2021 marks the end of another decade, and the world is relentlessly warming. Many are starting to see the effects of climate change first hand and it is evermore crucial for us to find a clean energy source. Many have touted green hydrogen as the solution, and we will review its viability in this article. 

Quick summary:


What is hydrogen?

Being the first item in the periodic table, hydrogen is the lightest and most abundant element in the universe (by far – we estimate that around 90% of all atoms are hydrogen). However, pure hydrogen cannot be found in nature; it needs to be decoupled from other elements, most often carbon, in animals, plants or petroleum. Once isolated, it is a versatile energy source that can be used in gas or liquid form and converted into electricity or fuel.


How is it produced?
How the hydrogen is obtained determines its “cleanliness”. The most popular method today is steam methane reforming, which involves high temperatures and a catalyst to produce hydrogen, carbon monoxide and small amounts of carbon dioxide. Fossil fuels are used to power the system, and thus emissions are quite high. If the carbon from the final step is captured, you obtain “blue hydrogen”, if not, then it is called “gray hydrogen”.

One can also produce hydrogen using electricity in a process called electrolysis. Water is driven through an electrolyzer, and is split into hydrogen and oxygen with an electrical current. If  the electricity is generated with renewable power, then the virtually emission-free hydrogen is called “green hydrogen”. 

The advantages

On top of its low emissions, electrolysis’ energy efficiency, that is the hydrogen-based energy produced for the amount of energy put into the process, is stellar.

energy efficiency comparison

Hydrogen has many uses, many of which are in industry, but it can also power household appliances and be used in fuel cells to power electrical systems. These fuel cells work like batteries, are 3 times more energy efficient than combustion engines and can be recharged in under four minutes.



However, there are many obstacles to overcome before green hydrogen can become a widely used energy source. First and foremost, its high flammability and light weight require specialized and careful handling. Its low density means it needs to be highly condensed to transport meaningful quantities; it needs to be cooled to -253˚C and turned into liquid, or compressed to 700 times atmospheric pressure. Pipelines are the easiest form of transport, but hydrogen makes steel brittle, so the current infrastructure is not suitable.

Next, while fuel cells are very practical, they contain expensive components like platinum, limiting their scalability. Research and development to find alternatives is ongoing, but even if this problem were solved, the scarcity of refueling stations would still curtail the technology’s widespread adoption. Further, consumer costs remain far higher for hydrogen than natural gas, and everything comes down to cost.

Although electrolyzer prices are dropping, electrolysis is expensive, especially compared to steam methane reforming. Gray and Blue hydrogen are simply far more attractive economically:

(Source: The hydrogen solution by Sonja van Reseen 2020)

Because large nations have committed to green hydrogen to achieve their Paris Agreement commitment, we can expect more government support for R&D, investment and infrastructure. 

List of countries that have set up hydrogen targets:


According to a pivotal report released by the International Renewable Energy Agency (IRENA) in December 2020, green hydrogen production costs have already begun to tumble largely owing to a decline in falling renewable power costs. With further reduction in the cost for electrolysis and scaling up of the industry, popularization of green hydrogen can surely be achieved in no time. 

The Future of Green Hydrogen

According to McKinsey, green hydrogen in the US could become a  $140 billion industry by 2030, generating around 700,000 jobs. However, despite the international interest, experts believe that our infrastructure is unadapted to the widespread use of hydrogen, and that it will take a long time to adapt. 

An optimistic prediction is that it will take 10 years to fully adopt hydrogen technology, but it will take investment and effort from every sector to achieve. Nonetheless, climate change makes it highly likely that we will unite behind this low carbon solution. 


This article was written by Wing Ki Leung and Owen Mulhern. Cover phhoto by César Couto on Unsplash.

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