The Eco-Friendliest Product You Can Buy

How my new pool cover is saving the planet.

Do pool covers help the environment?

What if I told you I had discovered an investment in energy efficiency that wouldn’t require much upfront cash, that would save you almost triple what you spent on it in a matter of weeks, and that would reduce carbon emissions and conserve water, all while saving valuable time, liberating you from backbreaking work, and generally improving your quality of life? Does that sound like something you might be interested in?

I didn’t find this perfect thing at a Cleantech conference, or in one of those Nordic countries where they’re so into energy independence, or in the pages of Wired. No, I found it at my pool-supply store.

Like many Americans whose homes are blessed (or cursed) with a swimming pool, I looked forward to the summer of 2008 with a certain amount of dread. I didn’t relish enduring four months of eco-guilt each time the hiss of the propane-fueled water heater pierced the air. And with the price of all types of fuel having skyrocketed, the 2008 swimming season was likely to be an expensive one. Knowing that the easy way out—not heating the pool at all—would inspire a domestic insurrection that would make the Civil War look like a slap fight by comparison, I looked into solar pool covers. Despite their name, solar pool covers don’t have much to do with the technology that converts the sun’s rays into electricity. They’re essentially plastic sheets with bubbles on one side that sit on the water’s surface, absorb thermal energy, and trap heat in the pool. The Thermo-Tex Solar Cover I bought made extravagant promises: It could cut heating costs up to 70 percent and reduce water evaporation by up to 95 percent. It almost lived up to them. (Third-party estimates of the utility of solar pool covers can be seen here and here.)

The cover itself was pretty cheap. But you need a reel to operate it. The total cost of my solar installation came to about $450 and required a few hours of assembly time. Over the last several months, I took pains to keep the pool at temperatures equal to or higher than last year and kept careful track of usage. Now that the swimming season in the Northeast has ended, we can tally the results. Compared with last summer, we cut deliveries of propane in half, or by about 600 gallons. Because the price of propane was up sharply since last year, this year’s propane bill fell by 37 percent. The investment of $450 yielded a savings of about $1,100, compared with the amount used in the past year. In other words, my upfront investment was paid back in several weeks, returned 144 percent over three months, and should pay similar dividends for many years.

While saving money, we also helped save the planet. As fuels go, propane is a relatively clean-burning one. But it still creates emissions. According to the Energy Information Administration, propane releases 12.67 pounds of carbon dioxide per gallon burned and 139.18 pounds per million BTUs produced. That compares with 19.56 and 156.43, respectively, for gasoline. Reducing propane use by 600 gallons thus prevented the release of 7,601.4 pounds (3.8 tons) of carbon dioxide into the atmosphere. That’s the same amount of emissions produced by driving 8,300 miles in a car that gets 20 miles per gallon.

Virtuous Earth-saving activity—driving a tiny car, biking instead of driving, forgoing air conditioning or enduring lower heat, eating vegetables only when they’re in season—frequently makes people feel as if they have to lower their standard of living or endure discomfort. But Al Gore and others have made the point that going green and carbon neutral is not the equivalent of donning a hair shirt. It can actually be pleasant, cheaper, good for the economy, and good for your quality of life. The pool cover ratifies this view. Just as an older person does, our older pool struggles with a creaky circulation system. As a result, jumping into the deep end can be like plunging into the Mariana Trench. You might encounter several different temperature zones as you plumb the depths. In addition to helping to keep the surface temperature warmer, the pool cover, by trapping heat, made the temperature more uniform. This summer, we didn’t have to run the heater all day to keep it in the mid-80s. (Please direct angry e-mails in re: the absurdity and immorality of keeping pools at this elevated temperature elsewhere.—ed.) It also saved a great deal of water. In typical summers, and especially during August, pool owners have to run a hose into the pool a few times a week to maintain the water level. The pool cover allowed rain water to enter but generally prevented evaporation. I didn’t run the hose all summer. The cover also delivered less easily quantifiable enhancements to quality of life. In summers past, I spent countless hours engaged in the Sisyphean task of fishing pine needles and leaves out of the water. The cover largely liberated me from those annoying labors. And fewer complaints from family members and visitors that the pool was too cold? Priceless.

Naturally, there are some downsides. A pool cover eliminates (or at least makes less comfortable) spontaneous jumps. While it is advertised as being easy to handle, it does require some wrestling. And like many other eco-friendly products, it carries a heavy aesthetic cost. A 20-foot wide spool of blue plastic bubble wrap doesn’t really fit in with any outdoor decorating scheme.

Yes, yes, the truly green alternative to an uncovered pool would be to disconnect the heater, drain the giant concrete bathtub and replace it with a massive compost heap, and instead seek summertime recreation in rivers, lakes, or the ocean. But the whole point of living in a bourgeois suburban society is to engage in bourgeois suburban activity. And half measures are better than none at all. Besides, the best reason to save energy is not to save the planet for the sake of your grandchildren; it’s to save money and time for your own sake.