Photovoltaics (PV) converts sun energy including UV and infrared lights directly into electric energy. It is environment-friendly. PV needs very few maintenances and effectivity is increased and costs are decreased in time. Sun energy will be a main energy source for the world in 20 years. With feed-in scale system, Germany has become the most dynamic sun-electric market in the Europe. A lot of European countries are used this system for their own needs.