Newb Asks: How come there aint Volt Hours?

[Gregski]

so we've all heard of Amp Hours and Watt Hours, hewk, even Killer What Hours. kWh, but how come there are no volt hours? vh or kVh

please explain knowing I lack an electrical engineer degree

[johu]

Take for example a hydro power station. Volts equate to the difference in height of the upper and lower reservoir. But as long as the valves are closed this height difference doesn't do any work. It's just like a battery sitting there with nothing connected. After one hour of doing that it will be in the same state as the hour before. So Vh is meaningless.

Now you open the valve of your power station to some degree and the water starts to pour down onto the turbines. The higher it falls the higher its velocity when it hits the turbine. Amps is the mass of water that hits the turbine. Volts are the velocity it is hit with. Do this for one hour and some kg (or pounds or whatever weird unit you use across the pond) have flown past the turbine. kgh so to speak. Same with amps, let 100A flow for one hour and 100A * 1h = 100 Ah did flow through your consumer. Add to it the velocity [V] that it flowed with and you've got 400V * 100A * 1h = 40000 VAh = 40000 Wh = 40 kWh of work have been done in your consumer (motor, heater, etc.)