Every day, the sun pours 100 000 billions of Petroleum Equivalent Tons (PET) while in 1998, the world consumption was 9,8 TEP. Hence the tempting idea to convert even a tiny bit of this inexhaustible source of energy.

All the more that its availability is not the only asset of fossil energies whose stocks are drying up due to the big rise in energy demand - this rise mainly boosted by the arrival on the market economy of great powers such as India or China.

But these considerations might be rather far from the ones that preoccupied physisict Edmond Becquerel when he discovered in 1839 photovoltaic effect, i.e. the mean by which light is directly transformed into electric current.

In 1875, Werner von Siemens, German physicist and industrial describes the principle of a photovoltaic cell made of Selenium and exposes PV effect in semiconductors in front of Berlin Science Academy.

But we will have to wait more than 80 years before photovoltaic cells are used for industrial purposes; in 1958 the American space industry will use cells having a 9% output to supply satellites.

It is only following the first Oil Crisis of 1973 that solar energy was seen as an interesting source of energy, hence guaranting it a privileged place in the world energetic mix, and taking it away from its restraints of scientific elites. The first house supplied by PV cells was built in 1973 by the University of Delaware.

As the highly powerful experimental stations built at that time did not turn out to be profitable compared with the traditional solutions, photovoltaic systems proved to be satisfactory for small production units, situated in remote locations and disconnected from the grid. This technology thus found very quickly its place in many applications such as telecommunications, cold, pumping and lighting.

Photovoltaic technology really starts taking off at the end of the 90’s, with the arrival of grid connection, a technology that enables to inject on the national grid the energy produced by a PV generator and converted into AC current by an inverter.

For some years, several European regions and countries have conducted voluntarist policies aiming at accelerating the access to solar electricity by proposing funding solutions such as subsidies or the bying back at special rates of photovoltaic electricity by the national operators.

This grid connection concept allows a decentralization of the electricity production, which reinforces the energetic security of the users in case of failure of the power stations or of destruction of the distribution network at time of bad weather.

Photovoltaic technology seems to have promising days ahead if we take into consideration the announced shortage of fossil energies and the rising awareness of the people that we cannot carry on destroying our environment. However this technology does not represent only important stakes in the long run. Its development will generate favorable consequences in terms of employment and industrial development to all the states that have actively supported the creation of local industries.

The 21st century, century of renewable energies, century of the sun.

Let us hope for it.