ASSESSING THE TECHNICAL VIABILITY OF ALL-ELECTRIC HYDROGEN-POWERED AIRCRAFTS

Decarbonisation is a major challenge for the aviation sector, necessitating a radical shift and the exploration of innovative solutions to mitigate its environmental impact. In this context, hydrogen-powered fuel cells have gained significant attention in recent years due to their capacity to eliminate carbon dioxide emissions during flight. This study aims to investigate the effectiveness and main barriers of using low-temperature PEM fuel cells in aviation. A design methodology is applied to derive the weight-optimal design of several hydrogen-powered configurations. For each configuration, a minimum-weight layout is derived by accurately estimating the weights of the main components involved in the propulsion system, including hydrogen storage, fuel cell stack and related auxiliaries. The analysis is specifically applied to a regional passenger aircraft, namely the ATR 72-600. Additionally, the technical viability of the fuel cell-based aircraft is explored by comparing its maximum take-off weight (MTOW) with that of the conventional kerosene-based layout. This study demonstrates that across all the examined scenarios, oversizing the number of fuel cell stacks emerges as a weight-optimal solution, as the resulting higher efficiency reduces both the hydrogen consumption and the heat generated during fuel cell operation. In particular, the weight-optimal number of stacks increases when considering hydrogen storage technologies characterised by low gravimetric density. It is also highlighted the need of decreasing the weight of both the hydrogen storage and the cooling system to enhance the competitiveness of the hydrogen-based solution in terms of weight compared to the kerosene configuration. Achieving gravimetric density values for hydrogen storage above approximately 15-20 wt% is crucial. Especially, future research should focus on the thermal management system, which can account for up to 50% of the total propulsion system weight.