1 AIT Asian Institute of Technology

Efficiency improvements in photovoltaic water pumping systems

AuthorKosie Yongyukantorn
Call NumberAIT Thesis no. ET-01-19
Subject(s)Solar pumps
NoteA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development
PublisherAsian Institute of Technology
AbstractAdequate supply of water for chinking and irrigation is essential for improving the quality of life in rural and remote areas. In areas where there is no electric grid, PV based water pumping system is an attractive option. However, their efficiencies are low and increasing efficiencies usually require expensive modification. This study investigated two low cost options to improve the efficiency of PV water pumping systems. The first is the use of mirrors to increase the radiation falling on the panel. The second is the use of spray cooling to reduce temperature of PV panel. The study analyzed the performance of PV water pumping system by conducting experiments to observe how efficiency could be improved by these techniques. Theoretical studies on addition of mirror was first.done to obtain the size and tilts required and ascertain by how much the increase in radiation could be obtained. The results of these estimations were first tested in laboratory. The system comprised of 7 panels, DC/AC 3 phase inverter and multistage centrifugal submersible motor/pump. Incident radiation, temperature, current and voltage were measured to estimated the DC power from PV panel and to find the efficiency of the system during different climatic conditions. The booster mirror was set up above and below PV panel. Due to additional radiation by booster mirror, it was observed that water pumped increased by 1 m3 /day (11 %). Field studies to verify the theory and experimental work were conducted at a PV water pumping system. The system comprised of 120 PV panels connected to two motor/pump units and used for ilTigation. The efficiency of PV panel, inverter, motor/pump and overall were obtained before and after installation of booster mirror to one motor/pump system. Data collected during a month for comparing the efficiency before and after modification and with the second unit, shows that the performance of system improved and the water pumped increased by 8 m3 /day or by 8.7%. A simple financial evaluation showed that this method has a payback time of around 2-3 years. The second method used was the spray cooling system. The PV panel was cooled by spraying water and thus reducing its temperature. The temperature on panel, solar radiation and DC power from PV panel were also measured. Studies show that about 20 °C temperature reduction was obtained at near noon condition which could enhance the PV panel efficiency .. Analysis shows that the performance of PV panel increased by 0.0117 % per temperature reduction per water sprayed per area and the average efficiency improved by about 0.3%. Improving the efficiency of PV water pumping system using these low cost methods has been demonstrated theoretically and by experiments both in laboratory and in field.
Year2001
TypeThesis
SchoolSchool of Environment, Resources, and Development (SERD)
DepartmentDepartment of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC))
Academic Program/FoSEnergy Technology (ET)
Chairperson(s) Kumar, S.
Examination Committee(s)Surapong Chirarattananon;Rajapakse, A.D.
Scholarship Donor(s)Royal Thai Government
DegreeThesis (M.Eng.) - Asian Institute of Technology, 2001


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