Advanced powertrain developer H2FLY is to lead a consortium in the development of a 350kW fuel cell system for commercial aircraft applications in a German government-backed project.

Called BALIS 2.0, the effort is one of several parallel programmes being carried out by H2FLY as it works towards the commercialisation of a future 2MW system in the early 2030s.

Hy4 flying-c-H2Fly

Source: H2FLY

Previous test activity has centred on HY4 demonstrator

Also involving Germany’s DLR national aerospace research centre and Diehl Aerospace, BALIS 2.0 will see ground tests of the 350kW system take place in 2025.

Unsurprisingly, it builds on the earlier BALIS 1.0 project which saw the construction of a 1MW-scale test facility in Empfingen operated by the DLR. That test stand will now be utilised for the ground runs in the follow-on programme.

In BALIS 2.0, H2FLY is responsible for the development and set-up of the fuel cell system, which sees the output of its existing H2F175 unit doubled.

“We will perform component redevelopment because we see the functionality is there, but the power density is not,” says H2FLY chief executive and co-founder Dr Josef Kallo.

Power density should improve to 1.4-1.5kW/kg from around 0.8kW/kg at present, he adds.

The DLR, meanwhile, will study the interaction of a 1MW-class system with an electric motor and optimise its overall operation, and Diehl Aerospace will continue the development of technology to allow the efficient “coupling and scaling of fuel cell systems”.

That aspect is key, allowing multiple 350kW “strings” – the fuel cell stacks and some balance of plant – to be brought together to deliver a more powerful system.


Source: H2FLY

H2FLY sees access to hydrogen and refuelling infrastructure as key to widespread adoption

Over the 2024-2026 period, the partners will receive a total of €9.3 million ($10 million) from the German Federal Ministry for Digital and Transport, to be matched by their own contributions.

But in parallel with BALIS 2.0, Joby Aviation-owned H2FLY is also working on several other German state-backed projects designed to deliver a high-performance and commercially viable fuel cell powertrain for regional aircraft.

In particular, these will enable system integration into a demonstrator aircraft – a modified Dornier 328 – and also optimisation and integration of components at sub-system or module level.

Working with the turboprop’s type certificate holder Deutsche Aircraft, H2FLY will provide a fuel cell system capable of generating peak power of 1.1MW, allowing the addition of electric motors to supplement the aircraft’s existing Pratt & Whitney Canada PW119 thermal engines.

A conceptual design review for the aircraft’s powertrain is under way and is around 75% complete, says Kallo. First flight is scheduled for 2026 or 2027, allowing for possible service entry in the 2030s, using a 2MW-class fuel cell system, as a follow on to Deutsche Aircraft’s current D328eco programme.

However, Kallo says the timing rests on the availability of hydrogen fuelling infrastructure. H2FLY has previously analysed the requirements of the fuelling process using its HY4 testbed and while he declines to be drawn on details, Kallo says additional trials may be in the pipeline.