The electric utility industry remains the largest user of coal.
Utility boilers in Illinois and a number of other states burn over 90% of the coal mined annually in Illinois. The rest goes to a variety of other types of customers.
In a typical fossil fuel power plant, coal, oil or gas is burned in a furnace to provide heat for changing water to steam. The steam turns the blades of a turbine, which spins a generator to produce electricity. It takes a little less than one pound of Illinois coal to produce one kilowatt-hour of electricity.
There are 1309 coal-fired power plant units in the United States which together produce about 40% of the nation's electricity. Coal is the largest fuel source for electricity in the U.S.
Coal generates about 47% of the electricity used in Illinois. Another 47% comes from nuclear facilities, with the balance from natural gas and renewables.
Years ago, a large amount of the coal mined in Illinois was used within the state. Now about 85% of coal mined in Illinois is shipped to other states or exported to foreign countries. In part, this trend can be attributed to air quality regulations which greatly restrict the burning of high-sulfur coal in many areas.