The photovoltaic technology allows you to transform directly into electrical energy the energy associated with the solar radiation.

It takes advantage of the so-called photovoltaic effect, based on the properties of certain semiconductor materials (the most widely used and the silicon, a very widespread in the nature) that, suitably treated, are able to generate electricity if affected by radiation Bright. 

The elementary device capable of operating a conversion of solar energy it defines photovoltaic cell and is able to produce a power of about 1.5 Watts. The basic component, commercially available, and instead the module consisting of multiple cells connected and encapsulated. 

More photovoltaic modules, which are connected in series and in parallel, form the sections of a plant, whose power can vary from a few hundred watts to million Watts.

The correct exposure to solar radiation of photovoltaic modules represents a key factor in order to obtain the optimum performance of the system in terms of manufacturability of electric energy. 

For example in Italy optimum exposure and toward the south with an inclination of about 30-35° degrees. In the map is shown for the italian territory the manufacturability of a photovoltaic system from 1kWp, optimally oriented and inclined, installed on a fixed structure (roughly from North to the South of Italy the specific production is variable from 1000 to 1400 kWh per kwp installed). 

In addition, each kwp installed requires a net space of about 8 - 10 m2 if the modules are installed in a coplanar to the surfaces of relevance of buildings;

Instead, we need a larger space if the plant is installed in several successive rows on support structures inclined placed on flat surfaces.

The configuration of the system provides for the inclusion downstream of photovoltaic modules of an inverter which converts the direct current generated by the cells in alternating current which can be used directly by users.          

Finally, the system is completed by a support structure to hold the modules to the surface of installation: the ground, the roof, facade, wall, etc. The structure can be fixed or movable, able to follow the sun along its path daily throughout the year.