Understanding the Hydrogen Rainbow
At SKYRE, we’re all about hydrogen and are committed to not wasting a molecule of it. Our mission is to decarbonize the world's energy system, and we’re doing that in part, by recycling hydrogen – leaving less waste and paving a smarter way to a better world.
Despite being a colorless and odorless gas, a question we often come across with hydrogen is what do the various colors of hydrogen represent? When we say something is green hydrogen - what does that mean?
It’s a proverbial rainbow of hydrogen and we have the color key.
Green
Also called renewable hydrogen, green hydrogen is generated using electrolysis within a unit called an electrolyzer. Electrolysis is the chemical process of using electricity to split water into hydrogen and oxygen. The key to green hydrogen is that the electricity used is derived entirely from renewable energy sources like wind and solar. Green hydrogen is considered a pillar of decarbonization. There is essentially no way to meet net-zero emissions at scale without hydrogen and thus it’s a key element in the world’s shift to decarbonization.
Pink
Pink hydrogen is created by electrolysis powered via electricity derived from nuclear power plants. While there is still skepticism around using nuclear energy as a green energy solution, pink hydrogen is gaining traction in the market as a sustainable and carbon neutral way to produce hydrogen.
Grey
By far the most common, grey hydrogen is created from natural gas, or methane, and produced with fossil fuels, using steam methane reformation but without capturing the greenhouse gases made in the process. Grey hydrogen is essentially the same as blue hydrogen, but without the use of carbon capture and storage, making it the cheapest and least renewable hydrogen.
Blue
Blue hydrogen is generated using natural gas, or methane, and relies on carbon capture and storage to reduce emissions, which has proven costly and has failed to meet emission reduction expectations. Blue hydrogen is created similarly to gray hydrogen but gray hydrogen does not capture and store its carbon emissions.
