Ever wonder where your electricity comes from? Coal provides about half of the electricity generation in the U.S. and more in some countries, such as China. Here's the San Juan Generating Station in the Four Corners area of northern New Mexico.
Coal is the cheapest way to produce power in the U.S. Environmentalists have pressured electricity provider PNM to clean up this decades-old plant or replace it. The utility says replacing the plant would be expensive and that it has recently installed controls to reduce harmful air pollutants, such as mercury, sulfur dioxide, nitrogen dioxide, and particulate matter.