Advancements and challenges in modelling renewable energy solutions for sustainable (and smart) buildings and communities

The global shift towards low-carbon energy systems requires targeted strategies to support the sustainable transformation of communities, particularly at local and regional levels. This special issue presents a collection of original research focused on innovative approaches to the design, optimization, and management of community energy systems based on renewable resources. The contributions address a wide range of topics, including hybrid renewable energy systems, microgrid operation, machine learning-based forecasting, photovoltaic integration, hydrogen technologies, power-to-X planning, energy storage optimization, and the role of digital platforms in smart asset control. Several papers highlight the importance of user engagement, energy justice, and the inclusion of vulnerable consumers in energy transition strategies. By combining modelling techniques with real-world case studies and practical tools, the articles in this issue offer valuable insights into the technical, economic, and social dimensions of energy transition. Overall, the special issue underscores the urgency of implementing integrated, resilient, and inclusive energy solutions to accelerate decarbonization and build sustainable communities worldwide.