Improved numerical modeling of photovoltaic double skin façades with spectral considerations: Methods and investigations

Photovoltaic double skin façades are crucial tools for mitigating the escalating energy consumption in buildings. However, current simulation studies often neglect the variation in solar spectra and focus on only limited operational modes, resulting in incomplete and less accurate modeling. In response to these limitations, this study proposes an improved numerical model incorporating temporal spectral variations and non-uniform surface temperatures, which comprehensively encompasses all operational modes of photovoltaic double skin facades. Real-time solar spectra are acquired using specialized software and remote sensing data, while the transportation and conversion of radiation energy will be solely solved at individual wavelength steps, providing the model with spectrum resolution. Built on the fundamental principles of optics, thermodynamics, and hydromechanics, the proposed two-dimensional numerical model consistently demonstrates desirable accuracy across various airflow paths and mechanical ventilation conditions. Based on the proposed model, the feasibility of the previously proposed parameter-based control strategy is proved, which offers potential energy savings of 25.9–341.6 MJ compared to the radical strategy and 67.5–170.7 MJ compared to the conservative strategy. The photovoltaic efficiency drop due to spectral mismatch is also quantified as about 15–35 %. These results highlight the potential of the proposed model as an efficient tool for future research.