Thermal solar panels

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.

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Solar Power Solar System

The solar energy is a renewable power produced by the sun, a star around which the earth moves. The sun is the gravitational centre and the only thermal energy source of our solar system. This form of energy can be converted into both thermal and electrical power.

If this enormous quantity of energy was adequately exploited, it could guarantee economic savings as well as less pollution. It is, in fact, an ideal clean and renewable power source, since it has a limited environmental impact, compared to fossil fuel such as petroleum and coal.

Thermal and Photovoltaic energy

The thermal energy, which is absorbed from the sun’s rays by a solar collector, can be used to meet various energetic needs, such us the production of both hot water - for heating as well as sanitary use – and electric as well as mechanic power. The main difference between the thermal and photovoltaic energy is that the first uses the Solar Power produced by a solar collector to heat fluid circulation, while the second produces electric power.

The energy derived from the sun is 15 000 times bigger than the energy currently in use. But there are some problems: the not constant sun’s rays of lights and the law concentration for surface unit make the power stations very expensive. But in a near future, research investments could improve this form of energy production with tangible benefits to the community.

More efficient Photovoltaic Cells

Nowadays most of the studies aim to the production of more efficient and less expensive photovoltaic cells. More ambitious studies aim to the building of orbiting solar stations, which should be constituted of photovoltaic cells that convert the light of the sun into electric power to be conveyed, afterwards, through an antenna, on earth. These solar stations should have strong rays influx not interrupted from atmospheric or seasonal agents. To make the research on this type of applications slower are the high prices of them and the few funds addressed to this purpose. According to the current projects, these solar stations will be installed not in the near future, and surely not before the year 2040.

The biggest photovoltaic Italian station is near Salerno; it has been working from 1995. Another one, always from ENEL, will be launched in 2008 in Montalto di Castro (Vt): ten hectares of solar panels. In Brindisi, the biggest European photovoltaic park will be probably built on the ex-petrochemical pole area. It should be finished by the year 2010 and it is supported by University of Puglia.

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