Belgium-based engineering consultancy Tractebel says it has developed the world’s first system for large-scale offshore storage of green hydrogen in underground salt caverns.

The offshore platform complex consists of a wellhead platform for the operation of the caverns and a series of compression platforms that enable a staged increase in storage, says Tractebel, which is part of French energy group Engie.

Underground salt caverns will be used as storage and a buffer for green hydrogen produced offshore, giving increased flexibility, before the gas is transported via the pipeline network to the onshore grid and finally to consumers and customers. The design assumes a capacity equivalent to converting 2GW of offshore wind power into hydrogen.

“Centralised offshore hydrogen hubs also facilitate the integration of smaller-scale hydrogen production, which is to be expected within the scope of capacity expansions while repowering offshore windfarms in the future,” says Klaas Oltmann, director of business development at Tractebel Overdick. 

“At the same time, they offer an economically viable option, as the export and compression of hydrogen produced offshore can be bundled. This significantly reduces the overall costs for future projects," he adds.

The system enables the compression and storage of up to 1.2mn m³ of hydrogen, says Tractebel.“These storage facilities buffer production peaks, optimise flow rates and therefore enable a more economical design of the export pipeline,” the company adds.

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Author: Stuart Penson