IDEA: Photovoltaic panels are not efficient!
Because they are based on Silicon and it’s not efficient to convert light into electricity.
The maximum of valence band and the minimum of conduction band are not line up: an electron needs to move up and right to jump into conduction band.
To try to solve this issue you can change the Silicon or increase the efficiency.
Well,. this idea use the second one:
A parabola will focus all light in a small (cheaper) panel and increase the efficiency to 40% (now) and 50% (with more enanchment).
Actually, to get more energy, they split the light according to the wavelenght and this enable the creation of 4 different photvoltaic panels: one per colors (violet, blue, green and red).
The source is here [ITA]:
Energie rinnovabili, l’Italia all’avanguardia nel fotovoltaico