Bremerhaven starts the hydrogen revolution: H2 Mare conquers the sea!

Bremerhaven starts the hydrogen revolution: H2 Mare conquers the sea!

The pilot phase of an ambitious project starts today in Bremerhaven: the “H2 Mare” project. This is a world first in which hydrogen is to be produced directly on the high seas using offshore wind turbines. The project is being implemented by renowned research institutions such as the German Aerospace Center (DLR) and the Fraunhofer Institute for Wind Energy Systems (IWES) as well as several industrial partners. A test platform is planned in the port of Bremerhaven, where the integration of water electrolyzers into wind turbines will be tested in order to reduce network costs and avoid the need for power cables. Due to their larger areas, offshore wind turbines can produce more energy than their onshore counterparts, with the average being 5 megawatts per turbine, while onshore turbines usually only produce 3.5 megawatts.

A particular focus of the project is on the sub-projects “H2Wind” and “OffgridWind”. H2Wind optimizes PEM electrolysis for the special conditions at sea, while OffgridWind develops models to simulate the entire production chain from wind use to hydrogen production. Another central element is seawater desalination, which is necessary for electrolysis. A test facility will be installed in Bremerhaven that filters and heats North Sea water.

Ecological aspects in focus

An important aspect of hydrogen production at sea is the ecological impact. The Helmholtz Center Hereon analyzes the consequences of offshore hydrogen production on the North Sea ecosystem. It turns out that the waste heat from a 500 megawatt offshore electrolysis can locally increase the water temperature by up to 2 degrees Celsius. These temperature changes can affect the vertical stratification of the water body, which in turn could disrupt nutrient transport from deeper water layers. Such changes could negatively impact the productivity of phytoplankton, which forms the basis of the marine food chain. Experts therefore recommend decentralized hydrogen production to minimize the impact on the environment.

The technical feasibility and economic viability of this offshore hydrogen production are currently being tested. After the pilot phase has been completed, the results will be presented at a final conference in autumn 2025. The “H2 Mare” project aims to realize the entire chain from wind power to hydrogen to possible downstream products, including sustainable fuels such as Fischer-Tropsch products and methanol, directly at sea.

Financing and partnerships

The project, which is part of Germany's national hydrogen strategy, aims to achieve an electrolysis output of ten gigawatts by 2030. With a funding code of 03HY300A-R and a total funding amount of 37.4 million euros, the H2 Mare project is supported by 18 partners, coordinated by the Karlsruhe Institute of Technology. In addition to the production of hydrogen, the raw materials water, CO2 and nitrogen also play a central role, which are to be obtained directly on site from the air or sea. These measures could ultimately help to reduce the costs of renewable energy infrastructure and better exploit the innovative potential of offshore areas.

The developments in Bremerhaven show that Germany is on the way to taking a pioneering role in hydrogen production, not just for the domestic market, but as a role model for the international scene. Projects like H2 Mare are an important step towards a sustainable and environmentally friendly energy future.