Coal is used almost exclusively to generate electricity. Coal power plants account for over 50 percent of all U.S. electricity generation. In 1999, the U.S. produced 1.1 billion tons of coal. Production of coal from federal and tribal lands accounted for 38 percent of that total, or over 400 million tons of coal.
Although coal is the nation's most abundant fossil energy source, production and market issues can affect the adequacy of supply. Production issues include the protection of public health, safety, property, and the environment, and the effectiveness of federal and state agencies implementing various laws governing coal mining. These issues have resulted in some coal resources becoming uneconomical to produce. However, technological advances in cleaner coal technology have allowed for some significant progress toward lifting the limits of production of some coal resources.