It’s safe to say that solar swimming pool covers (the blue ones that look like giant sheets of bubble wrap) are wildly popular.

 
Although they aren’t the most effective in keeping unwanted debris (or kids and pets) out of a pool, they’re inexpensive and add a touch of warmth to the water — sunlight gets the cover nice and toasty while the water cools it, leading to the transfer of heat. They also, of course, trap heat inside the pool which prevents evaporation — this is the largest source of swimming pool energy loss according to the U.S. Department of Energy’s EERE Energy Saver’s website. 
 

There are other types of pool covers out there — thick, long-lasting vinyl, not-so-long-lasting standard sheets of plastic, mesh, or hardtop covers for folks with safety on the mind — but when dealing with standard outdoor pools where heat retention and cost is a concern, solar bubble covers are the way to go.

That said, a solar pool cover won’t completely heat a pool (it would be sure nice if they did). If you’re looking to heat your pool exclusively with the sun, however, a solar water heater that heats just the pool, not the water in your entire home, is an option.

Here’s why solar water heaters for swimming pools are a fine idea despite the higher initial price tag (around $3,000 to $4,000) than conventional water heaters: pools, even if they’re just used in the summertime, require a ton of energy and frequent servicing. According to the California Energy Commission, heating a standard backyard pool requires the same amount of juice as it does to power a home for three months. This very expensive juice typically comes from carbon dioxide-spewing generating sources like coal and natural gas. The last time I checked, sunshine is free, renewable and non-polluting. Added bonus: some states provide tax rebates for solar pool heaters. 

 

I'm not going to delve into the science of solar swimming pool heaters here (it's much more simple than you would think) but I am going to highly recommend them to pool owners looking to break free from the massive amount of emissions and high energy bills (expect a return investment between 1.5 and 7 years) resulting from heating a swimming pool.

If this is you, check out the Find Solar website and the solar water heating companies listed below as a first step. Although these companies might not service your area, their websites provide plenty of helpful ins and outs of solar pool heating. That said, before you embark on installing a solar pool heating system (or any other major home improvement project) talk to an expert first. And if you're worried about the climate in your area, don't fret. Most solar water heating systems can function in more northern, less sunshine-y states as well. 

Solar Swim ( NY, NJ, eastern PA), Fafco (nationwide), SolarBLUE (Orlando, FL), Solar Industries (nationwide). EcoSun (nationwide). 

Photos: gtveloceSolarpoolheating

Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.