A kilowatt-hour (kWh) is a unit of energy, equivalent to one kilowatt (kW) of power being used for one hour.
Many people struggle to understand the difference between these terms. It can help to think of kW and kWh of in terms of something more tangible, such as speed and distance. kW is equivalent to the speed a car is travelling, while the kWh is equivalent to the distance travelled. If you can understand the difference between travelling at 30mph and travelling 30 miles in an hour, then you can understand the difference between kW and kWh.
A kettle, for example, may use electricity at the rate of 3 kW, but if it only takes two minutes to boil it will only use 0.1 kWh of energy in those two minutes (someone walking at 3mph will have travelled 0.1 miles in two minutes).
In real everyday terms - 1 kWh the amount of energy needed by a 5-watt LED light bulb being left on for 200 hours.
Here are some rough examples of what can use 1 kWh of electricity:
- Using a 10,000 watt electric shower for six minutes
- Keeping an immersion heater (3,000 watts) on for 20 minutes
- Around three hours watching a plasma TV (280 - 450 watts)
- Keeping a broadband router (7 - 10 watts) on for five days