kW vs. kWh: The Difference Explained.
kW is a measurement of electricity demand, while kWh is a measure of electricity usage or electric demand over time. To best understand the difference between kW and kWh, one must understand how energy consumption is measured. Below, we will define Kilowatts (kW) and Kilowatt-Hours (kWh) and the difference between the two.
Kilowatts
A kW is a measurement of electricity demand, or the amount of power being used at any given time. It can be thought of as current or instantaneous electrical power. For example, if you have a 15 kW hot water heater and it’s on full blast heating your water for one hour, it will use 15 kWh of electric energy (energy is measured in kiloWatt-hours). You would then see “15 kW X 60 Minutes = 900 kWh” on your utility bill that month under Electricity Usage/Demand Charges. In other words, kW reflects the rate of electricity usage during an instant in time – which corresponds to how much your electric meter spins forward while watching TV with everything turned on at once!
Kilowatt-Hours
A kWh is a measure of electricity usage or electric demand over time. To calculate kWh, you take the kW measurement and multiply it by the number of hours the appliance was used. For example, that 15 kW hot water heater running for one hour would use 15 kWh of electric energy (15 kW X 60 Minutes = 900 kWh). The total amount of energy consumed in kiloWatt-hours is what’s reported on your utility bill under Electricity Usage/Demand Charges each month. In other words, kWh indicates how much electricity has been used over a specific period of time – usually a month.
The difference between kW and kWh
Kilowatt-hour(s) – also known as “kilo” for short —is abbreviated kW/h or kWh. For example, A 500-watt microwave uses 500 watts per minute * 60 minutes in an hour–so it will use 500 watts x 60 minutes / 1000 = 0.50 kilowatt-hours in an hour.
As noted earlier, kW reflects the rate of electricity being used in kW, while kWh indicates the amount of electricity used. kW refers to instantaneous power and kWh refers to a period of time during which you use the appliance. kW is typically found on your electric bill under kilowatt-hour usage or demand charges, whereas kWh can be seen as kilowatts times hours (kW X Hours = kWh).
If you need help, your energy broker should be able to show you the difference between the two on your bill and show you how you can save money.
