Assessment of condensation and thermal control in a photovoltaic panel by PV/T and ground heat exchanger

Abstract

Solar photovoltaic panels are experiencing lower performance due to two reasons, high diurnal surface temperatures and nocturnal dew accumulation leading to mud formation on the surface of photovoltaic panels. The current paper presents a collective solution for the two problems of elevated cell temperatures and dew formation using a photovoltaic/thermal unit integrated with ground embedded heat exchanger. The proposed technique was assessed experimentally and mathematically. An experimental setup implemented in the solar research site of Universiti Teknologi PETRONAS was subjected to a series of measurements under various operational and environmental conditions. A mathematical model of the integrated solution was developed in MATLAB/Simulink environment. With only 6% error in PV surface temperatures, the mathematical model results and experimental measurements were in good agreement. The model determined the daily and annual variation of the PV surface temperature based on two real-time weather data sets: first, the nearly constant tropical climates as in Malaysia and secondly, the transient climatic conditions as in the desert of Qatar. The results show that the suggested idea of integrating a PV/T panel with an underground heat exchanger is able to increase the annual PV efficiency by 9%. This is due to a substantial reduction of diurnal PV cell temperatures and to resolving the setback of nocturnal dew formation.