Ardent Underground, a division of Abergeldie Complex Infrastructure (Abergeldie) has secured a patent in the United States of America for its innovative underground hydrogen storage solution, marking an important milestone in the development of infrastructure to support the transition to a low-carbon future.
The patent, titled Compressed Gas Storage Tank, System and Method, protects the intellectual property underpinning the Ardent Underground Hydrogen Storage solution, which applies Abergeldie’s specialist blind boring capability to large-scale underground hydrogen storage. US Patent No. 12,742,516 was issued on 22 September 2026.
Green hydrogen has the potential to play a significant role in the transition to a lower-carbon economy. However, its low volumetric density makes safe, efficient, and large-scale storage a key challenge for the emerging hydrogen industry. Established in 2019, Ardent Underground was developed to address this challenge, applying Abergeldie’s specialist blind boring expertise to create a scalable and replicable underground storage solution for compressed hydrogen while maintaining hydrogen purity.
The solution stores compressed hydrogen deep underground in purpose-built vertical shafts. The surrounding rock helps contain the hydrogen pressure, reducing the need for costly pressure containment materials, while the underground configuration provides a small above-ground footprint. The system can store up to 150 tonnes of hydrogen per shaft, and multiple shafts can be constructed at the same location for greater storage capacity.
At the heart of the solution is Abergeldie’s established expertise in blind bore shaft construction. Using the blind boring method, a large-diameter shaft is drilled vertically from the surface before a steel liner is installed, grouted into place, and connected to above-ground facilities. The patented technology incorporates an innovative storage arrangement designed to accommodate movement in the surrounding structure while maintaining the volume of the pressurised gas storage chamber.
Abergeldie Chief Executive Officer Mark Bruzzone said the US patent represented an important milestone for technology. “The granting of this patent is a significant milestone for Ardent Underground and recognises the innovation behind a solution that has a key role to play in supporting the development of the hydrogen industry. Abergeldie has always looked for innovative ways to solve complex infrastructure challenges. Ardent Underground brings together that mindset with our specialist underground engineering capability to address one of the challenges associated with hydrogen: storing it safely and effectively at scale.”