Electric power is the rate at which electric energy is transferred by an electric circuit. The unit of power is the Watt. Joule heating, is ohmic heating and resistive heating, it is the process by which the passage of an electric current through a conductor releases heat. It was initially studied by James Prescott Joule in 1841.There is potential power (no heating), instantaneous power and average power. When one volt is applied across a one ohm resistor, one ampere of current flows though the resistor. Since P=IE then the resistor is dissipating one Watt.