Photovoltaic

Photovoltaic technology is based on the photoelectric effect. When certain materials, called semiconductors, are exposed to solar rays, electrons from the valence band could be excited to the conduction band. In order to do so, the energy of the photons (sunlight) must be equal to or be above the break energy (band gap) between the valence band and the conduction of the semiconductor.

When this effect takes place, the physical structure of the semiconductor creates an electric field which sets the electrons path, thus generating direct electric current.

This way, the conventional electrical performance starts: the direct current produced goes to the electrical inverters which convert it into alternating current.

On a larger scale, continuous electrical power provided by photovoltaic panels can be  transformed into alternating current and be injected into the Grid. There are subsidies for a greater viability of the process.

The process, simplified, is as follows: energy is generated at low voltages (380-800 V) and at direct current. An inverter transforms it into alternating current. With a processing voltage, it rises to medium voltage(15 or 25 kV) and then it's reinjected into the networks of the company.