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

Abstract

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 layerthat 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 three-dimensional 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 100g/min, the maximum temperature of the modified cell with 60% BN and an aluminum back sheet is 66°C, while the conventional solar cell temperature is 108°C. Additionally, of the two cells, the modified solar cell produces the highest net power of 45W, and achieves the highest electrical and thermal efficiency of 17.5%, and 70.8%, respectively. Meanwhile, the conventional solar cell produces 34W, 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.