For anyone looking to green his or her home in a serious way, installing a solar water heater may be a good first step. Rating relatively high in ease of installation, cost effectiveness and environmental benefit, solar water heaters are an increasingly popular choice for eco-conscious homeowners in regions conducive to producing solar energy. (According to the Environmental and Energy Study Institute, about 40% of U.S. homes have sufficient access to sunlight to be able to use a solar water heater.) People have likely been harnessing the sun’s rays to heat water for hundreds, if not thousands, of years. And, incredibly, solar water heaters have been commercially available since the 19th century. What sets modern solar water heater systems apart is that they can blend into almost any home. Many models resemble skylights, lying flat against a home’s roof. Most home solar water heaters utilize solar thermal energy, which simply means that energy from the sun heats the water (as opposed to converting the sun’s rays to electric power, which would be needed to power an entire building). Although there are many types of solar water heaters, they all perform three key functions: collecting, transferring and storing energy. A solar collector is mounted on the roof, usually facing south, and as the sunlight passes through the collector’s surface, its energy is absorbed by rubber or metal. The rubber or metal material holds the heat, while a special glazing on the surface of the collector prevents the heat from escaping (much like a greenhouse, or a car in a warm parking lot). At that point, circulating fluids transfer the energy to a storage tank, where it heats the water. The water is then held in an insulation tank until it’s needed. A typical solar water heater produces about 80 to 100 gallons of hot water per day, though the effectiveness of the systems can vary depending on geographic location and system design. The most obvious benefit of installing a solar water heater is that it can save money on energy bills. Installation and other upfront costs can run anywhere from $4,000 down to $1,000 (even less if you construct your own system). Compared to traditional water heaters, which usually cost a few hundred dollars, solar water heaters may seem expensive. But, of course, the savings are found in the long term. Operational costs for most solar water heaters are almost nothing, and the systems themselves usually last for decades. So, after an initial investment of a few thousand dollars, you’ll be guaranteed virtually free hot water for many years to come. What’s more, the government now offers a tax credit of 30% (up to $2,000) of the cost of installing a certified solar water heater, so there’s even more of an economic incentive to set one up. Another clear benefit of heating your water with the power of the sun is environmental; according to some analysts, the amount of carbon dioxide produced annually by residential water heaters in North America is roughly equal to that produced by all of the cars and light trucks on the continent. So, if even a small percentage of the people who live in areas where a solar water heater is feasible actually installed one, it could make a huge dent in the nation’s carbon footprint. For more information on the many different types of solar water heaters, visit the U.S. Department of Energy website.
The ABCs of Solar Water Heaters
For anyone looking to green his or her home in a serious way, installing a solar water heater may be a good first step.