Hydrogen aircraft

Can hydrogen-powered flight trigger a reset for global travel?

Image credit: Scharfsinn86/Dreamstime

The transport sector needs a technology revolution that completely changes not just the way it operates but our whole attitude to getting from place to place. Hydrogen-based aircraft could be the answer.

Transport systems all over the world are grinding to a halt. Urbanisation and all the competing demands for easy, low-cost mobility and logistics mean congestion and pollution. For all the protests over new airport runways, the building of yet more roads and the climate emergency, we continue to live with old transport infrastructures and only a piecemeal and tentative introduction of potential green replacements.

What is needed is a powerful wave of new tech - transport's version of the internet technology revolution. Tech with such potential that it can drag the rest of the world - businesses, governments and regulators - along with it.

The internet overcame a host of business frustrations and limitations - speed, efficiency, cost, awareness, access, market insight - and we need the same for transport to sweep away the mess and tangle of approaches, where freedom of mobility is inextricably linked with environmental harm.

Hydrogen flight could well be that breakthrough. Fleets of hydrogen-powered aircraft would be the platform for a very different kind of transport system. Zero-carbon, but also quiet, which would make it possible for there to be a proliferation of small local airports, operating closer to communities, offering short hops. As well as offering a green and efficient link to large aerospace hubs, local airports would act as transport hubs linked into other more sustainable systems: electric trains or other mass-transit vehicles and electric cars where necessary. Digital communications and data-sharing could also provide travellers with a real-time picture of transport options, such as how to minimise carbon footprint as well as time and costs, all through a single app.

The aviation industry in particular is faced with huge and complex challenges when it comes to meeting its commitments to carbon reduction globally. The UK’s 'Jet Zero' strategy is adding new impetus and scrutiny to the domestic agenda, targeting net-zero aviation emissions by 2050. More than any other sector, building back better in aviation is fundamental to the sector’s future status and ability to prosper and grow. Sustainable aviation fuels can only ever be a temporary measure, a quick win by the industry to signal progress while the most important work is being done on R&D into technologies that can be the basis of a wholly new and zero-carbon aviation infrastructure.

Our experience at Cranfield Aerospace Solutions (CAeS) is that there are some severe limitations to the potential for battery-electric flight even when it comes to short hops. Hydrogen, whether combusted directly or used in a fuel cell to generate electricity, is showing a great deal more promise. Like batteries, hydrogen generates zero carbon, the only emissions being water and heat, and aircraft can be refuelled in much the same turnaround time as with conventional fuel. Per unit of mass, hydrogen delivers three times more energy than a conventional jet fuel like kerosene and a hundred times more than a lithium-ion battery.

New confidence in hydrogen is growing with Project Fresson, a partnership between the Aerospace Technology Institute, Department for Business, Energy & Industrial Strategy and Innovate UK, run by CAeS. More than blue-sky thinking on hydrogen-powered flight, this initiative is about delivering commercially viable services in the short-term: the world’s first truly green passenger-carrying services. Making use of its 25 years’ experience of working with OEMs on both design and certification of new aircraft, CAeS is developing a hydrogen powertrain solution for a nine-passenger Britten-Norman Islander aircraft, as well as looking at business models and overcoming any capability and supply chain issues. Project Fresson expects the hydrogen aircraft to be in service for short hops by 2025.

One of the biggest challenges we face is in the lack of certification rules for hydrogen-based aviation. Current standards don’t apply. Complex modifications to aircraft (and to how airports manage hydrogen as an aviation fuel) are necessary, meaning a need for the Civil Aviation Authority to be an active partner in the journey, to make sense of what is applicable and what is not fit for purpose. We need to keep pushing the case for certification forwards with proof of technology: there’s no time to wait if Jet Zero targets are ever going to be achievable.

Regular long-haul trips using hydrogen still look some way off, but are well within reach. Perhaps we won’t be able to fly from London to Perth directly in a zero-emissions aircraft, but this raises questions about why we need large ultra-long-haul aircraft anyway. It’s an environment-damaging extravagance and just because we can doesn’t mean we should. Again, we need to be thinking about the big picture of transport, what’s viable and what works.

We can quickly become used to a new convention, hopping our way around the world using a sustainable system of journeys made smooth and easy by digitised operations, being less obsessive and frantic about saving time. Wouldn’t travel become a richer experience?

Jenny Kavanagh is chief strategy officer with Cranfield Aerospace Solutions

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