It is an electric system that exploits solar energy to produce electrical energy by means of the photovoltaic effect (converting solar energy into electricity). This process is made possible by the physical properties of silicon.

The system consists of:
- photovoltaic basic cell;
- photovoltaic module containing individual cells, electrically interconnected;
- string, i.e., the assembly of modules or panels, electrically connected to obtain the correct voltage and direct current;
- inverter (checks regular operation and detects failures);
- photovoltaic generator, i.e., assembly of several strings.

There are two main types of photovoltaic systems:
- "isolated";
- "connected to the electrical network";
Isolated – it is generally low-powered and not connected to the electrical network. The current generated is stored in batteries. The cost is rather high due to the batteries and the system requires permanent scheduled maintenance.
Connected to the electrical network – the energy produced is quickly used or transferred to pre-existing network. It requires minimum maintenance and the system cost is definitely moderate. There are two types of connection:
Net metering – for systems up to 20 kW, the quantity of energy transferred is the quantity consumed, if one’s consumption is known. Instead, if production is greater, the distributor does not pay for it, but opens a credit for the following three years.
Total transfer – in case of large energy quantities and without self-consumption, all the energy produced is transferred to the distributor.

In the design stage, we study the requirements of the system according to individual needs and calculate what incentives are thereby applicable, as provided for by the decree of 19th February 2007.