Watts are joules per second. So power consumption would still be in Watts. A kWh, or in other words a 1000 Watts for an hour, is 1000 * 60 * 60 = 3600000 joules

Watts are joules per second. So power consumption would still be in Watts. A kWh, or in other words a 1000 Watts for an hour, is 1000 * 60 * 60 = 3600000 joules. So in practice people would use Mj (Megajoules) and save a syllable.