We have many discussions in different forums about the role of green hydrogen, but as my priority is that we start doing things from now, it is very important that we understand several fundamental aspects of this debate. In this way, with the data at hand, we can better combat deniers and “delayists”.
There is a great consensus in the scientific community regarding the need for Green Hydrogen to combat climate change. Just as we need solar panels, wind turbines, and batteries, we need green hydrogen to maintain the standards of this advanced world that make us live longer and better. But how much hydrogen do we need?
There are many projections and many discussions around this figure, but even in the projections of a very efficient world, enormous amounts of hydrogen are necessary. These predictions tell us that we will need at least 100 million tons (Mt) of hydrogen, that is, 100,000,000,000 kg of hydrogen, with all its zeros.
Figure 1a is from Michael Barnard, recently published in Clean Technica, and it shows projections of volumes above these 100 million tons for the coming decades. We also see the uses of this hydrogen, mainly industrial. These are projections that are very much in line with those of the H2 Science Coalition and even with those promoted by Michael Liebreich and his famous 'hydrogen ladder.' Regarding hydrogen projections, Michael is closer to 200 Mt than 100 Mt but far from other projections that reach even 600 Mt
a)
b)
Figure 1. a) Estimation of hydrogen demand made by Michael Bernard. b) Hydrogen Ladder by Michael Liebreich.
Therefore, at this point, we can safely say that 100-150 Mt of hydrogen is not a value that is incompatible with any critical position on hydrogen due to its evident need in our society. In this sense, the European Union proposes that by 2030, we have 20 Mt (10 Mt domestic + 10 Mt exported) of clean H2. We can admit the debate on how the European Union will produce those 20 Mt and what hydrogen to produce, but we cannot question the volume or the proposed date, because we are talking about a 15% reduction in emissions with this hydrogen and more than 600 thousand jobs.
Therefore, let's get to work. Among all the options offered by the wide range of H2 colors, the green option is the safest in terms of emissions. That is, we need to produce hydrogen through the electrolysis of water using renewable energy. At this point, and never forgetting the urgent situation we are in, we must also clarify how much green hydrogen we will produce by the end of this year, 0.5 Mt, a figure that we can see in Figure 2 of BloombergNEF in a recent article. In this same figure, there are forecasts of reaching 25 by 2030, still four times below the proposed target of 100 Mt.
Figure 2. BloombergNEF's estimate of the accumulated capacity of electrolyzers and consequent hydrogen production from now until 2030.
But then, why are we moving so slowly if we "only" need 100 Mt? Because 100 Mt is a lot of hydrogen, requiring the construction of many green hydrogen plants, which in turn require the manufacture of many electrolyzers powered by many renewables.
Putting the numbers in perspective: 100 Mt of Green Hydrogen = 1000 GW = 1 TW of electrolyzers whose annual production capacity is now and optimistically around 25 GW/year by the end of 2023, as can be seen in a recent calculation by Arup for the Scottish government (Figure 3) a pace that is not enough to meet our climate goals, which is, remember, what is important.
Figure 3. Electrolyzer manufacturing capacity in the coming years carried out by Arup for the Scottish government.
Finally, we should never forget that these electrolyzers need renewable energy to be powered. 1 TW of electrolyzers = 2-3 TW of renewable energy due to the intermittency of the renewable source and the specificities of producing green H2 at a competitive cost. And how much does installing 3 TW of solar energy occupy in surface area? About 60,000 km2, which is about the surface of Croatia or the region of Extremadura and Ciudad Real in Spain.
In summary, we must never forget that we are having this debate because of our urgency to eliminate emissions and combat climate change. Therefore, keep in mind that with these 100 million tonnes of green hydrogen, these 2-3 TW of renewable energy and 1 TW of electrolyzers necessary to produce it, we will avoid 15% of global emissions. Are we ready to get started?
Hello Carlos, thank you very much for your interesting and very well prepared contributions. How many emissions would you estimate we will cause to produce the infrastructure for 100 million tonnes of hydrogen? Thank you very much and saludos desde Vienna, Rudolf
The way forward must be to start producing hydrogen in those places where it is competitive vs the fossil alternative and for applications that only green hydrogen is the alternative for decarbonisation (i.e. all sectors very difficult to electrify, mainly industrial sectors). Places in South and North of Europe and other places in the world where renewable electricity is cheap and abundant can help to the technology to become cheaper and cheaper and minimise as much as possible the government support.