| Symbol | kWh |
|---|---|
| Equivalence | 1 kWh = 3,6 MJ |
| Quantity | Energy |
Definition and context
A kilowatt-hour corresponds to the energy transferred by a constant power of one kilowatt over one hour. It is equivalent to 3,6 million joules. It is written kWh and should not be confused with kW, which is a unit of power.
We can check the difference with a fictional case: equipment that maintains 0,5 kW for two hours uses 1 kWh. If we only know its kilowatts, the duration is missing, and perhaps the operating profile as well. In a battery, an amount expressed in kWh helps describe energy, while a figure in kW indicates delivery capability under specific conditions. Both can be relevant to the same use.
What we know and its limits
Introductory reference sheet. Properties and applications depend on measurement conditions; consult the sources before making comparisons.
Follow the evidence
The original sources for exploring this explanation and its limits.
- SI Units
National Institute of Standards and Technology
Base and derived units of the International System. - Guide to the SI · Units and Prefixes
National Institute of Standards and Technology
Derived units, names, symbols, and prefixes.
Image credits
SciClue · AI-generated illustration (OpenAI) · Original source · Recurso editorial de SciClue · generado con IA