Coal Gets Cleaner--and Better Connected
East of Tampa in rural Polk County, Fla., there's a $300 million state-of-the-art power plant that serves as Exhibit A in the case for "clean-coal" technology. The plant combines two technologies never brought together before. In the first, coal is converted into a cleaner, synthetic gas. Next, the heat is recycled. Put together, the technologies make Polk's generators up to 12% more efficient than last-generation plants. And that means more power from less coal. All told, this 250-megawatt showcase plant emits significantly less sulfur dioxide, nitrogen oxides, and other pollutants than conventional coal plants.
Engineers have spent billions of dollars of government and industry money over the past decade to develop such clean-coal technologies. These methods, they say, will allow coal--which now provides slightly more than half of the nation's electricity--to continue to play an important role in U.S. power generation without unduly polluting the environment.
Environmentalists and other critics shudder at the very mention of "clean" coal, arguing that it can never be made acceptable from an environmental standpoint. Extracting coal from the ground is a messy, polluting process. And burning it, in no matter what form, always releases carbon dioxide, a greenhouse gas. "The term `clean coal' is a myth, a very cynical term," says Lexi Schultz, a lawyer at the U.S. Public Interest Research Group. The advocates' goal, she says, "is to increase the use of coal, period."
That criticism isn't likely to go far in Washington, however. Clean coal's advocates have a powerful friend in President George W. Bush, who was the No. 1 recipient of coal-industry campaign contributions, according to the nonpartisan Center for Responsive Politics. Environmentalists say that his ties to the coal industry partly explain his February decision to withdraw U.S. support from the Kyoto Protocol, the international agreement to curb global warming by restricting carbon dioxide emissions from the burning of coal and other fossil fuels.
The Administration is also considering requests from the coal and utility industries to drop Clinton Administration-initiated lawsuits that would require new pollution controls to be installed on old coal-fired power plants. And Bush has shown no enthusiasm for a Senate bill that seeks to tighten restrictions on coal plant emissions and require older power plants to meet stringent Clean Air Act standards. Instead, the President has incorporated into his budget proposal $2 billion in federal funding to promote clean-coal technology.
MORE EFFICIENT. Tampa Electric's Polk Power Station relies on some of the latest advances in a field of research that began in the 1980s, when coal plants were shown to contribute to acid rain. In 1990, Congress amended the Clean Air Act, phasing in tighter limits on emissions of soot particles, nitrogen oxides, and sulfur dioxide from power plants. To help implement those limits, the Energy Dept. has since spent $1.8 billion on 39 clean-coal technology programs, while state governments and industry kicked in a further $3.4 billion.
Several of the resulting technologies are already in wide use. They include new equipment that cleans coal after it is mined, new methods of burning coal, and advances in treating gases after burning. This so-called reburn technology splits the burn into two stages for more complete combustion, which results in lower emissions of nitrogen oxides. The technology has already been adopted by three-quarters of the nation's coal-fired plants. Meanwhile, improvements in antipollution "scrubbers," designed to treat exhaust from smokestacks, have reduced emissions of sulfur dioxide by 95% or more.
In recent years, much of the research has focused on the development of more efficient burning methods so that more electricity can be extracted from less coal. An average pound of coal contains about 10,000 BTUs. Existing coal-fired plants capture only 33% to 35% of that. The rest is wasted. But plants built in the past five years, such as the one in Polk County, can extend that slightly, extracting 37% of the energy from a pound of coal. And those being built now, using the Polk plant combustion technology or a similar method, are expected to have efficiencies of about 40%.
LITTLE TO FEAR. In the future, clean-coal enthusiasts anticipate even more dramatic strides in efficiency and environmental quality. An Energy Dept. projection for coal sets an efficiency goal of 60% by 2025. On the environmental front, the trick, says Thomas A. Sarkus, senior engineer at Energy's National Energy Technology Laboratory, is balancing environmental measures with affordability. "It's not a technical matter," he says. "The more controls you want, the more it's going to cost."
The coal industry fears those higher costs. They could eliminate coal's biggest selling point--that it's cheaper than natural gas--thus forcing utilities to switch to other fuels, including gas. But so far, such a shift seems unlikely. "What's the alternative to coal?" asks Ronald H. Carty, director of the Illinois Clean Coal Institute. "If you're talking renewables, I don't know how you do it."
In fact, coal executives have little to fear from alternative energy. While coal provides more than 50% of the nation's electricity, alternative sources, such as solar and wind power, provide less than 3%. The percentage of BTUs generated from coal is expected to drop slightly in the next 20 years, says Sarkus, but demand for power will grow so much that coal usage, in tonnage, will jump 30%. Technologies such as those used in the Polk County plant in Florida are the only way to avoid the potentially harmful environmental consequences of that surge in coal use. Clean coal is clearly here to stay.
By Patrick A. McGuire