Comparative energy assessment of bifacial floating photovoltaics with different module orientations

Floating photovoltaics (FPV) represent a rapidly expanding deployment pathway, offering land-use advantages and distinct thermal and optical conditions relative to ground-mounted systems. Inland FPV installations, however, are constrained by the limited surface area of water bodies, making configuration choice and area-use efficiency critical design parameters. Despite the emergence of various FPV geometries, such as gable east–west layouts and floating single-axis trackers, there remains a lack of comparative performance benchmarks to guide configuration selection. This study conducts a comprehensive evaluation of three bifacial FPV configurations, south-oriented fixed (S-bFPV), east–west gable (EW-bFPV), and horizontal-axis tracking (HAT-bFPV), under identical ≈ 1 MWp and Mediterranean climatic conditions. Long-term field measurements are combined with a calibrated thermal–electrical model implemented in the System Advisor Model (SAM) to assess annual and seasonal energy yield, thermal behavior, and energy density. Results show that the HAT-bFPV configuration yields 1967.44 MWh annually, outperforming the fixed system by 12% and reaching seasonal gains of up to 30%, whereas the EW-bFPV layout produces 13.8% less energy. In contrast, energy density favors the EW-bFPV design, achieving annually 2908.15 MWh/ha—44% and 37% higher than S-bFPV and HAT-bFPV, respectively. All configurations exhibit similar performance ratios (~0.90), while the HAT-bFPV system experiences higher array capture losses during summer. These benchmarks provide actionable insights for FPV design selection, highlighting the trade-offs among tracking performance, spatial efficiency, and thermal behavior under real operating conditions.