Numerical investigation of the effects of the nano-enhanced phase change materials on the thermal and electrical performance of hybrid PV/thermal systems

Hybrid PV/phase change material (PV/PCM) module and PV/thermal (PV/T) system are reported as showing low heat rejection and non-uniform PV temperature distribution respectively. Combining both systems and inclusion of nanoparticles in the PCM at different loadings, which enhances the thermal behavior of PCMs, is employed in this study, as a potential solution. Using numerically-validated model, the influence of a layer of nano-enhanced phase change material (nanoPCM), located below the PV panel, on the thermal and electrical performance of a hybrid PV/thermal is evaluated. The effect of different weather and operating conditions is also evaluated. The numerical simulation results illustrate that the hybrid PV/thermal system with PCM (PV/T/PCM) has a better performance as compared to the standalone PV system. Inclusion of different loadings from the Graphene nanoplatelets (GNP) in the Paraffin wax (PW) PCM enhances the cooling of the PV panel and shows higher electrical efficiency. As nanoparticles loading-percentage is increased, PV panel temperature is lowered and the electrical efficiency is increased. The effect of the nanoparticles on the heat absorption by the cooling fluid and the thermal efficiency variation depends on the weather conditions. However, in most cases, low loadings of nanoparticles leads to higher thermal gains. For two days in mid-January (winter) and mid-July (summer) in Dhahran (Saudi Arabia), the hybrid PV/T/nanoPCM system with 10% of nanoparticles shows higher electrical efficiency (6.9 and 22%, respectively) compared to the standalone PV system.