Determining the effect of soil albedo on energy production of bifacial photovoltaic panels

Abstract

The performance of bifacial photovoltaic (PV) systems is strongly affected by site-specific environmental conditions, making field-based analyses essential for reliable performance evaluation. This study investigates the effect of ground albedo on the energy performance of a 686 kWp utility-scale bifacial PV power plant located in Konya, Türkiye, with primary emphasis on real operational data obtained under actual climatic conditions. The analysis is based on eight months of measured production data (March–October 2024) collected from two identical bifacial PV arrays installed over different ground surfaces: natural soil (albedo ≈ 0.20) and white gravel (albedo ≈ 0.50). Field measurements indicate that the system installed over white gravel produced 496.49 MWh, compared to 476.87 MWh generated by the soil-based system. This corresponds to an additional energy yield of 19.63 MWh and a relative increase of 4.26%. Monthly evaluations show that albedo-induced gains are more pronounced during periods of moderate solar altitude, while remaining positive throughout the entire measurement period. Numerical modelling and shading analyses were employed as supporting tools to interpret observed trends and assess long-term behavior. Shading simulations identified a fixed tilt angle of 25° as the most suitable configuration, providing an optimal balance between rear-side irradiance collection and shading losses. PVsyst simulations predicted an annual energy gain of 3.89% and a 3.25 percentage-point improvement in the performance ratio when ground albedo was increased from 0.20 to 0.50, consistent with the tendencies observed in the field data. Overall, the results confirm that ground albedo enhancement offers a consistent and measurable performance benefit for bifacial PV systems. High-reflectance surfaces such as white gravel represent a low-cost, passive, and practical strategy for improving energy yield and system efficiency. These findings provide valuable guidance for the design and optimization of fixed-tilt, utility-scale bifacial PV installations, particularly in high-irradiance, semi-arid regions.

Keywords

• Albedo
• bifacial photovoltaic panels
• shading analysis
• solar energy

Kaynakça

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