[defrost]

Built infrastructure for hydrogen storage and transport is always a challenge, it's a slippery little molecule that's expensive to contain in human built stuff.

That said, there's almost always a 'cheat' and for bulk hydrogen storage:

  Using salt caverns (cavities leached from salt deposits in the subsurface) for gas storage is an established technology. Salt caverns are good for storing gas because they have a very low permeability and cracks or fractures can re-seal to prevent leakage. The UK has salt deposits that are suitable for cavern storage and that have been used store natural gas since the 1960s. Hydrogen, used as a chemical feedstock, has been stored in salt caverns in Teesside since the 1970s.

~ https://assets.publishing.service.gov.uk/media/68aebcef3a052...

Currently there are a few geological structures in Australia being tested for suitability and pilot storage.