What is green hydrogen? What seems like a straight forward question is anything but.
Hydrogen, the ‘H’ in H₂O, was first discovered by Henry Cavendish in 1776. Besides being a key proponent in water, the lightest element in the world carries a heavy load in building a green future. Hydrogen powered vehicles already have a range 200km further than the best battery powered EVs. Let’s get technical.
There are three primary grades of hydrogen, grey, blue and green. Grey is hydrogen produced by either gasifying coal or reforming natural gas. Both these processes split the material into hydrogen and carbon.
Blue hydrogen is produced by doing the same thing as grey, but either capturing or utilising the carbon instead of letting it escape as an emission.
Which brings us to green hydrogen. Green hydrogen typically uses a machine called an electrolyser to split water into oxygen and hydrogen. The result, lower emissions.
However, an electrolyser is unusual because it’s only economical to operate if using renewable energy. Therefore, if you hear somebody is using an electrolyser to produce hydrogen, you can be sure it is green hydrogen being produced.
Green hydrogen isn’t an official term, and different organisations have inconsistent standards. In practice, green hydrogen has no adverse environmental impact from its production. But this is more complicated when you look at processes that produce hydrogen from fossil fuels.
Eden Innovations ($EDE) developed the pyrolysis process which takes methane and breaks it down into hydrogen and carbon. As part of the pyrolysis process, the carbon is directly converted into carbon tubes, an industrial product. What’s unclear is if this should be classified as green or blue hydrogen as it uses a fossil fuel, but produces no emissions.
Fortunately, governments around the world have taken a strong interest in hydrogen. So while we don’t have a timeline for term standardisation, organisations are already paving the way for an H₂ future.