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How Many Solar Panels Do I Need to Heat a Swimming Pool?

Written by K. Miller / Fact checked by J. Fussell

how many solar panels do I need to heat a swimming pool

Heating a swimming pool with solar panels can extend your swimming sessions during cold seasons and reduce the expensive cost of heating pools. But, how many solar panels do I need to heat a swimming pool?

Solar experts recommend one sq. ft. of solar panels for every square foot of pool surface. This estimate will be enough to allow complete coverage. This computation can also help you manage the required adjustments with consideration of the several factors that affect the process of heating pools.

To determine the required solar panels for swimming pools, you might want to consult a certified solar contractor to assist you in decision-making.

Factors Affecting the Number of Solar Panels for Pool Heating

As we said above, some factors could affect the solar pool heating process and in turn, the number of solar panels.

The factors that could affect the solar pool heating process are:

  • Shady locations.
  • Cold weather.
  • Inappropriate solar panel orientation.
  • Low collector efficiency.

If any of the above applies to your situation, you’ll probably need to install more solar panels.

On the other hand, if your roof is ideally facing southwest or south or has the opposite of what we listed above, you might set up fewer solar panels.

Another thing to consider is the length of time you intend to swim, particularly during cold seasons. If you want to swim in warm water all year, get a bigger heating system.

Having a deeper understanding of your specific goals will significantly help you figure out the number of solar panels needed and pick the ideal system for your requirements. The delightful news is that solar pool heaters are available in several different types, each of which has its own pros and precise fit.

For beginners, solar experts strongly suggest discussing your concerns and plans with an authorized solar contractor so that you can come up with the right number of solar panels to heat swimming pool.

How to Measure Your Swimming Pool?


When measuring the size of a solar pool heating system, you need to determine your pool’s surface area and not its volume.

For geometrically-shaped pools, you can use the following formulas for measuring your pool size:

Rectangular Shape: Length multiplied by the Width

Circular Shape: πr² (radius= half the diameter of your swimming pool, π=3.14)

Steps to consider when measuring kidney or freeform-shaped pools:

Measuring this pool requires the use of Google Maps, so the first thing you’ll need to do is to go to Google Maps and type in your current address. Select Satellite mode and zoom into your location. Then, right click on the map and choose “Measure distance.” You should now create a border around your pool by clicking.

Once done with the indicated steps, you will see the total area of your pool at the bottom section of your screen. Use the indicated surface area to compute the size of the system that you will need.

Is It Okay to Install More Solar Panels to Ensure More Excellent Heating Performance?

No. Solar experts don’t recommend going for more than 100 percent coverage. Some pool owners mistakenly think that setting up 200 percent coverage can increase the pool temperature even further.

It’s essential to understand that there’s a point of diminishing returns. When the pool water reaches the solar panel’s temperature, the heating stops and the water is simply directed back into the pool. This happens because solar pool heaters depend on a significant temperature difference to transport heat to the pool water.

That said, for those who frequently swim in the morning and require maximum temperature, installing more than 100 percent coverage might be appropriate.

Meanwhile, uncovering the pros and cons of a swimming pool solar heating panel might help you decide whether it’s a suitable option for you or not. You might want to check out this video:

The Bottom Line

How many solar panels do I need to heat a swimming pool? As stated above, you’ll need one sq. ft. of solar panels for every one sq. ft. of pool surface to allow 100 percent coverage. That said, lower this percentage if necessary by considering the factors we mentioned above.

We hope you find this article informative. Thank you for reading!

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