Kilowatt Hour (kWh)
The kilowatt hour is used as energy unit. It is defined as
Understanding the meaning of 1 kilowatt hour
A horse can deliver a (more or less) permanent power of 1 hourse power which is equivalent to 0.735 kilowatts. A horse delivers during 1.35 hours the amount of 1 kilowatt hour in terms of mechanical energy:
(0.75 kilowatt) x (1.35 hours) = ca. 1 kilowatt hour
Please observe that the kilowatt hour means kilowatt multiplicated by hour!
The kilowatt hour is mainly used to measure electric energy (= power, electricity) but can be used to describe the amount of energy for each type of energy.
As comparison a seleced list of fuels with their specific energy content is listet below.
|Fuel/energy carrier||Energy in kWh||Energy in Joule|
|1 cubic meter nat. gas||10||36 000 000|
|1 litre of gas or diesel||10||36 000 000|
|1 kg of hydrogen||33||100 000 000|
|1 kg of dry wood||5||18 000 000|
|1 kg rechargeable lithium ion battery||0.1-0.3||330 000 - 1 000 000|
|1 metric ton of water in hoover dam (200m)||0.5||2 000 000|