The Anonymous Widower

Gravitricity Makes Hydrogen Play With FlexiStore

The title of this post, is the same as that of this article on The Engineer.

This is the sub-heading.

Edinburgh-based energy storage firm Gravitricity is looking to green hydrogen, bringing a new underground storage solution to market.

The system is explained with a large graphic, showing an electrolyser, a FlexiStore and a hydrogen filling station, with this paragraph underneath.

Known as FlexiStore, the concept involves purpose-built, steel-lined shafts capable of holding up to 100 tonnes of compressed hydrogen at 220 bar – around 3.33GWh of energy, or enough to refuel over 1,000 HGVs, according to Gravitricity. Unlike naturally occurring underground storage like salt caverns, FlexiStores could be positioned anywhere, with the current plan to co-locate the storage as close as possible to renewable generation. Gravitricity says a single FlexiStore could serve a 460MW wind farm and that 1,000 units could meet the UK’s predicted hydrogen storage needs in 2050.


  1. The concept certainly solves the problem of storing hydrogen on a country-wide basis.
  2. I suspect, a machine could be designed and built to create the shafts.
  3. A 3.33 GWh store could supply 460 MW for nearly 33 hours. As a Control Engineer, that sounds a good balance for backing up a wind farm!

As ARUP has been involved in a feasibility study, I suspect there’s a fair chance that FlexiStores can be built.

January 5, 2023 - Posted by | Energy, Energy Storage, Hydrogen | , ,


  1. ?translation: we couldn’t get the gravity model to work so now we’re pivoting to hydrogen

    Comment by Brian Armitage | January 6, 2023 | Reply

    • They’ve always said that gravity and hydrogen could be combined in one system. I suspect, that, they’ve found the hydrogen can also stand alone.

      I was once talking about twenty years ago, to a well-known TV biologist and he told me about a hotel, where he had been a consultant was boring deep shafts to biodegrade part of the hotel’s waste. He had some interesting views on green science.

      Comment by AnonW | January 6, 2023 | Reply

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