Photovoltaics are the fastest developing sector of all renewable energy sources with the perspective to turn into our century’s key technology. There are several reasons for that: aspiration to decrease harmful emissions of carbon dioxide, continuously growing prices of carbon and energy security. Each owner of photovoltaic system contributes to the fight against carbon dioxide pollution and climate’s warming. 1 MWh(1000 kWh) electricity produced from photovoltaic system saves average of 850 kg harmful emissions of carbon dioxide per year to the environment.   
Energy sources we use in nowadays industrial era are exhaustible. In the first third of this century lack of easily accessible petrol and natural gas fields is expected. Even if new large fields of mineral resources are discovered, fuel will be enough for only few years more. Energy’s quantity in solar light reaching Earth’s surface exceeds world energy necessity 10 000 times.