Assessing Cement Durability in Hydrogen-driven Underground Storage Systems

As the world shifts towards renewable energy sources, the need for reliable, large-scale energy storage solutions becomes increasingly critical. Underground Hydrogen Storage (UHS) emerges as a promising option to bridge this gap. However, the success of UHS heavily depends on the durability of infrastructure materials, particularly cement, in wellbores and in unlined rock caverns (URCs) where it serves a dual role in grouting and sealing. This study explores the chemical interactions between hydrogen and cement in these environments, exploring how hydrogen might compromise cement integrity over time. We employed advanced thermodynamic analyses, kinetic batch tests, and 1D reactive transport models to simulate the behaviour of cement when exposed to hydrogen under conditions found in two potential UHS sites: the Haje URC in the Czech Republic and a depleted gas field in the Perth Basin, Western Australia. Our results reveal that while certain cement phases are vulnerable to dissolution, the overall increase in porosity is minimal, suggesting a lower risk of significant degradation. Notably, hydrogen was found to penetrate 5 cm of cement within just 4–5 days at both sites. These insights are crucial for enhancing the design and maintenance strategies of UHS facilities. Moreover, this study not only advances our understanding of material sciences in the context of hydrogen energy storage but also underscores the importance of sustainable infrastructure in the transition away from fossil fuels.