Computational procedure of solar irradiation: A new approach for high performance façades with experimental validation

Abstract

Promoting sustainable strategies at the urban scale requires reliable assessment of solar irradiation received by buildings envelope. This will guide modelers, urban planners, and policymakers in optimizing building designs and incorporating renewable energy modules. Existing tools for irradiation prediction suffer from several limitations, including high computational burden and reliance on data availability, which can impact the tool's reliability. This paper advances a recently developed trigonometric model by the authors for irradiation prediction that effectively captures the details of the surrounding environment while maintaining accurate results, compared to pixel counting and polygon clipping techniques. The new model successfully accounted for the discontinuities in the surroundings profile and the presence of multiple rows of surrounding buildings. Beam, diffuse, and reflected irradiation were correlated to different density indicators such as ground-space index, floor-space index, and spaciousness index. A statistical model was applied to investigate the impact of key variables on the irradiation span and the feasibility of solar modules. The computation time per façade was significantly reduced from 6.1 min to 0.8 s, with an acceptable error of 5.1%.