Photovoltaic solar energy: Generating electricity from sunlight

Do you know that, in the Sixties, satellites in earth orbit were equipped and powered with solar panels? Between that first use of solar panels in space and the applications we see today, much progress has been made.

centrale-photovoltaiqueFree, inexhaustible, and clean – solar energy is one type of renewable energy that continues to grow in use. In 2012, the share of solar energy in France’s electricity production grew by 62.5% ! And today, solar energy is even used to power road signs. How have we managed to generate electricity from a ray of sunlight?


 

Solar energy resources

Solar panels are installed in linked arrays. Under the influence of sunlight, a conducting material (silicon) contained in each cell releases electrons to create a direct electrical current. The latter is transformed into alternating current by an inverter so it can be more easily transmitted over lines in the medium voltage grid.

 

What about solar thermal energy?

When we speak of solar energy, we must not forget solar thermal energy, which transforms sunlight into heat and can heat water. The first solar hot water heaters appeared early in the 20th century in California.


Installation of solar panels by VINCI Energies

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For VINCI Energies business units, photovoltaic solar energy concerns two main markets. The first is ‘photovoltaic roofing’: the installation of small to medium surface areas on industrial buildings, parking garages, hypermarkets, etc. The second is high-power photovoltaic farms (above a megawatt) covering several hectares. VINCI Energies business units can thus take care of the installation and connection of panels or provide a complete package, including relations with the panel manufacturers and preparing simulations of return on investment.

Using the latter approach, the Group put into service the Estezargues photovoltaic power plant on a site of 20 hectares located near Avignon, making it the largest photovoltaic park completed by VINCI Energies. Also in France, the Group participated in the construction of the solar farms of Mées , Miradoux and Montéléger by installing photovoltaic panels. The two latter facilities each have the capacity to provide electricity for about 4,500 homes. Even in town, VINCI Energies installs photovoltaic panels: In Bordeaux, 60,000 solar panels were installed on parking shelters at the Bordeaux exhibition grounds, resulting in the largest urban photovoltaic park in France. The total surface area was the equivalent of 27 football fields1! In Brazil, Cegelec installed solar panels on the Maracaña stadium in Rio de Janeiro. The Group also provides maintenance services for certain photovoltaic facilities.

Hybrid facilities?

Research is also being done on hybrid diesel-solar power plants. For existing diesel power plants, the addition of solar energy reduces the consumption of diesel by many litres thus significantly reducing the maintenance costs for diesel generators due to the lower load factor.

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