First projects for large-scale hydrogen production at sea using wind power plants

by Juan Palencia | May 5, 2023 | Technical articles

The future large-scale generation of hydrogen at sea using offshore wind turbines is gradually becoming a reality. Researchers at the Fraunhofer Institute in Germany, mainly from the Department of Solar Energy (ISE), along with a number of European researchers, have been working for a long time on developing a new concept for offshore hydrogen production. For this purpose, using PEM technology electrolysers, they have conducted studies and carried out various technical and economic feasibility models.

This study specifically focuses on a 500 MW offshore wind power plant capable of producing 50,000 tonnes of hydrogen per year. A ship capable of carrying up to 400 tonnes of hydrogen in its compressed form will be used to transport the hydrogen. The purpose of this type of transport method aims to distinguish it from fixed transport lines (pipelines) in order to increase flexibility when delivering the offshore produced hydrogen.

Figure 1 – North Sea offshore wind platform

This pilot project will be used by the federal German authorities as a reference for the development of similar pilot projects in the old continent and, furthermore, it will be a guideline to set all regulatory and legal requirements around the project, as it represents a milestone in offshore hydrogen production using electrolysers above 500 MW in scale.

Similar projects

In 2022, the H2Mare project unveiled aims to harness the power of offshore wind, which is estimated to be twice as powerful as onshore wind and much more steady than onshore wind. The average offshore wind power systems produce twice as much energy, and their impact on the environment is far less than onshore wind parks.

The direct combination of wind turbine and electrolyser, the device in which water is split into its hydrogen and oxygen components, has the potential to significantly reduce H2 production costs compared to other renewable energy sources.

Figure 2 – H2Mare project simulation (Fraunhofer Institut)

Siemens Energy and Fraunhofer-Gesellschaft are the two main partners in the H2Mare project, which is funded by the federal government with €3.5 million. The project focuses on how an electrolyser can be integrated directly into a wind turbine and yet survive in the harsh marine environment, where is the best place to install the equipment, how seawater should be treated to be used as a starting material for hydrogen production, and how the hydrogen produced at sea can be stored and transported to land most efficiently. In the particular case of the H2Mare project, the transport will be done through pipelines towards the mainland.

By the end of April 2023, the German H2 Association announced the German government’s plan to create a stable regulatory framework by 2030 that aims to install at least 10 GW of wind-powered hydrogen generation capacity in the North Sea and to operate and develop the associated transport infrastructure. This would position the North Sea environment as the main focus for renewable hydrogen production in Europe.

Offshore wind park companies have expressed a negative reaction to the German federal government’s funding plans for offshore water electrolysis. They criticise the tendering of a single 95 km2 area for the production of hydrogen for being too large. Furthermore, they claim that it is necessary to have an exact knowledge of the subsidy for each project before the production tender can be drawn up. They also demand a fixed rate for the price of wind energy in the initial years of the project.

Spanish context

The Spanish Government has just approved the first “Planes de Ordenación del Espacio Marítimo (POEM)” (Maritime Space Management Plans) after five years of development work. These plans regulate offshore uses and set aside an area of almost 5,000 square kilometres for the deployment of offshore wind turbines. This initiative aims to meet the objectives of the PNIEC, which seeks to generate between 1 and 3 GW by the end of the decade using this technology, something that could be key to the development of green hydrogen projects, although it has its lights and shadows.

The 4,948 km of the waters in Spain that are set aside as areas of high offshore wind potential in the POEMs barely represent 0.46% and are divided into the North Atlantic, South Atlantic, the Strait of Gibraltar and Alboran, Levantine-Balearic and Canary Islands regions.

Figure 3 – Location of offshore wind power plants in the Iberian Peninsula

Spain is a global wind power leader in both equipment manufacturing and energy generation. It is the fifth largest country in the world, with 27.5 GW onshore installed capacity, behind China, the US, Germany and India. However, in offshore wind power (a very promising area for green hydrogen generation projects), there have been no significant advances so far, despite Spain’s favourable geographical location and the fact that we have a naval industry, a maritime-port sector and the technological capabilities that could make such projects feasible.

One of the main limitations for offshore wind energy to take off in our country is the high depth of our territorial waters, which makes it difficult to implement projects with fixed anchoring (unfeasible from a depth of 50 metres), the most consolidated method so far for setting up such platforms.


The massive potential of offshore wind energy provides us a challenge for achieving the ambitious global aims of industrial decarbonisation. The areas with the highest offshore wind potential are located where electricity transmission grids are very poor (‘uninhabited areas’), making hydrogen the perfect partner to fully exploit the energy potential offered by offshore wind.

Once the hydrogen is produced on-site, the most suitable transport option will be selected according to its end-use. As discussed in this article, it is not only the transport method that poses a challenge. The harsh marine environment for electrolysers, the way the water should be treated, the ideal location of the facility, either centralised on platforms (some projects are located on old oil platforms) or distributed (on each wind infrastructure)… There are many challenges to which innovation will have to provide an answer.

The North Sea area is emerging as Europe’s hydrogen production hotspot. Southern Europe, with a photovoltaic-wind mix, must not lose pace with the keen interest shown by Norway, Denmark, the United Kingdom and the Hanseatic areas to lead the race for the production of European, affordable, renewable hydrogen.

SynerHy, powering net zero!