Wind-induced loads on photovoltaic (PV) panels on low-sloped gable roofs: Panel size effects

This study evaluates the aerodynamic performance of photovoltaic (PV) panels mounted on gable roofs, examining the effects of panel size, orientation (portrait vs. landscape), and coverage (full vs. partial) on wind-induced loads. Twelve configurations were tested at the NHERI Wall of Wind Experimental Facility to assess PV panel wind load distributions. Results indicate that small and medium panel arrays in landscape orientation exhibit deeper mean and peak uplift (more negative $C_f$) than in portrait, whereas large arrays show negligible orientation dependence. Larger panel arrays—especially when installed in landscape orientation with full roof coverage—generally exhibit lower uplift coefficients (normalized per unit area) and smoother pressure distributions than smaller ones. In contrast, portrait orientation reduces overall uplift but may concentrate wind loads along vertical edges, occasionally leading to higher localized suctions under oblique winds. Area-averaged suction coefficients only occasionally exceeded ASCE 7–22 thresholds, while positive pressure forces frequently surpassed design limits, particularly for small and medium panels in landscape orientation and under both full and partial coverage. These findings underscore the importance of refining ASCE standards to better capture the aerodynamic behavior of PV panels with varying sizes and orientations. Future research should explore other roof types and slopes to support broader codification of PV wind load design.