What Does a Solar Pool Heater Cost to Run?

The heat itself is free

This page is about running cost, what it takes to keep a solar pool heater working month to month, not what it costs to put one in. For installation, see our post on how much it costs to install a solar pool heater.

With a gas heater you pay for fuel every time it fires. With an electric heat pump you pay for the electricity its compressor uses. With solar, the heat comes from sunlight landing on your roof, and nobody sends you a bill for that. That is the main reason solar is often the least costly way to heat a pool over time.

What you do pay for

Solar pool heating is not zero cost to run. The costs are just smaller and come from a few places:

Pump run time. Your pool pump moves water through the panels. It already runs to filter the pool, but some homeowners run it longer or at a higher speed during heating season. That extra run time is the main operating cost.
The controller and valve. These draw very little power compared with the pump.
Upkeep. Occasional cleaning, a yearly inspection and the odd repair as parts wear. We cover what wears out on our panel life expectancy page.

The costliest solar pool heater is the one turned off

If your pool panels were shut off after a leak and your installer is gone, you may be paying to heat the pool some other way. AllSolar Energy repairs and takes over solar pool heating from any brand and any installer, and has served more than 18,000 customers across 17 Florida counties since 1999.

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What makes running cost go up

When a solar system gets expensive to run, it is usually because something is not working the way it should:

An old single speed pump running long hours at full speed
A dirty filter that forces the pump to work harder for less flow
A controller that sends water to the roof when there is little sun to collect
A leak, which means topping off the pool with more water and chemicals
A system that has been shut off, so the homeowner falls back on a gas heater or heat pump to warm the pool

That last one is the most expensive of all, and it is common. Many Florida pool solar systems are shut off because of a small leak and a missing installer. Getting that system repaired is often the best thing you can do for your pool heating bill.

How to keep it low

Use a pool cover. The Florida Solar Energy Center found that a cover retains more than two thirds of the heat needed to keep a pool at a comfortable swimming temperature. Holding onto the heat you collect means less pump time chasing it.
Look at your pump. A variable speed pool pump can run at lower speeds for longer, which for many pools uses less electricity than an older single speed pump. If your pump is failing, see pool pump repair.
Keep the filter clean. Good flow makes the panels work better and the pump work less.
Check the controller settings. The system should only send water up when the roof can add heat.
Fix leaks early. A small panel leak costs water and chemicals every day it runs.

Comparing solar with gas and heat pump heaters

Gas heaters warm a pool quickly on demand, but you pay for fuel each time. Heat pumps are efficient, but they still run a compressor and fan on electricity, and they work harder as the air gets cooler. Solar heats more slowly and depends on the weather, but the energy is free. Many Florida homes use solar as the main heat and keep a gas heater or heat pump as a backup for cold, cloudy stretches, running the backup only when it is really needed.

We do not publish prices on this page, because your costs depend on your pool, your pump, your utility rate and how warm you like the water. If you would like help understanding what your system should cost to run, we are happy to look at it.

Common questions

How much does it cost to run a solar pool heater?

The heat from the sun is free. The running cost comes mostly from the electricity your pool pump uses to move water through the panels, plus occasional upkeep. The exact amount depends on your pump, how long it runs and your utility rate.

Is solar cheaper to run than a heat pump?

In most cases solar costs less to run, because a heat pump uses electricity for its compressor and fan while solar only needs the pool pump. Heat pumps can heat on demand, though, which is why many homes keep one as a backup.

Does a solar pool heater raise my electric bill?

Only through extra pump run time, if you run the pump longer or faster during heating season. A variable speed pump and a clean filter help keep that small.

Should I use a pool cover with solar heating?

Yes, a cover helps a great deal. The Florida Solar Energy Center found that using a cover retains more than two thirds of the heat needed to keep a pool comfortable.

Can I use solar with my gas heater or heat pump?

Yes. Many Florida homes use solar as the main heat and run a gas heater or heat pump only as a backup on cold, cloudy days.

Request help without repeating yourself

A service request from your Solar Home already carries your address, your equipment and your history, so you are not describing your system from memory on the phone. Free to create, and you never need a membership to request service.

Free to read first, no account needed: what you can safely check yourself before calling anyone, what a diagnostic visit involves, and what to have ready.

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