kWh is electricity measure consumed by an appliance during a certain period of operation and means Kilowatt-hour.
Watt-hour is a unit of measure of energy and hour is a unit of time. A Watt-hour is the amount of energy needed to power a load with a power of 1 Watt for 1 hour.
The power shown in each device indicates its power for a period of 1 hour. For example, a device with a power of 5400 W (Watts) will consume this power in one hour.
The greater the power of an appliance, the greater its energy consumption. And the longer the device remains on, its consumption will also be higher.
If the 5400 W appliance is left on for 5 hours, how much electricity will it use? In this case, simply multiply 5400 W x 5 h = 27,000 Wh or 27 kWh (you have to divide by 1,000 because 1 kWh equals 1,000 Wh).
1 Wh equals 3,600 joules (unit of energy). Other Watt-hour multiples are:
- Megawatt-hour (MWh) is equivalent to 1,000,000 Wh or 3.6×109 joules
- Gigawatt-hour (GWh) equals 109 Wh or 3.6×1012 joules
- Terawatt-hour (TWh) equals 1012 Wh or 3.6×1015 joules