Within the past year, public and private sector leaders worldwide have made ambitious plans to combat climate change. Within these plans, hydrogen often plays a critical role, and the source of this hydrogen energy has come under increasing interest and scrutiny. The challenge is, the vast majority of hydrogen is manufactured from fossil-fuel sources, and a simple colour association is being used in the absence of a standard for distinguishing the carbon intensity of hydrogen.
For the hydrogen industry to be an effective component of low carbon economies, it must reject the use of the so-called hydrogen rainbow, and cease using terms from blue to grey to green to denote the quality of the hydrogen being used. ‘Grey’ refers to hydrogen made by fossil fuels, ‘blue’ to hydrogen made by fossil fuels with carbon sequestration added, and ‘green’ to hydrogen made using electrolysis powered by renewable energy.
Though many categorise hydrogen using colours and see certain colours like green as good and grey as bad, in actuality, the spectrum is much more complex. Assigning hydrogen a particular colour doesn’t allow enough granularity to compare whether one method of production is quantifiably better to reduce carbon emissions than another or how a hydrogen-based solution compares to other alternatives such as electric vehicles.
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