Originally Posted by tincanman
well we have kilowatt per hour, why can't we have watt per hour
basically, it is (amp per hour) x (volts)
No, we have kilowatts (kW) x hours (h) = kilowatt hours (kWh).
Wattage is a measure of power. Power is energy/time. Specifically, 1 Watt = 1 Joule / 1 second. That's why, on your power bill, you are charged for kilowatt-hours... that's the total energy they had to supply you with that month.
A good analogy is speed. Speed is distance per time. Saying Watts per second is like saying mph per hour (this has the dimension of acceleration, not speed or distance). If you want to find out how far you drove (analogous to energy consumed), you multiply your speed (miles/hour) by your time (hours) and you get distance (miles). If you divided, you would get miles/hour/hour and a completely incorrect value.Edited by purduepilot - 12/31/10 at 8:07pm