Why does hydrogen have so many colours?

hydrogen colours

The 4th Hydrogen at the Centre conference, held on October 18, 2023 in Orléans (France), offered an overview of production and extraction methods of hydrogen. You must know that the diversity of ways in which hydrogen can be produced are associated with colours (even if, in theory, we should no longer use them because of regulations). But why does hydrogen have so many colours? Here’s an explanation.

From water to methane

At the event, there were talks about the CEA’s high-temperature electrolysis, Haffner Energy‘s thermolysis (using biomass, particularly wood) and Spark Cleantech‘s plasmalysis (using methane). Each of these solutions aims to reduce electricity consumption and achieve a production cost of around €2 per kilo (the CEA’s target), or even less. Besides, depending on the production method, by-products can be obtained that can be recycled.
Haffner produces syngas, which can be used as it is as an alternative to natural gas, or converted into industrial-grade hydrogen or hydrogen for mobility. It also generates biochar, a highly effective fertiliser. Spark also produces carbon black, which can be used in certain industries.

The colours of underground hydrogen: white or orange?

While Europe is pushing for green hydrogen, and therefore for electrolysis, we are also hearing that we need to be pragmatic and explore other avenues to make the price of hydrogen competitive. At the event, representatives from the CEA, Haffner Energy and Spark argued that each technology had its place and its use case. They also indicated that they had no fears about the strain on the resources used in their processes, whether water, biomass or methane.

The same session went on to discuss natural hydrogen (also known as white hydrogen) and the more controversial orange hydrogen (or stimulated hydrogen). Not authorised in France, orange hydrogen requires water to be injected into the rock to extract the hydrogen. The expert who spoke about this, a former researcher at *ISTO is in the process of creating his start-up. It will be carrying out his activity in the United States or Australia.

We can always sweep aside these alternative methods and swear by green hydrogen alone, which is indeed the most virtuous. However, the question of price is a key factor. And until it becomes competitive using electrolysis and renewable energies, intermediate phases will be necessary. But there are solutions for producing renewable hydrogen, with a carbon impact that is presented as negative in some cases.

*ISTO: Institut des Sciences de la Terre d’Orléans (French for Earth Sciences Institute of Orléans)

Article written by Laurent Meillaud and translated by Logan King 

If you liked it, share it

About the author

Picture of Logan King

Logan King

After an unusual career (3 years in the French army followed by a 3-year degree in Applied Foreign Languages), it was my passion for environmental issues that finally caught up with me and led me to join Seiya Consulting and H2 Today in June 2022. First as an end-of-study internship, then as Marketing & Communication Manager and translator at Hydrogen Today.

Our latest articles

interactive world map