How Do Solar Pool Heaters Work?
Solar pool heaters are an efficient and cost-effective way to keep swimming pools heated without relying on electric or gas heating. These systems use the natural energy absorbed from the sun's rays to warm a pool's water. Solar pool heaters use a circulation pump to move pool water through one or more solar collectors, consisting of devices filled with tubes that absorb and trap heat from the sun. This heated water is then returned to the pool, raising its temperature by up to 10 degrees Fahrenheit during normal use. Solar pool heaters are an excellent eco-friendly alternative for those looking to enjoy their outdoor aquatic activities without sacrificing sustainability.
Some heaters are designed to work better in temperate climates that do not require a lot of extra heating. Others are designed with more powerful solar collection systems to heat water in cooler climates. There are different types of pumps and collector systems, as well as several sizes of collectors, which will determine how much heat your solar pool heater will generate.
Swimming Pool Solar Heating System Cost by Collector Size
Pool heater costs range from $1,500 to $8,000, depending on the size and horsepower. Solar panels vary in size, but many are 4’ x 10’ or 4’ x 20’. The number of panels needed in a system depends on many factors, including the size of the pool, your climate, whether it is an in-ground pool or above-ground pool, and whether you use a pool cover. The solar pool heater’s collection area should always be positioned where it receives maximum sunlight. Typical locations are a roof or a nearby platform. In areas of the Northern Hemisphere, you will position the collector facing south to receive the most sunlight exposure.
Depending on where you live, the collector might require tilting by as much as 45 degrees east or west. Usually, the degree is determined by your region’s latitude minus 10 to 15 degrees. When you have the heater professionally installed, the installer will make the necessary adjustments based on your location. They will determine the area that receives the most sunlight. Here is a general example of the number of 4’ x 10’ glazed panels needed for an in-ground pool in a warm climate and their cost.
| Number of 4’ x 10’ Solar Panels | Cost (Materials Only) |
|---|
| 4 Panels (288 sq.ft.) | $1,500 - $4,500 |
| 6 Panels (512 sq.ft.) | $2,000 - $6,000 |
| 8 Panels (648 sq.ft.) | $2,400 - $7,200 |
| 10 Panels (800 sq.ft.) | $3,000 - $8,000 |
Solar Powered Pool Heater Costs by Type
The cost of a solar pool heater ranges from $1,000 to $10,000, depending on the type. All solar pool heaters function in a similar fashion but are made from varying materials and come in a spectrum of sizes. There are several types of solar pool heaters available. Some types work better in certain pools than others, depending on the type of pool and material. Batch collectors, evacuated tubes, and flat plate collection systems are the three main types. There are four options for flat plate heaters: propylene mats, glazed and unglazed solar panels, and high-temperature collectors. The table and subsections below show the costs and features of each.
| Type | Heater Cost (Installed) |
|---|
| Evacuated Tube Collector | $1,000 - $5,000 |
| Flat Plate Collector | $1,500 - $10,000 |
Evacuated Tube Solar Heater
You will spend between $1,000 and $5,000 for evacuated tubes as a collection system for your solar heater. Evacuated tube solar pool collectors are less common than flat plate collectors but are more efficient. They consist of a series of tubes placed parallel to each other, each of which is surrounded by a vacuum. The water is circulated through a series of evacuated tubes, which are heated by the sun's radiation. This heat is then transferred to the pool, where it can raise the temperature of the water. Evacuated tube solar pool heaters are an efficient way to heat pool water. They can be used in a variety of climates. In addition, they are typically very durable and require little maintenance.
Flat Plate Pool Collector
Expect to spend between $1,500 and $10,000 to install a flat plate pool water heater. Flat plate solar pool collectors are the most common pool water heater type in the U.S. The device consists of a flat panel that is made of material that is good at absorbing solar radiation, such as copper or black rubber. The sun's rays hit the plate and are absorbed by a layer of insulation. This heats the water in the pipes, which is then circulated back into the pool.
There are two types of flat plate pool collectors: unglazed and glazed. Glazed solar panels consist of copper tubing outfitted on an aluminum plate and covered with iron-tempered glass. The design is more efficient at capturing solar heat in areas with cold weather with less long, sunny days than unglazed systems. They are made of plastic or heavy-duty rubber mixed with UV light inhibitors but do not have the glazing or glass outer covering of glazed panels. Unglazed solar panels perform the same as glazed panels during warm months, but the glass covering allows them to perform better during cold months. Here is how much you can expect to spend on each type of flat plate solar pool collector.
| Flat Plate Collector Type | Cost (Installed) |
|---|
| Unglazed Solar Panels | $1,500 - $4,500 |
| Glazed Solar Panels | $3,000 - $10,000 |
Solar Pool Pump System Cost by Size
Solar pool heater pumps range from $50 to $1,300, depending on size or style. Solar pool heaters require a pump to circulate the warm water with the cooler water effectively. This pump can be powered by solar panels or by electricity. The dimensions of the pool will be used to determine the size of the pump needed, the number of gallons per minute needed to travel through the system, and the average feet of head in the system. To figure this out, determine the number of gallons of water in your pool. After you figure this out, you need to determine how many gallons per minute need to be pumped through your solar pool heating system. Horsepower (HP) denotes the pump's ability to pump 5,500 foot-pounds per second (745.7 watts). The more power the pump has, the greater the horsepower. A larger pump with more horsepower is often needed for a bigger pool to move the water effectively.
Choosing a pump with a variable flow rate could be a good idea so that you can dial in the flow rate depending on the number of panels in your system. After figuring gallons per minute, you next need to determine the average feet of head for the pump. This figure has to do with the amount of resistance working against your pump as it is pulling the water. These calculations take into account pipe lengths and any friction in the system. The table below shows a breakdown of different pump sizes, their costs, and the gallons per minute (GPM) for each.
| Size | Gallons per Minute | Pump Cost (Unit Only) |
|---|
| 0.5 HP | 40 | $50 - $400 |
| 1 HP | 60 | $150 - $600 |
| 1.5 HP | 68 | $200 - $700 |
| 2 HP | 76 | $500 - $750 |
| 2.5 HP | 80 | $600 - $800 |
| 3 HP | 85 | $700 - $1,300 |
Pool Solar Heating Prices by Brand
The options for pool solar heating prices by brand range from $300 to $10,500. Several brands make different types of solar pool heaters. Each has its own costs to consider. For example, what you pay for a SmartPool heater will be different from UMA Solar’s Heliocol solar pool heating cost if you choose that brand. Fafco and SunHeater make the most affordable kits. They are often sold as DIY products but might be better installed by the pros. Premium systems like those from SwimLux and Northern Lights include automatic controllers and other premium features. The table below shows a list of the most common brands and their prices for the heater unit only.
| Brand | Heater Cost (Unit Only) |
|---|
| SunHeater | $300 - $800 |
| Fafco | $350 - $1,500 |
| SmartPool | $350 - $1,800 |
| Enersol | $500 - $3,000 |
| SwimEasy | $800 - $4,000 |
| SwimLux | $900 - $6,000 |
| Heliocol | $2,000 - $7,000 |
| Northern Lights | $3,000 - $10,500 |
Labor Cost to Install a Solar Pool Heater
If you purchase a pool heater, you can expect to pay around $500 for labor. Solar pool heater installation for a large unit or one installed far from the pool can go up to $2,000. If you hire an electrician, you will spend between $40 and $120 per hour, depending on how detailed the installation process is. Pool installers can also do a lot of the work at a rate of $35 to $65 per hour. However, you will want an electrician for any electrical work that needs to be done. Working with a professional when installing a solar pool heating system yields the best results.
The entire process can take from a few hours to two days, depending on the size of the pool, system size and type, and distance between the pool and panels. To start, a professional helps choose and design the best system for your particular situation. They advise you about locations for the best sun exposure for the panels and calculate the size of the system. A consultation about your needs and habits helps the installer better position and size the heater to your pool to get the best results. Finally, the panels or collector system are installed and placed on a roof or nearby platform. These are thoroughly secured and strapped down to make sure that they remain stable.
All tubing is then connected to the system and run to your pool, where the pump is installed just outside the pool. Two sets of plumbing are installed from the collector--one uses the pump and a filter to pull the water up to the collector, and the other sends the water straight back from the collector to the pool. Your installer hides or minimizes the appearance of these pipes or tubes. In some cases, they can be discreetly run beneath surfaces or attached to the side of the home.
Solar Pool Heater BTU by Pool Size
A mathematical formula is used to determine the number of BTUs needed to heat your pool. It takes 10 BTUs every hour for each square foot of pool surface area for each degree you wish to raise the temperature of your pool. For example, if your pool is 20’ x 40’ and you wish to raise the temperature by five degrees, multiply 800 square feet times five. This equals 4,000. Now multiply this number by the 10 BTUs needed each hour, and you need 40,000 BTUs per hour.
Solar panels come with a BTU output rating. The sun generates close to 300 BTUs per square foot per hour. In optimal conditions, a solar panel only produces 50% to 75% efficiency. If you needed to collect 18,000 BTUs per hour and the solar panel is working at 50% efficiency, you would need at least 120 square feet of solar panel surface area. These numbers change based on each unique situation. The table below shows the square feet of solar panels needed if the panels function at 50 percent capacity.
| Pool Size | BTUs per Hour | Square Feet of Solar Panels |
|---|
| 108 sq.ft. | 9,000 | 60 |
| 216 sq.ft. | 18,000 | 120 |
| 432 sq.ft. | 36,000 | 240 |
| 648 sq.ft. | 54,000 | 360 |
| 756 sq.ft. | 63,000 | 420 |
Size
The solar pool heater collector size depends on the size of your pool, the climate you are in, whether your pool is above-ground or in-ground, and whether you use a pool cover. A professional can help you determine the exact number of panels for your situation. Those living in a cooler northern climate need more panels to heat the same-sized pool than those living in warmer southern climates.
A solar pool heater works better when it is the correct size for your pool. It will not work well to raise the temperature if it is too small, and too large of a system would be a waste of money. For cooler climates, it is usually a good idea to have the surface area of the collectors be equal to the surface area of your pool. In a warmer climate, the collector area should be about half the size of the surface area of your pool. Pool covers will trap heat and reduce the number of needed panels.
Maintenance
Most solar pool heaters do not require much maintenance to keep them running properly. Glazed panels may need to be cleaned periodically in dry climates to remove any built-up debris. Otherwise, the main focus is on keeping the filter clean and the pump regularly inspected. Each system has its own maintenance needs, so consult the owner’s manual for your system to find out how often the pump and components should be inspected or serviced.
Pros and Cons
Solar water heaters have many benefits for the user. They use no electricity, gas, or propane to run, so they pay for themselves over a few years. They last up to 20 years and require little regular maintenance. They heat a pool up to 7º and can also cool down a too-hot pool at night by circulating the water through the cooled tubes. These heaters are expensive to purchase and must be installed in the correct location to ensure they get the proper amount of sunlight. They also need to be appropriately sized, about equal to the surface area of the pool, to ensure that they perform sufficiently. Solar panels take a long while to heat a pool initially. It could take a day or two in a warm climate and up to an entire week in a colder one. The time it takes depends on the amount of cloud cover and temperatures. Once the pool reaches a comfortable temperature, it is important to use a cover at night and when not in use to maintain the temperature.
Efficiency
While solar energy is green and does not rely on electricity or gas, it still varies in how efficiently it heats your pool. When assessing your heater’s efficiency, you must consider its position, how much sunlight your area gets, the pool size, and how warm you want your pool to be. For example, some systems like propylene mats are not very efficient in northern climates. For this reason, have a professional assess your needs before purchasing a system to select a pool heater that can efficiently heat your pool to the desired temperature.
Above-Ground vs In-Ground Pool Solar Heater
The biggest difference between above-ground and in-ground pools is that in-ground pools have added insulation thanks to the dirt that surrounds them. The soil holds in the heat and does not let it escape as quickly. Above-ground pools lose heat faster since they do not have the insulation of the soil and need more panels for the same surface area compared to an in-ground pool. So, if you have an above-ground pool and an in-ground pool of the same size in the same climate, an above-ground pool will need a larger heating system and will cost more than the average solar heater for an in-ground pool. If you do have an above-ground pool, consider adding insulation to cut costs on the size of the solar heating system. Wrap the outside of the pool in foam insulation. Also, be sure to use a pool cover at night and when not in use. Costs will be more to install a system to heat an above-ground pool since you will need to add extra panels. Keep in mind that needing more panels not only increases the costs but also increases the space needed on your property for the panels.
Solar Pool Heater vs Heat Pump Price
Solar heaters cost $2,500 to $7,000 to install. Heat pumps 1 cost $2,500 to $6,500 and may be a more economical option for very large pools. Heat pumps are another popular way to heat a pool using the sun’s energy. As the sun warms the air, the pump draws in heat from the air and warms the pool. Both systems use some electricity to run their pumps and circulate the water. The cost of electricity is negligible compared to the cost of heating a pool using gas or propane.
In most cases, heat pumps extend the time you use the pool by about 2 to 3 months a year. The main difference is that the solar heater runs almost constantly during the day to heat the water, while heat pumps are only used as needed. Therefore, they may take longer to warm a pool, but they can raise the temperature slightly more than a solar heater. The table below shows a breakdown of the average costs of each heating option.
| Type | Heater Cost (Installed) |
|---|
| Heat Pump | $2,500 - $6,500 |
| Solar | $2,500 - $7,000 |
Solar vs Electric Pool Heater Price
Expect an electric pool heater to cost between $1,000 and $6,000, including installation. Solar pool heating systems range from $2,500 to $7,000. An electric pool heater is only practical for a small pool or for use in an area where the temperature is consistently over 55 degrees. An electric pool heater needs its own electrical circuit to provide enough energy. In an electric pool heating system, water is pumped through the system, heated by an element, and returned to the pool. In a solar heating unit, the water is pumped through solar panels that use the sun’s rays to heat the water. Electric units are relatively inexpensive compared to a solar heating system, but the cost to run them adds up quickly. In the table below, you’ll see a cost comparison of each type.
| Type | Heater Cost (Installed) |
|---|
| Electric | $1,000 - $6,000 |
| Solar | $2,500 - $7,000 |
Solar vs Gas Pool Heater Price
You will spend $1,500 to $5,500 on a gas pool heater, compared to the average of $2,500 to $6,000 for a solar pool heater. Solar pool heaters use the sun's rays to warm the water, making them an eco-friendly and cost-efficient choice. They also require less maintenance than gas heaters. However, solar systems need to be situated in direct sunlight for the best results. On the other hand, gas pool heaters are cheaper to install, much quicker at raising the water temperature, and useful year round. However, they are more expensive to operate due to higher energy costs. The table below shows a breakdown of the costs of each type installed.
| Type | Heater Cost (Installed) |
|---|
| Gas | $1,500 - $5,500 |
| Solar | $2,500 - $7,000 |
Enhancement and Improvement Costs
Cover
A solar pool cover 2 has an average cost of $30 to $400 for an inexpensive cover. However, costs can go as high as $1,500 to $3,000 for a mesh cover and $650 to $1,200 for a solid pool cover, depending on size, brand, and quality. A retractable pool cover for an in-ground pool can cost $2,000 to $20,000 for the cover and installation. A pool cover serves a multitude of purposes. Some are designed to help winterize the pool, while others aid in keeping the water warm, and some keep dirt and debris out of the water. Solar pool covers are typically designed to help keep in heat while keeping debris out.
Solar Sun Ring Cost
A solar sun ring costs between $45 and $70 each. This ring provides additional heat to your pool. If you live in a very hot climate, it may be all that you need. A solar sun ring is made of two layers of UV-resistant vinyl and floats on the surface of the swimming pool. The clear upper layer directs the sun's rays to the second blue layer. This layer absorbs the sunlight and converts it to heat. You can place multiple solar rings on the surface of your pool.
Additional Considerations and Costs
- Climate. If you live in a climate where you swim year-round, a solar water heater helps make the water comfortable on cooler days. However, it will not warm the water sufficiently for use in a cold climate.
- Location. As long as your building site has unshaded areas and faces south, you can use a solar pool heating system even if you do not live in a warm, sunny climate. Because the system uses direct and diffuse solar radiation, any sunlight will be sufficient.
- Installation company. Choose an installation company that has experience with the type of heater you are considering.
- Permits. In most areas, you need a permit to install a solar energy system on your property. Check local building codes and regulations before you begin.
- Estimates. Get at least three estimates for installations. Multiple estimates give you an idea of the cost range. You can then pick which installer you feel is the most qualified to complete the job based on how they answered your questions and their estimate. Ideally, you do not want to take the lowest or highest estimate.
- Repair. Common problems with a solar pool heater include panel leaks, plumbing repairs, panel replacements, valves, controllers, and sensor repairs that control automation. The repair cost varies based on the brand, the required part, the size, and the problem. Also, the extent of wear and damage impacts the cost because the part might be repairable or require complete replacement.
FAQs
- How many solar panels does it take to heat a pool?
Usually, it takes from six to ten panels to heat a pool, with the average being from seven to eight panels.
- How long does a solar pool heater last?
Solar pool heaters last from 10 to 15 years.
- Is solar pool heating worth it?
If you use your pool regularly and only need it warmed around 5º, then yes, it can save you a lot of money over a gas or propane 3 heater.
- How warm does a solar-heated pool get?
Depending on the heater type and pool size, the pool typically gets 5º to 7º warmer, on average.
- How long does it take to heat a pool with solar panels?
Depending on the size of the panels and the pool, most heaters need to run for a few hours to sufficiently warm the pool.
- Can you add solar heating to an existing pool?
You can add a solar heating system to the pool you have. Adding solar heat to the pool costs $3,000 to $7,000.
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