Drax cooling towers. View of the cooling towers of a Drax coal-powered power station. Water vapour can be seen rising from the station's cooling towers. This type of power station burns coal to heat water. This produces steam which drives a turbine which generates electricity. The steam is then condensed by water in a secondary circuit and returned to be boiled again. The water in the secondary circuit is then cooled by spraying it into the towers. Large, modern turbines produce electricity at about 25,000 volts. This is stepped up by transformers to about 400,000 volts for efficient transmission. Photographed near Selby, North Yorkshire, England.