Photovoltaics
Photovoltaics Solar Electric
The ability to produce electricity directly from the sun's energy is a revolutionary development. The technology involved in the production of these silicon cells is complicated and the efficiencies are still not even close to those of thermal solar applications, but these unique energy devices are now seen in places as common as the yard (solar powered lights), the highways (solar powered traffic lights and sign lights), and of course the common calculator.
Photovoltaics is the direct conversion of light into electricity. Some materials exhibit a property, known as the photoelectric effect, that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.
This electricity can then be used to power a load, such as a light bulb or a water pump. A typical four-inch silicon solar cell produces about one-and-a-half watts of electricityin bright noon-time sunshine.
Remote locations such as billboards, road signs and other areas where it is cost effective to install solar electric systems with battery backup are becoming more and more common.
Solar cells are made of the same semiconductor materials (usually silicon) used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other.
The basic components of a solar electric array are the photovoltaic panels, battery storage and other sub-assemblies that regulate the storage and release of the sun's electric current.
