Carbon Dioxide Emissions by the Electric Power Industry in the U.S. for 2007 and 2009
Electric power utility companies generate electricity using more than one fuel source, with each producing different levels of greenhouse gases, mostly in the form of carbon dioxide (CO2). Coal is the cheapest fuel used to produce electricity, so the coal firing facilities of electric utilities' power plants are run all the time at maximum capacity, since it produces the lowest cost electricity. However, burning coal also produces the most CO2 per unit of energy produced as well as other gases that contribute to acid rain (sulfur dioxide and nitrogen oxides). For the remainder of electricity needs, the electric utility companies use some combination of natural gas (produces about half of the CO2 that coal does), nuclear power, municipal waste incineration, hydropower and other renewable sources like wind, geothermal and solar. Nuclear power produces zero CO2, but you still have to deal with the nuclear waste, which is another story.
Note that there was a 10% decrease in total carbon dioxide emissions in 2009 as compared to 2007. This reduction was due in part to more natural gas and less coal being used to generate electricity, a significant increase in wind generated power, and lower industrial demand for electricity.
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