Gravitricity’s H2FlexiStore technology uses the geology of the earth to store up to 100 tonnes of pressurised hydrogen in a lined underground rock shaft. Gravitricity says it offers safe, low-cost storage which can be located wherever required.

Gas transmission system owner and operator National Gas (NG) is investigating the potential of hydrogen transportation in using the current network infrastructure to support the Net Zero transition. Hydrogen storage could be a key element of any future hydrogen network and options are being reviewed and considered by NG to support supply and demand management.

They have now been awarded the first phase of a grant from Ofgem’s £450 million Strategic Innovation Fund to conduct a three-month feasibility study on the use of Gravitricity’s H2FlexiStore, which could lead to a full-scale demonstrator project commencing in 2025.

H2FlexiStore could then provide an option for intermediate storage across the UK alongside long-term storage already in development with NG.

Commenting on the initiative, Gravitricity co-founder and executive chairman, Martin Wright, said: “The future large-scale adoption of green hydrogen in industrial processes and for heat and transport will require safe and cost-effective mid-scale hydrogen storage which can be located wherever required – both in distribution networks and at point of use.

“Each H2FlexiStore can store up to 100 tonnes of pressurised green hydrogen safely below ground in a lined rock shaft which can be built more cheaply than above ground vessels, with a much smaller visual footprint. We believe it will be a key technology in gas networks of the future and we look forward to working closely with National Gas to share our combined expertise.”

Corinna Jones, head of innovation at National Gas, added: “Hydrogen storage will be important in ensuring a robust and resilient supply of energy to the UK in the energy transition. Novel technologies and solutions such as this are key to helping us achieve net zero targets by 2050.”

The project will be funded by energy network users and consumers through the Strategic Innovation Fund (SIF), a programme from the UK’s independent energy regulator Ofgem managed in partnership with Innovate UK.

National Gas applied to Round 3 of the SIF as part of a consortium including Gravitricity, Southern Gas Networks, the University of Edinburgh, Energy Reform and Revolutionary Engineering and Design in the category: ‘Enabling power-to-gas (P2G)’ which has a theme focusing on “Commercial and technical innovation to secure system benefits from hydrogen storage deployments.”

National Gas and Gravitricity will now go through an initial Discovery phase which includes a feasibility study of 2-3 months. They may then be selected for future phases including:

• Alpha: proof of concept projects, lasting 6 months with a budget up to £500,000
• Beta: large-scale demonstrator developments, lasting up to 5 years, with no upper limit of funding.