The article discusses the role of hydrogen technologies in driving sustainable urban growth at the Smart City Expo in Barcelona. The rise of photovoltaic systems and high-power charging stations has led to increased electrical network complexity in cities. In response, hydrogen technologies and infrastructure are being developed as vital components for a resilient energy system. The Universitat Politècnica de Catalunya-BarcelonaTech (UPC) is actively leading these efforts, focusing on promoting decarbonizing technologies to support sustainable urban growth. These initiatives aim to meet the energy needs of cities while minimizing environmental impact, demonstrating a positive outlook on the integration of hydrogen in urban energy transitions.