Steam has been superseded by [[electricity]] and [[internal combustion]] for some classes of machines, but remains important in others. Large stationery power plants, such as those used to drive generators in electric power plants, are often steam-driven, and, in fact in most nuclear power plants, the nuclear reactor boil water into superheated steam, which in turn drives the steam turbines which drive the generators. | Steam has been superseded by [[electricity]] and [[internal combustion]] for some classes of machines, but remains important in others. Large stationery power plants, such as those used to drive generators in electric power plants, are often steam-driven, and, in fact in most nuclear power plants, the nuclear reactor boil water into superheated steam, which in turn drives the steam turbines which drive the generators. |