Use of Semi-transparent Photovoltaic Films as Shadowing Systems in Mediterranean Greenhouses

摘要

In Mediterranean greenhouses, active and passive cooling systems are almost always needed due to high values of solar radiation (nearly 1000 Wm~(-2)) -especially during summer season- and high values of air temperature (near 40°C). Nevertheless, the use of the above-mentioned systems imply the increase of the operating costs of greenhouses. The aim of the present study is to investigate the possible use of semi-transparent photovoltaic covers as shadowing systems in Mediterranean greenhouses. In order to reach this goal, the energy transfers have been calculated and the energy balance for a greenhouse has been determined. More precisely, three cases have been taken into account: traditional cover with EVA (Ethylene vinyl acetate)film, cover with double film, namely EVA for the internal part and polyethylene for the external one, and cover with double film, namely EVA for the internal part and semi-transparent photovoltaic film for the external one.