German advanced powertrain specialist H2FLY has successfully validated its latest hydrogen fuel cell system, achieving peak power of 175kW during bench testing.

Called the H2F175, the latest system – on display at the ILA Berlin air show – builds on earlier iterations rated at 55kW and 115kW.

Hy4 flying-c-H2Fly

Source: H2Fly

Stuttgart-based company has previously tested fuel cell powertrain aboard HY4 aircraft

“We have seen that we can increase the power and the new tests show we can achieve 175kW,” says Dr Josef Kallo, chief executive of the Joby Aviation-owned company.

“The new [fuel cell] stack technology inside is very promising.”

Bench tests at its Stuttgart facility showed the system could deliver 150kW at constant power, rising to 175kW at peak, although at lower efficiency levels.

However, Kallo declines to say whether the system will be taken to flight test.

Work is now under way to optimise the H2F175, ensuring the higher power rating can be delivered with maximum efficiency. In addition, H2FLY will look to halve the size of the system, a development it calls ‘Evo’ and which will arrive next year.

That activity will support the building of a 1MW-class system using multiple 175kW stacks. An additional product called the H2F500 is also in the works.

Achieving higher power outputs will enable H2FLY to target bigger aircraft; a 40-seat regional turboprop would require about 2MW, he says.

But a key step for H2FLY in the coming years will be to seek out additional partnerships to demonstrate real-world applications of its technology.

H2FKLY has previously flown its experimental fuel cell-powered HY4 aircraft to validate the hydrogen technology. But Kallo is uncertain whether the aircraft will return to the skies any time soon.

“At the moment we are so focused on ground testing and other activities that it is a lower priority.”

However, H2FLY will use the aircraft as part of its involvement in an Airbus-led a ground infrastructure and refueling test project called Goliat.