National Gas and Gravitricity have secured a £500,000 grant from Ofgem to develop an innovative underground hydrogen storage system called H2FlexiStore. This system, created by Edinburgh-based energy storage firm Gravitricity, is designed to store up to 100 tonnes of green hydrogen in lined geological shafts. The project aims to offer a flexible and resilient solution to meet future hydrogen network demands. The system is expected to have a demonstrator built by 2026 and is crucial for ensuring the readiness of the UK's gas networks for a hydrogen-powered future. The H2FlexiStore technology differentiates itself from salt caverns by offering more flexibility in siting, which is essential for addressing the challenge of storing large quantities of green hydrogen closer to its demand centers. The project consortium, including Southern Gas Networks, Guidehouse, Edinburgh University, Energy Reform, and Premtech, will be involved in modeling and designing the system. If successful, the project could receive multi-million-pound support from Ofgem's Strategic Innovation Fund for its final phase. Gravitricity estimates that each shaft could store 3.3GWh of energy, providing a solution that supports hydrogen export ambitions and aids in the decarbonisation of heat and power.