Reduce Your Energy Bills with a Solar Hot Water Heater

Enjoy free hot water simply by installing a solar hot water heater in your home.

| February/March 2007

Gas vs Solar

Solar hot water heaters have very low operating costs.


How would you like to have free hot water for the next 40 years? That should sound pretty good — about 15 percent to 20 percent of a typical household’s energy outlay goes to make sure the “H” tap means what it says. If energy prices increase by 6 percent annually, the average family would save thousands of dollars over the coming decades by installing a solar hot water heater that supplies just 65 percent of their hot water.

I mean “free” literally. Yes, you’ll spend money up front to install the heating system, but your home equity will increase instantly, often enough to offset the cost of installation. You’ll also pay reduced utility bills — saving more money every time rates rise. Within a few years, you’ll recover the initial expense. Experts agree, a solar hot water heater is far and away the easiest initial investment in renewable energy. Perhaps best of all, you’ll enjoy hot baths or showers with the satisfaction of knowing the energy comes directly from the sun.

A Good Deal, Getting Better

Solar hot water heaters vary in their details, but they all do the same basic things: gather heat in a solar collector; transfer the heat, directly or indirectly, to the water supply; and store the heated water until it’s used. They use relatively simple, time-tested technology, which is one reason they are a best bet in renewable energy.

It’s important to understand that solar water-heating systems have very low — sometimes zero — operating costs, and maintenance amounts to only about $2 per month. Say you might spend $7,000 to install a solar water heater, when you could install a conventional gas or electric heater for considerably less. But it’s so much less expensive to operate the solar heater that, at some point, you’ll make up the initial difference. When all costs for purchase, installation, maintenance and operation are taken into account, a solar water heater usually equals an electric heater after just eight and a half years, and equals a gas heater in just less than 15 years. From then on, through the expected 40-year life of the solar system, you’ve got free hot water (see Image Gallery).

Consider the positive environmental benefits of a solar hot water heater, and the deal just gets better. A typical residential solar water heater will offset greenhouse gas emissions by about 1,500 pounds of carbon dioxide (CO2) per year. That’s equal to the amount of CO2 released by an average vehicle every 1,685 miles (based on 19.6 pounds of CO2 per gallon at 22 mpg).

It’s cheaper to conserve energy than to purchase it, so the first thing you’ll want to do is reduce your hot water needs to the minimum. Start by reducing waste; then minimize consumption. Reducing your usage ensures that your solar heating system will provide the maximum possible portion of your hot water. Even if you don’t go solar, using the minimum necessary hot water is good for your wallet and good for the environment.

mike rogers_1
6/28/2009 9:42:50 AM

Great article, and right on. I’m glad to hear more poeple talking about this! Solar thermal (hot water) is an easy way to step into renewables (although I always recommend starting with energy-efficiency first). Check out a solar solar hot water hot water video at: Ron's comments miss a couple of things. First, currently there are federal tax credits for 30% of the sytem. And many states and utilities offer additional incentives. With incentives in cold and cloudy New York, for example, we see expected paybacks in the 5-6 year ranges. Second--it seems he's comparting the cost of an inefficient water heater, without installation, to the cost of a fully installed solar hot water system. Thanks, Mike

8/30/2008 9:09:19 PM

Aw, c'mon. Seven grand upfront for solar hot water. A water heater is about five hundred bucks, and costs about three hundred a year to operate. You are talking about a payback going on fifteen to twenty years. That's not realistic for most people. You really have to do better than that. You are throwing stuff out here as if we can't do basic math.

george works
8/18/2008 1:46:24 PM

I have solar hot water and love it. My wife and I live in the tropics on an island where sunlight is plentiful and electricity is costly. Three years ago we installed a solar water heater with an 80 gallon tank and two 15 square foot collector panels. Our heater uses a separate coolant loop to heat the tank with convective flow -- no pumps. The tank has a backup electric heater element which we did not connect. We have never had a day without hot water, even after two or three cloudy days. I should perhaps add that we learned to conserve water while living on a sailboat, and would do so anyway because our water comes from rain water stored in a cistern. Still, we both shower daily and wash dishes three times a day.

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