One Kilowatt Hour is Defined as

Kilowatt hour is the unit which defines the usage of electricity. It is used to measure electricity. One kilowatt hour refers to the electrical energy which is used by any appliances which run on electricity having power of 1 kW and is used for the duration of 1 hour.  Kilowatt hour is not a standard unit but it is used in only electrical appliances so it is present in the formal system.