Theoretical Study and Mathematical Modeling of Plate-Pin Fin Heat Exchanger for Solar Photovoltaic Cooling System R. Vijaykumar 1,a* , T. Mukesh 2,b , R. Rudramoorthy 3,c 1 Robert Bosch Engineering and Business solutions Ltd, Coimbatore, India 2 School of energy, PSG college of technology, Coimbatore, India 3 Principal, PSG college of technology, Coimbatore, India a vijaykumar.R@in.bosch.com, b mukeshmyst@outlook.com, c principal@psgtech.edu Keywords: Mathematical modeling, Plate-pin fin heat exchanger, PV/T collector, Fin spacing, Thermal modeling, Solar PV, PV cooling Abstract- Solar photovoltaic (PV) plays a major role in the renewable energy sector in the field of power production. Production of electricity from solar PV is gaining rapid importance due to its cleaner energy production capacity and it’s adaptability to various climatic conditions. PV cells suffer noticeable drop in efficiency as their operating temperature increases beyond a certain limit. In such cases cooling of the PV cells becomes mandatory. Since the efficiencies of PV cells are in the lower range (a maximum of 18%), a highly effective, inexpensive cooling system is necessary to be employed. Air cooling provides a solution to this cause and is meant to be an better counterpart to water cooling since it overcomes the problems of water cooling such as silt formation, evaporation, soiling and reflection losses. This paper presents a simple mathematical PV/T model to design the cooling system using plate-pin fin extended surface heat exchanger model. A relationship between the heat dissipated and the number of fins along with its dependence on individual fin area is also developed. This model will provide the researchers to design their cooling system according to their PV system geometry. Introduction Photovoltaic cells suffer from a drop in efficiency with the rise in temperature due to increased resistance. Such systems can be engineered to carry heat away from the PV cells thereby cooling the cells and thus improving their efficiency by lowering resistance. Various theoretical and experimental works have been carried out on the cooling potential and its corresponding potential effect on solar PV panel. Shuang-Ying Wu et al. [1] proposed a heat pipe photovoltaic/thermal hybrid system and showed that the overall thermal, electrical and exergy efficiencies of the heat pipe PV/T hybrid system corresponds to 63.65%, 8.45% and 10.26%, respectively. The possibility of using the waste heat from PV in a dessicant cooling machine was demonstrated by Li Mei et al. [2] and he achieved an average COP of 0.518. The feasibility of using fins and metallic sheets as cooling enhancing media is analyzed by J.K. Tonui et al. [3]. The use of a suspended thin flat metallic sheet and fins in an air duct was analyzed to improve its performance and achieved an efficiency improvement of 30% with fins and 28% with thin metallic sheet. The use of concentrating photovoltaic for higher energy yield also increases the thermal degradation of the PV cell material. Sendhil Kumar Natarajan et al. [4] investigated the use of fins for the cooling system. Based on a thermal model developed by him, he concluded that fins can be used to reduce the cell temperature. The possibility of cooling the solar PV by using water as a cooling media was carried out by R. Hosseini et al. [5]. He found out that a maximum temperature reduction of 18.7°C and a maximum