Many people confuse kilowatt (kw.) and kilowatt-hour (kw.-hr.). Kilowatts (watts divided by 1000) represent the number of units of energy used at any one time. Kilowatt-hours mean the amount of energy used over any given period of time.

To illustrate: Assume a motor of a different size makes an immediate demand on the power plant of 1 kw. If the motor continues running for two hours, the amount of electrical energy consumed is:

1 X 2 = 2 kw.-hrs.

That is, the motor demands 1 kw. and the consumption is 2 kw.-hrs.