Currently, the solar energy is exploited for the housing water heating through uses of thermal collector, and for the electric power production, thanks to the employment of photovoltaic panels. In the first case the main limit is the cost, whereas in the second, there is also the problem of the low efficiency of PV panel. This is due to the fact that the semiconductor material in the photovoltaic panel absorbs mainly the visible part of the solar radiation. At the same time, the phenomenon of the degradation of the silicon with the temperature increase cannot be neglected. and attain the 20% in hot summer days. However, it can be noticed that 2 centimeters of water are enough for strongly reducing the infrared solar radiation with a very small decrease of the panel efficiency. This reduction is partially compensated from the best efficiency obtained maintaining the silicon to relatively low temperatures.
Such considerations are the base of the idea that allows the realization of an hybrid systems in which the production of heat and electricity go together in an unique apparatus constituted from a photovoltaic system shielded from a water layer.
Thermal-photovoltaic panel TESPI is constituted from a water layer, of few centimeters, superposed to the photovoltaic panel. In the back part of the cell, an insulating layer reduces the thermal losses. The water circulates in the front part of the panel where it reaches the temperature 60-70°C , and is extracted and stored in a tank for domestic uses. The photovoltaic cell, at the same time, protect from an excess of radiation, can produce the electric energy without losing efficiency for the otherwise unavoidable problems of thermal drift. The apparatus therefore is in a position to taking advantage of the solar energy totally, proposing a thermal efficiency comparable to that of a standard thermal panel and an electric efficiency slightly better than a conventional photovoltaic system.
Although the state of the art present several solution that couple the production of thermal energy with that electric one, the TESPI particular architecture gives better performances optimizing the yield of conversion of the solar energy in thermal and electric energy . Furthermore the production costs are very low since they are limited to the substitution of the aluminum frame with the suitable polycarbonate box.
We receive many requests about the possibility of using our hybrid panel (photovoltaic and thermal) TESPI.
Thanks for your interest and we remind that we are working on putting into production of the panel with commercial standards and certification appropriate.
Recall that:
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The panel TESPI is based on an Italian and European patent owned by TESPI company (SIT srl and APRI Sviluppo are the shareholders).
The panel used as a basis regular photovoltaic panel that is mounted in a polycarbonate that allows the movement of water and glycol on the outside, exposed to solar radiation.
The panel must be connected to a standard inverter for the electric and a heat exchanger for the heat by current standards for normal thermal panels
The efficiency of the photovoltaic system is slightly longer than the standard trim panel, the thermal efficiency is that of normal thermal collectors.
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The land required for a photovoltaic system is 3 kW, depending on the area of 20-30 sqm, while the heat demand for a user is familiar with it fulfills a heating system of about 5 square meters. Consequently the plant TESPI has two different forms:
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TESPI partial coverage of the photovoltaics
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Total coverage, in which case the supply current 30 square meters for a living unit and heat for 4 standard units (suitable for condominiums) or additive heat for other purposes: swimming pool, dry, more.
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Thank you for your interest
The TESPI srl staff
