Photovoltaic energy is a process that takes sunlight, and converts it into electricity. A photovoltaic cell (PVC) or solar cell does not have any moving parts but t does have moving electrons. As a photon (a component of the suns energy) is absorbed into a semiconductor material it knocks electrons loose from the semiconductor, this is the initial transfer of energy. These electrons are positioned in a sandwich configuration between two surfaces. One surface attracts electrons more than the other and these dislodged electrons migrate to that surface creating a negative charge at that surface. The other surface is left with a more positive charge and the difference between the two charges is termed the electric potential. If these 2 surfaces have wires or any form of conduction to a motor or load, then current will flow, just as with any electric supply. The above described unit is called a PV, and many PVs together are termed a module and modules working together are called arrays which produce photovoltaic energy. Output of an array is determined by the PVC rating and photon concentration dependent on climate and global position. Up until now the average PVC is 15 percent efficient, but there is new technology available in the horizon and is reported to be several times more efficient.

PVCs produce direct current (DC) that will be converted to alternating current (AC). Batteries use DC but house hold electronics use AC. This requires a power inverter to convert DC to AC and rectifiers to convert AC to DC. The most important reason for a rectifier is so that there is DC made to charge batteries in a backup system.

Semiconductor film is extremely thin, only a few micrometers, and can be used for shingles, tiles, and skylights. Some solar cells use concentrated sunlight either from a lens (like a magnifying glass) or from mirrors that reflect several different areas of sunlight into one area on the module thereby concentrating the sunlight. Because the sun moves, it is nearly impossible to concentrate the sunlight onto a module or array without having a mechanical movement of the lens or mirrors.

The PVC was discovered in the 50s and was used to power satellites. PVCs don’t require cooling and have essentially no moving parts which makes them an excellent source of renewable photovoltaic energy.