Energy and exergy assessment of a photovoltaic-thermal (PVT) system cooled by single and hybrid nanofluids

Photovoltaic-thermal (PVT) concept is a novel methodology to lower the PV module temperature and consecutively produce thermal and electrical energies. This study assesses the thermal and electrical advancements of a PVT system using iron oxide (Fe2O3) single nanofluid and titanium oxide-iron oxide (TiO2-Fe2O3) hybrid nanofluid at 0.2 % and 0.3 % concentrations. The PVT energy and exergy efficiencies were presented and analyzed concerning the effect of proposed single and hybrid nanofluids. Study findings disclosed that dispersing 0.3% of TiO2- Fe2O3 nanocomposites into water has enhanced the nanofluid thermal conductivity, improving the Nusselt number by 90.64 %, while Fe2O3 nanoparticles achieved 31.75 %. Furthermore, employing TiO2- Fe2O3based nanofluid at 0.3 % has enhanced the PVT electrical efficiency by 13 % and, thermal efficiency by 44 % compared to Fe2O3-based nanofluid, which exhibited 12 %, and 33 %, respectively. Besides, the PVT electrical exergy efficiency was augmented by about 13 % using TiO2-Fe2O3-based hybrid nanofluid, against 11 % using Fe2O3 nanofluid. Reversely, the pressure drop was increased by a maximum of 62.9% when TiO2- Fe2O3 was applied due to the raised nanofluid density compared to the reference base fluid. Conclusively, hybrid nanofluid has a superior influence on the PVT performance than single nanofluids. However, further investigations are required to explore cost-effective hybrid nanofluids with a low pressure drop.