Editorial Feature

The World’s First Offshore Green Hydrogen Plant

The world’s first offshore green hydrogen plant, powered by floating wind turbines, is on track to go into operation in 2022 in France. This project will pave the way to achieving large-scale, industrial hydrogen as part of the global plight to eradicate fossil fuel reliance.

Image Credit: petrmalinak/Shutterstock.com

The ambitious development, led by renewable hydrogen project developer Lhyfe in collaboration with Chantiers de l’Atlantique, will be installed at the offshore testing site SEM-REV, where it will be connected to multiple renewable energy sources, including the 2 MW capacity floating wind turbine Floatgen. This test site will be crucial to validate the feasibility of offshore hydrogen production, with plans to expand to a system ranging from 10 MW to an astounding several hundred MW of carbon-neutral power in 2024.

What is Green Hydrogen?

When employed as a fuel cell, hydrogen produces purely water as its by-product, and is hence granted the accolade of being a “clean fuel”. However, not all methods of hydrogen production can be granted the title of “clean”.

According to the World Energy Council, currently, 96% of hydrogen is produced from fossil fuels (grey hydrogen), most commonly through steam methane reforming, resulting in substantial carbon and methane emissions. As such, if we are to truly achieve a carbon-neutral energy network, there must be a global shift towards an alternative form of a hydrogen production system. The most promising avenue is water electrolysis. This iconic decomposition of water produces only hydrogen and oxygen, resulting in overall net-zero carbon emissions when powered by renewable energy sources. This derived form of hydrogen is therefore classed as green hydrogen.

The World’s First Offshore Green Hydrogen Plant

Lhyfe has already successfully deployed onshore hydrogen electrolysis plants, powered purely by local renewable energy sources. Yet, with the oceans providing an unlimited supply of water, Lhyfe has identified offshore water electrolysis as being an untapped potential to upscale to industrial hydrogen production.

The water electrolyzer will be installed by Chantiers de l’Atlantique on GEPS Techno’s floating platform; an autonomous system harnessing both wave and solar energy. Additional energy required for the process will then be provided through a connection to various other sources of marine renewable power, most significantly the 2 MW capacity Floatgen wind turbine already in operation at the site. This, therefore, forms a truly integrated, flexible approach to renewable energy production, with the capability of responding to fluctuations in demand.

Collaboration from multiple companies has also been fundamental to the project. Engineering School, Central Nantes, has made available its research facilities to support the regulatory experimental and logistical phases, reporting that the test site meets all the criteria to validate offshore hydrogen production. This declaration is of huge significance to the overall project mission, as emphasized by Matthieu Guesné, CEO and founder of Lhyfe:

“We are convinced that offshore production of renewable hydrogen is a perfectly suitable solution for the massive deployment of hydrogen that is on the horizon. Through this partnership and the bringing together of the most advanced expertise in the field, we are making great strides forward in our development and are determined to be the first in the world to deploy a solution for offshore renewable hydrogen production.”

Industrial Scale Hydrogen Production

The Sem-Rev site is set to showcase to the world the capabilities of offshore green hydrogen production as a disruptive form of renewable energy. With support gained from key industry players, including Pays de la Loire Region, the Sea innovation cluster Pôle Mer Bretagne Atlantique and the Maritime Industry’s Strategic Committee, the project has gathered sufficient momentum for plans to be already underway for an industrial-scale plant. It is reported this site will have a staggering output of up to several hundred megawatts and, provided the validation process of the current test site continues on its current trajectory, will be deployed as early as 2024.

Although this is hugely promising in terms of proving the technical feasibility of this technology, the question yet remains as to whether large-scale offshore hydrogen production is an economical alternative to fossil fuel. An investigation carried out by independent energy research and business intelligence company, Rystad Energy, revealed that, at present, hydrogen from offshore electrolysis would come at an average cost four times greater than fossil fuel-derived hydrogen.

This calculation is however based upon the assumption of a 1 GW wind farm delivering half of its available power to the electrolyzer. In 2019 alone, 502 new offshore wind turbines went into operation in Europe generating an additional 3627 MW. Such projects have already aided in reducing the cost of offshore wind power, with no apparent halt to this rate of expansion on the horizon. Rystad Energy does also consider the significant impact that a higher carbon tax could have on green hydrogen costs.

“Offshore hydrogen production may become more interesting if a higher carbon tax is imposed on grey hydrogen production,” suggests Rystad energy research analyst, Petra Manuel. “This would force existing hydrogen manufacturers to shift more of the production to ‘blue’ hydrogen (grey hydrogen coupled with carbon capture and storage), which in turn would make green hydrogen projects more cost-competitive.”

With continued wind turbine funding and support from environmental regulatory bodies, the future of offshore green hydrogen production is certainly promising, with the Sem-Rev site leading the way towards a greener future.

References and Further Reading

Buljan, A. 2021. World’s First Offshore Green Hydrogen Plant to Go Online in France. [online] OffshoreWind.biz. Available at: https://www.offshorewind.biz/2021/06/04/worlds-first-offshore-green-hydrogen-plant-to-go-online-in-france/ (Accessed on 12th June 2021)

Collins, L. 2021. Offshore-wind Green-hydrogen Projects ‘Not Economically Viable’ Says Analyst. [online] Available at: https://www.rechargenews.com/wind/offshore-wind-green-hydrogen-projects-not-economically-viable-says-analyst/2-1-944077 (Accessed on 13th June 2021)

Cunningham, A. n.d. What is Green Hydrogen? And Why Should We Start Using it in 2019? [online] GeoPura. Available at: https://www.geopura.com/

Editor. 2021. Offshore Green Hydrogen Production: Partnership Between Lhyfe and Centrale Nantes on Track. [online] Energy Northern Perspective. Available at: (Accessed on 13th June 2021)

GEPS Techno. N.d. Autonomous Hybrid Offshore Platforms. [online] GEPS Techno. Available at: https://www.geps-techno.com/en/autonomous-hybrid-platforms/ (Accessed on 12th June 2021)

IEA. 2015. Technology Roadmap Hydrogen and Fuel Cells. [online] Available at: https://www.iea.org/reports/technology-roadmap-hydrogen-and-fuel-cells (Accessed on 12th June 2021)

Lhyfe. 2021. Our Solution. [online] Lhyfe. Available at: https://www.lhyfe.com/ (Accessed on 12th June 2021)

US Department of Energy. N.d. Hydrogen Fuel basics. [online] Energy.gov. Available at: https://www.energy.gov/eere/fuelcells/hydrogen-fuel-basics (Accessed on 13th June 2021)

Wind Europe. 2020. Offshore Wind in Europe Key trends and Statistics 2019. [online] Wind Europe. Available at: https://windeurope.org/about-wind/statistics/offshore/european-offshore-wind-industry-key-trends-statistics-2019/ (Accessed on 13th June 2021)

World Energy Council. 2019. New Hydrogen Economy – Hype or Hope. Innovation Insights Brief. https://www.worldenergy.org/assets/downloads/WEInsights-Brief-New-Hydrogen-economy-Hype-or-Hope-ExecSum.pdf

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Bea Howarth

Written by

Bea Howarth

Bea is an aerospace engineering graduate from the University of Liverpool. Having discovered a particular interest in the applications of novel technology within engineering, she began writing for AZoNework during her third year of university to pursue this passion with an increased commercial focus. She will soon begin a graduate role in a manufacturing technology company, for which sustainability and efficiency optimization are at the heart of all operations.


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