Green hydrogen has been claimed to be the clean energy source that could be an alternative to fossil fuels. But, what is it exactly?
Hydrogen. We have got plenty of it, it’s light, and it’s clean-burning! Whether it’s used in a fuel cell or being burned to create heat, the only ‘exhaust’ that hydrogen emits is clean water. It is no wonder why it is seen by many as the fuel of the future.
However, it is not without its obstacles. 96% of hydrogen today is made directly from fossil fuels – coal, oil, and natural gas – in a process known as reforming. Reforming involves combining fossil fuels with steam and heating them to around 800 degrees Celsius. The result is then CO2 and hydrogen.
The two gases are then separated, which means the hydrogen is now available to be used in everything from car engines to boilers, releasing its harmless water vapor. But what happens to the CO2?
The separated CO2 is often emitted into the atmosphere where it contributes to global heating. According to the International Energy Agency (IEA), the production of hydrogen is responsible for CO2 emissions of around 830 million tonnes of carbon dioxide per year. To combat these CO2 emissions, ‘green hydrogen’ was identified as a possible clean energy source alternative.
If you are somewhat interested in hydrogen, green hydrogen is probably a term that you have seen floating around.
Whilst the vast majority of hydrogen is produced from natural gas, green hydrogen is instead produced by the electrolysis of water. If the electric current is produced by a renewable source (e.g., wind, solar, or hydropower), the hydrogen produced is known as green hydrogen.
According to the IEA, less than 0.1% of hydrogen today is produced through the electrolysis of water. However, as we transition to low emissions and work towards a clean, healthy environment, green hydrogen might start to play a major role in making sustainable change.
Aside from the usual hydrogen stumbling blocks, producing green hydrogen is an expensive and energy-intensive process. This is why 99% of our current hydrogen supply comes from fossil fuels.
In most areas around the world, there simply isn’t enough renewable energy around to produce sizable amounts of green hydrogen. Therefore, the cost of making green hydrogen prices it out of competition with its fossil fuel neighbors.
Conventional hydrogen costs about $2 per kilogram (though this can vary), while green hydrogen can cost around twice as much. The production cost is determined by the renewable electricity price, the investment cost of the electrolyzer, and its operating hours.
If we are serious about pursuing green hydrogen, countries will need to massively ramp up their ambitions on wind, solar and other renewable technologies to bring down the cost of production.
However, the momentum behind green hydrogen is starting to pick up in a very positive direction.
The number of investments in green hydrogen has risen from none in 202 to 121 gigawatts across 136 projects in planning and development phases totaling over $500 billion in 2021. Companies across many countries have formed alliances to increase production fifty-fold in the next six years. There are mega-plants now slated for Australia, France, Germany, the Netherlands, Paraguay, Portugal, the U.K., and the U.S. The most ambitious plan is planned for the Pilbara region in Australia.
In 2020, the Australian Government fast-tracked approval for the world’s largest planned renewable energy export facility, The Asian Renewable Energy Hub.
The project is set to have up to 15 gigawatts of wind and solar generation capacity, 12 gigawatts of which will be dedicated to green hydrogen production. It is estimated that the hub will have 1 gigawatt of electrolysis capacity upon completion in 2027.
"This development will demonstrate Western Australia's credentials as a world-class investment destination for green energy generation, including the production of exportable commodities, like green hydrogen and ammonia, and green steel manufacturing,” says Regional Development Minister, Alannah MacTiernan.
"It will put Western Australia on the map as a major contributor to lowering global carbon emissions."
In 2021, energy companies announced plans to construct a “hydrogen valley” in New South Wales for $2 billion which would replace the region’s coal industry.
Furthermore, a report published by the Australian National University, Green hydrogen production costs in Australia: implications of renewable energy and electrolyzer costs, recently responded to the all-important question of whether green energy ever can be produced at an achievable cost.
And the answer was quite positive.
“We find that the cost of green hydrogen could readily be at or below A$3/kg in the near future and that the ‘stretch goal’ of A$2/kg mentioned in Australian strategy documents is likely to come into reach, possibly rapidly.” (Longden, Jotzo, Prasad, and Andrews, 2020)
As improvements in renewable energy technology are seen across the board, a future with green hydrogen might be sooner than we think.
Ready to get involved?
EIT’s sister company, IDC Events, is holding a technical engineering conference covering renewable, green, and clean hydrogen, hydrogen production, its conversion, application, transportation, and storage.
This two-day conference is not one to miss if you are interested in being at the forefront of hydrogen. It is a valuable opportunity to build your career and public profile, and contribute to Australian engineering practice in this vital area!
Find out more information through the conference page.
Longden T., Jotzo F., Prasad M. and Andrews, R. (2020), Green hydrogen production costs in Australia: implications of renewable energy and electrolyzer costs, CCEP Working Paper 20-07, ZCEAP Working Paper ZCWP03-20, August 2020, The Australian National University.
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