After the formal presentations, the speakers joined a panel to answer questions from the audience.
The first question, put by a number of the audience, was about the transport of hydrogen and whether it could, for example, be safely used in the gas grid. If so, could that allow hydrogen to be widely used in homes?
There is good confidence that the polyethylene pipe distribution system will be compatible with hydrogen. Indeed, town gas which was used in the last century contained up to 50% hydrogen. There are technical issues to do with the small size of the molecule and also about integrity of the high pressure system which is made of high strength steel with welds, but there are solutions available. The Committee on Climate Change estimates that the most cost-effective option will result in 10-11% of buildings being heated by hydrogen by 2050.
When not being transported in pipelines, hydrogen would need to be compressed with all the associated costs. There are emerging technologies where hydrogen can be adsorbed onto complex nanostructured particles: this could increase the energy density without requiring large amounts of energy for compression. Alternatively, it can be made into ammonia and then shipped in that form. Ammonia production and shipping are well-understood processes. This could also facilitate an export market for hydrogen.
Another question concerned how quickly the UK could switch to green hydrogen, and what exactly is to be the best source of electricity for this: nuclear power, offshore wind or other renewables?
If nuclear is part of our electricity system, it will be part of what we produce hydrogen with. The key, though, to unlock this technology lies in the fact that renewably-generated electricity has seen rapid reductions in price. If 80% of grid supply comes from renewables in future, with the associated variability of production, the grid will need balancing – which could be achieved by creating hydrogen from electrolysis.
The UK already has the technology to produce blue hydrogen with more than 95% of carbon capture. While that is not as sustainable as green, it is available today. So blue is an important part of the mix today while we prepare to transition to green.
The Conference of the Parties (COP26), taking place in November this year in Glasgow, will not include target-setting for green hydrogen. There could, however, be major announcements about collaborations and commitments on green hydrogen, as part of the broader conversation and context. For countries like South Africa and Australia, the developing hydrogen economy could be part of their ‘just transition’, where it provides jobs for people currently working in the coal industry as they make that transition quickly. So while the subject may figure quite significantly in Glasgow, it will not be part of the negotiations.
A number of people raised the question of what the future of aviation will look like. As Lord Willetts noted, this is one sector where conventional solutions may not work.
Cranfield has already flown an electric/hydrogen hybrid aircraft. The Climate Change Committee projections for aviation in 2050 are based on green hydrogen being used with captured CO2 to produce synthetic aviation fuel. While this is a more sustainable fuel it is, unfortunately, very energy intensive to manufacture.
Today, sustainable aviation fuels make up 0.01% of the global fuel mix, a tiny proportion. However, industrial transformations always follow an S-curve. Achieving 2% by 2025 may not seem like an ambitious goal, yet it is 200 times today’s level. The French bailout of Air France mandated 10% by 2030. With that kind of growth, it will soon become clear which are the best technologies and how soon they will be in a position to compete with kerosene.
What policies will be needed to stimulate green hydrogen? A carbon tax was suggested as well as invitations to bid for Contracts for Difference. Such mechanisms will help create the levels of competition that have been so successful in bringing down the costs of offshore wind. That will require standards for hydrogen: blue hydrogen made with 95% carbon capture and storage will have different contracts from green, electrolytic hydrogen. Appropriate support for R&D in order to develop new technologies is crucial. As initial projects get going, investment from both industry and Government must be made available, to prove the viability of the technologies themselves and also that they can work at scale.
One speaker proposed “an industrial strategy that backs British engineering and targets net zero by 2042”. This would drive industrial competitiveness, but in order to be effective it must be backed up with policies that will help the industry overcome the first part of the cost curve. That encompasses R&D into production itself but also associated technologies like carbon capture & storage and hydrogen transport methods. Support is needed on the demand side as well, on hydrogen fuelling stations for example. If the UK committed to fuel cell recharging infrastructure, there would be a much better chance of large numbers of hydrogen-powered vehicles being driven on UK roads.
Net Zero: The UK’s contribution to stopping global warming – Committee on Climate Change (2019)
Sixth Carbon Budget
Hydrogen Advisory Council – details of remit, membership and minutes are at:
Hydrogen – how can we overcome its limitations? Blog by Colin Matthews, Managing Director of JouleVert
The role of hydrogen technologies in reaching Net Zero – podcast with Sinead Lynch, Chair of Shell UK and Co-Chair of the Hydrogen Advisory Council.
How does hydrogen fit into the overall energy system? – podcast with Richard Halsey, Capabilities Director of the Energy Systems Catapult.
Hydrogen powered aviation – podcast with Professor Pericles Pilidis, Head of Power and Propulsion Department, Centre for Propulsion Engineering, Cranfield University.
Developing hydrogen technologies in the UK – podcast with Baroness Brown of Cambridge (May 2020)