Installation costs for coal-fired power plants have traditionally been estimated at $1.50–2.00 per watt. But the cost is rising rapidly; one current report says that in 2010 the costs are on the order of $3.50 per watt.48 At present, wind energy costs between $1 and $3 per installed watt. Let’s consider the less expensive case, where the costs are $1 per watt and the average power output from an installed watt is 2.347 kilowatt-hour over a year (a standard value). In the first year of use, the wind turbine would produce electricity at a cost of $0.43 per kilowatt-hour. Assume there are no maintenance or other costs, and therefore the total costs are contained in the installation, the cost after 10 years would be $0.043 per kilowatt-hour. At this cost per kilowatt-hour, wind matches electrical energy produced from coal when coal is $8.12/ton. Making the same assumptions for the wind turbine, after 20 years the cost would be $0.002 per kilowatt-hour, and coal would have to be priced at $0.41/ton to match this.
Solar is considerably more expensive, both because it costs more to install and because the yield per installed watt capacity is less. (Wind can blow at night, but the solar cells produce electricity only during the day.) Solar costs are typically estimated to be between $3 and $5 per installed watt. Let’s consider the less expensive case, where the costs are $3 per watt and the average power output is 1.245 kilowatt-hours per watt installed (a standard value). Assuming that there are no maintenance or other costs, and therefore the total costs are contained in the installation, the cost after 10 years would be $0.24 per kilowatt-hour. At this cost per kilowatt-hour, solar matches coal when coal is $462.7/ton. Making the same assumptions for the solar devices, after 20 years the cost would be $0.012 per kilowatt-hour, and coal would have to be priced at $46.27/ton to match this.
In short, wind is already cost-competitive against coal, and solar is approaching being cost-competitive against coal, with installation costs averaged over 20 years. And this does not include direct pollution and land-conservation effects (strip mining, erosion, sedimentation, and so on) are taken into account.
But worldwide, coal is selling at much higher prices, and prices have been rising. We will explain this in more detail in Chapter 13.
Wide recognition of the problems with coal resulted in a decline in building new coal power plants in the U.S. However, since there is so much coal, and since the technology for using it has been around for centuries, and since major power companies have a lot to gain from selling coal and the energy from it, there is now and will be more economic pressure to use coal.
In 2006 there were 476 coal-fired electric power plants in the United States, and they produced 2 trillion kilowatt-hours.49 Advocates for coal-fired power plants are working to have 150 more added.50 More than 100 conventional coal-fired power plants are in various stages of development in the U.S. By 2007, 28 were under construction, 6 were near the construction stage, and 13 more had received permits. When these are completed, they will increase the number of coal-fired power plants by 10%. The Department of Energy projects that by 2030 the equivalent of 450 new large (300 MW) coal-fired power plants will be completed.”51
China, too, is adding new coal-fired electric power plants. Right now, 78% of China’s electrical energy is produced from coal. The Natural Resources Defense Council estimates that China’s electrical power generation will increase from 600 billion watts in 2006 to 800 billion watts in 2010, much of it from coal. “China’s coal sector is not only the world’s largest, but also the most dangerous and most polluting,” the NRDC added.
Who is promoting this, and why?
Of course, the coal mining corporations and electric power companies support continued use of coal, as do the U.S. government and other national governments. The Energy Policy Act of 2005 included $1.65 billion in tax incentives for new coal plants, $1 billion of which has been allocated to nine projects around the country.52 World coal prices have risen (Figure 3.6), making it more attractive to mine, transport, and sell.
Figure 3.6 The price of coal rose sharply, doubling between 2007 and 2008 due to rising demand around the world. (Source: AP Images/Platts, AP)
In addition, some academics envision the continued use of coal. For example, a recent authoritative report by 13 distinguished scientists and scholars at MIT states that “coal will continue to be used to meet the world’s energy needs in significant quantities.” They go on to say that “CO2 capture and sequestration (CCS) is the critical enabling technology that would reduce CO2 emissions significantly while also allowing coal to meet the world’s pressing energy needs.”53 They concede that “no CO2 storage project that is currently operating...has the necessary modeling, monitoring, and verification (MMV) capability to resolve outstanding technical issues, at scale.” However, they “...have confidence that large-scale CO2 injection projects can be operated safely.”
This report is one of many that views greenhouse gases as the main concern about coal, and the writers are optimistic that new technology can take care of this. But given the history of the use of coal and the magnitude of its environmental effects, is such faith in an unproven technology justified and a wise risk for the future, in comparison to other energy opportunities?
Technologies to make coal cleaner
Earlier in this chapter I wrote about FutureGen and the possibility that coal might become a “clean” fuel. The technology involved burying (sequestering) the carbon dioxide produced when coal burned. How feasible is this? It’s not easy to bury carbon dioxide that comes off a hot coal fire. It’s much easier to get rid of it the old way, by releasing it into the air from tall smokestacks. In June 2009, Southern Company and American Electric Power withdrew from the project, while that same month, the Obama administration put $1 billion into the project as part of the federal stimulus package.54, 55
Craig Canine, writing for the Natural Resources Defense Council, describes his visit to one of the experimental carbon-sequestering plants near Weyburn, Saskatchewan, built by PanCanadian Petroleum. The plant was using the CO2 to force oil and gas out of deep wells—4,600 feet down—while at the same time burying the CO2.56 Basin Electric, the company generating electricity from coal, had to pump the CO2 some 205 miles from the power plant to the oil field and had to pressurize it to 2,000 pounds per square inch to do so, requiring one of the most powerful compressors ever made, and powering these with two 20,000-horsepower electric motors. The plan is to bury 20 million tons of CO2. Doing this for 20 years is expected to yield an additional 120 million barrels of oil from the field.
The Saskatchewan project is one of about a dozen around the world trying to bury CO2. The recent report by MIT scholars also focused on technologies to bury carbon dioxide emitted by coal fires, but there are three other approaches to trying to make coal “burn cleaner.” The first is to burn coal as it comes from the ground but use physical and chemical scrubbers to remove some of the pollutants on their way up the smokestack and neutralize acid-causing chemicals by adding limestone to the hot emissions. The second is to turn coal into a gas and then burn that. And the third is to turn coal into a liquid—basically into gasoline or diesel—and burn that. The first is self-explanatory, so let’s start by taking a look at the second.
Turning rock into a gas and then burning it
GreenPoint Corporation, the brainchild of Andrew Perlman, is testing new ways to convert solid coal into a gas that will burn cleaner than the original. As you already know, this is not a new idea—remember the 19th-century gas streetlamp in the chapter’s opening photo. What is new at the GreenPoint facility is a secret catalyst that is supposed to convert the solid coal to methane at temperatures much lower than previously needed and separate the pollutants from the gas. The pollutants still have to be disposed of somehow, but they are kept in one place rather than released into the atmosphere. The plant is experimental and has yet to operate.57
Turning rock into a liquid and then burning it
The third method proposed to make coal a “clean” fuel is to make a liquid fuel from
it. In the 1920s, two Germans, Franz Fischer and Hans Tropsch, developed a way to do this. Their method, which was used by the Nazi government during World War II to provide fuel for military vehicles,58 uses a catalyst that is supposed to leave the fuel much cleaner, with fewer particulate chemical pollutants.
Although making liquid fuel and some forms of gas fuel from coal are proven technologies, they add costs to the production of electricity and do not themselves dispose of toxic chemicals, dust, or ash. Therefore, it’s unclear whether they will provide a net benefit environmentally, economically, or to society. At the time of this writing, the future of clean-coal technology seems uncertain but also seems to depend on heavily government subsidies. Funds are going into these technologies and will likely continue to do so. FutureGen, directed by the Department of Energy, is funded to the tune of $1 billion. Is this the best use of federal research dollars in a search for cleaner and secure energy sources for the future?
The bottom line
• Coal is the most abundant fossil fuel and, although not evenly distributed around the Earth, occurs in more nations than do large deposits of oil and natural gas.
• Coal remains a cheap fuel to buy, largely because of government subsidies and other benefits, and especially if the price doesn’t include the costs of polluting the environment and damaging human health.
• Because of its availability and relatively low price, we can be fairly certain that coal use will increase in the next decades, especially to generate electricity.
• However, with few exceptions, the mining of coal, an ancient practice, has taken place at the cost of human lives, damage to health, and sometimes destruction of farms, towns and larger settlements, as well as natural environments—forests, wildlife habitats.
• The burning of coal is a major source of air pollution from soot and toxic chemicals that have affected human health, natural ecosystems, agricultural lands, wildlife, and freshwater fish. Coal dust also decreases visibility in the atmosphere.
• Burning coal is one of the major ways that people are adding carbon dioxide to the atmosphere. Hence, much of the recent concern about coal is about its effects on climate, and much of the current emphasis on “clean coal” is to reduce CO2 emissions into the atmosphere.
• And finally, mining and burning coal mar the beauty of the land and its diversity of life.
4. Water power
Roll on, Columbia, roll on,
Roll on, Columbia, roll on,
Your power is turning our darkness to dawn.
So roll on, Columbia, roll on.
—Woody Guthrie
Figure 4.1 Edwards Dam on the Kennebec River, at Augusta, ME, just before it was breached. (© AP Images)1
Key facts
• Water power provides about 10% of the electricity in the United States, at least half of the electricity used in about one-third of the countries of the world, and more than 90% of the electricity in 24 countries, including Brazil and Norway. Large dams generate 19% of the world’s electricity.
• The U.S. has about 80,000 dams more than 6-feet tall, many built to provide electricity.2 Worldwide, about 800,000 dams exist, and about 45,000 are “large,” meaning more than 15 meters (about 45 feet) high.3
• The United States has 2,400 dams that generate electricity.
About 17% of the rivers in the United States have dams, which in total block about 600,000 river miles.
• China has the greatest number of large dams, 22,000 of them.
• In developed nations, most or all the best sites for hydroelectric power have already been tapped, and there is little potential to increase this source of energy.
• Most of the remaining undeveloped water-power sites are in developing nations.
A story about water power: the breaching of Edwards Dam
In August 1999, I traveled to Augusta, Maine, to watch the breaching of Edwards Dam. I wrote this article about it, which appeared in the Los Angeles Times on August 22 of that year. It still seems to sum up my experiences, so here is what I wrote that day.4
As a crowd gathered along the east bluff of Edwards Dam, a great blue heron flew low above the Kennebec River and was soon out of view, traveling downstream from where water still flowed smoothly over the 161-year-old structure. The heron had been disturbed from its usual stalking territory, perhaps by the big diesel shovel digging bucketfuls of soil from a temporary dam across the river, or perhaps by the large crowd on the opposite shore, or the noise of a helicopter and a float plane circling overhead carrying television crews.
They had all shown up today to witness the breaching of a major hydropower dam, an unprecedented event in U.S. history. The dam was being removed to save migrating fish, restore Kennebec’s ecological habitats, and improve recreational fishing and boating. If the river’s fish population increased, it might be a boon for the heron as well.
Built in 1837, the dam was operating when Henry David Thoreau canoed Maine’s rivers in the 1840s. The dam’s demise was “a bittersweet event,” Augusta’s mayor said. It was a willing and willful removal of one of the triumphs of the machine age, a piece of Yankee ingenuity that had provided power, jobs, and prosperity for Augusta, but did so no more.
Each century and each generation has had its own approach to water power and rivers. Dams were built throughout the United States to provide power for many kinds of industries, from textile mills to aluminum refineries; to store water for irrigation; to control water levels as an aid to ships transporting grain and other goods; for flood control; and for recreation. But dams greatly altered stream habitat. As Thoreau observed on the Merrimack, migrating fish such as shad and salmon, once common there, were rare in his time since they could not pass over the dams already in place by the 1840s.
When a big bell in an Augusta church announced the time to breach Edwards Dam, the shovel dug deeper and deeper into the earthen dam until a shout went up from the crowd and water began to spill through. The thin trickle, moving ever faster, turned into a frothy, mud-laden torrent running down the far side of the Kennebec, tumbling against an old mill building and turning the main channel brown as the river began to cleanse itself of 150 years of deposits behind the old dam.
Some would say that removal of the dam was righting an old wrong. Others would say it was a mistake, wronging an old right. But it was not a matter of absolute right or wrong, it was a matter of a change in our society’s needs and desires, a continuation of change and progress, of new ideas, that have characterized U.S. society.
Edwards Dam was among the first of many to be removed. It was a relatively easy decision since the dam was old and dangerous and had ceased to be of much economic use to Augusta. Maine had begun to prosper more from tourism than from the dam and its mills. The industries along Augusta’s riverbanks were closed or were using electricity generated far away, mostly from fossil fuels whose “brown” pollution didn’t seem to touch Maine’s scenic landscapes and rivers. The new environmentalism would save the city and its landowners a bundle, paying to get rid of something that might cost them plenty if it broke on its own and flooded buildings downstream. Yes, the dam seemed only a negative, threatening migrating fish such as shad, which were in trouble along the coast. The majority of people wanted the river back as a renewable resource for living things. Other sources for energy could be found.
Elsewhere, other dams have caused much more conflict, with both sides claiming the environmental high ground. Opponents of hydropower side with those who argued for the removal of Edwards Dam. Supporters argue that dams are an important way to limit greenhouse gas emissions, that the reservoirs favor many kinds of wildlife and are major sources of recreation.
So today, water power seems to be a Dr. Jekyll and Mr. Hyde. It’s a Dr. Jekyll for global warming since it emits no greenhouse gases. It’s a Mr. Hyde about river habitats and the biological diversity of life in rivers, and the living things that depend on life in the rivers, including many people. What’s the right
balance about water power? Can it be an important source of energy in the future?
How much of our energy supply comes from water power today?
At present, the total U.S. hydroelectric power capacity, including pumped storage facilities, is about 95,000 megawatts, producing 2.14 million megawatt-hours5—about 10% of all the electricity and 3% of the total energy used in the United States.6 The world’s total electrical production from hydropower is about 2.3 trillion kilowatt-hours of electricity each year—about 19%7 to 24%8 of the world’s electricity. In some nations, such as Canada and Norway, most of the electricity is produced by water power.
Powering the Future: A Scientist's Guide to Energy Independence Page 9