In this guide, you’ll learn everything about solar pool heaters you always wanted to know but were afraid to ask! We’ll answer the questions like how they work, what the benefits are, things to look for when shopping, as well answer some frequently asked questions that bothered consumers. By the end of the guide, we’ll review the TOP 5 Best Solar Pool Heaters worth buying.

Nothing says luxury and success quite like having a private swimming pool in your yard. Sure, the above ground pools are pretty inexpensive, but are those real pools? Are that? Most would argue that no, they’re not. No, you want a nice, deep in-ground pool you can relax beside and enjoy the relaxing waters for at least half the year, right? Well, there’s a problem with that idea, and it’s not the expense of installing one (honestly, it’s not that expensive these days), nor is it the maintenance (which isn’t rocket science either). No, the thing is, water gets darn cold, even in the summer.

The thing with water is, it doesn’t store heat very well for long periods of time. This is why water heaters for your home plumbing have to actively maintain the hot water supply, and why it can be depleted by too many people taking excessively long showers.

With a pool, this problem is considerably magnified. The issue is surface area, which a pool has plenty of. This provides a lot of space for heat transfer back into the air. Just as hot air rises, so does hot water, which will collect at the surface, and shed the heat into the air through evaporation or simple thermal radiation.

Even on a sunny, relatively warm day in midsummer, you may be shocked when you jump into the water to come up gasping as the warmth your toes had reported extended, at best, six inches into the depths. While the idea of cool water on a hot day is nice, as human beings, our idea of “pleasant cool” isn’t very cool – the high seventies, for water, are pretty chilly indeed.

This calls for a heating system, which not only can abate the chill of water in the summer but can greatly extend the amount of the year you can enjoy your pool. Even in areas that have potent winters, pool owners often get an extra month of swimmable water out of a good heating system.

Of course, a lot of these heating systems are similar to home water heaters, with a water exchange system and a heating reservoir tank. But, this eats a good bit of power, so a lot of people find the idea of a solar heater to be appealing.

What Is a Solar Pool Heater? How Do They Work?

Solar pool heaters generally work in one of three ways. Some are still electric, using solar power as their supply, which is the best way to apply solar to heating much of anything. However, this relies on a lot of direct sunlight, as well as a battery array to store the power to continue functioning into the night.

The other two are more direct, transferring the thermal energy of the sunlight directly into heat in the water. This is done in one of two ways – through an exchange chamber, where it’s heated by focused light and circulated back into the pool, or through sheeting which sits atop the water’s surface. The latter transfers the energy directly down into the water, while also trapping it.

Solar Heaters In Above Ground and In-Ground Pools

Sometimes, you have no choice but to go with an above ground pool, due to zoning or lack of space in your yard for a full sized in-ground pool. These aren’t the same, and no owner of an above-ground pool would argue otherwise. But, they can still be made quite nice with some effort. With their larger volume to surface area, they tend to stay warm better than in-ground pools. Exchange heaters, which flow water through a heating chamber, can heat these very efficiently, though it generally takes an array of them if they’re small.

For in-ground pools, surface sheets are going to be far more effective. This is a slow process, but the amount of heat they’ll trap, especially when these sheets are kept over the pool during any disuse, means that you’ll have warm water for quite some time when you’re ready to use it.

How Much do these Solar Pool Heaters Raise the Temperature of Water in a Pool?

The problem with solar energy is it’s not as exact as electric or gas heat. While the amount of energy put out by the sun is macroscopically more or less constant, variables such as atmospheric conditions, weather, and randomness in water chemistry mean that there’s no way to predict how hot the water will get from them.

This also varies widely depending on the amount of water, the surface-to-volume ratio, and the size/volume of the heaters in use. Sheet heaters on a pool’s surface tend to raise it by about 10-15 degrees, sometimes more on a really sunny and hot day.

Exchange heaters, however, can get water very hot, even hotter than a hot shower if they get the right amount of heat. I’ve seen these heaters put out water that was well over 100 degrees. Don’t fear – they tend to cycle less than half the pool over a day, meaning this hot mixes with the cold for a nice temperature.

How Many BTU Pool Heater Do I Need? What Size Pool Heater Do I Need for a Specific Surface Area?

As said above, with solar energy, you can’t really predict this without some expensive meteorological equipment that can give you solar output over a period of time, and produce trends which you can convert into thermal units.

With surface sheet style heating, you want exactly the amount of material as the surface area of the water. For above ground pools, you will possibly want to line the sides of the pool with this material as well.

For exchange heaters, you’ll want to look at the amount of water that tends to pass through it in a period of time. You want it to put at least a third of your pool’s volume of water through it per day, if not more. It doesn’t have to cycle every drop of water – the water coming from exchange heaters will, theoretically, actually be a bit warmer than you want the pool to be, and the dilution and exchange with the cooler water will result in an overall even-temperature pool.

Things to Consider When Buying Solar Pool Heaters

  • Pool Form Factor – What kind of pool do you have? Above ground pools are easily enough heated with sheets or a very small exchange heater.
  • Distance from the House – How far away is the pool from your house? If it’s significantly far, then exchange heaters, best served on the roof, maybe less practical.
  • Installation – How much of an undertaking do you want the installation to be? Surface heaters are pretty unremarkable to install, but exchange heaters often require a pump as well as some construction.
  • Temperature – Do you just need a little bit of heat, or do you need to actively put a lot of thermal energy into it? If you live in a warmer, sunnier place like California, heaters like these don’t have to work very hard, but other parts of the world with unpredictable sunlight, they have to work harder and provide more heat too.
  • Warranty – Obviously, you want a good warranty on these, because there are a lot of things that can go wrong – don’t worry, I’ll tell you all about that in a minute.
  • Pool Function – Is this a leisure pool? Then you’ll want it between 88-90 degrees or so. This sounds hot, but for water, it’s really not. If this is an exercise pool, you’ll actually want it a bit cooler, as this encourages circulation and locomotion Between 78-85 degrees.

How to winterize solar pool heater?

Disconnect the water from the heater, and drain it, make sure it’s dry, and cover it with an insulating tarp. If you live in a place where it freezes, do not try to solar-heat your pool in the winter.

How to install a solar pool heater on the roof?

Usually, there will be some mountings that fasten down – screws or nails, and then two pipes, one leading in from the pump, one leading back to the pool. It’s honestly pretty easy usually.

Benefits of Pool Solar Panels

  • Solar energy is obviously very environmentally friendly, relying on renewable energy for the entirety of its power.
  • In turn, they’re energy savers despite the need for pumps in most cases. A pump is fairly power-efficient with modern engineering.
  • They’re quiet, reducing noise pollution though again, pumps are still needed. Pumps tend to be fairly quiet, though.
  • You get longer swimming time since their presence will actively keep the pool warm.
  • They require very little maintenance, at least in theory. I've got a little addendum to that we’ll get to right now.

Which one is the best? Personal Experience

But which heaters are the best for sunny California where it is almost always warm; and other states where the sun also shines during the day but the air temperature is lower or drops sharply at night?

I grew up in LA, and I now live in Florida. Contrary to what people from neither place may think, they’re very different climates. The presence of palm trees means little besides the lack of actual freezes in winter. Growing up in LA, we had a solar pool heater array, though we also had an electric heater as a backup.

In California, these solar heaters are actually fantastic, because you really only get two types of skies, at least in the southern part of the state where I was – stormy and rainy, or extremely sunny. You get so much sun, in fact, that we had to actually put a shut-off valve on the heater, because that water in mid-July at 2 in the afternoon, would scald you coming out of that thing. I still, decades later, have a scar to prove that in fact.

Florida, however, is a different kettle of fish. Does it get hot here? Oh yes, it gets very hot, and humid too. But, it’s not as sunny as people actually think. Florida, and indeed most of the East Coast, gets a real mixed bag of weather. It can be cloudy and do absolutely nothing, it can rain for days. Solar power of any sort, here, is not very reliable.

Another problem, which is why I said they’re theoretically low-maintenance, is the algae here. It’s in the air, and you don’t notice it, until it grows on window screens, in pools, and yes, in those hot, incubating solar panels as well.

My personal conclusion for places that aren’t the desert or Southern California is – yes, do install one. Be sure to treat the water with anti-algal chemicals too. Relax, they’re harmless just don’t drink shots of them. But, also have an electrical heater as a backup – believe me, you’ll need one at some point.

Top 5 Solar Pool Heaters

Hereinbelow, we’ll cover the best solar pool heaters we’ve found online. We’ll review all kinds of form factors and touch on various price categories from the most affordable (as low as 30 dollars) to the most expensive (as much as 200). But for the solid average solar pool heater prepare to spend around 100 dollars.

Sun2Solar Blue 33x33 sq. ft Solar Cover Heating Blanket – Best Surface Heater

Sun2Solar Blue Solar Cover Heating Blanket: photo

This is an interesting technology, and if you want a pool cover, to begin with, there’s no reason not to use material like this, aside from its expense. Looking up close like blue bubble wrap, this directly focuses the heat of the sun into the water. The little bubbles are actually convex lenses designed to focus literal heat rays into the water.

Along with the rack, this material is relatively easy to install and does kill two bird with one stone. It’s costly and does require an installation of the roller as well as hooks to fasten it to. But again, a pool cover would require this anyhow.

Features

  • Heater Type: Blanket.
  • Requires Pump: No.
  • Requires Installation: Yes.
  • Best Pool Type: In-Ground.

Performance

This isn’t a fast heating technology. If you’re trying to quickly get your pool heated up, it will take some time. This is better as a heat retention technology, keeping the heat in, and replenishing it over the long term.

You will need a pool cover if your pool isn’t in an enclosure, at which point, even if you have other heating technologies present, this is a nice way to have the cover pull double duty, and enhance your heating. This goes especially for temperate climates.

I wouldn’t recommend relying solely on this for heat unless you’re in a place with lots of sun, though.

Pros Cons
  • Easy installation.
  • Serves two purposes at once. 
  • Looks tasteful. 
  • Helps keep heat. 
  • Great addition to existing heating technologies.
  • Slow and inefficient on its own.
  • Very expensive. 
  • Fragile. 
  • Can be a nuisance to retract.


Conclusion 

This is a nice solution if you can’t mount panels, but are set on not using electric. But on its own, this technology isn’t that potent. It’s a great addition to other heating technology, though, and since it works as a cover, it will help keep your pumps and filters from clogging, and greatly reduce the amount of cleaning you need.

Sun2Solar: Check the current price

Smartpool S601P SunHeater – Quintessential Solar Panel Heater

Smartpool Quintessential Solar Panel Heater: photo

This is the definition of classic solar water heating, being installed on a roof, and capturing a lot of heat through surface area. This is a lot like the panels we had in California, and the water can come out of these bad boys at a very high temperature.

With the surface area they have, and advanced materials, this is the only style of a heater in this form factor I’ve seen actually perform admirably down here in Florida, though the performance is reduced compared to sunnier, hotter parts of the country.

The one downside is, this requires an installation kit which is sold separately. For shame.

Features

  • Heater Type: Panels.
  • Requires Pump: Yes.
  • Requires Installation: Yes.
  • Best Pool Type: Either.

Performance

With something like this, you’re not escaping the need for some use of electricity, as you will have to pump the water up. Any claims that these sorts of heaters can use vacuum and convection physics alone to move the water are absolute nonsense, the water’s too heavy for heat exchange to fight gravity like that.

However, if you can accept the fact that a pump is necessary – that’s still not that much power – this is a solid solution, and if you get decent sun, oh boy, does the water come out hot with this kind of heater.

Pros Cons
  • Very efficient.
  • Unobtrusive. 
  • Easy to set up. 
  • Affordable. 
  • Low maintenance.
  • Requires a pump.
  • May trap algae. 
  • Leaks could damage your roof. 
  • Needs trees to not obscure it at all. 
  • Must be dismantled if roof repairs or replacements have to be done.

Conclusion 

This, combined with the previous model for added heat-trapping, would be my go-to solution for solar heating, to be honest. But even on its own, if you have reliable sunlight during swimming season, even on a cooler day, the transfer of heat these focus into the water will make your pool quite pleasant and far from cold.

Smartpool: Check the current price

GAME 4714 SolarPRO Contour Solar Pool Heater – Greenhouse Heater

GAME 4714 SolarPRO Contour Solar Pool Heater: photo

This is a different take on exchange heaters, using the greenhouse effect of steam and evaporation to rapidly heat water. It may not look like much, but in a sufficiently sunny environment, this type of heater can handle a 10,000-gallon pool. At least, that’s the claim – I would recommend putting two of them on a pool that large because sunlight is rarely that cooperative in most of the world.

Still, these are powerful, and they’ll make as much possible use as they can out of the energy available. The heat inside the chamber also reduces the risk of algae or other problems as well, making them a relatively low-maintenance approach to the technology.

Features

  • Heater Type: Dome “Panel”.
  • Requires Pump: Yes.
  • Requires Installation: Yes.
  • Best Pool Type: Either.

Performance

This does still require a pump but is one of the most efficient heating technologies out there. This is ideal for climates where the available sun is less predictable in its quantity. I still maintain that one of these isn’t enough in most climates, but since they’re fairly affordable, installing two of these for a larger pool isn’t really that big of a deal.

The only thing to be aware of with these is how incredibly hot the water will be when this is performing at its peak.

Pros Cons
  • Very efficient.
  • Unobtrusive. 
  • Easy to set up. 
  • Affordable. 
  • Low maintenance.
  • Requires a pump.
  • Device itself can get very hot. 
  • Does require cleaning. 
  • Dome can crack. 
  • Pump needs to be calibrated to not overdo the pressure.

Conclusion 

In Florida or temperate climates, these would be good supplements to not work your powered heater so hard. In California or the southwest, I could see these being the entirety of your heating, except for at night. I’ve not experienced this technology very much – one friend of mine does have something a lot like this, and when it gets sun, it does put out some very hot water. According to him, though, these don’t like really high levels of chlorine and don’t work well at all with salt water pools. Who puts salt water in a pool, anyhow? Gross.

GAME 4714 SolarPRO: Check the current price

Intex Solar Heater Mat for Above Ground Swimming Pool – Dedicated Heater for Above Ground Pool

Intex Solar Heater Mat for Above Ground Swimming Pool: photo

This one doesn’t pretend it doesn’t need a pump, including a small portable one with the unit. This is a simpler solar approach, using the black material to trap the heat of the sun, and thus ambiently heat the water that runs through it.

For something with less volume, like an above ground pool, these are surprisingly effective and pretty quick. These tend to be fragile though, but with their affordability, that’s less of an issue than it would be for other models.

Features

  • Heater Type: Mat.
  • Requires Pump: Yes.
  • Requires Installation: No.
  • Best Pool Type: Above-ground.

Performance

I have a friend whose yard is just too small for an in-ground pool. But his above ground pool is quite nice, with wood finish, landscaping around it, and a partial deck connecting to it. He has a heater very similar to this, albeit about twice the size (this one is 47x47”). It takes about half an hour, on a hot, sunny day, to get his pool comfortably warm with it, so I’d say an hour with this one, for the average above-ground pool.

These work surprisingly well.

Pros Cons
  • Very efficient.
  • Unobtrusive. 
  • Easy to set up. 
  • Affordable. 
  • Low maintenance.
  • Takes about an hour to heat up.
  • Build quality is about what one expects for the price. 
  • Fragile.

Conclusion 

These do not work for in-ground pools, and I’d recommend using two or three of these to heat an above-ground pool of any significant size. This relies on the intensity of the sun to heat light-absorbent materials, which means it is much more dependent on the intensity of sunlight provided. So, these only work in a hot, sunny summer if you live in a place with seasons. You’ll want something electric as a backup otherwise.

Intex: Check the current price

GAME 4721 SolarPRO Curve Solar Panel Heater – Modern Panel Heater with No Installation

A Universal Pool Heater: photo

This is an interesting hybridization of solar panel exchange heating, and the portability inherent in the heater mat we looked at a moment ago. It requires a hefty pump, but the advanced materials and similar use of greenhouse steaming technologies mean this can produce some serious heat if it gets enough light.

The lack of installation makes this a lot less of a hassle, too.

Features

  • Heater Type: Mat.
  • Requires Pump: Yes.
  • Requires Installation: No.
  • Best Pool Type: Above-ground.

Performance

I like the idea of this, though again, this really does need the intense sun to provide a lot of warmth. This would take a while to get a cold pool warm, especially in areas that don’t have very intense sunlight (California, the southwest). But, it’s definitely faster than the previous model, and more convenient than the roof-mounted approaches.

I could see further advances of this technology actually managing to produce heat out of pretty weak sunlight, though it’s honestly not quite there yet. But, if you have the sunlight to heat water at all, this one will probably perform pretty admirably.

Pros Cons
  • Very efficient.
  • Unobtrusive. 
  • No installation. 
  • Relatively affordable. 
  • Low maintenance.
  • New technology, may have some maturing to do.
  • Heavy. 
  • Slightly fragile. 
  • Requires lots of light.

Conclusion 

I’ve seen similar technology used to provide power for camping. While not a huge camper myself, I’ve used such things to heat coffee makers during power outages from hurricanes, and similar situations. It produced a decent voltage by focusing the heat it got into thermal and photovoltaic heat – direct heat transfer to water should be moderately effective too.

GAME 4721 SolarPRO: Check the current price

Comparative Chart of Solar Pool Heaters

Product Features

Sun2Solar

Type: Blanket.
Requires Pump: No.
Requires Installation: Yes.
Best Pool Type: In-Ground.

Smartpool

Type: Panels.
Requires Pump: Yes.
Requires Installation: Yes.
Best Pool Type: Either.

GAME 4714 SolarPRO

Type: Dome “Panel”.
Requires Pump: Yes.
Requires Installation: Yes.
Best Pool Type: Either.

Intex

Type: Mat.
Requires Pump: Yes.
Requires Installation: No.
Best Pool Type: Above-ground.

GAME 4721 SolarPRO

Type: Mat.
Requires Pump: Yes.
Requires Installation: No.
Best Pool Type: Above-ground.

Pros & Cons of Solar Heat

Pros

  • Saves power, and thus money.
  • Is environmentally sound.
  • Is safe, with no shock hazards.
  • Is usually easy to install for the most part.
  • Problems are easy to diagnose.

Cons

  • Isn’t free of electricity, as most need pumps.
  • Takes time to heat cold pools.
  • Solar power is wholly unreliable.

FAQ

Solar or electric heater?
Honestly, I’ll recommend electric every time, as solar power is the very definition of unreliable. But, in really sunny places like California, you can see savings from using solar.

What size solar pool heater do I need?
This depends on the type of pool. Honestly, look at your gallon count, and your form factor, and compare that to a given pump. There is no answer to this question that’s true for everyone.

Is it really profitable to obtain a solar heater for an above ground pool in particular?
Potentially, though in climates that aren’t exceptionally sunny, it’s more of a reduction of your existing heating bill, not an elimination of it.

How do I assemble a complete solar heater?
This varies wildly, but most of them merely require a frame to be put together, and lines connected. A lot of them don’t even require this, simply needing to be fastened and lines connected.

Conclusion

I won’t pretend I’m a big fan of depending on solar energy in most parts of the world. These sorts of technologies are absolutely fantastic in places that’re sunny far more often than not – deserts particularly. Southern California, which is, in fact, a desert kept artificially green, benefits from solar to reduce smog. But, for the rest of the world, I wouldn’t say it’s useless – it’s a great supplement to reduce your heating costs, but you should have an electric heat source to supplement or replace it when the sun’s too weak. Accept this inevitability, and any one of these should actually be a big help.