Danish domestic aircraft will fly on hydrogen in 2025

“Danes must have the possibility of flying green on a domestic route by 2025 at the latest.”

That is what the Prime Minister said in her New Year’s speech on the first of January this year.

Speculation immediately began here at ing.dk as to whether it should be purely electric aircraft with batteries or traditional aircraft using green fuel, so-called SAF (sustainable aviation fuel).

In the latter case, it would require the production of a green fuel based on hydrogen and CO2 that could meet the aviation industry’s requirements for fuel certification.

But now, three companies—DAT, Everfuel, and Universal Hydrogen—joined forces to present a solution. And it will neither be an electric aircraft with batteries nor a traditional engine with a green jet fuel.

That is what Jesper Rungholm, pilot and CEO of DAT, tells us. In fact, the solution came as a bit of a surprise.

“Actually, we wanted to buy a used ATR 72-500 in the spring, but it was snatched under our noses and sold to a company called Universal Hydrogen, which wanted to use it for hydrogen tests,” Jesper Rungholm says.

A meeting with Universal Hydrogen was arranged, where the technological solutions were presented:

“There we could see that we were past the ‘thinking stage’ of the technology and that they actually had a realistic green solution for aviation,” he says.

Universal Hydrogen was founded by experienced professionals from the aviation industry in 2020 and is headquartered in California. The technological starting point is to convert existing regional aircraft, primarily ATR 72s and Dash 8s, so that they can fly on hydrogen. This is done by replacing the turboprop engine with an electric engine and installing fuel cells and hydrogen tanks in the aircraft.

But instead of filling up tanks with hydrogen inside the aircraft, as is done today with jet fuel, the tanks will be loaded into modules that are filled up elsewhere.

The modules will come in two sizes: standard and long-range, the latter of which will include a cooling system.

It was this solution that led Jesper Rungholm to the idea that hydrogen could be the future of green Danish air travel.

“I have driven an electric car myself for eight years and know how efficient electric engines are, but it was especially the idea that the hydrogen tanks were installed as modules at the back of the plane that I liked. This means that we will be less dependent on there being suitable infrastructure with hydrogen fuelling facilities at all the airports we fly to,” he explains.

Good solution for Denmark

In principle, according to Jesper Rungholm, a Danish domestic aircraft will be able to fly what pilots call “a round trip”, on a standard hydrogen module, which means that the aircraft will be able to fly to the destination and back and still have enough fuel left to comply with all fuel reserve requirements.

If a situation should nevertheless arise where the aircraft has been forced to fly longer than intended and therefore does not have enough fuel for the return flight, it will be possible to ship a hydrogen modular capsule in a truck to the airport where the aircraft has landed.

“If we instead choose to operate electric aircraft with batteries, we will be dependent on whether there is charging infrastructure at all airports. We avoid that with hydrogen,” Jesper Rungholm says.

At the same time, he also believes, although without having calculated it in detail, that it is a better idea to use hydrogen directly than, for example, to first convert it into green fuel when it comes to energy efficiency. This is both due to the fact that the conversion to SAF is energy-intensive, and that a combination of hydrogen fuel cells and electric engines is more efficient than a traditional turboprop engine.

“The calculations we have seen show that in this way we can transport a passenger with one fifth of green electricity compared to using SAF,” Jesper Rungholm says.

Cost efficiency is looking good

DAT is also optimistic when it comes to the cost efficiency. Unfortunately, it will be necessary to remove 12 seats out of 72 (16 for the long-range version) in the company’s ATRs. But conversely, Jesper Rungholm also expects that the costs of maintaining the engines will be far lower compared to turboprops—perhaps as low as a tenth.

“When we compare it with other projects for green regional air travel that we have looked at, it seems both technically and financially feasible. But if we are going to scale up to medium and long distance, then there is no way around SAF,” he says.

Everfuel will supply the green hydrogen for the Danish project. The first route must be in operation in 2025, and if all goes as planned, DAT may have converted all Danish domestic routes to hydrogen by 2030.