Underground energy storage specialist Gravitricity has signed a memorandum of understanding (MoU) with infrastructure major VSL Systems UK to complete the design of the purpose-built underground lined rock shafts.
They plan to build a scale demonstrator in the next 24 months ahead of commercial rollout across the UK.
VSL is part of the French Bouygues Construction group and is a specialist contractor for the construction, preservation and repair of major engineered structures and infrastructure.
Each rock shaft would be six metres in diameter and 365 metres deep and lined with steel.
A single store would hold up to 100 tonnes of green hydrogen, according to Gravitricity.
It added that,a single FlexiStore would store the green hydrogen generated by a 460MW offshore wind farm and could be emptied and refilled daily, whilst multiple stores could soak up vast amounts of otherwise wasted or ‘constrained’ wind.
The Edinburgh firm is now seeking funds along with VSL to build their first scale demonstrator project in the UK.
The company is also in advanced discussions with Cumbrian steel specialists Bendalls Engineering to fabricate the linings for the rock shafts.
Managing director of Gravitricity Charlie Blair said: “Green hydrogen will be a vital fuel of the future in industrial applications and in heavy transport, where electrification is just not feasible, or where industrial grey hydrogen is already used.
“Purpose-built lined rock shafts will be the safest and most affordable way to store large volumes of hydrogen near to where it will be required.
“It is difficult to transport hydrogen.
“It therefore makes sense to locate hydrogen storage systems close to sources of renewable power – which can generate green hydrogen – and to potential users.”