Green hydrogen has been receiving attention as a potential energy source of the future.
Below, we outline what it is, how it’s produced, how it compares to blue hydrogen and other types of hydrogen, what it’s potential pros and cons might be, along with other potentially important information to consider about the energy source.
What Is Green Hydrogen? (Definition/Meaning)
‘Green hydrogen’ is hydrogen that is manufactured/produced using renewable energy sources (like solar or wind energy)
How Is Green Hydrogen Made, & What Is It Made From?
Green hydrogen is hydrogen that is produced using the process of electrolysis, with renewable energy (from energy sources like solar, or wind)
The process of electrolysis for green hydrogen involves passing an electrical current over water to split/separate the water into hydrogen and oxygen, with the electrical current being generated with renewable energy
The renewable energy used might be surplus renewable energy (that would otherwise have to be stored in a battery for example)
Difference Between ‘Green Hydrogen’ & ‘Normal Hydrogen’
Some of the key differences might be:
‘Normal hydrogen’ is made via the steam reforming of natural gas (also called steam methane reforming)
The outputs from this process are hydrogen, and carbon dioxide (the carbon dioxide forms when water is added to the carbon monoxide that comes from the chemical reaction when natural gas is mixed with hot steam)
The vast majority of the world’s hydrogen is made this way
It is sometimes referred to as ‘grey hydrogen’
Read more about how ‘normal hydrogen’ is made in this guide
Instead of using natural gas and steam reforming during production, green hydrogen uses electrolysis and renewable energy
So, it uses a different process and energy source for production
Additionally, the output from the process is hydrogen and oxygen – not hydrogen and carbon dioxide
Much less hydrogen is produced worldwide using electrolysis compared to steam reforming
Blue Hydrogen vs Green Hydrogen vs Grey Hydrogen vs Brown Hydrogen: What’s The Difference?
Hydrogen can be referred to as different names, depending on the way it’s produced.
Some of those names, and the main differences between them might be:
‘Blue hydrogen’ is hydrogen made from steam methane reforming, but, it differs to normal hydrogen production (i.e. ‘grey hydrogen’) in that it uses carbon capture and storage to capture and store the carbon dioxide produced during production underground
So, it might be considered more sustainable than normal hydrogen production for this reason
We’ve described ‘green hydrogen’ elsewhere in this guide
‘Grey hydrogen’ is a phrase used to describe normal hydrogen
This is hydrogen produced with steam methane reforming, but without the use of carbon capture and storage
‘Brown hydrogen’ is hydrogen produced from black coal or brown coal
It is sometimes referred to as ‘black hydrogen’ too
Brown hydrogen is produced using the coal gasification process, whereby coal is subject to heat and pressure (via heat and oxygen), and broken down into a ‘syngas’
The outputs are hydrogen, carbon monoxide, and also carbon dioxide
What Is Green Hydrogen Used For?
Green hydrogen can be used for the same uses as regular hydrogen
For example, hydrogen can be used in a fuel cell, to generate electricity or heat
Some common uses of hydrogen are as a fuel for vehicles (in transportation), and for electricity or heat in buildings
Read more about the various uses of hydrogen in this guide
One example of a niche use of green hydrogen specifically might be for ‘green steel’
How Much Green Hydrogen Is Currently Being Produced?
From the data below, it might be accurate to say that only a very small % of hydrogen worldwide is green hydrogen, produced with electrolysis and renewable energy.
That % might be between 0.1% and 1%.
[In 2021 …] green hydrogen accounts for just 0.1% of global hydrogen production … (weforum.org)
Electricity had a global average renewable share of about 33% in 2021, which means that only about 1% of global hydrogen output is produced with renewable energy.
Electrolytic hydrogen from dedicated production remained limited to demonstration projects adding up to a total capacity 0.7 GW in 2021.
Largest Green Hydrogen Plants In The World Today (& Their Production Capacity)
Over the past few years, several countries have planned or undertaken construction for the largest green hydrogen plant in the world.
Each new plant in different locations has superseded the previous one in terms of size or production capacity.
As of 2023, construction started for the world’s biggest green hydrogen plant (using solar and wind for hydrogen production) in Inner Mongolia. This is a demonstration project.
According to chinadaily.com.cn: ‘The production capacity of hydrogen through electrolyzed water [for this plant] is 30,000 metric tons per year and the hydrogen storage capacity is 288,000 standard cubic meters’
prosperoevents.com also lists some of the other gigawatt-scale green hydrogen projects worldwide (either planned, or in construction) in their report
Potential Pros & Cons Of Green Hydrogen
We’ve already outlined what some of the pros and cons of hydrogen energy in general might be in a separate guide.
However, some of the potential pros and cons of green hydrogen specifically might be:
– Production of green hydrogen might be more sustainable in some ways than normal hydrogen
Because green hydrogen’s outputs are hydrogen and water vapor (from electrolysis), and it also uses renewable energy sources like solar and wind
This is compared to normal hydrogen for example, which has the outputs of hydrogen and carbon dioxide from steam methane reforming, and uses natural gas
chinadaily.com.cn for example outlines that (paraphrased) a new green hydrogen plant that has gone into construction in Inner Mongolia might save in the millions of tons of carbon dioxide emissions a year
– New green hydrogen projects have been planned or gone into construction recently
Over the last few years, new green hydrogen projects have been planned or gone into construction in multiple different countries worldwide
New plants obviously means production capacity is growing
prosperoevents.com for example mentions that: ‘In 2022, the global green hydrogen pipeline alone exceeds 250GW, 200 times the power produced in 2020.’
– May have economic benefits
chinadaily.com.cn for example mentions that (paraphrased) a new green hydrogen plant that has gone into construction in Inner Mongolia may contribute to local GDP, and also generate tax revenue
– Green hydrogen can be used for specific ‘green’ uses
For example, green hydrogen might be used to make ‘green steel’ (i.e. steel made without using fossil fuels)
– There might be several ways to decrease the cost to produce clean hydrogen
cnbc.com lists and explains three key ways in their report
– Production of green hydrogen is not anywhere near the scale of normal hydrogen right now
Green hydrogen makes up 1% or less of all hydrogen production right now
This number could be even lower when taking into consideration how many new plants might be demonstration plants
– Green hydrogen is yet to prove it can scale to the same extent of regular hydrogen, and other energy sources
More green hydrogen plants might need to be built and function effectively first, in addition to green hydrogen itself being used effectively for different applications
– New green hydrogen plants might expensive to build
Several different reports put the cost the build new green hydrogen plants at between $500 million to $1 billon dollars in different countries
– The cost of clean hydrogen might be expensive to produce
From cnbc.com: ‘Making hydrogen from natural gas costs about $1.50 per kilogram … [and] Clean hydrogen costs about $5 per kilogram.’
– Green hydrogen might be good for some uses, but inefficient for other uses
For example, it might be inefficient to convert renewable energy to hydrogen, and then to use that hydrogen as a fuel or for energy. It might be more efficient to store that surplus renewable energy in a battery, and use battery stored energy.
But, green hydrogen might be good for other uses like industrial uses (such as it’s use in fertilizer)
cnbc.com goes into both of the above points in more detail in their report
What Is The Future Of Green Hydrogen?
Right now, the vast majority of hydrogen being produced is ‘grey hydrogen’ from natural gas/methane, and not ‘green hydrogen’.
Purely from a production perspective, green hydrogen may not make up a large % of hydrogen production in the short term future.
However, with many countries having an emphasis on developing and using cleaner forms of energy in the future, production might grow in the medium to longer term future.
prosperoevents.com for example mentions that ‘[In 2022, there’s a] 20MW facility in Canada [, but] By the end of this decade … there will be plants a hundred times this capacity’
In the prosperoevents.com report, they list multiple green hydrogen plants worldwide that have stipulated completion dates between 2028 to 2040.
As we mentioned above in this guide though – green hydrogen might still need to prove it can scale and be used effectively first before it can realistically grow.
The potential drawbacks and limitations of hydrogen as an energy/fuel source, and green hydrogen production specifically have to be taken into account too.