P is Power, also known as Volts, also known as Electromotive Force (EMF).
I is Resistance, measured in Ohms
E is Amps, also known as Current
W is Watts, the multiplication of Power and Amperes.
kW is kilo-Watts, also known as 1000 Watts
kWh is kilo-Watt Hours, which is how many Watts are used in 60 minutes.
P = W / E
I = P / E
E = W / P
W = P * E
Alternatively:
Volts = Watts / Amps
Ohms = Power / Amps
Amps = Watts / Volts
Watts = Power * Amps
