干旱区生态环境知识资源中心

Agricultural efforts are normally carried in remote areas where electricity from national electric grid may not exist or grid connection is very expensive. Therefore, a stand-alone power supply is always in demand therein. In greenhouses, cooling and pumping equipments dominate the demand for electricity. The demand for electricity occurs during the periods when solar radiation is available and in abundance; an excellent harmony between demand and supply elucidates the feasibility of using solar energy. Therefore, utilization of solar energy for powering greenhouses in desert climate is considered amongst the important applications of solar energy and carries great significance and success. The main objective of this research project is to quantify the potential of using a photovoltaic (PV) system to power greenhouses. The greenhouse under investigation is located at al-Muzahmyah research station of the King Abdulaziz City for Science and Technology (KACST). The PV-greenhouse system consisted of the 14.72 kW PV arrays, a 3000 Amp-hr battery storage system, a 15 kWp power conditioning system, data measurement & collection system, and a 9 x 39 In fiberglass greenhouse. The solar radiation availability and the demand for electricity were studied and quantified to optimize the PV-greenhouse for desert climate operation. Several consecutive plantation cycles were completed. This paper describes the complete PV-greenhouse system and its components and presents the system operational performance under the Saudi Arabian and climate. The PV subsystem met the required load of the greenhouse under investigation. The performance of the PV subsystem, battery subsystem and greenhouse cooling system were satisfactory.