Yardley Voice – Going Green Solar Column – August 2011
Solar Water Heaters Make Sense and Save Cents
by Mark Bortman
When you think of sunny places, Germany, Austria, China and Japan don’t usually come to mind. But these countries with climates similar to ours are way ahead of us at taking advantage of the energy from the sun. They are global leaders in installing solar water heaters. Almost every new house gets one and many older houses are retrofitted. What do they know that we don’t?
In the United States, solar water heating is not as well known as the other type of solar panels that generate electricity. Solar water heaters, however, are very efficient at taking the sun’s energy and converting it to something useful — hot water for showers, dish washing and even space heating.
There are various types of solar water heaters, but the basic operation is the same. The collectors are placed in a sunny area, usually on a roof, and they get hot – just like a garden hose that has been sitting in the sun. A heat-transfer fluid gets pumped through the collectors and brings the heat energy to a storage tank. The water in the storage tank receives the sun’s energy from the fluid through a heat exchanger. On sunny days, the temperature of the water in the solar tanks can easily rise above 140 degrees. Moreover, solar water heaters always have a back-up heating system in place, for those times when it hasn’t been sunny. In many cases, the back-up is your existing water heater.
Solar water heaters have withstood the test of time – they have been available for over 100 years. More importantly, demand for them is increasing as PECO rates and oil prices rise. The addition of a rebate from the state Sunshine Program and a federal tax credit reduce the cost of a system by an incredible 65%. Many people don’t realize it, but water heating typically accounts for 15-25% of your overall utility bill. With a relatively small upfront investment, you can reduce your utility bill and help the environment.
There are additional, easy, steps you can take to reduce the amount of energy used to heat your water. These are as simple as making sure your dishwasher is full before running it and turning down the thermostat on your water heater or more involved such as installing low-flow shower heads or heat traps. Other measures include insulating your water heater and hot water pipes and fixing leaky faucets.