Photovoltaic painel

The term "photovoltaic" meaning "light", and "voltaic", meaning electric, from the name of the Italian physicist Volta, after whom a unit of electro-motive force, the volt, is named. The term "photo-voltaic" has been in use in English since 1849.

The photovoltaic effect was first recognized in 1839 by French physicist A. E. Becquerel. However, it was not until 1883 that the first solar cell was built, by Charles Fritts, who coated the semiconductor selenium with an extremely thin layer of gold to form the junctions. The device was only around 1% efficient. Subsequently Russian physicist Aleksandr Stoletov built the first solar cell based on the outer photoelectric effect (discovered by Heinrich Hertz in 1887). Albert Einstein explained the photoelectric effect in 1905 for which he received the Nobel prize in Physics in 1921. Russell Ohl patented the modern junction semiconductor solar cell in 1946, which was discovered while working on the series of advances that would lead to the transistor.

The modern age of solar power technology arrived in 1954 when Bell Laboratories, experimenting with semiconductors, accidentally found that silicon doped with certain impurities was very sensitive to light. Daryl Chapin, with Bell Labs colleagues Calvin Fuller and Gerald Pearson, invented the first practical device for converting sunlight into useful electrical power. This resulted in the production of the first useful solar cell with a sunlight energy conversion efficiency of around 6%.The solar battery was first demonstrated on April 25, 1954. The first spacecraft to use solar panels was the US satellite Vanguard 1, launched in March 1958 with solar cells made by Hoffman Electronics. This milestone created interest in producing and launching a geostationary communications satellite, in which solar energy would provide a viable power supply. This was a crucial development which stimulated funding from several governments into research for improved solar cells.
Photovoltaic painel is very usefull to product energy without polluting. Almost all countries are investing in the renovables energy to protect the environment. Besides most of people can´t buy this alternative because it is very expensive and profits are only visible in the long term!

By: Joana, Tina and Tânia ^^