Fuel cell systems for the propulsion of aerial passenger vehicle

The project should develop and demonstrate a fuel cell system dedicated to the propulsion of a 2 to 19 passengers regional aircraft emission free. The fuel cell system (FCS) architecture shall be modular and adaptable to different aerial vehicles such as UAVs with similar payloads capability. The aerial vehicle to be considered for demonstration should be able to carry a payload between 160 and 350 kg and have a range of 1 to 2 hours. The system to be developed should be based on an architecture involving elementary power modules and on technologies previously developed in the scope of previous FCH JU projects. The aim of such modular architecture is first to allow a scaling of the system to address a range of platforms and second to offer redundancy and therefore increase the reliability of the propulsive power source.

In order to bring a competitive and efficient solution, the following key objectives should be considered:

• Fuel cell system power output in the following ranges: fuel cell system total output power on demonstrator: 40 to 150 kW (multiple modules for 19 seater aircraft);
• Adjust or re-use key components and subsystems allowing to reach gravimetric energy and power density, safety and lifetime under aeronautic RCS requirements
  • Fuel cell stack (at least 2 kW/kg, re-used from previous project);
  • Air feeding subsystem (efficiency > 50 % at high pressure ratio);
  • Hydrogen storage (> 5,5 % mass efficiency);
  • Power converter (> 5 kW/kg);
  • System lifetime target at least 4 000 hours;
• Integration, installation into aircraft, industrialization and cost competitiveness have to be optimized in order to bring realistic solution. When applicable, aeronautic RCS have to be taken into account and compliance should be demonstrated (DO160, EASA CS-VLA, EASA CS23,…). Focus of the project will be the elaboration of the certification plan derived from existing RCS and to apply it to the system to be demonstrated in flight. The most-up to date RCS will be taken into account and gaps in the legislation will be highlighted;
• Implement simulation and model-based design methodology for optimal design trade-offs (performances, durability) and definition of most suitable control strategies;
• Experimental demonstration:
  • At laboratory level for components/subsystem/system, durability and reliability according to application requirements;
  • Under realistic conditions of system performance and range; for passenger aircraft, the demonstration will be performed with elementary power modules (not the full-scale power) composed of full-scale components;
  • An in-flight demonstration of at least a single module in an existing plane.
• Perform economical assessment and derive Fuel Cell system Total Cost of Ownership for the selected target application including hydrogen refueling and system maintenance; Perform environmental assessment and derive fuel cell propulsive system potential GHG emission reductions;

The project should start with a global TRL of 3 to 4 for the considered components and conclude to the demonstration of a TRL 6 with tests in representative conditions of real environment and in flight demonstration.
The consortium should gather both academic and industrials with previous experience in the field of fuel cell applications for aeronautic and able to bring expertise in development, conception and testing in conditions representative of an aeronautical environment.
Any safety-related event that may occur during execution of the project shall be reported to the European Commission's Joint Research Centre (JRC) dedicated mailbox JRC-PTT-H2SAFETY@ec.europa.eu, which manages the European hydrogen safety reference database, HIAD.
Test activities should collaborate and use the protocols developed by the JRC Harmonisation Roadmap (see section 3.2.B ""Collaboration with JRC – Rolling Plan 2018""), in order to benchmark performance of components and allow for comparison across different projects.

The FCH 2 JU considers that proposals requesting a contribution of EUR 4 million would allow the specific challenges to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts.
A maximum of 1 project may be funded under this topic.
Expected duration: 4 years

The aeronautic sector is currently entering a major transformation phase triggered by the environmental urgency, the evolution of humans’ movements associated to new transportation means and the emergence of new aerial platforms. The reduction of greenhouse gas emissions has driven the aeronautic industry to introduce the concept of More Electrical Aircraft, but a deeper transition is needed and hybrid-electric or even full electric propulsion is now considered to tackle the environmental challenge, as stated in the Clean Sky JU bi-annual work plan 2016-2017 [16]. This addresses the need for continuous work on Green Regional Aircraft to mature, validate and demonstrate the technologies best fitting the environmental goals set for the regional aircraft that will fly in 2020+. Accordingly, the Green Regional Aircraft has five main domains of research: low weight configuration, low noise configuration, all electric aircraft, mission and trajectory management, and new configuration. The power requirements for the propulsion of common aircraft are however tremendous (in the range of 1 MW for a 19 pax intercity commuter) and not reasonably achievable today. This assessment accounts for the necessity to start considering this technological challenge today with an intermediate step at lower scale.
The aeronautic industry sees new concepts appear to take advantage of operating in the airspace by introducing new flying platforms, either uninhabited (UAV) or inhabited (passenger aircraft). Personal flying vehicles (2 to 4 pax, 40 to 100 kW or more) are becoming a reality and most of them are based on electric powertrain (Lilium https://lilium.com/, E-Volo http://www.e-volo.com/index.php/en/). Even though fuel cell systems have already been introduced on light flying platforms, it is still necessary to bring it to larger scales, to deploy widely the technology, to make it compatible with market requirements and to address certification.
Most of new flying platforms concepts are electrically driven and powered by batteries. The bottleneck of such vehicles is the strong limitation in autonomy due to the poor energy and power density reached by battery systems. Hydrogen and fuel cell systems are a promising option to increase the range and thus the credibility of such new flying platforms, within a short term. In addition, fuel cell technologies offer more flexibility in operation such as fast refuelling.
The effects of high altitudes (and reduced O2 concentration and partial pressure levels) on performance need to be further addressed and modular architectures approach considered to optimize the efficiency. The BoP main components, such as the air compressor, the hydrogen storage and the power electronics, will have high requirements, which still need to be clearly defined in accordance with performance dependency to altitude. Even though work has been engaged to define RCS for hydrogen and fuel cells in aviation, a lot remains to be done, especially to consider propulsion applications.

Footnote [16]: ANNEX to GB decision no CS-GB-2015-12-18 Doc7a Decision WP and Budget 2016-2017 - CLEAN SKY 2 JOINT UNDERTAKING 2016-2017 BI-ANNUAL WORK PLAN and BUDGET – Green Regional Aircraft, GRA3 All Electric Aircraft (p. 38)

The first expected impact is to increase the range and autonomy of small battery based electrical aerial vehicles by a factor of two to four, allowing reaching relevant levels, compatible with targeted markets (people and goods transportation, industrial applications) and therefore, contributing to decarbonizing transportation. The second expected impact is to increase the credibility and therefore the consideration of fuel cell systems for the propulsion of passenger aircraft and UAVs in order to pave the way toward All Electric Aircraft. The development project of an All Electric 19 pax inter-city aircraft is a tremendous work, which will require major budget. It could only be initiated if feasibility is demonstrated at lower scale and if technical and economic targets are clearly and precisely established earlier.
Another expected impact is the demonstration of the compliance to aviation standards of safety validated and demonstrated, to provide recommendations for RCS definition/amendments in the aerospace sector, for qualification test campaigns. For that, a connection should be established with the EUROCAE WG80 and the FAA's Aviation Rulemaking Committee (ARC), which involve aeronautical industry, FAA and EASA for the development of standards for hydrogen Fuel Cell system for Airborne applications. The project should therefore demonstrate clear in-roads on the path to the certification process, still a major roadblock on future commercialization.
The outcome should also allow to demonstrate the economic viability of a fuel cell and hydrogen based solution for the propulsion of a small aerial platform.
The fuel cell system lifetime and durability under representative operating conditions (≥ 4000 h accumulated operation under load of the very same FCS) is also part of the expected impacts, in addition to the following:

• Silent FC-based powertrain system operation: < 60dB(A);
• Structuration of the European aerospace sector to be in a leading market position for aerospace fuel cell systems, fostering EU FC-supply chain and creation of highly qualified jobs across the complete supply chain;
• Strengthening synergies with Clean Sky 2 JU in order to promote the fuel cell & hydrogen technologies in line with the conclusion from the joint workshop in 2015 [17];
• Europe’s competitiveness in the field of FCS for aerial propulsion is key and USA, China, Canada have already demonstrated several prototypes or even products (MMC HyDrone 1800, BOEING EcoDemonstrator, …). The expected impact is to increase the market share to be taken by European industry, creating activity and jobs.

Footnote [17]: Final report from joint CLEANSKY 2 / FCH 2 JUs workshop on aeronautical applications of fuel cells and hydrogen technologies, 15 & 16 September 2015, Lampoldshausen, Germany.

Type of action: Research and Innovation Action
The conditions related to this topic are provided in the chapter 3.3 and in the General Annexes to the Horizon 2020 Work Programme 2018– 2020 which apply mutatis mutandis.