KILOWATT-hour (kWh) and joules (J) are units of energy.1 Kilowatt Hour = 3.6 x 106 Joules.1 Joule is equal to 1 watt per 1 secondHence 1 kWh is equal to 1 x 1000 x 60 x 60 ⇒ 3600000 JIT can ALSO be written as 3.6 x 106 Joules.Hence 1kWH is equal to 3.6 x 106 Joules.