Spotted: Increasingly, green hydrogen is touted as a crucial element in the world’s journey to carbon zero. UK startup and underground energy storage specialist, Gravitricity, is completing its design of purpose-built underground lined rock shafts which would enable efficient underground hydrogen storage. 

Gravitricity believes its storage technology, which it calls FlexiStore, is a ‘Goldilocks’ solution to the obstacles facing hydrogen storage. Unlike above-ground hydrogen storage alternatives, FlexiStore provides a much bigger and more secure system. It is also more flexible than subterranean salt caverns – another commonly suggested method of underground storage.  

One FlexiStore could store the green hydrogen generated by an offshore wind farm, but this would fill up daily and would need to be emptied regularly. To make the process more efficient, multiple stores could be constructed so that large amounts of wind energy that would otherwise go to waste could be soaked up. And unlike salt cavern storage, which naturally requires specific geological environments, Gravitricity’s stores can be built wherever they are needed.  

Gravitricity has already identified many sites for its UK pilot project and is discussing the project and future commercial schemes with site owners. The company recently completed a £300,000 (around €341,000) feasibility study, which showed it is technically and commercially viable to store large amounts of compressed hydrogen with the Flexistore technology.  

Springwise has spotted other innovations aimed at storing hydrogen. HydroSolid developed a way to store and transport large amounts of hydrogen at low pressures using a new nanomaterial, and EPRO found a way to transport green hydrogen in powder form.  

Written By: Anam Alam