But what is missing in this picture of a modern, efficient coal-fired power plant? Is this the “clean coal” that the industry likes to talk about? The Platte River Power Authority (PRPA) non-profit utility is justifiably proud of its efforts and expense to make this coal-fired power plant as clean as it can be. But it is not clean! It suffers from the Achilles’ heel that all coal plants suffer from—the production of invisible carbon dioxide (CO2) that is coming out of the smokestack. When pure hydrocarbon (the type of carbon in fossil fuels) burns, it produces CO2 and water. When coal burns, it produces CO2 and water, as well as various other pollutants. Coal is delivered to Rawhide every other day by an 80-car coal train from the Antelope mine in the Powder River Basin south of Gillette, Wyoming. The Powder River Basin provides about one-third of all the coal used in coal-fired plants in the United States because it has low sulfur content and ash, which reduces emissions, but also because it is close to the surface so it can be pit-mined with gargantuan machines. About 80 trains—each a mile long—are needed daily to carry the coal from the mine to the various coal plants throughout the country that depend on it. Transportation of these huge amounts of coal also produces a lot of CO2. The coal from the Powder River Basin is sub-bituminous, so its energy density is less than that of the bituminous coal that is predominant in Appalachia and Illinois. Sub-bituminous coal contains 35-45% carbon; bituminous coal contains 45-86% carbon (2). This means that more of it has to be burned to give the same amount of electricity. About a million tons of coal are burned in the Rawhide power plant every year.

I talked to Dave Ussery, the Environmental Services Manager for PRPA, to find out about the pollutants coming from the plant. The so-called criteria pollutants that have to be monitored are sulfur oxides that cause acid rain; nitrogen oxides that cause acid rain, ozone, and smog; and particulates that cause haze (3). The emis­sions of these pollutants from Rawhide are much lower than required by state and EPA standards and are among the lowest for coal plants in the country. Emissions of toxic hazardous air pollutants such as mercury are also low, and Rawhide has imple­mented technology to reduce mercury emissions even further. But the 800-pound gorilla in the room is CO2. The plant emits over two million tons of CO2 annu­ally (4)! And this is for a relatively small power plant. A more typical coal-fired power plant would produce about 1,000 MWe, or nearly four times as much as Rawhide with correspondingly more CO2 emitted (about 8 million tons). The larg­est coal-fired power plant, Plant Scherer in Georgia, produces over 3,000 MWe and generates about 23 million tons of CO2 annually (4). When you multiply this by the approximately 600 coal plants in the United States, you can begin to see the magni­tude of the CO2 problem! Altogether, coal-fired power plants in the United States contribute 2 billion tons (gigatons or Gt) of CO2 to the atmosphere annually (5), about one-third of total CO2 emissions in the United States.

Furthermore, while the Rawhide power plant uses the latest and best technol­ogy to reduce pollutants, many power plants do not. The 1970 Clean Air Act was passed by Congress to reduce the problem of acid rain caused by sulfur oxides by requiring scrubbers on new coal-fired power plants. Because of lobbying from coal states, coal-fired plants existing or licensed before 1973 were grandfathered in so they would not have to meet the standards. The idea was that as they made modifications, they would then have to meet modern standards. However, many of them simply decided to remain as they were so they would not have to add on scrubbers. More recent regulations, such as the 2005 Clean Air Interstate Rule by the EPA, requires that sulfur dioxide emissions be reduced by 57% by 2015, so some older plants are being phased out or are adding scrubbers. Still, about 60% of coal plants still do not have scrubbers (6, 7).