The technology (Proton Exchange Membrane Fuel Cell) that is emerging from the automotive industry through car manufacturers is of interest for aeronautic industry, but some issues are still to be solved (hydrogen storage and distribution from the tank to the fuel cell system are not considered here):

• Aviation needs are in the range of 1 to 5MW depending on the size of the aircraft and/or the systems to supply with power (propulsive or non-propulsive). This target is clearly defined in the Clean Aviation SRIA. Such power level requires capability to dissipate almost the same power of heat, in a dedicated thermal management system;
• Current fuel cell technologies developed by automotive industry operate lower than 100°C at constant operation, which means that fuel cell thermal management system will have to evacuate a large amount of power with a low-grade heat due to FC low temperature;
• Thermal management and especially heat dissipation using a low-grade heat have a massive impact on aircraft performance: aircraft drag increase implies to boost aircraft propulsive system sizing (leading to manage more heat) and requires more energy for the same mission (leading to take on more fuel, and therefore to boost aircraft propulsive system);
• Fuel cell operating temperature increase (120°C +) would significantly help to reduce thermal management effect on aircraft flight performances, and unlock fuel cells applications for high power generation systems;
• Current developed High Temperature PEM-FC technologies (Phosphoric acid doped PBI-based MEAs for instance) are not at the expected level of performance for aeronautic target.

Proposals should target a disruptive 120°C+ constant operating temperature fuel cell technology with the same performances as current state-of-the-art low Temperature PEM technologies.

The integration of such a new fuel cell technology into an aircraft fuel cell system needs to be considered and anticipated but is not the scope of this topic.