Solar power uses the sun’s energy. To do this, photovoltaic (PV) cells convert sunlight into electricity. The process looks like this: Sunlight consists of photons or particles of solar energy. The photons contain different amounts of energy, depending on the wavelength. A PV cell consists of semiconductor material. If a photon hits a PV cell, there are three possibilities: Either they are reflected by the cell, pass through the cell or are absorbed by the semiconductor material. Only in the latter case do the photons provide usable energy. Electrons from the atoms of the material are removed, causing a current flow. This in turn leads to a potential difference and a current circuit is created.
The efficiency of photovoltaic systems varies depending on the type of photovoltaic technology. Ultra-modern modules now reach 20%, the average efficiency of newer modules is around 15%.
Photovoltaic cells generate a direct current that can be used to charge batteries, which in turn supply devices with direct current. However, since almost all devices require alternating current, inverters are needed to convert the direct current into alternating current.
Not only the size of the PV modules defines their power capacity, but also the amount of energy from the sun, which varies geographically with the radiation intensity (W/m2), and the angle between radiation and module. Ideally, the module should be located at southern latitudes and there should be a 90° angle between the radiation and the module.