• Energy & Power

Heating Water with Solar Energy

Another way to use renewable energy in your home is to use solar energy for heating. Today’s systems carry a rating that tells you how well they’ll meet your hot needs. And they provide a clean, reliable, and cost-effective source of hot .

Solar water heaters can be either active or passive. An active system uses an electric pump to circulate the heat transfer fluid; a passive system has no pump.

Most systems use a roof mounted solar collector, so you’ll need a south facing roof with good solar exposure. A typical solar water heating system circulates water or an antifreeze solution through this solar collector, where the sun’s heat warms the liquid.

If water is used, the system circulates the water between the solar collector and a storage tank in your house, and the storage tank serves as your source of hot water. If an antifreeze solution is used, the system will also circulate it between the solar collector and a storage tank, but water is circulated through coils in the tank to provide your hot water. In some cases, an additional tank is then used to store the hot water.

If you’re currently using an electric water heater, solar water heating is a cost-effective alternative. In fact, a study by the Florida Solar Energy Center showed solar water heater owners saved as much as 50% to 85% annually on their utility bills as compared to electric water heating. If you’re building a new home, the cost of the system can be spread over the term of your mortgage. The only pollution generated by solar water heating is the pollution produced in generating electricity to power the pumps and controls.

Some systems even operate without pumps, reducing the environmental effects to a negligible amount and helps reduce greenhouse gases. When a solar water heater replaces an electric water heater, the electricity displaced over 20 years represents more than 50 tons of avoided carbon dioxide (a greenhouse gas) emissions alone.

Take the same care in choosing a solar water heater that you would in purchasing any major appliance. Your best protection is to consider only certified and labeled systems. The Solar Rating and Certification Corporation (SRCC), a nonprofit, independent third party organization formed by the solar industry, state energy officials, and consumer advocates certifies and rates solar water heaters.

As with all renewable energy systems, you should check to see if any special rebates or financing deals are provided in your state. Rebates are often offered through your local electric utility. Consult with your state energy office.

Active closed-loop solar water heater
Active closed-loop solar water heater