Terawatt-hour

The terawatt-hour (TWh) is a unit for measuring energy. It corresponds to 1,000,000,000 kilowatt-hours (kWh). It is the amount of energy that would be produced by a 1,000,000 MW generator over a period of 1 hour, or a 114 MW generator over a period of approximately one year.

The unit TWh is commonly used for large amounts of electrical energy, since it may be easier to understand in a practical context than the proper SI unit for energy, the joule, which is a Ws (watt-second).

1 TWh = 1,000,000,000 kWh = 3,600,000,000,000,000 joules.