A new plan for storing hydrogen underground

Two companies have received funding to explore the use of underground shafts for the storage of hydrogen

Spotted: Hydrogen has great potential as an energy storage system for the future, but there are a number of challenges that need to be overcome first. These include clean generation of hydrogen and developing large-scale hydrogen storage facilities. Edinburgh-based energy storage firm Gravitricity and British environmental consultancy Arup are developing a system to tackle the latter issue.

Arup and Gravitricity have recently been awarded a £300,000 (around €350,000) grant to study the feasibility of storing hydrogen underground. The project involves creating a demonstration pressurised hydrogen storage vessel using a purpose-built concrete-lined vertical underground shaft with a domed cap. The project will also integrate Gravitricity’s gravity energy storage system and a heat exchange system.

Gravitricity’s system uses very heavy weights (up to 12,000 tonnes) suspended in a deep shaft. Electricity is stored as potential energy by raising the weights. Power is then generated by lowering the weights to turn a generator. Stored hydrogen could also be used as a power source to raise the weights. If the hydrogen were generated using green energy, such as wind power, then the entire system could form a sustainable loop.

Gravitricity’s hydrogen and thermal storage lead Sally Molyneux points out that “Storing hydrogen in underground shafts is intrinsically safer and less obtrusive than above-ground options and is a solution that does not require unique geology such as salt caverns. We believe Gravitricity’s innovation is a scalable storage method which is cost-effective, extremely durable, and can be implemented everywhere.”

At Springwise we have spotted several green hydrogen innovations including an artificial island dedicated to green hydrogen, a hydrogen power plant for the home, and a facility in Chile producing hydrogen for use in synthetic fuel.