Energy analysis of bifacial photovoltaic systems on different soils and orientations in a coastal low-latitude area

Abstract

Coastal low-latitude regions exhibit consistent annual solar irradiance, offering stable solar resource availability that enhances their suitability for year-round photovoltaic energy generation. This study analyzes the annual energy production of bifacial photovoltaic (PV) systems under varying ground albedo conditions and installation orientations, accounting for the effects of tilt angle, ground clearance height, ground coverage ratio (GCR), and row spacing. Meteorological parameters were derived from Japan's Himawari-8/9 satellite data, which were integrated into the System Advisor Model and the National Renewable Energy Laboratory database to compute front‑ and rear‑side solar irradiance. Electrical measurements from bifacial PV systems were used to evaluate annual energy output and bifacial gain. Results demonstrate that landscape-oriented bifacial PV systems consistently outperformed portrait-oriented configurations in both energy production and bifacial gain. For systems with optimized parameters, landscape orientations achieved annual energy outputs 0.70%, 0.51%, and 0.42% higher than portrait orientations for white dry sands, white sands with granite rocks, and white wet sand substrates, respectively. Similarly, bifacial gain values for landscape-oriented systems reached 18.64%, 15.47%, and 12.43% across these substrates, surpassing portrait-oriented systems. The findings highlight the crucial influence of ground albedo and panel orientation on optimizing the performance of bifacial photovoltaic systems in coastal low‑latitude regions.