While some people see hydrogen as a key energy vector for the future, others do not, claiming that its benefits have been oversold. ‘Much of the hype for hydrogen is coming from the oil and gas sector, in the hope that gullible politicians, seduced by an unattainable vision of limitless green hydrogen, will subsidise the vast investments needed to capture the emissions from gas-powered hydrogen. Their motivation couldn’t be clearer: to postpone the inevitable decline of their industry’. So says Jonathon Porritt in the Guardian.
Well yes, most greens don’t want ‘grey’ fossil fuel-derived hydrogen - ‘black’ if from coal, ‘brown’ if from lignite. Neither do they want ‘blue’ hydrogen- derived from steam reforming natural gas and capturing (some of) the resultant carbon dioxide gas. For most greens that is just a way to allow for the continued uses of fossil fuel, via reliance on as yet unproven large- scale CCS. But they do want zero carbon green hydrogen, made by the electrolysis of water using renewable electricity. And lots of it. Although that is only part of the story. Porritt also says ‘we need to be clear about what that green hydrogen should be used for: not for electricity; not for heating homes and non-domestic buildings; and not for cars, where electric vehicles will always be better. Instead we will need it for what are called the “hard-to-abate” sectors: for steel – replacing carbon-intensive coking coal – cement and shipping’.
Well there are arguably some problems with that list. Certainly it is (usually) much more efficient to use electricity in heat pumps for home heating than to use green hydrogen gas, or indeed any type of hydrogen, but that assumes that enough green electricity will be available when needed. At times of peak heat demand it may not be, in which case gas heating may have to be used as a back up. Maybe a job for stored green hydrogen, made earlier, when there was surplus renewable power. That stored green hydrogen can also be used to make electricity to meet lulls in renewable supply. Indeed, using green electricity to make green hydrogen and then green power again, may be the key solution to the problem of variable renewable intermittency.
The trouble is that it may take a while for green hydrogen from renewables to be available in bulk. It’s improving, but it’s still expensive to produce via electrolysis. Some projections are that it may be competitive with fossil fuel-derived hydrogen by 2030, although with renewable costs falling and fossil costs rising that may be pessimistic. There are already plans and proposals for projects with offshore wind-derived hydrogen being used for home heating as well as other purposes. Clearly it’s on the way for a range of end uses, but it will take time.
Push for blue hydrogen
Meantime, some say we should go for fossil fuel-derived blue hydrogen, with Carbon Capture and Storage (CCS), as an interim low carbon option. The European Parliament’s draft resolution on the European Commission’s hydrogen strategy, tabled in July 2020, called for the promotion of the use of low-carbon hydrogen in the short to medium term, as a way to develop the hydrogen market. Predictably the greens were not happy with this. Euractiv quoted Imke Lübbeke, head of climate and energy at WWF European Policy Office as saying ‘the European Parliament had an opportunity to deliver a vision for the efficient, strategic development of hydrogen, but they squandered it.’ It also quoted Adrien Assous from Sandbag: ‘The regressive themes of the Parliament’s discussion reflect the worrying trend to promote hydrogen in all forms, for all uses, without considering what other more efficient options exist and whether a particular application of hydrogen makes sense in the broader context of energy system decarbonisation.’
There have been attempts to include hydrogen produced using power or heat from nuclear plants in the package, as well as more generally for the inclusion of nuclear within the post-Covid economic stimulus plan. So far it has been excluded from the latter. However, Paula Abreu Marques, head of unit for renewables and CCS policy at the EC’s energy directorate told the European Parliament in November last year that the European Commission considers hydrogen produced from nuclear power as ‘low-carbon’, although it is not mentioned in the EU Hydrogen Strategy. As yet nuclear hydrogen does not seem to have a generally agreed colour associated with it, though some call it ‘pink hydrogen’. I’ve also see it called ‘purple hydrogen’. But whatever its colour label, like nuclear generally, it seems likely to be very expensive.
Conclusions
It’s hard to predict what path will be taken in terms of hydrogen use. Grid balancing will become an urgent issue soon, as the use of variable renewables expands, so Power to Gas/Gas to Power systems, based on stored green hydrogen, may begin to proliferate, but the transport sector may be the defining one in the short to medium term. Hydrogen may prove to be the best option for heavy vehicles, ships and possibly even aircraft. Although biofuels may be a rival in some case (for direct heating too), there are biodiversity and land use constraints. Electric cars clearly have merit, but material scarcity and extraction issues may contain the use of Lithium Ion batteries, making cars powered by hydrogen fuel cells more attractive.
Another key factor that may shape hydrogen progress is the development of cheaper, safer and more efficient hydrogen storage- better than the inevitably bulky/heavy options of compressed storage of gaseous hydrogen in pressurised tanks and cryogenic storage of liquid hydrogen in insulated tanks. Various metal hydride options are being looked at for solid state storage, including some novel slurry and paste based systems. Some may be suited to mobile applications or for home energy storage. Though for large scale storage for power and heating use, there is the option of bulk storage in salt caverns underground.
The battle is clearly on in terms of what type of hydrogen is to be produced and stored. For example, in the UK, the HyNet North West project has been given £72 million of funding for the production of blue hydrogen from natural gas and linked carbon capture and storage infrastructure. But at the same time Centrica is looking to large scale cavern storage of hydrogen - although that’s likely to be blue hydrogen, at least initially. Meanwhile, ITM Power, Orsted and Siemens are working on a green hydrogen ‘power to gas’ project, using power from offshore wind, and there are also plans for using an underground salt cavern hydrogen store. It is all new pioneering stuff, with plenty of room for technical problems and economic uncertainties, but that’s what innovation is all about.
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