A comparative study on bifacial photovoltaic/thermal modules with various cooling methods

The bifacial photovoltaic/thermal module is an emerging concept that can provide electricity and heat simultaneously, taking advantage of both front and rear sides of the panel; therefore, exhibiting a better performance compared to a conventional photovoltaic module or photovoltaic thermal module. In this study, four configurations of the bifacial photovoltaic/thermal module with different cooling methods have been proposed, i.e., cooling performed at either the upper or the lower surface, in parallel (applied to both upper and lower surfaces having similar start/endpoints), and swinging air back and forth (by guiding the air over the upper and lower surfaces, respectively). The computational fluid dynamic software is used to numerically investigate the performance of the studied configurations, and a novel radiation model is used to study bifacial photovoltaic/ thermal modules in steady-state and transient conditions. This study demonstrates that the system with back and forth channel performs best if thermal energy/exergy is more important while the bifacial photovoltaic/thermal module with lower side channels is a better option in terms of electrical output. The transient simulation shows that the system with lower side channel can generate more electrical power on sunny and cloudy days. Also, seasonal analysis shows that the average of overall energy and exergy output of the module with back and forth channels can reach 230 and 45 W in the summer. Interestingly, increasing albedo from 0.1 to 0.9 reduces electrical efficiency from 13.5% to 12.7%, while thermal efficiency rises from 52% to 57%.