Performance evaluation of new modified low-concentrator polycrystalline silicon photovoltaic/thermal systems

A modified polycrystalline silicon solar cell structure is introduced to enhance the heat dissipation process from the cell's silicon layer. The modification involves two steps. First, the Ethylene-Vinyl Acetate (EVA) layer underneath the silicon wafer of a conventional solar cell is replaced with a nanocomposite layer that includes an EVA matrix doped with Boron Nitride (BN) nanoparticles at different loading ratios of 20, 40, and 60%. Second, the Tedlar Polyester Tedlar (TPT) layer is substituted with a high thermal conductivity aluminum backing foil layer. To assess the enhancements to the modified solar cell in comparison to the conventional cell, a threedimensional thermo-fluid model is developed. The model is numerically simulated and the results are validated with the available experimental, numerical, and analytical results. The findings reveal that at a concentration ratio up to 3.5 where no external cooling technique is used, the modified cell attains a slight reduction in solar cell temperature compared to the conventional cell. On the other hand, at a concentration ratio of 20, where the solar cell is integrated with a microchannel heat sink, a significant reduction of cell temperature is observed compared to the conventional cell. It is found that at a concentration ratio of 20, and a coolant mass rate of 100 g/min, the maximum temperature of the modified cell with 60% BN and an aluminum back sheet is 66 degrees C, while the conventional solar cell temperature is 108 degrees C. Additionally, of the two cells, the modified solar cell produces the highest net power of 45 W, and achieves the highest electrical and thermal efficiency of 17.5%, and 70.8%, respectively. Meanwhile, the conventional solar cell produces 34 W, and attains an electrical and thermal efficiency of 13.5%, and 69%, respectively. These findings can guide designers in the industrial field to adopt this type of modified solar cell to improve the performance of low concentrator photovoltaic systems.