Definition from Wiktionary, the free dictionary
- Any technology that may mitigate emissions of carbon dioxide and other greenhouse gasses that arise from the burning of coal for electrical power.
- (dated) anthracite (a cleaner burning variety of coal, which is usually hard and bluish, with fewer impurities; making it acceptable for uses needing cleaner coal)
- (dated) coke (a coked version of coal, that has been cleaned of many of its impurities, making it acceptable for use in steel-making and other uses needing cleaner coal)
- (coke): dirty coal (non-anthracite coal, regular coal, high-sulfur coal)
- (anthracite): dirty coal (lignite)