Hydrogen applications in buildings: A systematic review of decarbonization pathways

The building sector is a major contributor to global energy use and carbon emissions, positioning it as a key target for decarbonization. Hydrogen, as a clean and flexible energy carrier, offers significant potential in supporting this transition. This review synthesizes recent advances in hydrogen applications for buildings, highlighting experimental findings, technological feasibility, socio-technical considerations, and policy developments. Key deployment models include hydrogen fuel cell integration, hydrogen-based microgrids, and combined heat and power systems. Emerging innovations such as renewable-powered hydrogen production, decentralized storage, and cross-sector integration with transport systems are also examined. In particular, the role of hydrogen-powered vehicles as energy buffers is emphasized for enhancing building energy autonomy. Despite its promise, hydrogen deployment faces technical, economic, and institutional challenges. The study calls for coordinated strategies that integrate hydrogen with other renewables, improve policy frameworks, and foster public acceptance. Future research should prioritize system integration pathways, techno-economic optimization, real-world demonstrations, and interdisciplinary collaboration. This review offers a strategic reference for scaling up hydrogen use in the built environment and underscores its critical role in achieving net-zero emissions and sustainable urban energy systems.