A groundbreaking initiative to produce synthetic fuels at sea is now afloat off the German coast.

Led by the Karlsruhe Institute of Technology (KIT), the 'PtX-Wind' project has installed a modular, off-grid plant on a barge anchored in Bremerhaven.

Designed to harness wind energy, seawater, and ambient air, the platform will begin producing synthetic fuels near Helgoland later this year. 

Floating platform with modular container facility for the offshore production of synthetic fuels from wind energy, seawater, and ambient air. Image: DLR/KIT.

As part of Germany’s H2Mare hydrogen lead project, this is the first floating test platform demonstrating a complete Power-to-X process chain. According to KIT, it aims to shape future concepts for large-scale offshore fuel production using renewable energy. 

Recently, China launched the world’s most powerful 17MW direct-drive floating wind turbine, developed by Huaneng and Dongfang, marking a leap in renewable energy.

Floating fuel factory

KIT and partners have launched a pioneering project to produce synthetic fuels directly at sea using only wind energy, seawater, and ambient air.

Central to this initiative is a modular, off-grid plant mounted on a floating barge, developed under Germany’s H2Mare hydrogen lead project. The system integrates a direct air capture (DAC) unit to extract CO₂ from the atmosphere, a seawater desalination facility, and a high-temperature electrolysis unit that produces hydrogen-rich synthesis gas.

This gas is then used in a Fischer-Tropsch synthesis process to generate liquid synthetic fuels from green hydrogen and CO₂. 

According to 4C Offshore, the platform’s modular design allows it to operate independently of the power grid and dynamically adapt to the fluctuating supply of offshore wind energy. Initial testing begins in July 2025 at Bremerhaven’s port, followed by offshore deployment near Helgoland.

Researchers will evaluate the performance of the full process chain under real marine conditions, studying its environmental impacts, material behaviour, and legal frameworks relevant to off-grid fuel production. 

Beyond synthetic fuels, the PtX-Wind team will also explore additional Power-to-X technologies at KIT, including methods for generating liquid methane, methanol, and ammonia. These findings aim to support the design of larger-scale, wind-powered offshore production platforms for climate-neutral energy carriers.

“We wanted to test the entire planning process, including approval, construction, and real-world operation of the plant to learn how to draw up concepts for building larger production platforms,” said Professor Roland Dittmeyer, head of KIT’s Institute for Micro Process Engineering and co-ordinator of the 'PtX-Wind' H₂Mare project, in a statement.

Wind-driven fuel

The H2Mare flagship project is advancing offshore hydrogen production by harnessing wind energy at sea, where conditions are ideal for generating renewable electricity.

Unlike onshore systems, offshore wind turbines offer higher and more consistent output – averaging 5MW compared to 3.5MW on land – enabling cost-effective green hydrogen generation without grid connection. Funded by Germany’s Federal Ministry of Research, Technology, and Space (BMBH), H2Mare integrates several sub-projects to develop innovative offshore Power-to-X technologies. 

A key initiative, PtX-Wind, led by KIT in partnership with DLR and TU Berlin, investigates converting offshore green hydrogen into derivatives like e-fuels. The core goal is to directly couple electrolysers with wind turbines, eliminating the need for grid infrastructure.

According to BMBH, this approach lowers hydrogen production costs and relieves stress on local grid systems. H2Wind focuses on adapting electrolysers to marine environments, while OffgridWind optimises wind turbines for direct integration with hydrogen systems. 

H2Mare explores the production of green methanol and seawater electrolysis to expand the offshore Power-to-X potential. These innovations leverage the vast spatial availability offshore and reduce dependence on freshwater. Alongside technological development, H2Mare assesses safety, environmental impact, and life cycle performance.