Performance Evaluation of Installed Bifacial PV Modules: Towards the Ground Albedo Enhancement

The growing deployment of bifacial photovoltaic (bPV) modules in large-scale utility PV power plants is driven by their potential to achieve higher energy output with minimal additional cost. The present study evaluates the performance of bPV modules installed in Grimstad, Norway, by analyzing their specific yield and assessing the impact of reflector integration on energy gains. A detailed review of ground reflectors used to enhance albedo and, consequently, bPV performance is presented. Reflectors were tested under real outdoor conditions to determine their effectiveness in improving bPV output. The installed system demonstrated substantial performance under Nordic conditions, achieving an annual specific yield of approximately 1282 kWh/kWp. The study evaluated two reflector types: white reflectors showed superior stability and consistent power gains, whereas semi-mirrored reflectors provided variable performance due to mismatch effects from uneven rear-side illumination. Experimental results indicated limited gains of 0.86-1.14% under optimal configurations, with some approaches yielding negative performance for semi-mirrored reflectors. These findings suggest that reflector implementation may not be economically viable for standard bPV installations until significant cost reductions are achieved. The study highlights the importance of experimental validation over simulation-based predictions, as optical interactions between reflective materials and atmospheric conditions may not be accurately captured by simulations. Future research should focus on utilizing larger areas for installation and exploring elevated configurations to fully validate the potential of reflector-enhanced bPV systems, while emphasizing their rentability.