Rapid urbanization has exacerbated the urban heat island effect, significantly increasing cooling energy demand. Daytime radiative cooling (RC) offers a promising zero-energy passive cooling strategy; however, urban-scale evaluations of RC potential and the specific influence of urban morphology remain scarce. This study integrates a physical RC model with the local climate zone (LCZ) framework to simulate 10,549 buildings across 85 LCZ models in Shenzhen, China. To improve spatial generalization, we developed rapid machine learning assessment models evaluated via 5-fold spatial cross-validation. Additionally, ensemble SHapley Additive exPlanations (SHAP) analysis was utilized to quantify the impacts of meteorological and morphological parameters. The results demonstrate that CatBoost and XGBoost are the optimal algorithms for predicting roof and facade RC energy savings, achieving average test-set R² values of 0.888 and 0.854, respectively. SHAP analysis revealed that meteorological conditions (primarily solar irradiance and wind speed) dictate performance, contributing 66.0% and 65.1% to roof and facade RC. Urban morphology acts as a major constraint; specifically, compact high-rise zones severely hinder facade cooling potential due to mutual shading. Finally, the annual theoretical RC energy-saving potential for roofs and facades in Shenzhen is estimated at 372.9 GWh and 446.8 GWh, respectively. Combined, this 819.8 GWh capacity could offset approximately 0.833% of the city’s 2019 total electricity consumption. This research provides urban planners with quantitative, transferable insights for mitigating energy demands in the built environment.

The bifacial photovoltaic green facade (BPVGF) system was introduced to maximize the energy and environmental advantages offered by photovoltaic buildings and vertical greening technologies, thereby contributing to the realization of the zero-carbon target in the construction sector. This system involves the vertical installation of bifacial photovoltaic panels on building facades, which are overlaid with climbing vegetation or modular plant systems. Solar radiation incident upon these facades is partially harnessed as electricity by the bifacial photovoltaic panels, while the remainder is absorbed by the plants, beneficial for summer thermal insulation. Meanwhile, the plants aid in cooling the photovoltaic materials through evapotranspiration, thereby enhancing the solar-to-electricity conversion efficiency. In this study, a computational fluid dynamics (CFD) model of the BPVGF was developed to evaluate its thermal performance. The findings indicate that the incorporation of vertical greening with varying parameters can significantly mitigate the temperatures of both the interior and exterior walls, as well as the bifacial PV panels. Specifically, with a greening thickness of 80 mm, the maximum temperature reductions for the interior and exterior wall surfaces, and the bifacial PV panels were recorded at 2.59 ℃, 5.29 ℃, and 4.72 ℃, respectively. Moreover, the photovoltaic efficiency of the bifacial PV panels experienced an increase of 2.5%. This study highlights the dual potential of vertical greening in optimizing thermal environments and elevating PV conversion efficiency.