If you are planning to buy solar panels, of course you want to know how many solar panels you will need. Wondering how to calculate the number of solar panels for your roof? You can read it in this blog.

Calculating the number of solar panels

To calculate the number of solar panels for your roof, you need to consider several factors. How many solar panels you need depends on your power consumption, the location of your roof and the yield of the solar panels you have in mind.

Solar panels provide the highest yield when the output is as well matched as possible to your energy consumption. In addition, it is useful to take into account your future consumption: perhaps you will drive electrically or you plan to purchase a heat pump.

To calculate the number of solar panels, you need the following:

  • The yield of the solar panels (the capacity in watt peak)
  • Your current (or future) energy consumption
  • The size and orientation of your roof

Calculating how many solar panels you need yourself

An installer can accurately calculate the yield of solar panels for you and tell you how the orientation of your roof affects the calculation of the number of solar panels. Would you like to calculate the number of solar panels yourself in advance? Then use the following formula:
Annual energy consumption x 1.1* / the capacity of 1 panel in watt peak
To get you started, here is an example calculation:

  • Your annual energy consumption is 3000 kWh

Because of the varying yield and degradation of the panels, you may then choose to install 10 solar panels. Want to know the exact yield of solar panels in kilowatt-hours? Then see how to calculate solar panel yield here.
Note: this example assumes an ideal location without shade.

* This is a safe factor to calculate with for good quality solar panels such as the Solarwatt glass-glass solar panels.

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Calculate price for solar panels

Now that you know the number of solar panels, you may also want to calculate the price for solar panels. The price for solar panels depends on a number of factors:

  • The provider
  • The type of solar panel
  • The quality of all the components
  • The number of solar panels
  • The type of roof
  • The cable route
  • The method of installation: working safely according to applicable laws and regulations

So the price for solar panels is not so easy to calculate and varies from one situation to another.
Prices for solar panels vary enormously. It is important to compare solar panels not only on price, but especially to look at quality, guarantees and long-term return. Our tips for comparing solar panels can be found in this comprehensive checklist.
Want to calculate the price of Solarwatt solar panels? A certified Solarwatt installer can provide you with an itemized quote.