Hydrogen is the most common molecule in the Universe, and on earth we have a lot of water, as well as hydrocarbon fossil deposits, from which hydrogen can be extracted. There are even a few geological sources of natural hydrogen around the world. Since it produces mainly just water when it’s burnt, some look to a future hydrogen-based society, with hydrogen acting as a key clean energy vector. It’s a lively field for research and discussion, with a quite wide range of options being on the table and much debate about choices as to which should be followed up and the way ahead.
An Open University webinar last November, part of its Green Infrastructure week, looked at ‘what would it take for hydrogen to have a place in the UK’s net zero energy future?’ It was hosted by Dr Victoria Hands, OU Sustainability Director, with a panel of OU experts led by Dr William J. Nuttall, OU Professor of Energy. He argued that, though green power electrification was very important, we would not have enough green power, or green hydrogen derived electrolytically from it, to decarbonise all end uses. We will need synthetic hydrogen and derivatives made via hydrocarbons, with carbon capture and storage at geological sites underground to make it greener. There is still a way to go on that, but he said there will be an incentive to produce hydrogen given that the market could be huge, especially for heavy transport, including trucks.
The other speakers presented interesting more detailed accounts of how, whichever way hydrogen has been produced, it can be stored, for example (like CO2) in giant caverns underground, and transported, for example (since hydrogen is expensive to liquify) as hydrogen derivatives such as LNG, ammonia and other more exotic stuff, like methyl-hexane.
It’s fascinating to see what the chemical engineers (and geologists) have come up with! And as Nuttall said, there are opportunities for significant innovation in the hydrocarbon field and a major role can be played in reducing emissions by the hydrocarbon industry. Indeed he sees it making a lot of the running. However there can be also problems with the various proposed uses of fossil gas, including potential methane leaks. Carbon Capture and Utilisation may also sound clever, especially if captured from industry, but if it’s used to make new fuel and that is burnt, it will just add more CO2 back in the atmosphere.
While Nuttall admitted there may be issues, he said that fossil tech-led incremental gains can be worth-while and that ‘net zero’ should be seen as an aspiration, not as a strict target. And so he also said it doesn’t matter what colour hydrogen we use- green (from renewables), grey (fossil gas derived), blue (fossil gas with CCS), pink (nuclear) or white/gold (natural). We will need it all.
Not everyone will agree with that. For example, quite apart from the costs and risks of nuclear, there will be carbon emissions from making blue hydrogen from fossil gas, even if some of them can be captured and stored. But Nuttall is also keen on renewables, as far as they go, including conversion of surplus green power to hydrogen to back up variable green power supplies. Though, if anything he is also even more keen on nuclear! But even so, and despite also clearly being ‘soft on fossil gas’ and CCS, that’s how the current UK government sometimes feels, so he’s not a full contrarian squad member!
Mind you, it is sometimes hard nowadays to say who is a contrarian and who is not. Some commentators are quite hostile to hydrogen, for home heating especially, and certainly there will be big power-to-gas conversion losses with electrolysis to make hydrogen from renewables- or indeed nuclear power. That may make heating by hydrogen costly. Certainly heat pumps are inherently more efficient and should be cheaper. However, they have sometimes got a bad press, with installation costs being high and installation possibly being a disruptive fit in some small houses. There may also be noise issues in some locations, although that is likely to be small. In most cases, overall, heat pumps do seem a good deal for many houses, and large ones may make even more sense for industrial process heating.
Although, as I have reported in recent posts, the debate on all of this still goes on. And, although there has been resistance by some local communities to the use of piped-in hydrogen for home heating, UK gas company Cadent is still pushing ahead with its hydrogen network programme, with 4.4GW of green hydrogen planned by 2030. Some are also looking to admix hydrogen and fossil gas as an interim step to full conversion, although, in some locations the addition of renewable biomethane to the fossil gas supplies is being looked at possibly as an alternative. And in parallel there’s interest in green heat supply networks. So there are several possible routes to green heating, and plans are all somewhat in flux around the country, with hydrogen being just one route.
Similar issues are being faced overseas, but for example in Europe, where there were cut backs in imported Russia gas, and the shift against fossil gas has been perhaps more pronounced. And, as Nuttall notes, there, and also globally, hydrogen use is likely to grow, with green hydrogen electrolyser markets looking set to expand quite dramatically, and major hydrogen projects around the world emerging. That includes in the US, Europe and Asia, and there are also plans for green hydrogen production for export in some parts of Africa.
How will it go? There is still all to play for, although some sources and some end uses make more sense than others. Blue hydrogen may be initially seen as cheaper, despite the costs and risks of CCS and nuclear hydrogen also has its fans, but although its use for home heating may not be sensible, given technical progress with electrolysis and cheaper renewables, I would hope that we will soon be moving to a world in which renewables-based green hydrogen production, storage, transmission and use increasingly play key roles.
*As the webinar indicated, there is a some work going on at the OU on hydrogen and derivatives from hydrocarbons, including conversion and storage, as well as CCS and allied fields, but renewable energy is also a long established focus of interest there, with, for example, Renew having been fed into the long-running renewable energy undergraduate module for many years as an update service for students. The OU also has a focus on wider sustainability, with for example a new study on skill development and the sustainability skills gap. See also my earlier article on green skills. It’s good to see the OU rising to the green challenge.
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