Understanding energy units

Energy is measured in kilo-watt-hours (kWh/kWhs), a standardised unit used all over the world to measure energy usage.

One kilo-watt-hour (kWh) is the amount of energy you would use if you kept a 1000 watt (= 1 kilowatt/kW) appliance (see 'Understanding appliance energy rating') running for one hour.

You can calculate the energy usage of any appliance with this equation:

Cost = Power of appliance in kW x Run Time in Hours x Cost per unit

The wattage (power rating) (1) can be found on the bottom of the appliance or sometimes near the name of the appliance, either in W (watt) or kW (kilowatt).