A kilowatt-hour is the unit of electrical energy and is abbreviated as kWh.

To consume 1 kWh, a machine with a constant energy consumption of 1 kW (1 kilowatt) must work for 1 hour. 1 kW is 1000 watts.

Worldwide - also in the Netherlands - the kilowatt-hour is the unit of measure for the electricity bill. The more kilowatt-hours are used, the higher the invoice amount.

Pearls of Wisdom

kWh is not an SI unit; it is the joule. A kilowatt-hour is equivalent to 3,600,000 J or 3.6 MJ (megajoule).

Calculations

E = P * t
E = 1000 watts × 3600 seconds
    = 3,600,000 joules