Green Hydrogen: Path to Mass Production?

On Thursday, September 30, 2021, Lhyfe inaugurated one of the first industrial facilities for the production of “green” hydrogen in Europe. To make this carbon-free hydrogen, its Bouin-based factory in the Vendée wetlands feeds directly at the foot of the wind turbines with the aim of distributing it locally. In particular, it will supply the fleets of buses and dump trucks from neighboring towns such as La Roche-sur-Yon and Saint-Nazaire. The bet is very high because, today, most of the hydrogen comes from the operation of reforming with natural gas steam, therefore of fossil origin. However, the ambitious French Hydrogen Plan, launched in 2020, places among its priorities the mass production of renewable and low-carbon hydrogen to decarbonise heavy transport and industry in the medium term.

>> Read also: Towards green hydrogen more accessible for tomorrow’s vehicles?

Lhyfe is based on electrolysis, a process that consists of “breaking” molecules of water (H2O) using electricity (in this case that of wind turbines), to obtain, on the one hand, the famous hydrogen (H2) , and, on the other, hand, oxygen (O2). So far, nothing new: the electrolysis reaction has been known and dominated for over two hundred years. Except that electrolyzers are usually designed to operate with well-calibrated and stable electricity, such as that circulating in the national electricity grid. What just came out of the wind turbines is much less convenient: its intensity fluctuates constantly depending on the strength of the wind. result, “If you connect an electrolyzer directly to this type of intermittent current, at best its output is low, at worst it degrades quickly,” explains Thomas Créach, technical director of Lhyfe.

To solve this problem, the start-up has developed several technological bricks. First, an algorithm predicts the production of wind turbines, for example taking into account meteorological data. Next, “Between the wind turbines and the electrolytic, we have placed a series of intermediate components, called power electronics, whose function is to soften and ‘direct’ the current before injecting it into the electrolyzer.” add. Finally, the start-up also assembled the custom electrolyser, from the electrolysis cells – which are the basic components of the system such as transistors for a computer – to the routing of water and the electricity to each of them, as well as the final drainage of oxygen and hydrogen.


Lhyfe will thus produce 1 ton of hydrogen a day in Bouin. “The projects have already demonstrated the possibility of connecting electrolyzers to renewable, but low-power, electricity sources of the order of a few kilowatts. Here, our electrolyzer shows a power of 2.3 MW and produces the hydrogen reliably, to meet the needs of our customers who must be able to supply their vehicle fleets at any time. ” explains the engineer. In fact, outside the factory, the trucks recover the precious gas, stored in large pressure vessels, to be delivered to the service stations of the neighboring towns.

Betting on this relocated approach, the Nantes start-up, which already has about sixty factory projects across Europe, hopes to limit the distances of hydrogen transport. Because currently this transport is very expensive. “It can be done through networks of dedicated pipes, which are currently largely non-existent, or by truck,” explains Laurent Antoni, head of public affairs for hydrogen technologies at the CEA. Instead of opting for tanker trucks that handle liquefied hydrogen at -253 ° C (an extremely energy-intensive and expensive operation), Lhyfe preferred gaseous transport, in pressure vessels at about 350 bar. Ultimately, the nerve of the war is to reduce the costs of carbon-free hydrogen, from € 9 / kg currently to € 1.80 / kg (price of fossil hydrogen) by 2030, as predicted by the European route.


Made in San Miniato, Italy, McPhy Energy’s high capacity McLyzer 400-30 electrolyzers, with a capacity of 2 MW, can each produce a normal 400 cubic meters (Nm3 / h) of “green” hydrogen per hour at 30 bar .

Decarbonized hydrogen, on the way to mass production


Since 2018, the Floatgen wind turbine has been floating at the test site at sea of ​​the École Centrale de Nantes, Sem-Rev. A test that allowed 6.8 GWh of electricity to be injected into the grid in 2020.


This additional cost is also linked to the price of electrolyzers. That’s why companies like McPhy Energy or Elogen have planned to lift gigafactories (mega-factories) each able to manufacture, in 2030, about 1 GW of electrolyzers per year, and thus lower prices, as happened with photovoltaic panels. The Genvia company is committed to innovative technology: its megafactory aims to industrialize the so-called high-temperature electrolyzers. Unlike the two existing electrolysis technologies, known as alkaline membrane and proton exchange (PEM), this 100% French technology developed at CEA does not use water at room temperature, but water vapor at 150 ° C. superiors. “This high temperature work allows you to gain up to 20 points of creep”, supports Laurent Antoni, recovering heat lost by industrial processes to produce carbon-free hydrogen in situ “which can be consumed directly by the factory as a raw material, for example in chemicals or steel, or resold for mobility or other services”, continues the specialist. In the longer term, these electrolyzers could also be coupled with the heat and electricity produced by dedicated nuclear reactors, such as the SMRs currently under development.

>> Read also: Do ​​we have to worry about the proliferation of small nuclear reactors?

Another limitation to the competitiveness of carbon-free hydrogen is that electrolyzers never run 100% of the time, due to the intermittency of the power source. Which ultimately means mobilizing a lot of renewable electricity: Lhyfe thus “grabs” the equivalent of three wind turbines to run about fifty heavy vehicles. “Our long-term vision is to produce hydrogen at sea, where there is no problem of space … and wind in abundance,” says Thomas Créach. In fact, offshore wind turbines benefit from almost twice as much wind as their onshore counterparts. “We could place electrolysers at the foot of offshore wind turbines, such as today’s offshore oil rigs, and then repatriate the hydrogen by ship or by pipeline.” he continues. The advantage of this strategy would also be to exploit maritime sites too far from the coast to connect them to the electricity grid. It is with this in mind that Lhyfe is working on an experimental project in Saint-Nazaire, in collaboration with the University of Nantes.

Our long-term vision is to produce hydrogen in the sea, where there is no problem of space … and a lot of wind.

The goal? Check if your electrolyzer is able to operate at the foot of a floating wind turbine, in a very aggressive marine environment in terms of waves and corrosion.


But there are other promising strategies. Engie is studying the construction of a gigantic 400 MW electrolysis plant in Dunkirk with the aim of recombining hydrogen with CO2 from the chimney of ArcelorMittal’s next metallurgical plant to produce synthetic kerosene for aviation. It’s all based on the so-called Fischer-Tropsch process, which converts carbon dioxide and hydrogen gas into liquid hydrocarbons. While this additional chemical step lowers performance, it would have two advantages: offering a more easily transportable product than hydrogen, and quickly decarbonizing certain sectors such as aeronautics, which are still far from a transition to hydrogen.

However, in this type of centralized approach, hydrogen would not come, a priori, directly from renewable sources as Lhyfe does. Electrolysers would prefer to be connected to the national electricity grid, hydrogen simply being guaranteed “carbon-free” by certificates for the production of renewable electricity produced elsewhere. “The French strategy aims, first and foremost, to democratize short-term electrolysis to mass-produce carbon-free hydrogen, which will largely depend on the electricity grid.” granted by Laurent Antoni. Whatever its technical modalities, the industrialization of carbon-free hydrogen is, in any case, on track.

>> Read also: Here is a material capable of producing hydrogen from sunlight

After oil, a new geopolitics of hydrogen?

After abandoning nuclear power, Germany is now heavily dependent on fossil fuel power plants to compensate for the intermittency of renewable energy. Therefore, our neighbor is committed to an even more massive development of carbon-free hydrogen to replace gas in the medium and long term. “with a clear will to import much of it, because not everything can be produced in their territory, term “, analyzes Laurent Antoni, head of public affairs for hydrogen technologies at the CEA. That is why the country has established a strategic partnership with Morocco, which enjoys a huge solar field. “This type of agreement draws a future geopolitics of hydrogen, with countries that position themselves as future exporters, such as Morocco, but also Chile, Australia, Namibia. or Spain and Portugal “, continues the researcher. In Europe, gas network operators are already working on the development of a giant hydrogen pipeline, which connects the southern countries (Portugal and Spain) to supply the less sunny northern countries. Key name: “European Backbone”, or “French backbone” in French.

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