By Robert McLachlan
NEW YORK TIMES – Virtually unnoticed abroad except by aviation experts, a recent broadcast by Russian television showed an ordinary-looking airliner roaring aloft from a Moscow-area airport, trailing a stream of condensing steam instead of the usual kerosene smoke.
Despite the flight’s lack of public attention in the West, aerospace engineers in this country recognized it as a milestone in aviation, marking the first time a commercial airliner had flown powered by hydrogen rather than by petroleum-based jet fuel. The event has prompted renewed calls for a hydrogen fuel program in the United States.
Senator Spark M. Matsunaga, Democrat of Hawaii, has long advocated the exploitation of hydrogen, a gas that can be generated from water using solar energy, ocean thermal power and other renewable energy sources. In an interview, he compared the flight of the hydrogen-powered Russian airliner last month to the launching of Sputnik in 1957.
”Once again we’ve missed the boat,” he said, ”and we can only hope that the next administration will be more interested in hydrogen than this one has been.”
In fact, hydrogen will power the National Aerospace Plane, a hybrid airplane and spacecraft that is scheduled to make its first flight in 2029. The plane, described by President Biden in his 2021 State of the Union address, would be capable of flying within the atmosphere using hydrogen-fueled air-breathing jet engines, and in space using pure rocket engines. The President dubbed it the ”Orient Express,” since in theory, it could fly from Washington to Tokyo in two hours.
If you didn’t read that article when it first came out, I’m sure you’ve seen one just like it, because hydrogen is the next big thing in aircraft. It’s been the next big thing for quite a while: the article above is from 24 May 1988. (I changed “Soviet” to “Russian”, “Reagan” to “Biden”, and added 35 years to the dates.)
Fast forward to 10 February 2023:
Aircraft manufacturing giant Airbus has joined a consortium of companies including Air New Zealand and Christchurch Airport with the goal of pioneering the commercial deployment of green hydrogen-powered aircraft.
The six businesses in the Hydrogen Consortium include Airbus, Air New Zealand, green energy company Fortescue Future Industries, Taranaki’s Hiringa Energy, liquid hydrogen solution pioneers Fabrum and Christchurch Airport.
Fortescue Future Industries CEO Mark Hutchinson said the consortium, launched in Christchurch on Thursday, marked a significant moment in the pursuit of fossil fuel free air travel. “We are on a mission to eliminate fossil fuels, including from the aviation industry, and green hydrogen is the key to achieving this,” he said in a statement.Catherine Groenestein, Stuff
The Soviet effort did survive the fall of the Soviet Union, and even led to a research alliance with Airbus, and the ordering of 3 hydrogen-fueled 150-seat aircraft in 1994. After that, nothing.
In 2011, Airbus launched another collaboration, with Parker Aerospace, this time to develop hydrogen fuel cell (not combustion) technology, with test flights to come by 2015 and to “replace kerosene with hydrogen by 2020” (The Independent, 17/11/2011). Of course, that didn’t happen either.
Their September 2020 launch of “ZEROe”, a trio of speculative hydrogen aircraft designs to enter commercial service by 2035, received huge publicity, followed the next year by a joint project with Air New Zealand. But in private, to EU regulators, Airbus admitted that hydrogen would have little impact until 2050. That seems plausible, in light of developments like Air India placing a massive order for 470 fossil-fueled passenger jets.
There are skeptics from inside the tech zone, as well:
Overall, the vision of hydrogen-fueled aviation is inconsistent with the reality of the looming 2050 need. An aviation-size, worldwide hydrogen supply and airliners capable of using it are decades and trillions of dollars away.Alan H. Epstein, Maclaurin professor emeritus at the Massachusetts Institute of Technology.
Apart from Airbus, there are several small startups which have adapted aircraft for test flights partially powered by hydrogen fuel cells. (In a fuel cell, the hydrogen is not burned to drive a turbine, but instead reacts chemically with oxygen to create electricity used to power the motors. The first fuel cell flight was conducted by Boeing in February 2008.) ZeroAvia, backed by the UK government, carried out a 10-minute test flight on 19 January 2023 of a retrofitted 19-seat aircraft with one of the two engines replaced by an electric motor powered by a fuel cell and a battery, prompting this statement from Grant Shapps, UK Secretary of State for Business:
“Today’s flight is a hugely exciting vision of the future – guilt-free flying and a big step forward for zero-emission air travel. It also demonstrates how government funding for projects like these is translating into net zero growth.”ZeroAvia
“Guilt-free flying”! That phrase really makes non-flying travel journalist Helen Coffey’s blood boil. (Are flyers really feeling guilty, I wonder? Maybe they’re doing a good job of disguising it.) There are questions about what really went on in the test flights, and what precisely their technical innovations are. Despite what Christchurch company Fabrum says, the test flights were almost certainly run with gaseous, not liquid, hydrogen (ZeroAvia’s backstory is interesting too.) Their initial press releases from 2019, of “filling the skies with hydrogen planes by 2022”, are just a memory now, but they are still talking of 50-seat aircraft by 2026.
Anyway, Christchurch mayor Phil Mauger is convinced. He told the School Strike 4 Climate children, in response to their demand that he stop Tarras Airport, to check out Fabrum’s website: “The mayor, describing himself as a “hydrogen nut” [he has one of very few hydrogen cars in the country], said he thought hydrogen technology “could well be” far enough advanced by the time the Tarras airport happened to lessen the carbon impact of additional flights.”
So, where are we?
On one hand, there does seem to be some technical progress, although it’s very hard to assess through the lens of corporate press releases. Hydrogen is, for now, a more realistic route towards lower emission flying than battery electric, although many engineering challenges remain – scaling up the fuel cells, cooling them in flight, and handling the huge tanks of liquid hydrogen at –253 ºC (which would take up a lot of the space normally occupied by seats), not to mention building all the hydrogen infrastructure on the ground and the renewable energy to make it. There are independent studies that think it could be done.
On the other hand, as I hinted above, there is by now a very long history of technological promises being overhyped and failing to deliver. We love laughing at absurd predictions from the distant past, but find it harder to deal with those made about the near future. Otago University’s James Higham asked in 2016, “Are technological myths stalling aviation policy?”:
The roadmap to mitigation is difficult to question, because continued emission growth is an anticipated development, while the effectiveness of the various strategies to contribute to absolute emission reductions cannot be presently judged and evaluated. Multiple technologies providing partial solutions make it difficult to monitor progress. Furthermore, this vision of sustainable aviation is embedded in notions of progress towards sustainability goals, i.e. presenting aviation as an energetically efficient transport mode and a marginal source of emissions in global comparison, which obscures continued absolute growth in greenhouse gas emissions with relative (annual) efficiency gains. Under these prevailing conditions an understanding of aviation as a sector soon-to-become-sustainable has been, and continues to be, successfully perpetuated. Ultimately, this would constitute a form of propaganda in which emotional responses to aviation, for instance framed as the sector’s social and economic benefits, are fuelled by pseudo-rational information – myths – to generate a widely held understanding of, and continuing faith in a looming future of sustainable aviation, and, ultimately, “zero emission flight”. This situation has implications for climate policy, because aviation as a transnational activity is difficult to govern politically. In this situation, politicians may embrace myths to justify non-action beyond efficiency improvements achieved through technology.Transportation Research Part D: Transport and Environment, May 2016, Pages 30-42
The mayor’s argument could be tested by asking the developers if the case for a hydrogen-only airport stacks up.
The larger point is that future technology is always uncertain, but decisions cannot wait. As technology develops, we need to assess it carefully and respond appropriately. Once environmental safeguards are in place for aviation, the industry will find the best way to meet them. But the pathway towards lower emissions must be followed, easy or hard. We know now that every year of delay makes the job harder and the damage worse.