Experimental investigation of photovoltaic thermal (PVT) system incorporating water-copper oxide nanofluid

The present study investigates energy performance characteristics by incorporating spiral flow rectangular thermal absorber using water, CuO-water nanofluid and comparing it with a non-cooled PV system. The study aims to introduce advance method to enhance thermo-electrical performance and lifespan of PV by reducing PV surface temperature. The study present newly designed PVT configuration, nanofluid preparation, characterization at altering concentration, experimental methodology and its significance in identifying the optimum design of PVT system. The non-cooled system reached an average PV temperature of 61.4 °C reduced to 50.80 °C with water cooling and further reduced to 45.30 °C with nanofluid-associated cooling. The electrical efficiency of PVT with nanofluid was 9.05 % which was 7.1 % with water cooling and limited to 5.74 % for non-cooled systems. The thermal efficiency of nanofluid PVT was 67.40 % which was 56.52 % higher than water-cooled PVT due to improved heat recovery by nanoparticles. The energy-saving efficiency of PVT with water and PVT with nanofluid coolant was 20.91 % and 31.22 % respectively. It was seen that increasing nanoparticle concentration increases heat transfer thereby electro-thermal efficiency of PVT with nanofluid. The study was performed for 1 -5wt% CuO-nanoparticle concentration and found that the highest thermal, electrical, and energy-saving efficiency of 67.40 %, 9.05 %, and 31.22 % were obtained at 5 wt% concentration values. It is concluded that designed PVT system maximize performance efficiency than water and conventional non cooled system and can in implemented in large scale and has potential in domestic and industrial applications for commercialization with slight modifications. It was also found that increasing nanoparticle concentration also increases friction factor and pressure drop and also carries additional manufacturing and processing costs as a counterpart.