Outdoor Performance Comparison of Bifacial and Monofacial Photovoltaic Modules in Temperate Climate and Industrial-like Rooftops

To fully exploit the advantages of bifacial PV (bPV) modules and understand their performance under real-world conditions, a comprehensive investigation was conducted. It was focused on bPV installations with some mounting constraints, as in industrial rooftops, where the ideal high module-to-ground height for optimal bPV performances is not feasible due to structural reasons. The experimental setup involved measuring the I-V curves of conventional and bifacial modules under diverse atmospheric conditions, including different solar irradiance levels and ambient temperatures, as well as mounting configurations. The results show a proportional increment of power generation between 4.3% and 7.8% if compared with two different conventional modules and a bifacial power gain between 2 and 15% under identical conditions. Additionally, the negative potential influence of the mounting structure was observed. Small differences in the alignment between the module and structural beams can virtually eliminate the bifacial contribution, with an estimated reduction up to 8.5 W (a potential bifacial gain of 3.43%).