Notice: PG&E stopped accepting solar water heating program applications August 1, 2020. In compliance with Assembly Bill 797, Advice Letter 4090-G established July 31, 2020 as the final date to submit new applications to the program. Projects participating in the solar water heating program must follow the requirements listed in the CSI-Thermal Program Handbook.


How a common system works:


  1. Solar collectors work with the sun. A pump circulates fluid to the solar collectors on your roof to absorb the sun's thermal heat.
  2. Solar storage tanks keep the water warm. The solar heated fluid is then pumped through an insulated water storage tank via sealed coils. These hot coils heat the water stored in the tanks.
  3. Preheated water now flows into your conventional water heater. Any additional hot water needed is generated by your original water heater.
  4. Plentiful hot water is available. Through the solar water heater, hot water is supplied around the clock. This water can meet all your needs, if you choose the right system.

Other considerations:


Reducing the amount of hot water used in your home or business can reduce the size and cost of the system that you must install. Before you install a solar water heating system, consider other energy efficient upgrades. The upgrades can include high-efficiency washers and dishwashers, and low-flow showers and toilets.


Ensure your roof is in good shape. Consider replacing your roof when you install your hot water heating system, if the roof is in poor condition. Ensure that enough roof space is exposed to the sun to accommodate your system. Establish a space near your current water heater to install the separate solar storage tank.


Solar water heating systems are designed to be reliable. A typical setup can last 20 to 25 years. In addition, the systems require very little maintenance if they are installed properly.


Discover other solar water heating resources

Watch the Satchwells' story of installing solar water heating

See how one family used solar water heating to save energy and help the environment.