The Anonymous Widower

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.

 

October 8, 2025 - Posted by AnonW | Design, Hydrogen, Transport/Travel | Decarbonisation, Freight, Hydrogen-Powered Aircraft, Hydrogen-Powered Locomotives, Hydrogen-Powered Ships, Innovation, Liquid Hydrogen, Liquified Natural Gas, LNG Carrier, Ricardo, TruckTrain