photovoltaic

The photovoltaic panel are constituted by sylicon cells that permits to produce electric energy if irradiated by the sun light.

Single photovoltaic modules are usually mechanically assembled through a framework that protects them by atmospheric agents, living life to the photovoltaic panels. The panels are installed in a position in which they can be exposed to the sunbeams (roofs, terrace, courtyard).

There are two types of installations:

1. Stand alone: are installations not connected to the electric net and that requires the installation of batteries to accumulate energy that can be used when there isn’t the sun. During the day the photovoltaic installation will produce energy for users and for the charge of the battery. During the night the batteries will act as energy generator. The energy produced from this type of installations, doesn’t have the incentives foreseen by the Conto Energia.

2. Grid connected: are connected to an electric net, allowing to give at the supplying company the surplus of the energy produced and to collect from the net when the photovoltaic system is off or doesn’t produce a sufficient quantity of energy to satisfy the request of users.

The collection is done by the net. In the hours in which the photovoltaic generator doesn’t produce sufficient energy to satisfy the request (for example in the hour of biggest charge or during the night), is the net that supplies the energy requested. Vice – versa if the photovoltaic system produces more energy than what is requested, the surplus is transferred to the net.

HOW THEY WORK

Photovoltaic means: photo = light and Voltaic = Alessandro Volta (the inventor of battery).

The base component of panels is the photovoltaic cell, constituted by a semiconductor, squared foil of little dimensions. A module is constituted by a variable number of cells in series.

Every single photovoltaic cell can produce 3,5 watt of power at a standard temperature of 25°C. The power of the panel will vary on the base of the number of cells connected in series. To transfer the current produced by modules at the net a series of transformation and adaptation devices are needed.

The electric energy of the module pass through these devices in order to adapt the continuous current and transform it in alternate current with the correct values of tension and frequency requested by the net manager.

The energy modified is introduced in the electric net to feed the local electricity consume or to give it at the net.

ADVANTAGES

The installation of a photovoltaic system permits to:

• produce and use free energy for 30 years;
• obtain a state funding for 20 years at free grant (incentive tarif regulated by Conto Energia) that permits to recuperate the 100% of the purchase cost of the installation within the first 7 – 9 years and to realize good profits in the following 10 years;
• reduce pollution;
• give value to the building;
• transmit a “green and clean” image;
• have low maintenance costs;
• occupy surfaces not used in a building and save ground that can be exploited in other ways;
• use electric energy in the same place in which it is produced, with consequently reduction of dispersion.