L'énergie est la capacité d'effectuer un travail.Il existe sous diverses formes, telles que cinétique, potentiel, thermique, etc. Il est mesuré en joules (J).
1 kWh = 1,000 Wh 
1 Wh = 0.001 kWh 
Exemple: 
Convertir 15 Kilowatt Hour en Watt heure:
15 kWh = 15,000 Wh 
| Kilowatt Hour | Watt heure | 
|---|---|
| 0.01 kWh | 10 Wh | 
| 0.1 kWh | 100 Wh | 
| 1 kWh | 1,000 Wh | 
| 2 kWh | 2,000 Wh | 
| 3 kWh | 3,000 Wh | 
| 5 kWh | 5,000 Wh | 
| 10 kWh | 10,000 Wh | 
| 20 kWh | 20,000 Wh | 
| 30 kWh | 30,000 Wh | 
| 40 kWh | 40,000 Wh | 
| 50 kWh | 50,000 Wh | 
| 60 kWh | 60,000 Wh | 
| 70 kWh | 70,000 Wh | 
| 80 kWh | 80,000 Wh | 
| 90 kWh | 90,000 Wh | 
| 100 kWh | 100,000 Wh | 
| 250 kWh | 250,000 Wh | 
| 500 kWh | 500,000 Wh | 
| 750 kWh | 750,000 Wh | 
| 1000 kWh | 1,000,000 Wh | 
| 10000 kWh | 10,000,000 Wh | 
| 100000 kWh | 100,000,000 Wh |