OffsH2ore: KONGSTEIN takes a lead role in defining the next steps of maritime hydrogen logistics

After years of hard work, the project has met its planned technical milestones. KONGSTEIN is now setting sails for the next steps in gaining competence for building a green hydrogen value chain at sea.

Green hydrogen produced sustainably from renewable energies is expected to become a key pillar for the decarbonisation of our energy systems. For countries like Germany for instance, where the large-scale production of green hydrogen can be a challenge due to land use competition or other challenges relating to the development of renewable energy projects on land, import strategies for green hydrogen are being devised, such as from Australia or Northern Africa. However, hydrogen production at sea using offshore wind power can overcome some of those challenges, while also offering high full-load hours and at the same time creating opportunities for domestic supply chains.

The two-year project “OffsH2ore”, funded by the Federal Ministry for Economic Affairs and Climate Action (BMWK), will deliver a technically and economically optimized design of an integrated offshore hydrogen production facility, including a maritime logistics solution, based on the transport of compressed gaseous hydrogen. This first-of-its-kind concept is meant to serve as blueprint and launching point for the development of pilot and full-scale projects.

The basis for this pioneering concept is an offshore wind farm, which is directly connected to a 500 MW electrolysis platform to produce up to 50,000 tons of green hydrogen per year. The system is based on a scalable and modular design, which can be easily adapted to different hydrogen production capacities. Fresh water for the PEM electrolyser is supplied by desalination of sea water, using waste heat from the electrolysis. The produced hydrogen is purified and dried, compressed to up to 500 bar and transferred to a transport vessel by direct shuttling, which delivers between 400-500 tons of hydrogen per shipment from the offshore platform to shore.

Next to the technical and economic challenges with regards to the operating conditions at sea, the design study will specifically address relevant questions around storage, transport and logistics of hydrogen, operation and maintenance of the offshore facilities as well as regulatory aspects. In particular, the project aims to identify innovative technical solutions related to the implementation of an integrated maritime hydrogen supply chain, including hydrogen loading arrangement, vessel design and transport concept from offshore site to shore.

By focusing on storage and transport of hydrogen in compressed gaseous form the chosen technical approach clearly and deliberately sets itself apart from existing project ideas and concept studies for offshore hydrogen production or hydrogen shipping concepts. Although the logistics concept is being developed for an offshore hydrogen production platform, the proposed transport solution for compressed hydrogen is independent from the offshore production of hydrogen and generically viable for long-distance shipping of hydrogen.




Key insights from the project include:

  • Offshore production of hydrogen from offshore wind and shipping of compressed gaseous hydrogen is technically doable.
  • PEM electrolysis is the preferred technology for the offshore environment due to space limitations and dynamic operation behaviour.
  • The project approach and logistics concept based on transporting hydrogen in compressed gaseous form, while generally overlooked, is unique.
  • A compression-based hydrogen supply chain seems preferable in combination with intermittent hydrogen production from renewable electricity, like (onshore) wind and solar (in an island mode setting).

With the project coordinator PNE AG, the Fraunhofer Institute for Solar Energy Systems ISE, SILICA Verfahrenstechnik GmbH, KONGSTEIN and Wystrach GmbH, the project “OffsH2ore” brings together an experienced and complementary consortium of industry partners and academia from across the value chain.

KONGSTEIN, with its unique experience in logistics concept planning and transport & installation activities in complex offshore operations, will be responsible for the development of a hydrogen offshore logistics concept, including hydrogen loading arrangements, vessel design and transport concept from offshore site to shore.


KONGSTEIN enables the green shift in the energy industry by supporting clients striving towards a sustainable use of resources. It provides technical advisory and project management to deliver innovative, efficient solutions to the offshore renewables and maritime industries.   

KONGSTEIN combines its expertise in these industries with providing state of the art services in green hydrogen. The common thread throughout our markets and clients is our clear commitment to clean energy at sea, facilitated by our network of Norwegian and German engineers and mariners. 

About PNE AG

PNE AG is a clean energy solutions provider for markets and industries regionally, nationally and internationally. Its core competencies are the project planning and operation of renewable energy projects. In addition, PNE AG is advancing the storage of renewable energies and power-to-x technology. In this way, it is consistently pursuing the goal of a secure, sustainable and profitable energy supply which is fed 100 percent from renewable energies. Around 400 employees work under the umbrella of the PNE Group in 13 countries on four continents. The headquarters of PNE AG are located in Cuxhaven.

About Fraunhofer Institute for Solar Energy Systems ISE

With a staff of close to 1300, the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany is the largest solar energy research institute in Europe. Fraunhofer ISE is committed to promoting sustainable, economic, safe and socially just energy supply systems based on renewable energies. Its research provides the technological foundations for supplying energy efficiently and on an environmentally sound basis in industrialized, threshold and developing countries throughout the world. Focusing on energy efficiency, energy conversion, energy distribution and energy storage, the Institute develops materials, components, systems and processes in five business areas. One particular feature of Fraunhofer ISE is its excellent technical infrastructure, which is organized into eight laboratory centers and four technology evaluation centers providing testing and experimental services on a production scale. In addition, the Institute has several accredited testing facilities. The Institute is a member of the Fraunhofer-Gesellschaft, Europe’s largest application-oriented research organization.

About SILICA Verfahrenstechnik GmbH

For more than 90 years, Silica Verfahrenstechnik GmbH has been designing and manufacturing process plants for the purification, drying and liquefaction of gases at its site in Berlin. The topic of hydrogen compression and purification has occupied the company since the delivery of the first hydrogen plant in 1941. Since that time, we built a vast number of Hydrogen units and Silica plants became a part of technological development in this field. Besides of the high quality level and reliability of the plants Silica contributes decades of experiences in the integration of process packages into a complex overall system in compliance with current engineering standards and regulations. More recently, Silica has been involved in engineering and manufacturing of various projects for the production and further processing of “green” hydrogen.

About Wystrach GmbH

Wystrach GmbH is a full-service provider in the field of high-pressure solutions for stationary and mobile storage systems for hydrogen and other gases. The product range includes stationary bundles; containers of all sizes; tank systems for trains, buses, and trucks; and storage solutions, e.g. for power-to-gas applications as well as Plug&Play hydrogen refuelling stations. The company has 200 employees and more than 30 years of experience in this field; more than 140,000 compressed gas bundles and over 450 transport systems are on the market worldwide.