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renewable energy

Solar irradiation

Solar irradiation is uniformly spread across space, reaching the outer layer of the Earth’s atmosphere with a power equal to 1353W per square meter and the Earth’s surface, on account of absorption and diffusion, with a power of 1kW per square meter.

The solar energy arriving at the Earth’s surface annually exceeds 10,000 times the annual demand for energy of the global population and is greater than the reserves of fossil fuels or nuclear power.

Each year the energy supplied per square meter by the sun varies in relation to the season and latitude (in Central Europe it is estimated at 1.1kWh/m2), which is equal to the energy contained in 100 litres of oil.

Meteorological conditions in Italy are excellent for the exploitation of solar energy. The irradiation value is between 1200 and 1750 kWh/m2 annually with a difference between north and south of about 40%.

It goes without saying that the yield from this source is dependent on a number of factors: meteorological, geographic, orientation and inclination of the surfaces of the panels and so on.

As regards Italian latitudes the maximum yield is obtained by orientation the modules towards the south with an angle of 32-45 degrees vis-à-vis the horizon.

Under standard conditions (at 25° with 1kW/m2 irradiation) a cell produces roughly 1.5 Watts (Wp- peak power).