This article is about Photovoltaic systems (that use the solar energy technology) and Photovoltaic Street-Lamp (very useful in those areas where the powerline is not present). As long as the petrol prices are so high let's try to find some others energy sources.

The photovoltaic system (a solar energy based technology) is the system that uses solar energy technology to convert light in electricity. The conversion of the solar energy in electric energy, through the physical phenomenon of the luminous radiation interaction with the valence electrons in the semiconductor materials, is named photovoltaic effect. Let's explain, briefly, the semiconductor electric properties.