Experimental study of using Al2O3/methanol nanofluid in a two phase closed thermosyphon (TPCT) array as a novel photovoltaic/thermal system

In this study, a novel two phase closed thermosyphons (TPCTs) photovoltaic/thermal (PV/T) system was constructed that was able to generate electrical and thermal power simultaneously. Methanol and Al2O3/methanol nanofluid were used as working fluid of the thermal system. The effect of filling ratio (at levels of 30, 40, 50, and 60%) as well as Al2O3 nanoparticles concentration in the working fluid (at values of 1.0, 1.5, and 2 wt%) on electrical and thermal performance of the PV/T module was investigated experimentally. The results suggested an optimum value for the filling ratio and the nanoparticles concentration at 50% and 1.5 wt%, respectively. The PV/T module at these conditions had 14.52 °C lower panel temperature and generated 1.42 W more electrical power output than an equivalent conventional PV panel. Furthermore, energy and exergy efficiencies of the system were calculated. The average electrical energy, the average total energy (including thermal efficiency), and the total exergy efficiencies for PV/T module (working with nanofluid) at optimum operating conditions increased about 1.0, 27.3%, and 1.1% respectively compared to the conventional PV module.