High-efficiency periodic groove structured glass with broad angle antireflection for facade‑mounted photovoltaic modules

The facade‑mounted photovoltaic (PV) modules suffered severe efficiency losses because the reflectance at the air/planar glass interface rose from ∼10 % to ∼90 % as the angle of incidence (AOI) increased from 60° to 89° Conventional antireflective coatings or textured glass performed excellently at the AOI below 70°, making them suitable only for horizontally installed PV modules rather than vertically mounted modules. This paper designed a high-efficiency periodic groove light-trapping structure on the surface of the glass by employing COBYLA (Constrained Optimization BY Linear Approximation) numerical optimization algorithms and ray optics simulation. The structure functioned effectively over an AOI range of 0° to 89°, demonstrating significant advantages at large AOIs (70° to 89°) compared to the microstructures reported in the literature. Within a wavelength range of 400 nm∼1050 nm, the average reflectance (R_avg) of the air/groove structured glass interface fell below 2.4 % for AOI up to 60°, and its maximum value was only 12.6 % when the AOI reached 89° The absorption of facade‑mounted crystalline silicon solar module encapsulated with this groove structured glass increased by 12% at the AOI of 70° and 73% at 89° versus planar glass encapsulated modules. In addition, this light‑trapping structure retained its superior light‑trapping performance under moderate linear scaling and internal segment angles perturbations. All design parameters, including an aspect ratio of 0.76 and a smooth contour cross-section, had been carefully selected to ensure manufacturability. Therefore, this groove structured glass presented a clear potential for boosting power generation for facade‑mounted PV systems.