How to Heat Your Pool with Solar Panels

Side Solar PV Pool Heater

Installing a solar-powered swimming pool heater is a great alternative to gas and electric heaters and heat pumps. Not only do solar-powered pool heaters keep your pool warm throughout the year, but they also help you save money on utilities. We’ll teach you all about how to heat your pool with solar panels so you can significantly reduce pool heating costs and enjoy a longer swimming season.

Solar panels are versatile and work with different pool sizes and types, so whether your pool is small, large, above, or in-ground, you have the option to heat your pool with solar energy.

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How Do Solar Panels Work?

Energy from the sunlight shining on a solar panel is absorbed by the many photovoltaic cells (or PV cells) in the panel. This energy creates electrical charges that cause electricity to flow. Solar panels allow particles of light to knock electrons free from atoms to generate this flow of electricity.

Why Heat a Swimming Pool with Solar Energy?

A lot of people choose to use solar panels because they are one of the most cost-effective uses of solar energy. Installing a solar pool heater can significantly reduce swimming pool heating costs and annual operating costs.

More environmentally conscious homeowners might choose solar pool heating systems because they are a good choice for the environment that cuts down on emissions and protects the planet.

Parts of a Solar Pool Heater 

Unlike solar heaters to heat homes, solar pool heaters do not require a storage tank since the pool provides all the necessary storage. Solar pool heating systems enhance the natural heating effect of the sun on the water with these components: 

  • Pump: The pool pump pushes water through the filter and then pumps it into the solar panel.
  • Filter: The filter strains any leaves and debris from the pool water.
  • Solar Thermal Collector: A solar collector is mounted on whatever location has good sun exposure. The water is heated as it flows through the panel and back into the pool. They are available in two types: glazed and unglazed. Glazed is built with metal and encased in glass, while unglazed is made of black plastic or rubber. Unglazed don’t heat as effectively as glazed, but are less expensive and last longer.
  • Check Valve: A check valve is a one-way flow valve to keep the pool water from flowing backward or bypassing loops.
  • Flow Control Valve: A flow control valve regulates the flow or pressure of the pool water. They respond to signals generated by flow meters or temperature gauges.
  • Heat Sensor: A heat sensor accurately measures the pool water’s temperature whenever the pool pump is running.

How Does Heating a Pool with Solar Panels Work?

A solar pool heater is to other pool heaters by being located at the back end of the pool’s pumping and filtration system. The difference though is that the solar collector is located where it can be directly exposed to the sun for as many hours as possible.

Heating a pool with solar energy works a little something like this:

  1. Water from the pool is pumped through the filter to remove any debris.
  1. The water is pumped through the valves to the solar thermal collectors.
  1. Water enters collectors through the bottom and rises to the top through individual tubes.
  1. As the water gradually rises, it’s heated by solar energy.
  1. The heat sensor detects the temperature of the water.
  1. The heated water returns to the pool and repeats the cycle until your pool reaches the temperature set by the thermostat.

Most solar pool heating systems can automatically detect the water temperature and transfer it to the solar collector. When the water reaches your preferred temperature, the flow control valve diverts the flow from the solar collector directly back to the pool.

In colder areas, the solar collector is usually oversized so that it can keep heating the pool, even during significantly low temperatures. If you want your pool to be even warmer, solar pool heaters can be used with gas or electric heaters.

What Type of Pool Can You Heat with Solar Panels?

Though you obviously can’t use them with an inflatable pool or a plastic kiddie pool, solar pool heaters can be used for both above-ground pools and in-ground pools.

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Benefits of Heating Your Pool with Solar

What are the pros of solar pool heaters, and why do homeowners install them? Here are just some of the reasons you may want a solar pool heater.

More Time Swimming 

If your swimming pool is too cold to swim, then you aren’t able to enjoy your investment year-round. A solar heating system can double the amount of time you get to use your pool since you won’t be limited to only swimming during the swimming season. 

A solar pool heater increases the pool temperature by 5 to 15 degrees higher than its current temperature, so you can expect the water to be comfortable for most of the year.

Energy Efficient 

Compared to conventional gas heaters and electric heat pumps, a solar panel heating system pays for itself in energy savings on the electric bill. Solar pool heaters greatly reduce your heating costs while also requiring minimal operating expenses. solar heaters require only $0 to $120 yearly to run, while natural gas heaters require an average of $1,400 to $4,800 per year.

Since your heater doesn’t require fossil fuels or electricity, you’re only paying for the product, which should pay for itself in 2 to 7 years.

Increases Property Value 

A solar pool heating system adds an 8% of extra value to your home. Demand is the main reason a pool heater increases the value of the home. Having a pool with an already installed solar pool heater is very attractive to most people. This means the home will sell at a premium.

Low-Maintenance

Solar heaters require very little servicing and maintenance, which means less cost and less hassle to raise your water temperature. Because solar heaters run cleanly and effectively, they typically last 15 to 20 years, unlike gas heaters, which only last around five years. 

Gas heaters need to be inspected twice a year for corrosion, water cracks, and burner tray build-up. Their components will need to be cleaned, adjusted, and lubricated, and will need to be tested for safety.

Solar pool heaters still benefit from a yearly inspection, and, like with any pool heater, you will need to check the filter cartridge monthly and replace the filter every 6 to 12 months.

Environmentally Safe 

Solar water heaters use clean energy to raise your pool temperature without polluting the environment. Since it doesn’t use fossil fuels, solar energy is one of the cleanest forms of energy and doesn’t produce carbon dioxide emissions that can hurt the planet.

According to a U.S. Solar Market Insight Report, solar electricity offset over 122 million metric tons of CO2 emissions in just the first two quarters of 2021.

Things to Consider When Choosing a Solar Pool Heater

Pool solar panels
Photo Credit: Brandon Shaw / Flickr / CC BY-SA 2.0

The Size of Your Solar Pool Heating System

Choosing the right size solar pool system is important for producing the best results. The surface area of your solar collector should equal 50%–100% of the surface area of your pool. You may need to increase the ratio in cooler or cloudy areas.

The Size of Your Pool Pump

An important factor in a solar pool heating system is choosing the correct size pool pump. You may need a larger pump than the current pump or a separate, smaller pump.

Your Roof Style

Another thing to consider is the roof. You’ll want your solar panels to be mounted in a way that provides the most solar energy. Solar pool heating systems can be mounted on most types of roofs, but there is always a slight chance that they won’t be compatible with yours. Roofing materials that are not ideal for solar include wood and slate roofs because they are so brittle.

Permit Requirements

Solar panel projects require certain permits before they can be installed. There are different regulations and requirements based on location. It’s important to select a certified roofer who is properly licensed and insured to ensure that the solar panels are properly installed.

Your Location

In order to work efficiently, your solar pool heating system needs plenty of exposure to sunlight to generate enough energy to heat your pool. However, if your home is in a spot that is completely shaded, solar heating may not be the best option for you.

Cost of a Solar Pool Heater

You can expect to spend between $2,835 to $7,335, or a national average of $5,085, for a solar pool heater. Many factors can impact the overall solar pool heater cost, including pool square footage, the size of the collector panels, the amount of panels, the type of panels, the pump size, and the brand.

FAQ About Solar Pool Heaters

Should I turn my solar pool heater off at night?

Yes, leaving your pool heater turned on overnight will cost a fortune in energy fees which will also increase on colder nights.

How long do solar pool heaters last?

Solar pool heating systems can last 20-25 years or longer.

Does a solar pool heater qualify for tax credit?

Yes, under the Consolidated Appropriations Act of 2021, solar pool heaters can qualify for a tax credit. The program started in 2022 and expires in 2035. Solar installed between‌ 2022 to 2032 are eligible for a 30% credit. Systems installed in 2033 are only eligible for a 26% credit, and those installed in 2034 will receive a 22% credit.  There is no maximum amount a homeowner can claim. 

Are You Ready to Dive into a Solar Pool Heater?

Clean energy is the way of the future, so don’t get stuck in the past heating water with your old pool heater.

If you are in the market for a solar pool heating system and want to reduce your carbon footprint, let PoolGnome connect you to a solar professional near you to learn about the solar process and materials for your next big project.

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Main Image Credit: Noya Fields / Flickr / CC BY-SA 2.0

Lydian Pine

Lydian Pine is a creative writer and studio artist whose work first debuted in a short story anthology. She graduated from the University of North Texas in 2020 and enjoys video games, theatre, and swimming. Lately, she has started to study entomology as a hobby.