FUELS USED IN THE U.S. COULD BE GROWN HERE IN THE
U.S. ON AN ANNUAL AND CYCLICAL BASIS. SO WE WOULD BE GROWING OUR OWN TRANSPORTATION FUEL. Narrator: BIOMASS FUELS ALONG WITH OTHER RENEWABLE ENERGY SOURCES CARBON SEQUESTRATION NUCLEAR ENERGY, AND NEW EFFICIENCIES WILL ALL CONTRIBUTE TO PROVIDING AFFORDABLE ENERGY FOR OUR RAPIDLY INCREASING GLOBAL POPULATION AND REDUCE THE IMPACT OF CLIMATE-CHANGING GREENHOUSE GASES. FUNDING FOR THIS PROGRAM IS PROVIDED BY ANNENBERG MEDIA. FOR INFORMATION ABOUT THIS AND OTHER ANNENBERG MEDIA PROGRAMS, CALL… AND VISIT US AT…
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Living in the Environment (MindTap Course List)
20th Edition
ISBN-13: 978-0357142202, ISBN-10: 0170291502
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Compose a 300-word (minimum) essay on the topic below. Essays must be double-spaced and use APA-style in-text citations to reference ideas or quotes that are not your own. You must include a separate bibliography.
What would happen if the market price of nuclear-generated electricity included all the costs of the fuel cycle? Explain. How are the costs of the nuclear fuel cycle paid today? How would this affect the use of nuclear power to produce electricity? How would this affect the development of sustainable energy?
You should cite and quote from assigned readings, AVP's, videos, and module activities to support the ideas in your essay.
Compose a 300
–
word
(minimum) essay on the topic below. Essays must be double
–
spaced
and use APA
–
style in
–
text citations to reference ideas or quotes that are not your own.
You
must include a separate bibliography.
What would happen if the market price of
nuclear
–
generated electricity included all the
costs of the fuel cycle? Explain. How are the costs of the nuclear fuel cycle paid today?
How would this affect the use of nuclear power to produce electricity? How would this
affect the development of sustai
nable energy?
You should cite and quote from assigned readings, AVP's, videos, and module activities to
support the ideas in your essay.
Compose a 300-word (minimum) essay on the topic below. Essays must be double-spaced
and use APA-style in-text citations to reference ideas or quotes that are not your own. You
must include a separate bibliography.
What would happen if the market price of nuclear-generated electricity included all the
costs of the fuel cycle? Explain. How are the costs of the nuclear fuel cycle paid today?
How would this affect the use of nuclear power to produce electricity? How would this
affect the development of sustainable energy?
You should cite and quote from assigned readings, AVP's, videos, and module activities to
support the ideas in your essay.
