La energía es la capacidad de realizar el trabajo.Existe en varias formas, como cinética, potencial, térmica, etc. Se mide en Joules (J).
1 th cal = 1.1622e-6 kWh 
1 kWh = 860,420.65 th cal 
Ejemplo: 
Convertir 15 Calorías termoquímicas a Kilovatio hora:
15 th cal = 1.7433e-5 kWh 
| Calorías termoquímicas | Kilovatio hora | 
|---|---|
| 0.01 th cal | 1.1622e-8 kWh | 
| 0.1 th cal | 1.1622e-7 kWh | 
| 1 th cal | 1.1622e-6 kWh | 
| 2 th cal | 2.3244e-6 kWh | 
| 3 th cal | 3.4867e-6 kWh | 
| 5 th cal | 5.8111e-6 kWh | 
| 10 th cal | 1.1622e-5 kWh | 
| 20 th cal | 2.3244e-5 kWh | 
| 30 th cal | 3.4867e-5 kWh | 
| 40 th cal | 4.6489e-5 kWh | 
| 50 th cal | 5.8111e-5 kWh | 
| 60 th cal | 6.9733e-5 kWh | 
| 70 th cal | 8.1356e-5 kWh | 
| 80 th cal | 9.2978e-5 kWh | 
| 90 th cal | 0 kWh | 
| 100 th cal | 0 kWh | 
| 250 th cal | 0 kWh | 
| 500 th cal | 0.001 kWh | 
| 750 th cal | 0.001 kWh | 
| 1000 th cal | 0.001 kWh | 
| 10000 th cal | 0.012 kWh | 
| 100000 th cal | 0.116 kWh |