The Jet Zero Council launches a drive for emissions-free aviation

ZeroAvia conducts the world’s first hydrogen-electric passenger plane flight in a retrofitted Piper M-class on 24th September 2020

ZeroAvia conducts the world’s first hydrogen-electric passenger plane flight in a retrofitted Piper M-class on 24th September 2020

In a normal, non-pandemic year, an estimated ten percent of the UK’s CO2 emissions are attributable to aviation. In order for the UK to hit its legally-binding target of achieving net zero emissions by 2050, it needs to find ways to decrease air travel – or decarbonise it. Enter the UK’s newly-convened Jet Zero Council with its bold aim – “To take the world towards zero-carbon flight.”

In virtual attendance at the group’s launch on 22nd July were the British secretaries of state for transport and business, three junior ministers, the CEOs and VPs of Rolls-Royce, Virgin Atlantic, easyJet, Airbus, Heathrow and a roster of other airline industry luminaries, energy company representatives and academics. This heavyweight collection was addressed by British prime minister Boris Johnson, who set them a challenge: to achieve the first zero-emission commercial transatlantic passenger flight by 2025.

For all the heft of the group, however, it is ZeroAvia – a start-up launched just three years ago and one of the smallest organisations on the Council – that seems likely to make the swiftest progress on the PM’s grand ambition. Founded by pilot and tech entrepreneur Val Miftakhov and with bases in the US and UK, it is run by a group of engineers and scientists including Sergey Kiselev, its head of Europe. Kiselev is cheerful about the prospect of going head to head with some of the biggest companies in the world in search of sustainable aviation. “Why not?” he says. “If not now, then when? If not us, then who?”

“We showed the world that the hydrogen fuel cell can actually lift the aircraft in the air”

ZeroAvia’s plan is to retrofit existing planes so they can be driven by hydrogen-powered electric engines. They’re far from the first to notice the potential of hydrogen as a transport fuel. It was in 1808 that an emissions-free car-like vehicle with an internal combustion engine that ran on hydrogen gas had its first outing, and the hydrogen-powered Toyota Mirai car (Japanese for ‘future’), has been on the market since 2014. There’s even some hydrogen history in aviation – the world’s first experimental aircraft operating on liquid hydrogen, the Tupolev Tu-155, took off in 1988.

However, while the Tupolev burned hydrogen, ZeroAvia’s model, like the Mirai, deploys a combustion-free hydrogen fuel cell to turn its engines. A chemical reaction within the cell creates an electrical current with just two byproducts: water and heat. The temperatures created by the engines are much lower than in conventional planes burning kerosene. “It makes the longevity of the system much better,” says Kiselev. “We don’t have high temperatures which stress the metal and all the components”. A lack of moving parts also makes for less maintenance and quieter planes.

On 21st September, multinational aerospace giant Airbus signalled its intentions to enter the market, releasing artist’s impressions of three no-emission hydrogen-fuelled concept planes which it said could enter regular service by 2035. The three craft – one ‘turbofan’, one ‘turboprop’ and a futuristic-looking ‘blended wing body’ model – are designed to carry between 100 and 200 passengers on flights of up to 2,000 nautical miles.

On 24th September, meanwhile, ZeroAvia made the first flight of a commercial-sized hydrogen fuel cell aircraft. ZeroAvia’s retrofitted Piper M-class, an aircraft with room for a pilot and five passengers, took off from a runway outside Milton Keynes and swooped triumphantly above the airfield before returning safely to ground.

“We showed the world that the hydrogen fuel cell can actually lift the aircraft in the air,” says Kiselev. “Now we are working on expanding our range from just flying around the airport to between 200 and 300 nautical miles.” In December, says Kiselev, ZeroAvia will also start work on designs for a 19-seater aircraft, the type of plane he describes as “the workhorse used by the small regional airlines.”

“By switching to green hydrogen we will be able to save the majority of the emissions from the aviation sector”

Before we can all start zipping about the skies in guilt-free 19-seaters, however, the thorny issue of fuelling has to be resolved. The good news is that the price of so-called ‘green’ hydrogen, made with renewable energy, is falling, although it still makes up less than 0.1 percent of global production. “We believe that in a few years the price of green hydrogen will be so low that the direct costs of operating the aircraft on a hydrogen and electric powertrain [the main parts that generate power and deliver it to the air] will reach parity with a conventional jet engine,” says Kiselev.

There are also some extraordinary potential technologies in the pipeline that could help ZeroAvia and the broader Jet Zero Council. In October, for example, new research by the University of Oxford’s Department of Chemistry published in Nature Catalysis laid out a method of converting plastic waste into hydrogen using catalyst particles activated by microwaves.

While Kiselev is intrigued by new sources of hydrogen, he’s most keen to allow his clients to make their own by conventional methods – and to that end, ZeroAvia has developed its own airport refuelling ecosystem. “The idea is that nobody will buy a hydrogen electric powertrain without a supply of hydrogen,” says Kiselev. “We believe that the most rational and energy-secure way is for airports to produce the fuel themselves. We have created a small electrolyser which breaks water into hydrogen and oxygen. We compress the hydrogen and store it on a fuel truck, which then dispenses it.”

The potential effects of this closed-loop system are significant. “By switching to green hydrogen we will be able to save pretty much the majority of the emissions from the aviation sector,” says Kiselev. “But this hydrogen revolution produces other effects on other transportation modes. When airports, which are heavy consumers of hydrogen for airplanes, switch all the ground transportation to both electrical and hydrogen, and then switch all the taxis and buses which connect to the cities, we will save millions and millions of tonnes
of emissions.”

“There will be other impacts,” continues Kiselev, “because by switching to hydrogen and enabling small aircraft and small airports to produce their own fuel and be more independent, we will start to increase the usage of the small airports as well… we will actually move some of the travel from the larger airlines and larger aircraft, and maybe even from different modes of transportation.”

Kiselev envisages a new world of more short-hop flights and regional travel, with less congestion around the big hubs. “If you think about this, the road system in the UK is basically radial,” he says. “That means that very often you need to go through London, even if you only need to travel 50 miles. [But with our planes] you can hop across in a very short time if needed, at a very competitive price.” Fleets of small, green, low-cost planes could potentially operate like Uber Pool cabs – an algorithm could bring together small groups who wanted to fly to and from the same places, and automatically commission a plane on their behalf.

This new world could come into focus faster than we might think. Kiselev envisages ZeroAvia planes carrying paying passengers in 2024. “The idea is that we will certify the powertrain by the end of 2023, and we’ll start retrofitting right after that,” he says. “We already have 20-plus operators who would like to work with us.”

Since its grand launch in July, the Jet Zero Council has not reconvened, and there are still major stumbling blocks in the way of Johnson’s dream of zero-emission commercial transatlantic passenger flight by 2025. Bigger planes flying longer distances would need to carry significant amounts of hydrogen. Storing it as a compressed gas poses major weight and volume problems, and storing it in liquid form (in which it contains 2.8 times more energy than aircraft kerosene per kilogram) means keeping the fuel at less than -253°C: one option may be to use similar liquid propellant storage vessels as are used in space rockets.

However, ZeroAvia’s flight in September does give grounds for some optimism, at least about the prospect for emissions-free short hop flights in small planes. For Kiselev it was an emotional moment. “It was a huge relief, I couldn’t even speak,” says Kiselev. “I’m a bit of a romantic, right? So I had tears in my eyes… Safety for us is the number one priority, so you see that everything you have done is right, all the technical parameters and the safety measures are implemented and then you see that little blue dot flying in the air above you.”

He pauses. “I don’t have children. But I think that seeing that was probably close to that type of feeling, when a child is born.”

Airbus’s artist’s impression of a ‘blended wing body’ hydrogen concept plane

Posted on Thursday, September 14th, 2023 - Categories: #40 - Jul-Sep 2020, App Issues.