Scaling and integrating digital twin applications for battery energy storage systems from building to city

Battery Energy Storage Systems (BESS) play a critical role in enhancing the sustainability, flexibility, and resilience of future urban energy systems. As intelligent cyber-physical platforms, digital twin (DT) technologies are emerging as enablers of smart and adaptive energy management through real-time monitoring, predictive control, and life-cycle optimization. However, existing studies and applications of DT-driven BESS remains fragmented across spatial scales, often limited to isolated building- or community applications with low interoperability and scalability. This study presents a systematic review of DT-driven BESS technologies across three spatial scales — building, community, and city — through a comprehensive review of 640 publications. The results identify cross-scale limitations related to data interoperability, control integration, and integrative governance, despite rapid progress in predictive control, real-time optimization, and energy sharing within each scale. To address these gaps, this study proposes a multi-scale technology roadmap and city-scale integrated architecture for scalable DT-driven BESS tailored to advance scalable, interoperable, and policy-linked digital twin systems for energy storage. The proposed roadmap defines short-, mid-, and long-term development directions, emphasizing real-time data synchronization, alignment of bottom-up and top-down control, and the design of interoperable architectures that bridge different spatial levels. This study provides a strategic foundation for the evolution of DT-driven BESS from isolated control tools to intelligent infrastructures that enhance urban energy resilience, carbon neutrality, and the achievement of smart energy policy objectives.