Photovoltaics refers to the direct conversion of radiant energy into electrical energy. The term is composed of the Greek word for light (“phos”) and the name of Alessandro Volta, who pioneered electricity and gave his name to the Volt unit. The supply of light releases positive and negative charge carriers with the so-called photoelectric effect, which generates direct current. Depending on the orientation, solar radiation and module type, an area of 10 m² can generate approx. 1 kWp of power – i.e. about 800 to 1,000 kWh of electricity per year.