The Hydrogen Dilemma
One of this year’s new IASS fellows is Aliaksei (Alex) Patonia. He is a research fellow in commercial hydrogen development at the Energy Transition Research Initiative (ETRI), which is run by the Oxford Institute for Energy Studies. He is concerned with the challenges of the evolving hydrogen economy.
You're currently researching the possibilities of transporting hydrogen over long distances. What is your conclusion at this point?
Aliaksei (Alex) Patonia: Well, there doesn’t seem to be any single solution available that can successfully address all the challenges associated with hydrogen, as it’s a substance that’s not easily transportable. In our most recent piece of research, we looked at the four most-considered options for delivering hydrogen over transoceanic distances, let's say from Chile to Germany or from Australia to Japan. In these cases, pipelines don't work and you need to use marine vessels. So, the four main options right now are liquid hydrogen, liquid ammonia, toluene/methylcyclohexane (MCH, a “liquid organic hydrogen carrier”), and methanol. One of the conclusions of our investigation is that none of those options perform well across all the necessary or critical categories. There's neither a single nor a one-size-fits-all solution because we have to consider both the thermodynamic and economic features of each hydrogen carrier, and the social, geopolitical and strategic rationales. In general, though, of the four options we explored, the cheapest and most effective way to transport hydrogen over long distances would be ammonia and methanol. But that doesn't mean they are ideal.
What are the difficulties involved?
Patonia: Some of the difficulties are related to additional steps in the process of hydrogen delivery. For instance, with liquid hydrogen and with hydrogen in general, the greatest challenge currently appears to be its liquefaction, which involves cooling it to -253°C, which is almost absolute zero. It's a cryogenic temperature, and maintaining it requires a lot of energy. And then you need to store the liquefied hydrogen and keep it at that extremely low temperature for a long period of time. We more or less face a similar situation with ammonia. You need to cool it to -33°C. Although it demands much less energy, ammonia needs to be cracked (dehydrogenated) at the end point so that the hydrogen can be used. Toluene/MCH is a very heavy substance with a relatively low hydrogen content. It’s actually the least effective hydrogen carrier of the four. Even though the toluene could be reused after dehydrogenation of the MCH, it has to be delivered to the supplier, which will result in further costs. Methanol molecules, in turn, contain carbon. So when methanol is dehydrogenated, the carbon will have to be properly managed (either removed and stored, or used). So, as I said, none of the fuels, none of the options, seem to be ideal and none of them eliminate all the challenges.
Can hydrogen help us Europeans out of the current critical gas supply situation?
Patonia: Not at this point, at least. In principle, the idea would be to substitute natural gas with something like hydrogen that doesn’t produce carbon dioxide when burned. Hydrogen could also potentially be used in more sectors than just natural gas: as well as providing heating and electricity, it could serve as a feedstock for some industries such as oil refining. However, one of the main problems with hydrogen at this point is that 99 percent of it is produced from fossil fuels, and natural gas is the main feedstock for its production. Although the EU is heavily emphasizing the need to build up the generation of zero-carbon “green” hydrogen that’s made using water and renewable electricity, the current scale of production is much lower than that of conventional “polluting” hydrogen from fossil fuels. Even if Europe decides to import green hydrogen produced elsewhere, the challenges associated with its transportation and storage have not been fully addressed yet, so replacing natural gas with hydrogen doesn’t seem feasible at this point.
But even if we could transport hydrogen over long distances, how environmentally friendly would it be in the end? For example, if hydrogen is delivered from Australia to Japan, does that make any sense at all?
Patonia: That's a great question. So far, there have only been pilot shipments of hydrogen and hydrogen derivatives between different places. For instance, blue ammonia was shipped from Saudi Arabia to Japan in 2020, MCH was sent from Brunei to Japan the same year, and liquid hydrogen was delivered from Australia to Japan in February 2022. All these projects were the first of their kind, so their main aim was to demonstrate the possibility of delivering hydrogen in each of the respective forms to the end user. At the same time, not that much is known about the pure economic and environmental side of these projects. Obviously, none of the undertakings were cheap and there was a carbon footprint associated with delivering the fuels by sea (using marine fuel causes emissions, for instance). In this respect, developing sustainable carbon management technologies to potentially abate the emissions from fossil fuels could minimize or eliminate the need to engage in the complexity of transoceanic hydrogen delivery altogether.
In July 2020, the European Commission proposed a hydrogen strategy for a climate-neutral Europe, which aims to accelerate the development of clean hydrogen and ensure its role as a cornerstone for a climate-neutral energy system by 2050. Why do you believe this is optimistic?
Patonia: It's optimistic for several reasons. First and foremost, although it sets targets for hydrogen capacity, the strategy doesn’t provide a sound argumentation of how they could be achieved. The document openly admits that the EU will have to import hydrogen, while the internal production capacity within Europe is limited. The follow-up REPowerEU plan assumes that, with sufficient development of electrolyser technologies and renewable energy build-up, 10 million tonnes of renewable hydrogen will be produced within the EU and 10 million tonnes more will have to be imported by 2030. Given that the biggest (10 MW) PEM electrolyser currently operating in Europe is capable of producing only around 1,300 tonnes of green hydrogen per year, Europe will surely need a lot more installations of this kind to be able to deliver its share.Also, a lot more renewable energy will need to be generated for this specific purpose. If we assume that this will be done by new wind farms and solar panels specifically built for this purpose, will the EU have the physical space necessary for all these installations?Finally, will Europe be able to develop the infrastructure to transport and store all this hydrogen? At the moment, all this is questionable. For instance, because of hydrogen’s different physical characteristics, replacing Europe’s underground storage of natural gas with hydrogen will dramatically reduce the amount of energy that we would be able to use. It would give us around 60 TWh instead of the 1,200 TWh we have from natural gas. So in order to create a truly hydrogen-based economy, Europe will have to come up with some sound solutions to these challenges.
If hydrogen is that problematic, shouldn’t Europe then push renewables forward in a more active way?
Patonia: Renewables are great, but the main problem with energy sources such as wind and sun is their intermittency – they are not stable in generating electricity, so they can’t provide stable load to the grid. Since the electric grid needs to be balanced at all times, the idea behind producing green hydrogen is also about storing renewable power when there is a surplus, and discharging it when there is a shortage.
Could the solution also lie in regions like Europe working together on a regional hydrogen solution, rather than in a global solution because of this transporting dilemma?
Patonia: Hydrogen development around the world is actually happening in regional clusters already. This is partly because of the issues associated with hydrogen transportation. But it’s also because regional cooperation – as a result of historic, economic and other reasons – may facilitate faster knowledge exchange and overall development of specific niches in this sector. For instance, Europe is currently the world leader in the R&D and manufacturing of PEM electrolysers – those that are most suitable for being connected to variable renewable energy sources. However, for hydrogen to become a global “thing”, it will ultimately need to go beyond regional borders. Nevertheless, it’s not clear whether this will happen. At least not at this point.