A photo of the Sealhyfe offshore green hydrogen production platform next to the Floatgen floating wind turbine

Lhyfe’s work on ocean reoxygenation through H2 production advances

French hydrogen producer Lhyfe has completed the first step in its work on ocean reoxygenation with the publication, by IRD Brest, of a first scientific article on the results of the research carried out in recent months.

Sealhyfe offshore green hydrogen production platform; Courtesy of Lhyfe

The work is a part of Lhyfe’s ambition to decarbonize transport and industry by producing and supplying renewable hydrogen, while at the same time helping to reoxygenate the oceans.

According to Lhyfe, the production of offshore hydrogen is progressing step by step. The company launched the production of renewable green hydrogen with Sealhyfe, a pilot plant capable of producing up to 400 kilos of hydrogen a day, off the Atlantic coast, installed at sea in the second half of 2022, and it announced the HOPE project (Hydrogen Offshore Production for Europe), which will produce up to four tons of offshore hydrogen a day, off Ostend in Belgium, by 2026.


In parallel, Lhyfe said it is conducting research into ocean reoxygenation and hopes to one day realize this project, in conjunction with the deployment of future offshore production platforms.

It noted that, back in June 2020, it began working with a number of research organizations, such as the Institute of Research for Development (IRD) in Brest. It financed all the work involved in the project and commissioned some of its experts to help move the research forward.

Lhyfe said the article, published in Environmental Research Letters (IOP Science), discusses the role of oxygen in aquatic environments, how the production of renewable green hydrogen produces oxygen as a byproduct, the contents of the research carried out by the physical and biogeochemical ocean modelling experts of IRD Brest and the results of the research, which revealed highly contrasting regional oxygen inventory responses, highlighting the extent to which the large-scale industrial artificial reoxygenation of oceans could have an impact on oxygen minimum zones (OMZ) worldwide, and must be treated with extreme caution.

Based on these initial results, Lhyfe stated it is initiating a series of next steps in order to take the necessary precautions when approaching this issue. They include:

  • Focusing its collaborative efforts more on a regional scale, specifically the European shelf seas. They have been identified as a potential relevant zone for artificial ocean reoxygenation notably due to their episodic to permanent low oxic conditions and wind energy potential.
  • Building on previous knowledge and work with experts in the targeted regions as well as reoxygenation experts from both research institutions and industry.
  • Furthering and evaluating the technical options with regard to injecting oxygen into the sea.

Patricia Handmann, Oxygenation Advisor at Lhyfe, commented: “Ocean deoxygenation is a major issue for our planet, which deserves our full attention… This first work is very encouraging, and with our partners, we will be pursuing it in the coming months, rigorously and responsibly. We now aim to build an adequate scientific, legal and technological basis, which will pave the way for the effective implementation of ocean reoxygenation at our future offshore green hydrogen production sites.”


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