An increasingly popular useof solar energy involves solarelectric systems, called“Photovoltaics” .
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Photovoltaic (PV) systems convertsunlight directly into electricity , andare potentially one of the most usefulof the renewable energy technologies.
There are three typesof Cells
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Monocrystalline Cells
•They are obtained froma single large crystalof silicon.
•They are used for hotclimates .
Polycrystalline Cells
•They are obtained frommany silicon crystals.
•They are used forcontinental climates.
Amorphous Cells
•They are formed by stripsof amorphous silicon.
•They are used for coldclimates.
Benefits of Solar
•Absence of pollutantemissions ;
•saving of fossil fuels ;
•High reliability
•Reduced maintenance costs ;
•Modularity of the system .
Disadvantages ofPhotovoltaic
•High initial investment ;
•High available surface withrespect to installed capacity
•Variability and uncertainty ofthe energy source ( solarradiation ).
How much electricity does a photovoltaicsystem produces in one year time?
It depends on several factors:
•Solar radiation ;
•Orientation andinclination of the surface ofthe modules;
•Absence / presenceof shading;
•Technical performance ofplant components .
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The production of1 kWh electricity needsapproximately 2.56kW of combustion fossilfuels . Air combustionemits about 0.53 kg ofcarbon dioxide . So,every kWh produced bya photovoltaicsystem limits theemission of 0.53 kgof carbon dioxide (CO2).