on June 29th, 2022

The appeal of hydrogen fuel is that as a resource on earth it’s nearly inexhaustible. But how should engineers approach green hydrogen?

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.

The separated CO2 is often emitted into the atmosphere which 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.

IEA, Hydrogen demand in industry, 2020, IEA, Paris https://www.iea.org/data-and-statistics/charts/hydrogen-demand-in-industry-2020https://www.iea.org/data-and-statistics/charts/hydrogen-demand-in-industry-2020

How did Green Hydrogen become such a buzzword?

Expectations for the hydrogen economy, first proposed in the 1970s, have been high. But hydrogen as a renewable, low-carbon fuel for vehicles, heating, and energy storage has remained evasive, held back by high costs, low efficiency, and a lack of infrastructure and storage technologies.

Yet change is in the air. The International Energy Agency (IEA) calls this a year of “unprecedented momentum” for hydrogen in its June 2019 report, The Future of Hydrogen  According to the paper Electrolysis for hydrogen production in the past initiatives focused on hydrogen fuel cells for vehicles was a complete focus. 

In 2022 it’s different with pressure to decarbonize the global economy has nudged policymakers and companies to look at hydrogen as a way to lower emissions in sectors beyond transport. 

The cost to make and use hydrogen is lowering and renewables have become a key driver. 

Hydrogen is seen as one of the lower-cost options available for storing surplus power, as opposed to wind or solar power generation. 

Source: https://www.iea.org/data-and-statistics/charts/global-installed-electrolysis-capacity-by-technology-2015-2020IEA, Global installed electrolysis capacity by technology, 2015-2020, IEA, Paris https://www.iea.org/data-and-statistics/charts/global-installed-electrolysis-capacity-by-technology-2015-2020

So, What’s the Catch?

The paper estimates that nearly 70 million metric tons of hydrogen used annually (for the production of petroleum and ammonia) is made by cracking natural gas through stream reforming which is a carbon-intensive method. 

For it to be clean electrolysis is still the most viable option for green hydrogen. 

The problem is that hydrogen from electrolysis today is the cost. It’s as much as two times more expensive than steam reforming. 

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.

But there are also a number of changes that need to be considered.

Electrolyzer costs are expected to come to the forefront as renewables provide cheap electricity in the future. 

Materials scientists and engineers are now working on better catalysts, membranes, and structural components, as well as manufacturing methods, that could reduce operating costs and make hydrogen from water part of the low-carbon economy. 

Available technology includes the current estimate that electrolysis accounts for roughly 4% of the hydrogen produced today, but the technology has seen a surge in interest in recent years. 

The number and size of installations are increasing for the use of this hydrogen. Over 20MW of electrolyzer capacity came online in 2018.  

Two electrolyzer technologies are commercially available on a large scale in their current lifecycle. 

Proton-exchange membrane (PEM) and alkaline electrolysis. Both these work at low temperatures of 50–80°C, as opposed to high-temperature electrolysis. Much of the current research in electrolysis aims to reduce costs even more. 

Will Australia Be the Next Green Hydrogen Superpower?

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. 

These efforts are set to make Australia a world leader in hydrogen as power and in 2022 hydrogen activity across the country is soaring. In June 2022 it was announced that a A$600m ($413.3m USD) green hydrogen distribution network in Australia has signed off. It will be built by Hydrogen Fuels Australia (H2FA) and CLARA Energy. 

The hydrogen super highway will include five hydrogen refueling stations along the Hume Highway, between Melbourne and Sydney, to support freight and logistics companies transition fleets to hydrogen. 

At the same time, CLARA Energy plans to start operations of what it says could be one of the world’s largest green hydrogen production facilities in New South Wales (NSW) by 2025. 

IEA, Annual announcements of government hydrogen strategies, 2018-September 2021, IEA, Paris https://www.iea.org/data-and-statistics/charts/annual-announcements-of-government-hydrogen-strategies-2018-september-2021https://www.iea.org/data-and-statistics/charts/annual-announcements-of-government-hydrogen-strategies-2018-september-2021

The facility could produce 25,000kg of green hydrogen every day in the first phase of operations, with the potential to scale up to 100,000kg per day. 

It is seen as one of the only effective ways to decarbonize Australia. 

Engineers should make a note of hydrogen being part of their line of work, as 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. 

If you would like to be part of the green hydrogen future, the Professional Certificate of Competency in Hydrogen Energy – Production, Delivery, Storage, and Use course may be what you are looking for.

References

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.

Patel, P., & Ayers, K. (2019). Electrolysis for hydrogen production. MRS Bulletin, 44(09), 684–685. https://doi.org/10.1557/MRS.2019.210

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