Equation for electrical power

google 'Ohms Law'

Ohm's Law has nothing whatsoever to do with power.

The fundamental equation for power in a d.c. system is: P = E I (where P = power, E = supply voltage, and I = load current). From this equation, two others can be derived: P = I2R and P = E2/R, where R = resistance.

For a.c. systems, the fundamental equation must be multiplied by the load's power factor (cosine of the phase angle).