Investigation of optimal water utilization for water spray cooled photovoltaic panel: a three-dimensional computational study

Abstract

The study focused on the development of a three-dimensional computational model for water spray cooling of photovoltaic panels. A water spray cooling technique can ensure performance improvement due to a reduction in panel operating temperatures due to its self-cleaning effect. The model was used to estimate the optimal amount of overall water utilization for cleaning and cooling. Excess water consumption affects power requirements for the pump and affects the overall cooling system performance. The model was also used to investigate the flow rate impact of water ejected from the nozzles onto the panel temperature profiles. The model was successfully validated with available experimental data of panel temperature at different flow rates. An average deviation of 1.4 K between the simulated and experimental data was well within permissible limits. The dependence of water spray volume fraction on heat transfer coefficients between the PV panel and water was also studied to understand the heat transfer characteristics. The optimum flow rate for the efficient operation of the system containing a photovoltaic panel and pump was 170 L/h. At 170 L/h, the electrical efficiency of the panel was 15.73%, panel power output was 40.25 W and the pump power required was 0.77 W. A maximum power output of 39.48 W for the system was achieved at a flow rate of 170 L/h.