Investigating the Effect of Cu-Al2O3 Hybrid Nanofluids on the Electrical Performance of PV/T Systems with Backward Step Flow Channel

Photovoltaic thermal (PV/T) systems, which generate electrical energy by harnessing solar radiation, often face efficiency challenges due to heat buildup. To address this issue, we propose a novel solution integrating a flow channel to facilitate coolant flow, thereby reducing the cell temperature. This study aims to numerically investigate the electrical performance of two-dimensional PV/T systems with a backward step flow channel using Cu-Al2O3 hybrid nanofluids. Employing COMSOL 6.2 software, we vary parameters such as Reynolds number (100-400), downstream height (0.25-0.7 mm), copper volume fraction (0.01-0.2), and inlet temperature (5°C-40°C) to examine their impact on cell efficiency (%). Our findings indicate that the cell efficiency decreases along the length of the channel. Increasing the volume fraction and Reynolds number improves cell efficiency, while higher inlet temperatures and downstream heights decrease efficiency. The study identified an optimal cell efficiency of approximately 5.99% with a copper volume fraction of 0.2. Specifically, efficiency improved by up to 0.23% with increased copper volume, decreased by 4.5% at 40°C, and increased by up to 0.33% with higher Reynolds numbers. However, increasing the downstream height reduced efficiency, suggesting that the backward flow channel did not benefit the system.