Solar Power is an inexhaustible source continuously generated by the Sun's
internal nuclear reactions. This incredible quantity of power reaches our
planet as electromagnetic radiations that move in the air and reach the ground.
This energy is estimated to exceed by 15,000 times the world's needs.
In Italy, for instance, the daily average radiation over the course of one
year goes from 3.6 kWh per square metre in the Po Valley to 5.4 kWh per square
metre in Sicily. Practically, only an irradiated surface of less than 2 square
meters in Central Italy could produce enough solar energy to meet the yearly
needs of an average household (around 3,000 kWh).
A considerable portion of this energy can be used by photovoltaic or solar
thermal plants to produce electricity or hot water.
Solar Thermal Plants
They use solar radiation to produce heat. The main use is low temperature hot
water production (up to 80°C) for sanitary purposes and to heat private
In countries with a high solar radiation, electricity can also be produced, in
facilities that work with high temperatures and more sophisticated technologies
and are large enough to reach the capacity of an electric power plant.
Italy, with its 500 thousand square meters of solar thermal panels, is still
far from the performance achieved by European neighbours, like Germany, which
produces over 6.5 million square metres or Greece, 3 million.
They convert solar radiation into electricity by exploiting the properties of
semiconducting materials such as silicon, suitably treated to generate
electricity when the sunlight reaches them. The produced energy can be stored
in batteries, so that it can always be available, or it can be grid-connected
and used immediately.