Verified answer

Your question is a good one that puzzled me until I did A-Levels and saw how the units were derived.

KW per hour would be because the number of KW would be divided by the number of hours they were used for. That really makes no sense.

To send you a bill, they want to know how many KW you used AND for how many hours, so it is the number of KW TIMES the number of hours you used that ammount of power for.

So you have KW.h, not KW/h

I will sometimes use an actual example to get something clear in my mind. Imagine running a 1KW fire for 2 hours and also for 4 hours.

If it was KWph for 2 hours:

1 / 2 = 0.5KWph (a half of a "unit")

For 4 hours =

1 / 4 = 0.25 KWph ( a quarter of a "unit")

So the longer you ran the fire, the smaller of a fraction of a unit you would actually pay. That makes no sense.

BUT KWh is the number of KW times the hours used,

So for 2 hours =

1 * 2 = 2 "units"

For 4 hours =

1 * 4 = 4 "units"

So that is why it KWh and not how many KW used in each seperate hour (KWph).

Hope that helps clear it up a bit!

kWh is a unit of energy. kW is a unit of power, which is 1000 Joules per second. When you take a kW and multiply it by an hour (3600 seconds), the units of seconds cancel out, changing the unit from power into a unit of energy. So 1 kWh = 3,600,000 Joules of energy.

If you divided kW by hours (kW per h) you would have power over time, which is not a unit I'm familiar with.

power=energy consumed/time taken

energy consumed = power * time

in SI units it is watt second (joule)

but this is a very small unit compared to average electricity consumption of houses

so commercially a bigger unit kilowatt hour( 1000watt*3600seconds)

is used