May 27, 2024


Hydrogen is being hailed as, if not a silver bullet, then at least a crucial component to decarbonising the world’s energy sources. And no wonder — when burned, hydrogen produces zero greenhouse gas emissions. However, the transition to a renewable hydrogen economy must first overcome a non-insignificant list of challenges. 

So-called green hydrogen, produced through electrolysis of water using renewable energy, currently accounts for only about 1% of global production. It is also about three times as expensive as its grey counterpart, produced from fossil fuel sources. 

One of the major pieces of the puzzle to scaling green hydrogen is access to vast amounts of renewable energy and water. Enter fully offshore wind-to-hydrogen, where high capacity factor floating wind turbines are connected to electrolysers that utilise seawater. 

“What is complex and costly in deploying an offshore [wind farm] site is actually converting the energy at sea and bringing it in a cable to shore,” Stéphane Le Berre, offshore project manager at renewable hydrogen producer Lhyfe tells TNW, adding that for the latest large-scale projects, this part alone amounts to billions of euros. 

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“One solution for offshore wind park developers to suppress the need for expensive electric substations and cables is to replace them with a hydrogen production plant, which converts the electricity to hydrogen,” Le Berre states. The hydrogen can then be transported through a pipeline — already in plenty of supply in the North Sea, courtesy of the oil and gas industry. 

Aiming for green (hydrogen) unicorn status

Founded with six people in 2017 by Matthieu Guesné, today Nantes-based Lhyfe employs 200 people and is present in 16 countries. It has attracted around €80mn in funding, and says its mission is to become a “green unicorn.” Rather than measuring its status in valuation, it hopes to reach a billion tonnes of avoided CO2 emissions. Lhyfe’s onshore site in Bouin, running since H2 2021, currently produces 300kg of green hydrogen per day. One kilogram of hydrogen is the energy equivalent of one gallon (3.78 litres) of petrol, which produces a little over 9kg of CO2 when burned. 

That Lhyfe became a hydrogen producer at all is almost something of a side effect. In fact, it came about partly motivated by addressing another aspect of global warming — the oxygen depletion of the oceans. 

When producing one kilogram of hydrogen through electrolysis, you also release eight kilograms of oxygen as a by-product. Lhyfe has the intention of pumping it back into the sea, to potentially help restore the balance of marine ecosystems disrupted by climate change.

“When we started Lhyfe, we wanted to make offshore hydrogen so that we would have economic viability to bring oxygen to the ocean,” Le Berre says.

World’s first offshore wind-to-hydrogen pilot

In September last year, Lhyfe inaugurated the world’s first offshore renewable hydrogen production pilot site. In June, the company announced that the 1MW demonstrator project, called Sealhyfe, had produced its first kilograms of green hydrogen. (Chinese state-owned Donfang Electric may have beaten Lhyfe to the actual production by a couple of weeks.)

Sealhyfe is located approximately 20km off the coast of Le Croisic, France. Today it produces half a tonne of hydrogen per day. It is plugged into the SEM-REV powerhub — the first European floating wind farm and site for multi-technology offshore testing. 

SEM-REV has an underwater hub, which is like a giant block with four sockets. One of them is used to connect the SEM-REV wind turbine, and another the cable connecting the site to the grid onshore. This leaves two highly coveted sockets available for demonstration projects, one of which now allows the Sealhyfe platform to draw electricity directly from the wind turbine. 

The Sealhyfe electrolyser sits on a floating platform, engineered to stabilise the production unit at sea, and uses desalinated water for the electrolysis. One kilogram of green hydrogen requires nine litres of water, and with potable water scarcity projected to increase significantly over the coming decades, this is one of the main arguments for locating production sites by or on the sea. 

Lhyfe has until May next year before it needs to disconnect from the SEM-REV hub. Until then, it hopes to prove not only that the technology works, but that it can withstand even the harsh conditions of the Atlantic Ocean in winter. 

Hydrogen HOPE

Lessons from Sealhyfe will inform future offshore projects. This includes the unprecedentedly large-scale 10MW HOPE, which Lhyfe is coordinating with another eight partners. The European Clean HydrogenPartnership program has selected the project for a €20mn grant.

HOPE will produce up to four tonnes of green hydrogen a day. Intentions are to have it up and running outside the coast of Belgium in 2026. By 2030, Lhyfe means to have multiplied several 10MW projects for a total capacity of 100MW. 

Lhyfe employees in front of electrolyser platform at inauguration