Hybrid cooling techniques to improve the performance of solar photovoltaic modules

Abstract

Photovoltaic (PV) module efficiency is often impeded by concomitant temperature elevations, which may lead to cell degeneration and decreased electrical efficiency. Cooling techniques are commonly used to avoid this problem; however, current techniques, such as water-sprayer and active cooling systems, still have limitations, including the scattering and reflection of photons. In this study, we present a new active dual-cooling system design using two thermoelectric cooling (TEC) units fixed to the back of a PV module to provide rear-end cooling, which were experimentally and numerically studied. A water-thin film cooling system (WFCS) was maintained at the top surface of the module using a small affixed 72-W DC pump, for improving efficiency. For testing, the system was installed on the roof of an agricultural building in South Korea, and its performance efficiency was compared with that of a reference cooling-free PV module. The results showed that the innovation led to a decrease in the module temperature to 21 °C, which led to an efficiency improvement of 11.23 % with an increase in the daily output energy of 8.3 %. Additionally, a numerical simulation model based on the Finite Element Method (FEM) was used to evaluate the temperature profile of the PV module owing to the cooling technique and temperature distribution on the module’s top surface. The maximum temperature reductions were 17.27 and 12 °C in the experimental and simulation results, respectively.