Coal

Coal is a fossil fuel extracted from the ground by deep mining, coal mining (open-pit mining or strip mining). It is a readily combustible black or brownish-black sedimentary rock. It is composed primarily of carbon and hydrocarbons, along with assorted other elements, including sulfur. Often associated with the Industrial Revolution, coal remains an enormously important fuel and is the most common source of electricity world-wide. In the United States, for example, the burning of coal generates over half the electricity consumed by the nation.

World coal reserves

It has been estimated that, as of 1996, there is around one exagram (1 × 1015 kg) of total coal reserves economically accessible using current mining technology, approximately half of it being hard coal. The energy value of all the world's coal is well over 100,000 quadrillion Btu (100 zettajoules). There probably is enough coal to last for 300 years. However, this estimate assumes no rise in population, and no increased use of coal to attempt to compensate for the depletion of natural gas and petroleum. A recent (2003) study by scientist Gregson Vaux, which takes those factors into account, estimates that coal could peak in the United States as early as 2046, on average. "Peak" doesn't mean coal will disappear, but defines the time after which no matter what efforts are expended coal production will begin to decline in quantity and energy content. The disappearance of coal will occur much later, around the year 2267, assuming all other factors do not change, which they naturally will.{{ref|www.fromthewilderness.com.764}}

Related Topics:
Exagram - Btu - Zettajoules - Gregson Vaux

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The United States Department of Energy uses estimates of coal reserves in the region of 1,081,279 million short tons, which is about 4,786 BBOE (billion barrels of oil equivalent) {{ref|www.eia.doe.gov.765}}. The amount of coal burned during 2001 was calculated as 2.337 GTOE (gigatonnes of oil equivalent), which is about 46 MBOED (million barrels of oil equivalent per day) {{ref|www.iea.org.766}}. At that rate those reserves will last 285 years. As a comparison natural gas provided 51 MBOED, and oil 76 MBD (million barrels per day) during 2001.

Related Topics:
United States Department of Energy - Barrels of oil equivalent - GTOE

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