Photovoltaic (PV) refers to the process of turning sunlight into electricity. Individual PV cells are connected to panels. Solar panels convert sunlight into direct current (DC) electricity where an inverter converts DC into alternating current (AC) for electricity in the home.
The utility meter records the net amount of energy you use when you are enrolled in PG&E's net energy metering program. When you're generating more electricity with your PV system than you're using, your meter will "spin backwards" and the excess electricity is sent to the electric grid. This provides you with a surplus to help offset the cost of your electricity usage at night or on cloudy days when your system is not producing.
Solar water heaters—also called solar domestic hot water systems—can be a cost-effective way to generate hot water for your home or business. They can be used in any climate, and the fuel they use—sunshine—is free.
Although there are different types of solar water heating systems, most have four components: solar collectors, circulating pumps, controls and a storage tank. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank. Depending upon your needs, your solar water heating contractor can help determine which type of system is right for you.
Solar water heating systems can be a cost-effective way to generate hot water for a home or business. They can be used in any climate, and the fuel they use—sunshine—is free. There may be financial incentives and tax credits available to offset the cost of installing a solar water heating system at your home.
The four basic components of a solar water heating system are:
- The sun heats a fluid on the roof
- The controller turns on the pumps when it detects the solar-heated fluid
Pump (Active Systems)
- The solar-heated fluid is pumped into a storage tank
Solar Storage Tank
- The conventional water heater draws the hot water out of the solar storage tank when there is a demand for hot water. If needed, the conventional water heater may boost the temperature of the solar heated water before sending it through the home
Additionally, single family residential solar water heating systems must have a Solar Rating and Certification Corporation (SRCC) OG-300 System Certification. Solar collectors used in multifamily residential, commercial, or industrial water heating shall have SRCC OG-100 Collector Certification.
Wind turbines use the motion of the wind to turn a shaft attached to a generator, which makes electricity. The size of the turbine and the speed of the wind determine how much electricity it will make.
Small wind systems can be the most cost-effective home-based renewable energy system, if sufficient land and wind are available. They can potentially decrease energy costs and provide a supplemental power supply.
While residential customers are not excluded from wind generation technology, the minimum 30 kilowatt system size for renewable technologies generally limits most applications to non-residential energy consumers.
Based on the conversion of sewer gas, landfill gas, or other renewable sources of hydrogen or hydrogen-rich gases into electricity by a direct chemical process.
A fuel cell is a device that uses natural gas to combine hydrogen and oxygen to produce energy (electricity and heat) by chemical reaction.
For more information on this technology and to determine if it is right for your customer, please visit the U.S. Department of Energy's website