Fostering Sustainable Urban Energy Transitions: Backcasting for Positive Energy Districts and Digital Twin strategies in a European context

Positive Energy Districts (PEDs) have emerged as a key urban innovation to accelerate the transition toward climate neutrality and sustainability in cities. This study explores the integration of backcasting methodologies and Digital Twin (DT) strategies to advance the development of PEDs. A two-step approach was employed: participatory backcasting workshops to co-create long-term visions and actionable strategies, and DT technology applications tailored to three Urban Living Labs (ULLs) in Vienna (Austria), Gothenburg (Sweden), and Sakarya (Türkiye). The backcasting process facilitated the identification of pathways to energy efficiency, renewable energy integration, and decarbonization, creating a structured yet adaptable roadmap for PED development. DT functionalities—including Digitize, Visualize, Simulate, Predict, and Orchestrate—transformed these plans into operational tools, enabling real-time monitoring, predictive modeling, and adaptive energy management. The study underscores the critical role of stakeholder collaboration in aligning local priorities with sustainability goals and demonstrates the capacity of DT frameworks and PEDs to enhance energy efficiency in diverse urban contexts. However, challenges such as scalability, resource intensity, and sustaining long-term engagement persist. This dual approach highlights the potential of integrating participatory planning with advanced digital tools to bridge the gap between visionary energy goals and practical implementation, offering a replicable framework for urban energy transitions and decarbonization.