When you run wires past a magnetic field you generate electrical current . The number and length's of wire wrapped around a shaft of a generator help determine the voltage moving voltage oscillating back and forth is called alternating current and the current flow or pulse is measured In hurts which is a function of how fast the field winding wires on a generator are turned and from what i understand our power companies generate 3 phase power and we only use one leg of that power for our homes electricity and the have to balance the other legs of those wires with other power needs and commercial power uses all 3 phases to there building's as opposed to our split leg 220 oar our single phase 120 voltage. wattage is volts times amps which is the measure of electricity.