German partners reveal plans for 10 MW offshore electrolyzer demo at Alpha Ventus

German offshore wind and hydrogen developers NorthH2, Deutsche Offshore-Testfeld- und Infrastruktur (DOTI), and the Offshore-Windenergie Foundation have joined forces to build an offshore electrolyzer demonstrator at the Alpha Ventus wind farm in the North Sea.

In a move described as “a groundbreaking step for a sustainable energy future”, the partners signed a letter of intent (LoI) on November 26, 2024, to work together on the construction of a 10 MW offshore electrolysis demonstrator at Germany’s first offshore wind farm, Alpha Ventus.

This research and demonstration project is part of the NORTHSEA Hydrogen project pipeline developed by NorthH2. It aims to demonstrate the feasibility and efficiency of hydrogen production directly at sea and test required components by using a foundation from a prototype wind turbine.

Power from Alpha Ventus will be used to supply the proton exchange membrane electrolyzer (PEM). First, the seawater will be desalinated using the waste heat generated during electrolysis and then split into hydrogen and oxygen in the electrolyzer.

The hydrogen will be stored and during low-wind periods reconversion will be tested. The partners said options for using the hydrogen produced directly at sea are currently being investigated.

As explained, the quantities generated are too small for offshore loading and ship transport to land to justify the high costs of the corresponding logistics. However, as soon as the AquaDuctus pipeline, which is part of the hydrogen core network, connects the North Sea with the pipeline network on land, the demonstrator can be connected, and the hydrogen will be fed in.

According to the partners, this project is intended to provide important insights that will enable offshore electrolyzers to be operated commercially at sea in the future.

An important part of the project is to provide a platform for industrial partners and research, accompanying ecological research, and to test and optimize systems and components under real conditions.

The project development and implementation are also expected to offer the authorities involved the opportunity to establish the necessary regulatory framework for specifications and approval of offshore electrolysis projects.

Andreas Wellbrock, Managing Director of NorthH2, said: “The 10MW offshore electrolysis demonstrator is a crucial step towards enabling the production of green hydrogen directly at sea. This will help us to significantly increase the efficiency and sustainability of hydrogen production while avoiding the challenges of grid connection issues.”

Karina Würtz, Managing Director of the Offshore-Windenergie Foundation, added: “The market ramp-up in the hydrogen sector is currently confronted with many different technical and economic challenges that need to be overcome. This is even more true for hydrogen production offshore, i.e. at sea. Here, one should first test with a cool head how the harsh conditions of the North Sea affect the technology components and maintenance requirements – we therefore welcome this initiative and are pleased to be able to provide a test opportunity on the Alpha Ventus test field area.”