Calculating Energy Use & Cost - kWh Use
While electrical power measured in kilowatts is important to the people who design and size the electrical system, most consumers are more interested in the amount of electrical energy that is used in their house, or by a single appliance. The term used in measuring electrical energy is the "kilowatt-hour." This is a measure of the amount of electrical power used in one hour. Kilowatt-hours are what the electric meter on the side of your house measures. This is the basis for calculating your monthly electric bill.
Once you know the energy use of any appliance, you can figure the cost to run that appliance. There are three methods of finding the amount of electrical energy being used by a piece of equipment.
2. using the kilowatt-hour meter;
3. and installing a check meter.