Economic Aspects of Aircraft Propulsion Electrification

Abstract

Aircraft propulsion electrification is currently being considered by industry and academia as one of the most promising strategies to reduce air transport emissions and increase overall efficiency levels. In the past decade, several papers were published on this subject, with the majority indicating encouraging fuel burn benefits versus conventional, fossil-fuel-based propulsion systems when future technologies, novel aircraft configurations, and synergistic propulsive-airframe integration are employed. However, a much smaller effort has been applied to the economic aspects of hybrid and fully electric propulsion, which are crucial for a successful product introduction. The present paper describes the modeling of a baseline general-aviation-type aircraft and its propulsion system retrofit with electrified architectures, exploring different electrification strategies for a fixed airframe design. Analyses are performed at the aircraft level, comparing recurring and cash operating costs for several cost and durability scenarios. While considerable CO2 reductions may be achieved in some electrification strategies, aircraft performance is significantly penalized, and important improvements in economic figures of merit are needed in order to make electrified propulsion cost-competitive. Electrified architectures tend to increase costs: turboelectric increases recurring equipment costs, while hybrid-electric increases recurring and direct maintenance costs, especially at higher degrees of energy hybridization.