Coupling renewable energy with urban greening: quantifying the sustainable development potential of photovoltaic-green roofs

Abstract

Photovoltaic–Green Roof (PV-GR) systems, integrating clean energy production with ecological greening, represent an emerging form of three-dimensional greening with substantial potential to promote urban sustainability. However, most existing studies focus on isolated benefits, without a comprehensive assessment framework or consideration of future pathways. Consequently, the sustainable development potential of PV-GR systems remains insufficiently explored. To address this gap, we propose a scalable and replicable integrated evaluation framework to assess the sustainable development potential of PV-GR systems. The framework incorporates rooftop suitability identification, Area Solar Radiation, the Denitrification–Decomposition model, multidimensional SDG indicator quantification, and multi-scenario dynamic simulation. Using the high-density urban core within Fuzhou’s Third Ring Road as a case study, we identified approximately 975.23 hectares of potentially suitable rooftop space. Under full deployment, PV-GR systems could annually generate 5936 GWh of electricity, reduce carbon emissions by 4.118×10⁶ t CO₂, and generate 1.079×10⁶ kg C yr⁻¹ of green biomass. Additionally, the PV-GR could create 75,092 jobs, deliver 2.401×10⁹ CNY in economic returns, and retain 5.013×10⁶ m³ of rainwater annually. Two future scenarios were simulated: S1 Photovoltaic–Green Roof Synergy Scenario and S2 Policy Incentive Scenario. Vegetation was found to enhance photovoltaic efficiency, leading to steady increases in electricity generation and carbon reduction—by up to 20.37 % and 6.7 %, respectively. Moreover, policy incentives significantly amplified system benefits. The findings reveal the sustainable development potential of PV-GR systems and offer a scalable and replicable framework to support the deployment of three-dimensional greening and the formulation of sustainable urban policies.