Couple of basic things here, without trying to overcomplicate it.
- KVA is not the same as KW
- KWH (or KVAH) is simply the consumption (in kilowatts or kilovolt-amps)
MULTIPLIED by the time (in hours)
So if you have a load taking 500 watts, and you run it for one hour, that is 500 watt-hours (or 0.5 kilowatt-hours, 0.5 KWH)
If you have a load that takes 500 watts for half the time, and 1500 watts for the other half of the time, it will take (on average) 1000 watts over the hour, so 1 KWH per hour run.
If you have a load that takes 10KW, it will use 10 KWH in an hour, or 1KWH in 6 minutes
VA (volt-amps) or KVA (kilo-volt-amps) is simply the voltage times the current (in amps). For DC circuits, VA = Watts.
For AC circuits, because of power-factors, and the fact that loads often have a reactive component (inductive or capacitive), you can draw a lot of amps even though the actual power is less. Thats why alternators are usually rated in KVA, because they don't want you burning out the windings!
If you are running a purely resistive load (heaters etc) then KVA is near enough to KW for your purposes.
Hope this helps rather than confuses!
