Multi-Objective Optimization of Combined BIPV-Glass Facades to Enhance Energy Generation and Visual Comfort (Case Study: Office Buildings in Yazd City)

Building-integrated photovoltaic (BIPV) facades are increasingly seen as a sustainable solution for reducing energy use and greenhouse emissions while improving indoor quality. However, traditional BIPV panels can limit natural light and cause visual discomfort. This study investigates a combined BIPV-Glass facade that enhances both energy generation and daylighting, focusing on identifying the optimal angle between the photovoltaic (PV) surface and glazing for maximum efficiency and comfort in Yazd, Iran's hot and dry climate. A multi-objective optimization framework utilized parametric modeling, energy simulations, and genetic algorithms. Rhino software, with Honeybee and Ladybug plugins, handled daylight and energy evaluations, while the Octopus plugin used the Strength Pareto Evolutionary Algorithm (SPEA2) for optimization. The analysis centered on three performance indicators: electricity generation (GE), daylight autonomy (DA), and discomfort glare probability (DGP). The process revealed five optimal angles: <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$171.11^{\circ}, 177.11^{\circ}$</tex>, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$175.39^{\circ}, 163.86^{\circ}$</tex>, and 160.56°, with 171.11° (OOM model) providing the best compromise between energy and daylight. Specific models emerged for each goal: the GEOM model (108.07°) for peak energy, DAOM model (177.66°) for best daylight autonomy, and DGPOM model (179.74°) for minimal glare. Results show that increasing the PV-glass angle doesn't guarantee enhanced energy generation and daylighting concurrently; optimal angles depend on local climate and design goals. These findings offer essential insights for architects and engineers designing effective BIPV facades that optimize energy use and comfort. Future studies should include real-world conditions, costeffectiveness, and long-term performance assessments for advancing BIPV technology in building design.