What’s the difference between kW and kWh?

Let’s start with the terminology. A kilowatt (abbreviated as kW) is the same as 1,000 watts (or W). A kilowatt-hour (abbreviated as kWh) is the same as 1,000 watt-hours (or Wh).

A watt is a measure of the amount of power flowing at one moment in time. If a solar array has a capacity rating of 4 kW, then it is capable of putting out a flow of 4 kW of energy under the right conditions.

If that solar array produces at a rate of 4 kW for one hour of time, then it has created 4 kWh of energy.

Think of watts (or kW) as a car’s speed—its capacity to move at a certain rate—and watt-hours (or kWhs) as the distance the car travels. You might be in a car that is going wicked fast, but if it only drives for 5 minutes before running out of gas, then it won’t take you far.

In general, what you want from your car is its ability to get you to your destination even it it does so in a slow-and-steady-wins-the-race sort of way. For solar, your “destination” is the creation of enough kWhs of energy to cover the needs of your electrical appliances, which is how you reduce your electric bill. If you can get those kWhs with the purchase of fewer kW of capacity, you are getting the best value out of your investment.

By tracking the sun, the Solaflect PV Tracker generates the maximum possible number of kWhs of energy from the watts of solar panel capacity.

Comments for this post are closed.