While the initial purchase price of a solar water heater is high compared to standard models, they can be cost effective, because the sun’s energy is harnessed to reduce operating costs. Solar water heating systems require a conventional water heater as a backup water heating source to ensure hot water is available when solar energy is not. Solar water heaters come in a wide variety of designs, all including a collector and storage tank, and all using the sun's thermal energy to heat water. Solar water heaters are typically described according to the type of collector and the circulation system.
According to ENERGY STAR, a solar heating system may cut your hot water heating costs by as much as 50%. A solar heating system can work with a natural gas, electric, propane, or oil heating system. Most solar water heating systems are installed on the roof of a home, so your roof should have direct sunlight between 10 a.m. to 4 p.m., all year round. If you are mounting a solar system on the roof, it is best if it faces south, toward the sun.
Before installation, have a qualified contractor determine if your roof is appropriate for a solar heater. And if you are unsure about instilling a solar heating system on your roof, a system can be installed on land where there is full sun and no shade. For more information, visit the ENERGY STAR website