Thermal solar panels utilize solar energy, which is captured by a solar collector, to produce thermal power that is subsequently transferred towards an accumulator for subsequent use. Therefore it is a device with a panel, with a heat exchanger where the fluid utilized for energy transfer circulate, and with a tank in which the power is cumulated.
Natural and forced circulation
The system can have either natural or forced circulation. In the natural circulation option the vectorial fluid, once got hot, floats – differently from the cold fluid – and it heads towards the exchanger where it releases heat.
This method is fairly cheap, also considering that with no pump, which wouldbe used to let the fluid move, there is no extra-electric energy expenditure.
In forced circulation, instead, fluid circulation occurs by the pump when the water inside the panels has a temperature superior to the fluid contained in tank.
This system makes panels slightly more efficient; but obviously its cost is higher. The hot water, therefore, can be used either as health hot water or in small environments, for houses and small housing complexes.
Panels for thermal energy
Hardly, however, it substitutes entirely the traditional methods of eating; this happens because of the solar energy unsteadiness, whose flux is influenced by seasons and other meteorological factors: for example, in cloudy weather the power produced is low.
Such an inconvenient, however, using new panels is going to disappear as heat will be absorbed also from solar rays’ infrared radiations. Panels will produce thermal energy even without sun reflecting directly on them.
Electric energy with panels
In addition to hot water, solar panels can be used to produce electric power. When water starts boiling, its steam activates a thermoelectric heat pump that produces electric power.
This device requires ample spaces, high investments and the continuous presence of the sun. Some of these power stations are already in desert, and in Italy one is under construction.
Domestic solar panels are a very worthwhile investment in medium-long period, so that its costs write off within 10 years and the device lasts also 20 years.
What is more, there are more and more fiscal reductions for those choosing this renewable energy, in addition to the environmental benefits deriving from a lower fossil fuel use.