This book compiles high-quality selected papers from the VIII Ibero-American Congress of Smart Cities (ICSC-CITIES 2025), a leading event in the field of smart urban development. Smart cities are a response to the increasingly urgent need to reorient our lives towards sustainability. In an era of rapid urbanization and growing environmental challenges, these cities are designed to optimize resources, reduce environmental impact, and enhance the overall quality of life for their citizens. By leveraging advanced infrastructure, innovative solutions, and cutting-edge technology, smart cities aim to create more efficient, resilient, and livable urban environments. Within this framework, energy plays a pivotal role in enhancing the sustainability and functionality of our cities. The papers explore a wide range of topics, including smart grids, electric systems, energy efficiency, urban mobility, environmental monitoring, and other areas critical to the development of sustainable cities. The insights and research presented in this book contribute to the ongoing dialogue on how cities can better serve their populations while addressing the challenges of climate change, resource management, and technological integration. ICSC-CITIES 2025 takes place on November 10–12, 2025, in the vibrant city of Puebla, Mexico. As the eighth edition of the Ibero-American Congress of Smart Cities, this conference continues to be a key platform for academics, professionals, and policymakers to share knowledge, exchange ideas, and collaborate on the future of urban living. Authors invite the academic community and industry experts to engage in discussions and contribute to shaping the energy-related aspects and overall development of the cities of tomorrow.