An Etymological Dictionary of Astronomy and Astrophysics

Unit of work or energy, equal to one watt for one hour, or 3.6 x 10¹⁰ ergs., or 3600 joules. The kilowatt-hour (kWh), i.e. 1,000 watts over the period of one hour, is the usual unit or measure of electricity supply or consumption. 1 kWh = 3.6 x 10⁶ J.

See also: → watt; → hour.