Letters to the Editor

Coal economics

I applaud your editorial on coal’s diminishing role; you may not realize just how strong the technical and economic forces are to reduce coal consumption.

According to an American Society of Mechanical Engineers article, a dozen years ago the most efficient combined-cycle natural gas power plant was just less than 50 percent efficient in turning heat into electricity. Today, both GE and Siemens sell CCNG plans that are over 61 percent efficient. Improved efficiency means more than 23 percent more electricity for the same fuel and operating costs.

TVA, Duke Power and Florida Power & Light, all Kentucky coal customers, are building many CCNG plants. They will be cheaper to operate in mild weather, so most remaining power plants will not burn coal in the spring and fall. Last June, for the first time, natural gas generated more electricity than coal in the United States. That trend will continue, even with much higher natural gas prices.

Only one new, very experimental coal plant is under construction in the U.S. Only about 10 percent of coal plants have been built since 1990; most date to 1965 to 1980. Economics will force utilities to retire old, expensive to operate and maintain coal plants.

Alan Drake