Reduce swimming pool heating costs by installing a solar pool heater. They're cost competitive with both gas and heat pump pool heaters, and they have very low annual operating costs. Actually, solar pool heating is the most cost-effective use of solar energy in many climates.
HOW THEY WORK
Most solar pool heating systems include the following:
Some systems include sensors and an automatic or manual valve to divert water through the collector(s) when the collector temperature is sufficiently greater than the pool temperature. When the collector temperature is similar to the pool temperature, filtered water simply bypasses the collector(s) and is returned to the pool.
Solar pool collectors are made out of different materials. The type you'll need depends on your climate and how you intend to use the collector. If you'll only be using your pool when temperatures are above freezing, then you'll probably only need an unglazed collector system. Unglazed collectors don't include a glass covering (glazing). They are generally made of heavy-duty rubber or plastic treated with an ultraviolet (UV) light inhibitor to extend the life of the panels. Because of their inexpensive parts and simple design, unglazed collectors are usually less expensive than glazed collectors. These unglazed systems can even work for indoor pools in cold climates if the system is designed to drain back to the pool when not in use. Even if you have to shut the system down during cold weather, unglazed collectors may be more cost effective than installing a more expensive glazed collector system.
Example of how a solar collector works.
Glazed collector systems are generally made of copper tubing on an aluminum plate with an iron-tempered glass covering, which increases their cost. In colder weather, glazed collector systems—with heat exchangers and transfer fluids—capture solar heat more efficiently than unglazed systems.
Therefore, they can be used year-round in many climates. Glazed collectors also can be used to heat domestic hot water year-round.
Both glazed and unglazed collector systems should include freeze protection if they'll be used in colder conditions.
SELECTING A SOLAR POOL HEATER
A solar water heater usually costs between $3,000 and $4,000 to buy and install. This provides a payback of between 1.5 and 7 years, depending on your local fuel costs. They also typically last longer than gas and heat pump pool heaters. Your actual cost and payback depend on many factors. Therefore, before you purchase and install a solar pool heating system, you should do the following:
EVALUATING YOUR SITE'S SOLAR RESOURCE
Before you buy and install a solar pool heating system, you first need to consider your site's solar resource. The efficiency and design of a solar pool heater depends on how much of the sun's energy reaches your building site.
Solar pool heating systems use both direct and diffuse solar radiation. Therefore, even if you don't live in a climate that's warm and sunny most of the time -- like the southwestern United States -- your site still might have an adequate solar resource. Basically, if your building site has unshaded areas and generally faces south, it's a good candidate for a solar pool heating system.
Your local solar system supplier or installer can perform a solar site analysis.
SIZING A SOLAR POOL HEATER
Sizing a solar swimming pool heating system involves many factors:
Solar system contractors use worksheets and computer programs to help determine system requirements and collector sizing.
Basically, the surface area of your solar collector should equal 50%–100% of the surface area of your pool. In cooler and cloudier areas, you may need to increase the ratio between the collector area and the pool surface area. Adding collector square footage also lengthens the swimming season.
In any climate, you can usually decrease the required collector area by using a pool cover.
You'll also want a properly sized pool pump for a solar system. If you're replacing a conventional pool heating system with a solar system, you may need a pump larger than your current one or a separate, smaller pump to move the pool's water to and through the collectors.