Unlocking Efficiency With Cryogenic Cooling Of GaN Traction Inverters
The title of this post, is the same as this insight on the Ricardo web site.
This is the introduction.
As the mobility sector accelerates toward zero-carbon propulsion, hydrogen fuel cell systems (HFCS) are emerging as a cornerstone technology for aviation, marine, and long-haul road transport. Among the most promising innovations in this space is the use of liquid hydrogen (LH₂) not only as a fuel source but also as a cryogenic coolant for electric powertrains. This dual-purpose approach offers transformative potential in system efficiency, packaging, and weight reduction—especially when paired with Gallium Nitride (GaN) semiconductors.
It is a very simple concept, but it appears to give worthwhile efficiency gains.
This was the article’s conclusion.
Ricardo’s cryogenic GaN inverter concept represents a bold leap toward ultra-efficient, lightweight, and integrated hydrogen propulsion systems. While challenges remain in materials, packaging, and reliability, the experimental results are compelling. With efficiencies nearing 99.8% and mass reductions over 50%, cryogenic cooling could redefine the future of electric mobility.
As the hydrogen economy matures, innovations like this will be pivotal in delivering clean, scalable, and high-performance solutions across all mobility sectors.
I very much suggest, that you take the time to read the whole insight.
Using The Concept In a Liquid Hydrogen Carrier
This Wikipedia entry describes the design and operation of an ocean-going liquid hydrogen carrier.
This is a paragraph.
Similar to an LNG carrier the boil off gas can be used for propulsion of the ship.
Ricardo’s concept would appear to be advantageous in the design of liquid hydrogen carriers and I would expect, it could also be applied to the design of LNG carriers.
I would not be surprised to see liquid hydrogen and LNG carriers were the first application of Ricardo’s concept.
This Wikipedia entry describes the Suiso Frontier, which is the world’s only liquid hydrogen carrier.
I believe that Ricardo’s concept could lead to the construction of a more of these ships. Will they mean that liquid hydrogen carriers will deliver hydrogen from sunny climes to places like Europe, Japan, Korea and Canada.
The concept would also enable efficient small liquid hydrogen carriers, that could deliver hydrogen on routes like the North of Scotland to Germany.
Using The Concept In A Railway Locomotive
I could see freight locomotives being designed as a large liquid hydrogen tank with appropriately-sized fuel cells and added electrical gubbins.
- They would be self-powered and would not require any electrification.
- They would be much quieter than current diesels.
- They could pull the heaviest freight trains, between Europe and Asia.
- They could even pull passenger trains, if an electrical hotel supply were to be arranged.
- They could be designed with very long ranges.
But above all they would be zero-carbon.
Note that I’ve written about long freight routes before.
- China, Russia And The EU’s Intermarium Bloc
- How To Move 100,000 Containers A Year Between Germany And China
- Georgia, Azerbaijan and Iran Discuss New Freight Corridor To link India And Europe
- Finland And Norway To Explore Building Arctic Rail Link
- A New Gateway To China: Europe Prepares For The Launch Of Baku–Tbilisi–Kars Railway
I believe that a long-distance liquid-hydrogen locomotive, that was based on the Ricardo concept, would be ideal for some of these routes.
A Specialised Hydrogen Delivery Train
In April 2022, I wrote The TruckTrain, where this is a simple description of the concept.
The Basic Design Concept
The leaflet on their web site describes the concept.
This visualisation at the bottom of the leaflet shows four TruckTrains forming a train carrying twelve intermodal containers, each of which I suspect are 20 feet long.
I believe that the TruckTrain concept could be converted into a hydrogen delivery train.
- It would be an appropriate length.
- It would be powered by the on-board hydrogen.
- The hydrogen would be stored as liquid hydrogen.
It would be able to go most places on the UK rail network.
Conclusion
Ricardo’s concept could revolutionise the use of hydrogen.
Zero-Carbon Emission Flights To Anywhere In The World Possible With Just One Stop
The title of this post, is the same as that of this press release from the Aerospace Technology Institute.
This is the first sentence of the press release.
Passengers could one day fly anywhere in the world with no carbon emissions and just one stop on board a concept aircraft unveiled by the Aerospace Technology Institute (ATI) today.
These three paragraphs describe the concept.
Up to 279 passengers could fly between London and San Francisco, USA direct or Auckland, New Zealand with just one stop with the same speed and comfort as today’s aircraft, revolutionising the future of air travel.
Developed by a team of aerospace and aviation experts from across the UK collaborating on the government backed FlyZero project, the concept demonstrates the huge potential of green liquid hydrogen for air travel not just regionally or in short haul flight but for global connectivity. Liquid hydrogen is a lightweight fuel, which has three times the energy of kerosene and sixty times the energy of batteries per kilogramme and emits no CO2 when burned.
Realising a larger, longer range aircraft also allows the concentration of new infrastructure to fewer international airports accelerating the rollout of a global network of zero-carbon emission flights and tackling emissions from long haul flights.
These are my thoughts.
The Airframe
This picture downloaded from the Aerospace Technology Institute web site is a visualisation of their Fly Anywhere Aircraft.
Some features stand out.
The wings are long, narrow and thin, almost like those of a sailplane. High aspect ratio wings like these offer more lift and stability at high altitude, so will the plane fly higher than the 41,000-43,000 feet of an Airbus A350?
I wouldn’t be surprised if it does, as the higher you go, the thinner the air and the less fuel you will burn to maintain speed and altitude.
The horizontal stabiliser is also small as this will reduce drag and better balance with the wing.
The tailfin also appears small for drag reduction.
The body is bloated compared to say an Airbus A 350 or a Boeing 777. Could this be to provide space for the liquid hydrogen, which can’t be stored in the thin wings?
The fuselage also appears to be a lifting body, with the wings blended into the fat body. I suspect that the hydrogen is carried in this part of the fuselage, which would be about the centre of lift of the aeroplane.
The design of the airframe appears to be all about the following.
- Low drag.
- high lift and stability.
- Large internal capacity to hold the liquid hydrogen.
It may just look fat, but it could be as radical as the first Boeing 747 was in 1969.
The Engines
I suspect the engines will be developments of current engines like the Rolls-Royce Trent XWB, which will be modified to run on hydrogen.
If they are modified Trent engines, it will be astonishing to think, that these engines can be traced in an unbroken line to the RB211, which was first run in 1969.
The Flight Controls
Most airliners these days and certainly all those built by Airbus have sophisticated computer control systems and this plane will take them to another level.
The Flight Profile
If you want to fly any aircraft a long distance, you generally climb to a high level fairly quickly and then fly straight and level, before timing the descent so you land at the destination with as small amount of fuel as is safe, to allow a diversion to another airport.
I once flew from Southend to Naples in a Cessna 340.
- I made sure that the tanks were filled to the brim with fuel.
- I climbed to a high altitude as I left Southend Airport.
- For the journey across France I asked for and was given a transit at Flight Level 195 (19,500 feet), which was all legal in France under visual flight rules.
- When the French handed me over to the Italians, legally I should have descended, but the Italians thought I’d been happy across France at FL195, so they didn’t bother to ask me to descend.
- I flew down the West Coast of Italy at the same height, with an airspeed of 185 knots (213 mph)
- I was then vectored into Naples Airport by radar.
I remember the flight of 981 miles took around six hours. That is an average of 163.5 mph.
I would expect the proposed aircraft would fly a similar profile, but the high level cruise would be somewhere above the 41,000-43,000 feet of an Airbus A 350. We must have a lot of data about flying higher as Concorde flew at 60,000 feet and some military aircraft fly at over 80,000 feet.
The press release talks about London to San Francisco, which is a distance of 5368 miles.
This aircraft wouldn’t sell unless it was able to beat current flight time of eleven hours and five minutes on that route.
Ground Handling
When the Boeing 747 started flying in the 1970s, size was a big problem and this aircraft with its long wing may need modifications to runways, taxiways and terminals.
Passenger Capacity
The press release states that the capacity of the aircraft will be 279 passengers, as against the 315 and 369 passengers of the two versions of the A 350.
So will there be more flights carrying less passengers?
Liquid Hydrogen Refuelling
NASA were doing this successfully in the 1960s for Saturn rockets and the Space Shuttle.
Conclusion
This aircraft is feasible.
The Anonymous Widower 