National Gas – the UK’s gas transmission system owner and operator – has secured Strategic Innovation Funding (SIF) from the UK energy regulator Ofgem to study a new kind of underground hydrogen energy storage – developed by Edinburgh storage specialists Gravitricity – as a potential technology as part of its plan to decarbonise the UK gas network.

Gravitricity has developed H2FlexiStore – a patented technology that store up to 100 tonnes of pressurised hydrogen in a storage tank formed by lining an underground rock shaft – to offer a safe, low-cost storage which can, says its maker, be located wherever required, below ground level in a storage location that can be created more cheaply than an above-ground vessel, and with a much smaller visual footprint.

Backed by funding from Ofgem’s £450m Strategic Innovation Fund, National Gas will now conduct a three-month feasibility study on the use of H2FlexiStore. National Gas is currently investigating the potential of hydrogen transportation via the existing natural gas delivery network and its infrastructure, indirectly supporting the Net Zero transition and the hydrogen storage that is likely to be a key element of any future hydrogen network.

The next step will be to conduct the three-month feasibility study, which could lead to a full-scale demonstrator project commencing in 2025. National Gas and Gravitricity will go through an initial ‘discovery’ phase which includes the 2–3 month feasibility study. They may then be selected for future phases including ‘Alpha’, which are proof of concept projects, lasting 6 months with a budget up to £500 000: and ‘Beta’, large-scale demonstrator developments, lasting up to 5 years, with no upper limit of funding.

 Image: Gravitricity's H2FlexiStore (courtesy of Gravitricity)