Photovoltaic Greenhouses: Comparison of Optical and Thermal Behaviour for Energy Savings

The production of energy from renewable sources, the diversification of the productive activities, and the development of photovoltaic technology and integrated systems have led to the development of solar greenhouses. The interest of the developers and designers is now to seek new approaches to combine the electricity and food production optimally. The interaction of factors as outside local climate, exposure, slope, soil, altitude, wind conditions, structural materials, or cultivated plant species, influences greatly the energy balance. This paper illustrates the comparison of optical and thermal behavior of a solar greenhouse and a similar glass greenhouse, devoted to the production of soil-less tomatoes in three different Italian areas, with computational aspects and methods of the TRNSYS simulation. Values of climatic parameters are obtained as a responce for the feasibility of the cultivation under PV modules. The results show energy savings both for heating and cooling due to PV panels, adding a new reason for the realization of these systems.