KONGSTEIN has developed a compressed gaseous hydrogen carrier vessel for the transport and direct shuttling of hydrogen from an offshore wind farm to a dedicated offloading port.
The work was carried out as part of the two-year “OffsH2ore” project funded by the Federal Ministry of Economic Affairs and Climate Action (BMWK).
The aim of the overall project was to develop a technically and economically optimised design for an integrated offshore hydrogen production plant using proton exchange membrane (PEM) electrolysis, including a concept for transport of compressed gaseous hydrogen (CGH2) to shore. The present results can serve as a blueprint and starting point for the development of pilot and large-scale projects and the elaboration of corresponding regulations.
The offshore hydrogen production on the scale of 500 MW as well as the transport of compressed gaseous hydrogen has not yet been realised. With the concept presented by the consortium, a rapid and large-scale implementation has become realistic.
The concept is based on an offshore wind farm that is directly connected to a 500 MW electrolysis platform that produces up to 50,000 tonnes of green hydrogen per year. The system has a scalable, modular design that can be easily adapted to different hydrogen production capacities. The freshwater for the PEM electrolyser is provided by desalination of seawater, using the waste heat from the electrolysis.
The hydrogen produced is purified and dried, compressed to up to 500 bar and transferred to a transport vessel that delivers 400 tonnes of hydrogen per shipment from the offshore platform to shore. This concept is independent of hydrogen transport pipelines and offers flexibility in the choice of location.
In addition to KONGSTEIN GmbH, the consortium included PNE AG, an international project developer for renewable energy plants as project coordinator; SILICA Verfahrenstechnik GmbH, a process engineering and plant construction company; Fraunhofer ISE, the largest solar research institute in Europe and active in hydrogen systems; and Wystrach GmbH, a supplier of high-pressure storage systems for hydrogen. The “OffsH2ore” project thus brought together an experienced and complementary consortium of industrial partners and scientists from the entire value chain.
“Green hydrogen produced sustainably from renewable energies will become an important pillar for the decarbonisation of our energy systems. For countries like Germany, where the large-scale production of green hydrogen is a challenge due to land-use competition, for example, hydrogen production at sea with the help of offshore wind energy is an additional option” explains Marius Holst. “Hydrogen production offshore simultaneously offers high full-load hours and the opportunity to cover the entire value chain on a national level, while at the same time decoupling offshore wind and grid expansion”, Holst continues.
The work packages of KONGSTEIN comprised the implementation of an integrated maritime hydrogen supply chain, including hydrogen loading arrangement, vessel design and transport concept from offshore site to shore.
“Vessel-based transport of CGH2 is an alternative if pipeline-based transport is not possible and can be adapted for offshore-to-port and port-to-port logistics. It will allow us to enter markets much earlier and to react faster as well as be more flexible on the energy supply chain. Direct shuttling of CGH2 allows us to transport the hydrogen directly without the use of expensive intermediate storage systems. The transport of pure hydrogen gives us advantages in terms of energy efficiency and reduces the additional conversion systems off- and onshore compared to derivatives” explains Lukas Niebergall.
The next steps will be to further develop the hydrogen transport vessel and bring it to the Approval-in-Principle (AiP).