Factorial analysis and experimental study of water-based cooling system effect on the performance of photovoltaic module

Abstract

A study of the performance of a photovoltaic system with water cooling was carried out experimentally. Three main parameters, namely the water flow rate, the setpoint temperature of the photovoltaic panel, and the maximum allowable temperature difference of the photovoltaic panel, were investigated. In addition, the effect of dust accumulation, in terms of the cleanness factor, ambient temperature, and relative humidity, was studied. An experimental setup was constructed to investigate the cooling effect of water flowing over the panel surface on the performance of a photovoltaic module built at the campus of Jordan University of Science and Technology. Cooling of the photovoltaic module was performed for the period from June to September 2015. The photovoltaic module temperature was controlled to be between 30 and 50 °C, with different levels of water flow rate: high, medium, and low, i.e., 0.9, 0.6, and 0.3 m3/h, respectively. In addition, a statistical factorial analysis of the three-level full factorial design for the experimental data was conducted. It was found that the photovoltaic system performance was higher under water-cooling conditions. The optimum photovoltaic panels cooling temperature was shown to be 37 °C. The designed cooling system achieved an acceptable percentage of excess energy production, i.e., 15.28–17.75%, with minimum water losses. Furthermore, it was found from the statistical analysis that the setpoint temperature of the photovoltaic module had the largest effect on the percentage of excess energy production from photovoltaic, while the effect of maximum allowable temperature difference was negligible.