Benefits and Challenges of Electric Propulsion for Commuter Aircraft

This paper presents the Library for Unified Conceptual Aircraft Synthesis (LUCAS) sizing and optimization framework, which is largely based on Stanford's Stanford University Aerospace Vehicle Environment (SUAVE). LUCAS is applied to a commuter mission carrying 19 passengers. Results show that energy usage benefits depend on mission range and electrical component technology and that reserve requirements play a significant role in the feasibility of electrified aircraft. It is found that storing more energy in batteries rather than fuel reduces the mission energy requirement at the expense of aircraft weight growth. All-electric aircraft could provide onboard energy savings of upward of 30% for a 180 km mission, but this would only become feasible if battery specific energy reached the high value of 900 W & sdot;h/kg. Range could be increased to 550 km if part of the reserve mission requirements is relaxed. Under more realistic technology assumptions, a hybrid design storing energy in fuel and batteries could fly commuter missions with energy savings of 6%. A beneficial use case of hybrid configurations is a mode of operation where the aircraft uses only batteries during the main mission and fuel to store all the reserve energy. If reserves are not required for a particular flight, energy savings are still maximized, while the availability of fuel ensures certification requirements are met with fewer penalties.