SARDINIA P.TORRES 22-01-12 27-01-12

Photovoltaic

Photovoltaic :Energy for the New Millennium

An increasingly popular use of solar energy involves solar

electric systems, called “Photovoltaics” .

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Photovoltaic (PV) systems convert sunlight directly into electricity , and are potentially one of the most useful of the renewable energy technologies.

There are  three types of

Cells Monocrystalline cells Polycrystalline  cellsAmorphous cells

Monocrystalline Cells

• They are obtained from a single large crystal of silicon.

• They are used for hot climates .

Polycrystalline  Cells

• They are obtained from many silicon crystals.

• They are used for continental climates.

Amorphous Cells • They are formed by strips

of amorphous silicon.

• They are used for cold climates.

Benefits  of Solar

• Absence of pollutant emissions ;

• saving of fossil fuels ;• High reliability • Reduced maintenance costs ;• Modularity of the system .

Disadvantages  of Photovoltaic

• High initial investment ;

•High available surface with respect to installed capacity

•Variability and uncertainty of the energy source ( solar radiation ).

How much electricity does  a photovoltaic system 

produces in one year time? It depends on several factors:• Solar radiation ;• Orientation and

inclination of the surface of the modules;

• Absence / presence of shading;

• Technical performance of plant components .

How much CO2 does a photovoltaic system

reduce ?

The production of 1 kWh electricity needs approximately 2.56 kW of combustion fossil fuels . Air combustion emits about 0.53 kg of carbon dioxide . So, every kWh produced by a photovoltaic system limits the emission of 0.53 kg of carbon dioxide (CO2).

PHOTOVOLTAIC IN SARDINIA

“Su Scioffu”In Sardinia (Villasor), was inaugurated the largest photovoltaic plant greenhouses in the world.

The photovoltaic plant is located in the south-west of the island, it covers about 26 hectares, is capable of producing 20 megawatts of clean electricity.