(Hamburg) – Tractebel Overdick GmbH has developed a concept for offshore hydrogen storage together with partner companies. According to the information, this is a scalable platform for the compression and storage of up to 1,2 million cubic meters of hydrogen. 
Underground salt caverns will serve as storage and buffer for the green hydrogen produced at sea before the gas is transported via a pipeline to the onshore network and ultimately to consumers. The offshore platform consists of a “wellhead platform” for operating the caverns as well as a series of compressor platforms that enable a gradual increase in performance. According to the study, the storage and compressor platforms could absorb hydrogen with a volume of 400.000 standard cubic meters per hour, which is temporarily stored far under the sea at a pressure of up to 180 bar. These buffered production peaks, optimized flow rates and thus enabled a more economical design of the export pipeline.
Caverns in the North Sea are well suited
Due to the geological conditions and the underground rock salt formations, the North Sea is well suited for this solution. Caverns would be mined there to create large storage volumes. In addition to Tractebel, DEEP.KBB GmbH and PSE Engineering GmbH were also involved in the concept study. 
Tractebel is part of the French energy supplier Engie and has branches in Europe, Africa, Asia, the Middle East and Latin America. Tractebel Overdick has been active in offshore technology for more than 20 years. The Hamburg-based company with around 50 employees has been part of the Brussels-based Tractebel Group since October 2018.
DEEP.KBB GmbH is an engineering company that plans, builds and operates underground energy storage and brine extraction systems in mining. One area of expertise is energy storage in various geological structures such as salt formations, aquifer layers and depleted deposits. PSE Engineering specializes in planning and engineering for plant technology and component delivery; also on the development and application of new technologies in the area of production and storage of hydrogen, but also on the separation and long-term transfer of carbon dioxide.
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Design study: Concept for an offshore infrastructure for storing hydrogen in caverns. © Tractebel Overdick
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Offshore hydrogen hub with two compressor platforms and a “wellhead platform” (right). © Tractebel Overdick
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Representation of the offshore infrastructure with the caverns. © Tractebel Overdick
