Solar water heaters work by installing thermal panels on an unshaded, south-facing portion of a roof. These panels collect heat from the sun's rays to warm a liquid that moves through pipes connected to the panels. This liquid is either the home's water itself, or a heat-transfer fluid like anti-freeze. If a heat-transfer fluid is used, the fluid flows through a heat exchanger in the water heater, warming the water just like an electric or gas heater would.
Solar water heating systems cost between $1,500 to $3,000. Although this is a much higher up front cost than a traditional water heater, those using solar power can see savings on thier electric bill by 50 to 80 percent.
