Solar Pool Heaters Explained – Is Solar Pool Heating Worth It?

Heating a pool is expensive. Some homeowners use solar pool heaters to reduce costs.

Solar pool heaters can eliminate pool heating costs. Using the power of the sun, a solar pool heater transfers heat into your pool to keep it warm year-round. Priced at around $3,500, an average solar pool heater pays for itself within two to eight years, depending on usage.

How do solar pool heaters work? Is solar pool heating worth it? Keep reading to discover everything you need to know about solar pool heaters and how they work.

What is a Solar Pool Heater?

A solar pool heater is a system that warms up your swimming pool using energy gathered from the sun. Depending on your climate and other factors, a good solar pool heater could keep your pool warm all year long.

Many homeowners use solar pool heaters to significantly reduce the costs of heating a swimming pool. They cost around the same as a gas or heat pump pool heater, yet they have much lower annual operating costs. In fact, solar pool heaters are some of the most efficient solar energy devices in many warm climates, gathering energy from the sun more efficiently than other solar devices. 

How Does a Solar Pool Heater Work?

A typical solar pool heating system consists of a solar collector, a filter, a pump, and a flow control valve. These devices collect energy from the sun, then circulate water through the system to heat it up.

Here’s how each component works:

• Solar Collector: The solar collector is the device that pool water flows through, gathering heat from the sun.
• Filter: The filter removes debris from the pool water before pumping it through the solar collector.
• Pump: The pump circulates water through the system, forcing it through the filter and solar collector before pushing it back to the pool.
• Flow Control Valve: The flow control valve is an automatic or manual device that diverts pool water through the solar collector.

To start, the pump pushes water through the filter and into the solar collector. The water remains in the solar collector, where the sunlight heats the water. Once the water has reached a sufficient temperature, the pump pushes the heated water back into the pool, warming it up.

In hot climates, solar pool heaters can also keep your pool cool. The collector can automatically circulate water through the collector at night, using the same mechanism to circulate cool water into the pool.

Automatic Versus Manual Valves

Solar pool heaters have automatic or manual valves. 

With an automatic system, you have sensors and an automatic valve that diverts water through the collectors when the temperature of the collector reaches a certain point. If the water in the solar collector has not yet reached that point, then the filter simply bypasses the collector before returning the water to the pool.

How Much Does a Solar Pool Heater Cost?

A Solar pool heater costs between $3,000 and $4,000, according to Energy.gov, including all purchasing and installation costs.

Depending on your pool and climate, the solar pool heater could pay for itself in 1.5 to 7 years. 

Solar pool heaters also have less maintenance than gas and heat pump pool heaters. You spend roughly the same amount of money up front to install the heater. However, annual maintenance costs and operating expenses are much smaller.

Should I Buy a Solar Pool Heater?

You may be surprised by how effective a solar pool heater can be. Even if you don’t live in a climate that’s hot and sunny year-round, you could benefit from a solar pool heater.

According to Energy.gov, any building site with unshaded areas that face south is a good candidate for a solar pool heating system.

You could benefit from a solar pool heater in warmer climates. However, even if you live in cold climates, you could benefit from a solar pool heater. Solar pool heaters use both direct and diffuse solar radiation. That means your home could have more than enough solar energy to heat up a pool – even if it doesn’t seem like it. 

How to Choose the Right Size of Solar Pool Heater

 You need to consider multiple things to determine the right size of pool heater for your unique needs.

Things to consider include:

• Pool size
• Length of swimming season
• Climate
• Desired pool temperature
• Solar energy hitting your pool area (Are there trees?)
• Collector orientation and tilt
• Collector efficiency
• Whether or not you use a pool cover

As a general rule, your solar collector should be 50% to 100% of the surface area of the pool. 

If you want to keep your pool warmer, or if you swim in your pool all 12 months of the year, then you’ll need a larger solar collector to accommodate all months (because of lower solar energy production and cooler temperatures in the winter months). 

Alternatively, if you want a cooler pool, or if you only swim in your pool a few months of the year, then your solar collector could be 50% to 60% of the size of the pool. 

If you use a pool cover in any climate, then you can reduce the size of your solar collector. 

Collector orientation and tilt also matter. The collector should be oriented to maximize the amount of daily and seasonal solar energy that reaches the collector. For homes in the northern hemisphere, that means the solar collector should face true south. 

The tilt, meanwhile, also affects energy production. The angle at which your collector should be tilted depends on your latitude and the length of your swimming season. The sun is higher in the sky during the summer months and lower in the winter months. 

How Solar Pool Heater Installation Works

Installing a solar pool heater is straightforward. A contractor in your area should be able to install a solar pool heater. Alternatively, some homeowners do it themselves.

The basic process for installing a solar pool heater includes:

Step 1) Install the Solar Collector: Install your solar collectors and set them in the right direction. You want them to absorb as much solar energy as possible. Choose the right direction, angle, size, mounting, and tilt. Then, plug the collectors together to connect them.

Step 2) Install the Flow Control Valve: Install the flow control valve to ensure the right water flows through your collectors to heat your pool. 

Step 3) Install Plumbing from the Pump to the Collector and the Valve: Next, you need to install the plumbing to connect your pump, collector, and valve. Set the desired roots for your pipes, then set them in place.

Obviously, installing a solar pool heater can quickly get complicated. However, these are the basic steps you or a contractor will follow to install a solar pool heater on your property.

Solar Pool Heaters Versus Gas Swimming Pool Heaters

Many homeowners use gas swimming pool heaters to keep their pool comfortable year-round. Gas swimming pool heaters burn natural gas or propane to heat the water. 

Compared to a solar pool heater, gas pool heaters have a cheaper upfront cost, including lower installation and equipment expenses. However, they cost anywhere from $1,500 to $4,000 per year in gas and propane expenses, depending on your location and heating habits. 

Solar Pool Heaters Versus Heat Pumps

Many homeowners use heat pumps to heat their pools. A heat pump, like a gas pump, tends to be cheaper upfront than a solar pool heater for equipment and installation. However, it can quickly become more expensive.

Heat pumps use electricity to heat water. Depending on electricity costs in your area, heat pumps could cost you anywhere from $1,000 to $3,000 in extra electricity. If you live in a cooler climate or swim in your pool year-round, then your heat pump will cost you near the upper end of this range.

Pros and Cons of Solar Pool Heaters

Other advantages and disadvantages to consider with solar pool heaters include:

Pros

Lower Annual Operating Costs: Instead of using gas or electricity to heat your pool, you’re using energy from the sun. That energy already hits your home daily. A solar pool heater lets you capture the energy and use it. Instead of spending $1,000 to $3,000 per month on gas or electricity, you can spend $0 on sunlight.

Cheap Maintenance: Solar pool heaters tend to require less maintenance than heat pumps and gas pool heaters. A good solar pool heater lasts 15 to 20 years. If you clean the filtering system and the collectors and check the pool’s chemical balance regularly, then your solar pool heater should last a long time.  

Easy to Install: You could install a pool heater on your own. Many homeowners tackle it as a DIY project. With gas and heat pump systems, you may need to hire a plumber or pool specialist. 

Eco-Friendly: If you want to reduce your environmental impact while still enjoying your pool, then solar pool heaters are a good option. Instead of burning electricity or fossil fuels, you’re using energy from the sun.

Cons

Space Requirements: Solar pool heaters take up more physical space than other pool heating methods. Your solar collectors need to be 50% to 100% of the size of your pool, depending on your climate and heating requirements. 

More Visible: Gas and heat pump systems can be discreet. Solar pool heaters, however, are more visible. If you are cramped for space in your backyard, then solar pool heaters may need to sit in a visible place.

Unpredictable Output: With heat pumps and gas systems, you know your pool will stay at whatever temperature you like. With solar pool heaters, energy production can vary throughout the year. If it’s a cloudy or stormy day, then your solar pool heater may struggle to keep up.

Final Word on Solar Pool Heaters

Solar pool heaters are more popular and affordable than ever. By installing a solar pool heater today, you could make your pool more energy-efficient – and avoid thousands of dollars per year in pool heating expenses.