Other things which caught my eye from the conference were:

' Although sustainable aviation fuel (SAF) — i.e., derived from non-fossil sources, with a lower carbon footprint than conventional jet fuel — is needed in the near term to reduce CO2 emissions, it does not solve the local emissions issue and can consume up to three times more energy than hydrogen to produce with electrolysis. '

?? Does it? And if so, why? My thermogoddamits is not up to figuring out what is going on! Help!

And:

'Hydrogen-electric powertrains would have two-to-three times higher endurance than a battery-electric propulsion system, Rainville said. Hydrogen “fuel cells are predicted to have a significantly longer service life than batteries or potentially a gas turbine,” he added, noting that “fuel cells are quiet and smooth,” and generate power that leads to only water vapor and oxygen-depleted air being emitted. There are challenges, he cautioned. “Fuel cells make about as much heat as they do power,” he noted, adding that a fuel-cell driv'en system is “more complex than a pure battery-electric system.”

Controlling the heat generated seems to be a major issue.

For hydrogen use in airports, a modest step forward is being taken locally to me, at Bristol airport, with hydrogen powered ground support equipment, with the aim of proving that hydrogen can be safely handled in the environment of a working airport, a necessary step, although obviously a long way from flying the planes on hydrogen:
https://fuelcellsworks.com/news/easyjet-cranfield-university-and-bristol-airport-collaborate-on-hydrogen-refueling-trial/

On page 6, of the Whitepaper “Multimodal H2-Airport Hub”, sponsored by the Vertical Flight Society:
“Also, as indicated in the diagram below, SAF production requires 3X the energy required to produce LH2. The renewable Hydrogen used as an aviation fuel has the potential to be 3X less expensive than SAF and substantially less expensive
than kerosene today.”
Figure 3: Energy and cost comparison of liquid hydrogen to SAF power to liquid (courtesy of universal hydrogen).
Depicts SAF based on Direct Air Capture and capex amortization not included.
https://vtol.org/files/dmfile/h2-aero-whitepaper--multimodal-h2-airport-hub-2022_public-final.pdf
The H2-Aero Team Chair Jesse Schneider that presented the VFS Whitepaper is the CEO of ZEV Station (H2 Fueling Stations).
https://zev-station.com/about-us/

Marketing documents.

I'll just note here that Japan is putting massive funds into developing within 5 years a 4MW fuel cell engine, apparently aimed at an 80 seater plane:

https://www.hydrogeninsight.com/transport/japan-pours-billions-of-yen-into-plan-to-build-the-world-s-largest-hydrogen-fuel-cell-for-aviation/2-1-1625690

RyanAir is also very keen on hydrogen for regional aircraft transport, which would enable them to continue to send luggage and passengers to different destinations throughout Europe, for instance, but in a far less polluting although likely just as irritating a fashion.

I note however, and this is from someone who is, relatively speaking, a hydrogen enthusiast, that there is currently not a single aircraft of any size at all, not even a one-seater, running on hydrogen fuel cells, and just certification as well as development takes years.

I fully support efforts to develop both, but the notion that they can substantially reduce aviation emissions over the next 25 years when most of the GHG anyway comes from long distance flight would be absurd.

@Gryf said:

' Maybe adding the Mercedes Subcooled Liquid H2 tanks would give these racecars the range for the Dakar Rally.'

Wow! That would give a severe work out to the ability to control the temperature safely without excessive venting. Wonderful proving ground for any European long distance routes.

I'm wondering if it is more severe than on an aeroplane, although perhaps the vehicles would not change inclination so much as has to be allowed for on a plane, which is one of the many issues for hydrogen fuel cells in aircraft and makes it tough to keep constant pressure of the gas.

Dunno how far the race is, but the the Desert X Prix in Jeddah has at least one car (?) which is hydrogen powered:

https://fuelcellsworks.com/news/enowa-showcases-its-green-hydrogen-offering-at-saudi-season-opener-2/