The demand for green hydrogen – that is, hydrogen produced using renewable energy sources – is expected to increase significantly in the future. The reasons for this are the growing challenges to global energy supply and efforts to decarbonize industry. Currently, however, the production capacities for green hydrogen in Europe are very limited. After all, the supply of electrical energy from renewable sources to businesses and consumers must be realized in parallel.
To contribute to a secure and resilient energy infrastructure of the future, the Institute of Fluid Dynamics and Ship Theory (FDS) at the Hamburg University of Technology (TUHH), together with its partners, has developed a floating hydrogen production unit. The partners include CRUSE Offshore GmbH,the Institute of Chemical Reaction Engineering at Friedrich-Alexander University Erlangen-Nürnberg (FAU), RENK GmbH, and H&R GmbH & Co. KGaA.
Existing infrastructure can be utilized
The innovative unit is designed for sea areas outside the potential locations of conventional offshore wind farms. The research project ProHyGen is funded by the Federal Ministry for Economic Affairs and Energy with a grant of around 1.5 million euros. Recently, the results of the project were presented to Dr. Christoph Ploß, Federal Government Coordinator for Maritime Economy and Tourism, during a technical discussion at TUHH.
On a floating platform, energy for producing hydrogen from desalinated seawater is directly generated using a wind turbine. Through an innovative method for storing hydrogen at ambient pressure based on a liquid organic hydrogen carrier (LOHC), safe transport using slightly modified conventional tank ships is made possible. In this way, an autonomous facility for the production and storage of green hydrogen is created that does not compete for space with other wind and solar installations and also offers cost advantages compared to the production of hydrogen from other renewable energy sources.
Thanks to LOHC technology, the existing infrastructure of the industry – tank trucks, tank ships, tank farms, and filling stations—can be utilized, and this with a lower hazard classification. The LOHC loaded with hydrogen is hardly flammable and classified in water hazard class 2. On land, the hydrogen is separated from the LOHC and thereby available as pure hydrogen. The unloaded LOHC can be transported back to the floating unit and reloaded.
Fully autonomous, highly scalable
Thanks to the integration of energy production on the floating hydrogen producer, the system is fully autonomous. In addition, the concept of the floating hydrogen producer is highly scalable and can be deployed in wind-rich sea areas. The deployed units would, if used worldwide, technically be capable of covering a large part of the demand for green hydrogen cost-effectively. Due to the autonomous energy supply of the hydrogen producer via the integrated wind turbine, continuous availability of renewable electricity is ensured. The required amount of water is also always available through the seawater desalination unit.
By forgoing grid connection, large transformer platforms, and undersea cables, investment costs are significantly reduced. The floating hydrogen production unit is anchored to the seabed only with conventional mooring lines, thereby minimizing environmental impact.
In the ProHyGen project, running until the end of 2026, the planning of a prototype for an autonomous offshore hydrogen production unit with a nominal output of 5 megawatts as well as its scaling to 15 megawatts has been completed. Moreover, the preliminary planning and economic analysis of a hydrogen park in European sea areas have been carried out. The next step toward green, resilient energy supply in Germany is the construction of a first prototype. Possibilities for realization were discussed together with the Coordinator for Maritime Economy and industry partners.
