How many solar panels do I need?

Max BM
Last Updated: 9 months ago



How many solar panels are needed for my system?


The first thing to do is calculate how big of a battery bank you need.  Please read our article on sizing your battery bank here.

Now that we know what size battery bank you need, it’s time to figure out how many solar panels (watts) you need to charge the battery bank in a reasonable amount of time.

We suggest running this calculation under the assumption you want to be able to fully recharge the battery bank everyday, so that at night time the batteries are topped off.  Using the standard 5 good sun hours per day, you’ll want to divide the battery bank size by 5.

For example:  If you need a 2400wh battery bank, you will want to divide that by 5 hours to figure out how much solar you will need

  • 2,400 wh / 5 hours = 480Watts of solar panels

This means that you would need a minimum of a 480 watt solar array in order to charge this battery bank in one day with great conditions.

Since solar panels are one of the most affordable parts of a system and we never know what type of sun conditions we’ll get, we always recommend going with slightly larger solar array just to be safe. 

In the example above, we would probably suggest 600 watts just to be safe.  

Check out our solar panel options

Was this article helpful?