kW vs kWh: power, energy and your bill

Understand watts, kilowatts and kilowatt-hours with a simple appliance-cost example.

A speed and a total

A kilowatt (kW) measures power. A kilowatt-hour (kWh) measures energy. Holding 1 kW for one hour uses 1 kWh. A 2 kW appliance running for 30 minutes also uses 1 kWh.

Try the arithmetic

Suppose a heater draws 1.5 kW for two hours. That is 3 kWh. At an assumed $0.20 per kWh, its energy charge is $0.60. This example excludes other bill items and assumes constant power.

Read the map correctly

wattya shows hourly average power in GW. One GW is one million kW. A reported hourly energy quantity divided by one hour becomes average power; it is not an instantaneous meter reading.