- energy contained in 1 hour of [[Watt]] [[Power]] output - Kilowatt is 1000 [[Watt|Watts]] used for 60 min - so 3.6 million [[Joule|Joules]] - is a measure of [[Energy]], so a pure amount - not a rate like [[Watt]], which is a measure of [[Power]] - the "Hour" on right denotes an hour already multiplied to denominator