Coal

Coal

Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.

Industry: Energy

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Coal

Minority carrier

Energy; Coal

A current carrier, either an electron or a hole, that is in the minority in a specific layer of a semiconductor material; the diffusion of minority carriers under the action of the cell junction ...

Load loss (3 hours)

Energy; Coal

Any significant incident onan electric utility system that results in a continuous outage of 3 hours or longer to more than 50,000 customers or more than one half ofthe total customers being served ...

Purchased power adjustment

Energy; Coal

A clause in a rate schedule that provides for adjustments to the bill when energy from another electric system is acquired and its cost varies from a specified unit base amount.

Sinter

Energy; Coal

A chemical sedimentary rock deposited by precipitation from mineral waters, especially siliceous sinter and calcareous sinter.

Underground mine

Energy; Coal

A mine where coal is produced by tunnelling into the earth to the coalbed, which is then mined with underground mining equipment such as cutting machines and continuous, longwall, and shortwall ...

Open access transmission tariff (electric)

Energy; Coal

Electronic transmission tariff accepted by the U.S. Federal Energy Regulatory Commission requiring the Transmission Service Provider to furnish to all shippers with non-discriminating service ...