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Green Hydrogen


The Green Hydrogen, not to be confused with the Grey Hydrogen and the Blue Hydrogen, is the production of Hydrogen from water (H20) splitting.

The Green Hydrogen production is based on the water Electrolysis. Meaning, the electricity injected in the liquid is going to separate the water molecule into hydrogen and oxygen.

Green Hydrogen
Green Hydrogen production by Electrolysis

The chemical reaction happening thanks to the injection of electricity is the split of the liquid molecule of water (H20), into two gases: Di-Hydrogen (H2) and Di-Oxygen (O2).


The Green Hydrogen owes its name to the fact that its production is not a direct emitter of carbon dioxide (CO2) gases, thus it may the one clean process by nature to produce hydrogen.

Yet, the problematic faced by the Green Hydrogen lies into the electricity production used for the electrolysis. Because there is no point of producing a clean fuel gas if the required electrical power originates from fossil energy.

Consequently, the first challenge of the Green Hydrogen is to source its electricity from clean Renewable Energies only.

Green Hydrogen Integration
Green Hydrogen production from Renewable Energy

The second challenge is about the water production at the quality level required for an efficient electrolysis, meaning pure distilled water.  Processes for mass production in costs effective and environmental acceptable conditions remain to be developped.

The third challenge of the Green Hydrogen production is to scale up its capacities. As today largest electrolyzers are on the scale of 10MW, while the world would requires capacities 50 time larger for Hydrogen to be largely used in industrial and domestic applications.

Consequently, the electorolyzer which is the critical equipment at the heart of the electrolysis reaction and thus the Green Hydrogen production, is the subject of many R&D interests, and is gaining every year in power.

There are 3 main technologies of electrolyzers on the market with each different operating conditions:

  • Solid Oxide Electrolyzer cells (SOE)
    Atmospheric pressure, Temperature ~800°C
  • Polymer Electrolyte Membrane cells (PEM)
    Pressure 200 bar, Temperature ~50°C
  • Alkaline Water Electrolysis cells (AWE)
    Pressure 20 bar, Temperature ~70°C

For these 3 technologies, large demonstrators are now in construction to prove their respective efficiency. Meaning, these first few tests of large scale hydrogen production facilities will serve as references for the coming wave of Green Hydrogen projects.

Of course, you can count on Project Smart Explorer
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