The rapid pace of urbanization and rising energy demands have intensified environmental and climatic vulnerabilities in cities, necessitating resilient and sustainable urban planning. This study, Key Factors of Green Energy Synergy in Urban Planning with Emphasis on Environmental Resilience, aims to identify critical factors enhancing the integration of renewable energy in urban systems to bolster environmental resilience. Employing a mixed-methods approach, the study utilized the Delphi technique with 14 experts to identify 32 key indicators, followed by structural analysis using MICMAC software to map their interactions. The results revealed a high interaction matrix fill rate of 81.5%, confirming strong interdependencies among the factors. The total direct influence and dependency scores across all indicators were 1571 each, with indirect effects exceeding 120,000, highlighting the systemic complexity of the urban energy–resilience nexus. Among the indicators, thermal energy recovery (C20, direct influence = 55), urban system flexibility (C14, dependency = 54), and infrastructure recovery speed (C12, influence = 54) demonstrated the highest leverage in shaping system dynamics. Nine strategic indicators emerged as pivotal: smart energy grid efficiency, urban system flexibility, thermal energy recycling, green transportation share, urban innovation, resilience to climate change, digital infrastructure resilience, greenhouse gas emission reduction, and policy stability. These factors collectively enhance energy efficiency, reduce environmental impacts, and strengthen urban adaptability, particularly in developing countries. The findings offer a robust framework for policymakers to prioritize green energy integration, fostering sustainable and resilient urban development.