Photovoltaics 

Due to declining supplies of fossil fuels such as oil, gas and coal, renewable energies are becoming more and more important.
Energy needs increase every year and, according to forecasts from the German Solar Industry Association (BSW), they will double by 2050.
Just 0.01% of the sun's energy would be enough to cover the current global energy demand.
Photovoltaics are thus an important factor in terms of future energy supplies. 

What does photovoltaic means? 

The term comes from the Greek word for light (photos) and the name of Italian physicist Alessandro Volta (1745-1827).
Photovoltaics is based on the so-called photoelectric effect discovered in 1839 by Alexandre Edmond Becquerel (1820-1891) called "release of charge carriers in a solid body under the influence of light."

In 1905 Albert Einstein was able to explain the photoelectric effect properly, for which he was awarded the Nobel Prize for Physics in 1921.