The Colors of Hydrogen

August 19, 2021

Is hydrogen the fuel of the future? 

Temperature records shattered last month across western Canada and the U.S. Pacific Northwest, with Canada breaking its country temperature record at 49.6°C (121.3°F). As the nation fought over AC units and made homes in department stores to avoid melting, our global leaders pointed fingers at one culprit – climate change.

Source: Meteorological Service of Canada, U.S. National Weather Service

The solution? Well, it is definitely no fast-food joint, and won’t be a quick fix; however, hydrogen, as a renewable energy source, would not be a bad place to start.


By definition,

“Hydrogen (H) is a colourless, odourless, tasteless, flammable gaseous substance that is the simplest member of the family of chemical elements.”[1]

In the energy industry, however, hydrogen is by no means colourless. In fact, hydrogen has almost every color of the rainbow. But isn’t hydrogen a colourless gas? Confusing – I know. Although there is no visible difference between the different colours of hydrogen, the colourful names are used as codes within the energy industry to differentiate the different ways hydrogen is produced. It is important to note, not all hydrogen is equal, and each type will provide varying contributions to emission reductions and overall climate change mitigation as a renewable energy source.

Source: Sembcorp, 2021 [2]

Brown Hydrogen

Brown hydrogen is the by-product of black coal or lignite (brown coal) gasification. Gasification is a process often used in industrial processes to create coal gas or syngas for heating and lighting. In the hydrogen spectrum, brown hydrogen is by far the most carbon intensive and damaging to the environment due to the greenhouse gas (GHG) emissions released during the process.

Black/Grey Hydrogen

Black/grey hydrogen is created using steam methane reformation (SMR) from a methane source such as fossil fuels, and natural gas. SMR is a process which heats methane with steam, typically using a catalyst, to produce a combination of carbon monoxide and hydrogen. Although a bit better than brown hydrogen in the hydrogen spectrum, black/grey hydrogen is still considered a high carbon emitter with a large carbon footprint, as the process does not capture the GHG emissions released during SMR.

Blue Hydrogen

Blue hydrogen is produced in the same way as black/grey hydrogen, using SMR from a methane source such as natural gas, but with one large differentiator: the GHG emissions released during SMR are greatly reduced through the use of carbon capture and storage (CCS). CCS captures, transports, and stores GHG emissions by injecting them back into the ground. This process is deemed lower carbon intensive than the other listed hydrogens so far, but still does not represent zero-emission, as although CCS reduces GHG emissions, the SMR process does not avoid the production of GHG emissions overall.

Green Hydrogen

Green hydrogen is produced using clean electricity from renewable energy sources, such as solar or wind power, to facilitate water electrolysis. Water electrolysis in this case is a process which sends clean electricity through water to cause an electrochemical reaction splitting water into its hydrogen and oxygen components. Green hydrogen is considered a zero-emissions hydrogen production process, with the use of renewable sources eliminating all carbon emissions.

These represent only a select sample of hydrogen colours used within the energy industry. Countless other hydrogen colours such as turquoise, pink and yellow hydrogen also exist. As clean hydrogen technology and production expands, I’m curious to see what colours they come up with next!


Hydrogen has been coined in the energy industry as “the fuel of the future.”[3] This is true in many ways. Hydrogen is an energy carrier that will enable us to decarbonize various energy sectors through its reduced or zero-emission applications in transportation, industry, and power generation. 

Additional advantages of hydrogen as a fuel source include its high energy density (high energy level per unit of mass), safety, and lack of carbon emissions or pollutants during hydrogen combustion at point of use.

By 2050, according to the NRCan Hydrogen Strategy [4], if hydrogen opportunities are pursued, Canada alone could see:

  • Up to 190 Mt-CO2e of annual GHG reductions
  • A nationwide hydrogen fueling network
  • New industries enabled by a low-cost hydrogen supply network
  • ~350,000 hydrogen sector jobs
  • >$50 billion in direct hydrogen sector revenue for the domestic market
  • An established and competitive hydrogen export market


In any case, I am excited to see what role hydrogen will play in not only the renewable energy space, but in achieving net-zero targets and our overall fight against climate change.

[1] Encyclopaedia Britannica (n.d.) Hydrogen. Retrieved from

[2] Sembcorp (2021) Hydrogen and the path to Net Zero. Retrieved from

[3] IEA (2019) The Future of Hydrogen. Retrieved from

[4] NRCan (2020) Hydrogen Strategy for Canada. Retrieved from

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