La energía es la capacidad de realizar el trabajo.Existe en varias formas, como cinética, potencial, térmica, etc. Se mide en Joules (J).
1 MWh = 3,600,000,000 J 
1 J = 2.7778e-10 MWh 
Ejemplo: 
Convertir 15 Megawatt Hour a Joule:
15 MWh = 54,000,000,000 J 
| Megawatt Hour | Joule | 
|---|---|
| 0.01 MWh | 36,000,000 J | 
| 0.1 MWh | 360,000,000 J | 
| 1 MWh | 3,600,000,000 J | 
| 2 MWh | 7,200,000,000 J | 
| 3 MWh | 10,800,000,000 J | 
| 5 MWh | 18,000,000,000 J | 
| 10 MWh | 36,000,000,000 J | 
| 20 MWh | 72,000,000,000 J | 
| 30 MWh | 108,000,000,000 J | 
| 40 MWh | 144,000,000,000 J | 
| 50 MWh | 180,000,000,000 J | 
| 60 MWh | 216,000,000,000 J | 
| 70 MWh | 252,000,000,000 J | 
| 80 MWh | 288,000,000,000 J | 
| 90 MWh | 324,000,000,000 J | 
| 100 MWh | 360,000,000,000 J | 
| 250 MWh | 900,000,000,000 J | 
| 500 MWh | 1,800,000,000,000 J | 
| 750 MWh | 2,700,000,000,000 J | 
| 1000 MWh | 3,600,000,000,000 J | 
| 10000 MWh | 36,000,000,000,000 J | 
| 100000 MWh | 360,000,000,000,000 J |