You’re hearing the terms KW and KWH regularly tossed around. So what do they mean, and how do they relate to your energy bill? Try thinking about it like this:
KW —> Energy Demand
KWH —> Energy Consumption
How Does This Difference Affect Your Utility Bill?
Utilities employ what are called ‘Demand Charges’. Picture this: You and Bob both use 1,000 KWH in February. You used an average of 34 KWH per day, but Bob used 200 KWH in just one day! Bob’s bill at the end of the month will be significantly higher than yours because of the greater demand placed on the grid during that certain day.
How Does KW and KWH Affect My Solar System?
When designing a solar system, its size (KW) is determined by both your annual consumption (KWH), and by the amount of energy your solar panels can produce.
Think of KW (Watts) as the speed you’re running and KWH (Watt-hours) as how far you’ve actually run. A kilowatt-hour is the amount of energy equivalent to a power of 1 kilowatt running for 1 hour. If you leave a 100 Watt light bulb on for 1 hour, you’ve done gone and used up 100 watt-hours.
But your electric company will bill you by the kilowatt-hour, so you’ll get a bill for .1 kWh, multiplied by your per-kWh rate. That means if you run a 100 watt bulb for an hour a day for 30 days in a month, and you pay $.10/kWh, your bill will be for .1 kWh x 30 days x $.10, or $.30.