America has plenty of coal. Its mines produced 1.2 billion tons in 2008, nearly all of it destined for electricity generation. That was a record year, but it barely scratched the surface of U.S. recoverable coal reserves, which are estimated at about 270 billion tons. In fact, more than one-fourth of the total known world coal reserves are located in the United States. Despite such coal riches, questions have recently been raised about how accessible these reserves truly are. The location, quality, and recoverability of the coal could significantly impact these supply estimates and experts caution that the reserves should be analyzed more closely with these factors in mind.
Demand for coal in the United States is projected to increase by 21% between now and 2030, propelled by the rising use of electricity and possibly the expanded use of still-developing technology that converts coal to liquid fuel. Most of the increased supply will probably come from western states, which now provide about six-tenths of the nation’s coal. Wyoming alone accounted for 38% of all domestic coal mined in 2006.
More than one-fourth of the total known world coal reserves are in the United States.
Of all the fossil-fuel sources, coal is the least expensive for its energy content. In 2008, a million Btu of energy from coal carried a production price—i.e., the original price of the resource at its point of origin—of $1.60, compared to $7.30 for natural gas and $16.20 for petroleum. However, burning coal in electric power plants is a major source of CO2 emissions, and its use has repercussions on the environment beyond combustion. Mining coal disturbs the land and modifies the chemistry of rainwater runoff, which in turn affects stream and river water quality. Coal-fired power plant emissions include oxides of nitrogen, sulfur dioxide, particulate matter, and heavy metals (such as mercury) that affect air quality and human health, often even hundreds of miles from the power plant. In response to strict environmental laws, advanced coal—also known as “clean coal”—technologies are being developed to reduce harmful emissions and improve the efficiency of these plants.