Electrical Energy and Power #8211; The electrical energy produced in a conductor of resistance R, having current I in time t is = I<sup>2</sup>Rt = V<sup>2</sup>t/R. SI unit of electrical energy is joule (J). The electrical power is the electrical energy produced in unit time = I<sup>2</sup>R = V<sup>2</sup>/R = VI Thus, the electrical power is the product of voltage and current. Its SI unit is watt = J/s = watt (W) Other units of power 1kW = 10<sup>3</sup> W, 1 HP = 746 W