Operating and Environmental Cost Considerations Comparison for Hybrid-Electric Propulsion Architecture Variants

Abstract

A promising solution for sustainable aviation is hybrid-electric propulsion, which is gaining popularity in recent years. However, hybrid-electric propulsion variants are affected by the technological maturity of electric components, which have a direct impact on the electrification benefit, compared to conventional propulsive configurations. This work aims in investigating three different Entry Into Service dates, i.e., 2027, 2030, and 2040, for two hybrid-electric propulsive configurations, namely the Series and the Parallel. Six hybrid variants are sized, one for each date and configuration, using an in-house tool, and their mission performance metrics, operating costs, and environmental impact are compared to a conventional aircraft with technological assumptions of 2014. Results indicate that the Parallel variants promise a block fuel and energy reduction of up to 33 % and 28 % respectively for 2040, whereas the Series variants show a respective reduction of 66 % and 58 % accordingly. Moreover, the 2027 Parallel aircraft has reduced annual operating costs compared to the Series 2027, whereas a turnaround point exists in which the Series becomes more economical to operate, compared to both Parallel and the Reference aircraft after 2030. Finally, the Life Cycle Assessment suggests that the Series variants have a lower environmental impact compared to the respective Parallel variants and that both configurations have better scores than the Reference aircraft. The Parallel and Series configurations of 2030 promise an environmental impact reduction of up to 22.8 % and 59.8 % respectively, compared to the reference aircraft.