Experimental investigation of nanofluid usage in a photovoltaic thermal (PVT) system

In this study, a Photovoltaic Thermal System (PVT) is coupled with a partitioned rectangular-shaped aluminum-made cooler design, which was placed on the rear surface of the PV panel. The cooler blocks, which come in five types that differ in the dimensions, have been arranged in different configuration modes share the same total contact area with the back surface of the panel (Mode-I, mode-II, mode-III, mode-IV, and mode-V) to study their performances comparatively in terms of electrical and thermal efficiencies as a function of various levels of solar radiation and volumetric flow rates using two fluid types. Water was applied first in all configuration modes to obtain the results, and then they were further optimized by Response Surface Methodology (RSM) to recommend the best performance combination that satisfy the highest results to apply various concentrations of TiO2/water nanofluid in that mode. The highest electrical efficiency was obtained by mode-III to be 19.39% at 1.50 L/min and 900 W/m2, while the highest thermal efficiency was obtained by the same mode with a value of 63.72% at 0.50 L/min and 300 W/m2. The RSM recommended mode-III to be the best performance and TiO2/water was applied in that mode. The highest electrical efficiency was obtained with 0.3 wt% 21.71% at 1.50 L/min and 900 W/m2, while the highest thermal efficiency was obtained with the same concentration at 72.49% with a value of 63.72% at 0.50 L/min and 300 W/m2.