|SI multiples of watt-hour|
The watt-hour (symbol W·h) is a unit of energy commonly used to measure electricity. One watt-hour is the amount of electrical energy equivalent to a one-watt load drawing power for one hour. For example, a 100-watt light bulb uses 100 watt-hours of energy every hour. The is commonly used in the form of the kilowatt-hour, which is 1,000 watt-hours. The watt-hour It is not an SI unit, despite being based on the watt. The SI unit of energy is the joule (J), equal to one watt-second.
In the inch-pounds unit system, a watt-hour is equivalent to 3.412 Btu.
- How Many? A Dictionary of Units of Measurement, Russ Rowlett, Center for Mathematics and Science Education, University of North Carolina at Chapel Hill
- SI base units and SI derived units, the Physics Laboratory, National Institute of Standards and Technology
- Energy conversion tool at unitconversion.org