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Study Shows Moving from Coal to Gas for Electricity Would Sharply Cut Pollution, Help Meet Greenhouse Pledges, at Relatively Low Cost

December 2000

Switching half of the nation’s coal-fired electricity generation to high-efficiency natural gas turbines over the next decade would dramatically reduce air pollution at a relatively low cost, according to a study by the Environmental Law Institute®, an independent policy research center. Such a shift would dramatically reduce emissions from the utility sector, a major contributor to the nation’s air pollution. Emissions of acid-rain causing sulfur dioxide fall by 50 percent, and or nitrogen oxides, which cause both acid rain and smog, by 40 percent.

In addition, major air toxics such as mercury would fall dramatically. As a further measure of the benefits of switching to natural gas, such a change would bring the United States about a third of the way to its greenhouse reduction pledges under the Kyoto Protocol.

The study was based on a sophisticated computer model of the utility industry constructed by Resources for the Future, an economic research organization. The model conservatively assumes that natural gas prices will rise significantly during the phase-in period, and the study’s long-term conclusions are not affected by the spike in gas prices already underway as the United States faces an unusually cold winter and a tight gas market.

“Overall, coal-fired plants, most of which were built before 1980, emit roughly two-thirds of the nation’s sulfur dioxide and one-third of total loading of nitrogen oxides and mercury, a toxic metal,” said ELI Senior Attorney Byron Swift, Director of the Institute’s Energy and Innovation Center. “Modern natural gas turbines are far more efficient and cleaner, thus producing none or very little of the regulated air pollutants emitted by coal-fired plants. Their efficiency also means far less carbon dioxide. Thus, such a switchover would go a long way toward solving the central pollution problems addressed by the Clean Air Act and U.S. international climate change commitments.”

The costs of such a move are relatively low, according to the model. Nationally, electricity prices would average 6.6 cents per kilowatt-hour — six tenths of a cent over a “business as usual” scenario, but equal to today’s price. Meanwhile, of course, the hidden social and environmental costs of air pollution are reduced substantially.

Swift pointed out that the study results have major policy implications for States that are developing ways to reduce NOx pollution in response to the U.S. Environmental Protection Agency’s “SIP call” initiative. This initiative would require eastern States to sharply reduce NOx emissions in the power sector by 2003. “Replacing coal plants with natural gas plants has the potential to achieve very significant multi-pollutant benefits while producing as dramatic reductions in NOx as switching to low-sulfur coal had in reducing SOx in the now famous acid rain cap-and-trade program launched in 1990.”

The greenhouse benefits come as a free bonus. According to Swift, new combined cycle gas turbines are about fifty percent more efficient than coal boilers in producing power from fossil fuel, and produce only half of the carbon dioxide, the chief greenhouse gas. Thus, according to the model, the switchover would reduce carbon from electricity generation by 25 percent — about a third of the reduction to meet the 1990 baseline level established by the 1997 Kyoto Protocol to the Climate Change Convention.

Cleaner Power: The Benefits
and Costs of Moving from Coal to Natural Gas Power Generation
can downloaded for free or ordered by calling (800) 433-5120 or sending an email to orders@eli.org. For press copies, please contact pressrequest@eli.org.