Includes local incentives


Calculate how many solar panels you need on your home



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How to work out how many solar panels you need?

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Step 1 - Your goals

To work out how many solar panels you need for your home firstly you have to tell us what percentage of your average monthly electricity bill you want your solar panels to eliminate. The above solar panels calculator defaults to assume that you want to eliminate your electricity bill completely although you can alter this assumption if you wish.


Step 2 - Your location

The reason we need to know your location is that solar panels produce different amounts of power depending on the location they are installed in. The electricity produced by solar panels is measured in kilowatt hours per day or per year. This figure is usually quoted as the number of kilowatt hours produced daily or annually per 1 kw of DC peak solar power capacity installed.

This figure varies from a low of 3 kWh per day per 1 kW of peak DC solar panels in some areas of the north east and around the great lakes up to highs of 4.7 kWh per day in parts of Southern California, Arizona, Utah, New Mexico and Nevada. To annualize these numbers we get a range between 1095 kWh per year per 1 kw of solar panels up to a high of 1715 kWh per year per kilowatt in areas with the greatest solar irradiation. This obviously makes a big difference to the amount of solar panels you need to produce a specific amount of electricity and this is why we need to know your location to do these calculations.


Step 3 Your Utility

It is important that we know which utility you are with because we have the residential electricity rates for each of the utility companies in our database and this means if you tell us your average monthly bill we can work out how many kilowatt hours of power you need your solar panels to produce.