Thermal Modeling and Simulation of a Photovoltaic Greenhouse Prototype

Abstract. The integration of solar photovoltaic (PV) technology into greenhouse systems brings electricity and food production together into a complimentary arrangement that maximizes the use of solar radiation and land. Such systems have the potential to achieve year-round controlled food production with net-zero energy consumption. This paper investigates options for PV integration into a passive greenhouse system used for lettuce production. A thermal network model is described. The model is used to simulate the response of the PV greenhouse system to annual and daily variations in environmental conditions. Indoor temperature, light availability, and PV energy conversion are evaluated. Results suggest that PV integration does not affect night time temperatures, and therefore does not limit production of cold sensitive crops. Moreover for heat sensitive crops, daytime shading may extend the growing season. PV does reduce light availability leading to a reduction in expected crop yields. This loss in yield however is less than the value of the electric energy produced by the panels, suggesting that the arrangement can make more efficient use of land and sunlight.