We can change sunlight directly to electricity using solar cells. Every day, light hits your roof's solar panels with photons (particles of sunlight). The solar panel converts those photons into electrons of direct current ("DC") electricity. The electrons flow out of the solar panel and into an inverter and other electrical safety devices. The inverter converts that "DC" power (commonly used in batteries) into alternating current or "AC" power. AC power is the kind of electrical that your television, computer, and toasters use when plugged into the wall outlet.
A net energy meter keeps track of the all the power your solar system produces. Any solar energy that you do not use simultaneous with production will go back into the electrical grid through the meter. At night or on cloudy days, when your system is not producing more than your building needs, you will consume electricity from the grid as normal. Your utility will bill you for the "net" consumption for any given billing period and provide you with a dollar credit for any excess during a given period. You can carry your bill credit forward for up to a year.
Solar cells are small, square-shaped panel semiconductors made from silicon and other conductive materials, manufactured in thin film layers. When sunlight strikes a solar cell, chemical reactions release electrons, generating electric current. Solar cells are also called photovoltaic cells or "PV cells" and can be found on many small appliances such as calculators.
PV systems today can be blended easily into both traditional and nontraditional homes, powering appliances and electric systems. PV cells can be installed as a stand-alone module that is attached to your roof or on a separate system, or using integrated roofing materials with dual functions - that as a regular roofing shingle and as a solar cell making electricity. The most common practice is to mount modules onto a south-facing roof or wall. PV systems likewise can be blended into virtually every conceivable structure for commercial buildings. You will find PV used outdoors for security lighting as well as in structures that serve as covers for parking lots and bus shelters.
A photovoltaic (PV) system needs unobstructed access to the sun's rays for most or all of the day to be effective. Shading on the system can significantly reduce energy output. Climate is not a major concern because PV systems are relatively unaffected by air temperatures. Abundant year-round sunshine makes solar energy systems useful and effective nearly everywhere in California.
A building permit is required to install a solar PV energy system.