Solar Power: Solar energy, power from the sun, is free and inexhaustible. By the time it reaches the earth's surface, the energy in sunlight has fallen to about 1,000 watts per square meter. If you average this over the entire surface of the earth each square meter collects the energy equivalent of a barrel of oil. So each day, on average, a square meter collects 4.2 kilowatt-hours of energy.
How It Works: 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.
Liquids: 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.
Costs: 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 their electric bill by 50 to 80 percent.
Did You Know?:
- Solar power can also be used to cool water.
- There are tax credits available to those who take advantage of solar heating.