Can Hydrogen Help Commercial Aviation Decarbonize?

­Dutch airline KLM has teamed up with British-American startup ZeroAvia to expedite the development of a liquid hydrogen-powered turboprop aircraft. What that means for the future of commercial aviation is anyone’s guess.

While the majority of the transportation sector has embraced electrification and moved to decarbonize, commercial aviation is stuck in a fossil fuel rut. And for all of commercial aviation’s shady business practices, maintaining a death grip on aviation turbine fuel is the only logical solution, and all it all boils down to weight.

As Bill Gates pointed out in his book, “How to Avoid a Climate Disaster: The Solutions We Have and the Breakthroughs We Need”, you’d need about 35x more batteries by weight to get the same energy as jet fuel, especially since jet fuel is already about 20-40% of the takeoff weight of a plane.  

Taking that into account, it’s no surprise that electric planes can hold a tiny fraction the passengers as fuel-based jetliners.

Hydrogen is a promising alternative to jet fuel, but it, too, has volumetric density issues. Specifically, its volumetric density is about 4x worse than jet fuel, and so the special cryogenic cylinders necessary to store hydrogen at approximately -420°F (-250°C) couldn’t fit below the wings.

But hydrogen is at least an option, and KLM’s partner, ZeroAvia – which builds hydrogen-electric powertrains to retrofit onto existing aircraft – has already raised over $300 million from Airbus, Amazon, and British Airways.

ZeroAvia has already begun work on a larger engine, ZA2000, that when fitted to a large regional turboprop, could transport about 80-passenger aircraft up to 994 miles (1,600 km).

KLM’s job will be to help identify the right routes and airports and to deal with the necessary permits, which will be momentous.

The two companies plan to conduct a demonstration flight in 2026, and ZeroAvia hopes to start selling its new ZA2000 powertrain in 2027.