* 1 kilowatt-hour (kWh) is the energy used by a 1 kilowatt (kW) device operating for one hour.

* 1 kilowatt (kW) is equal to 1000 watts (W).

* 1 watt (W) is equal to 1 joule per second (J/s).

Calculation:

1. Convert kWh to watt-hours: 1 kWh = 1000 watt-hours (Wh)

2. Convert watt-hours to watt-seconds (joules): 1 Wh = 3600 Ws (since there are 3600 seconds in an hour)

3. Therefore, 1 kWh = 1000 Wh * 3600 Ws/Wh = 3,600,000 joules (J)

So, 1 kWh is equal to 3,600,000 joules.