Hybrid-electric propulsion retrofits in regional aviation – A review

Hybrid-electric propulsion systems are being explored as a promising way to improve the environmental performance of regional aircraft. This paper examines the potential for retrofitting hybrid-electric propulsion systems into existing regional aircraft, aiming to improve sustainability and efficiency in regional aviation. By integrating electric powertrains with traditional combustion engines, the study highlights advancements in power distribution across different flight phases and considers alternative energy storage solutions such as supercapacitors, fuel cells, and SAF-based systems. The paper addresses technical and operational challenges, including power density, system weight, and regulatory hurdles, while exploring the potential benefits of reduced fuel consumption and emissions. Studies have shown that hybrid electric propulsion has a potential emission reduction of 10–60 %, depending on the flight mission and hybrid configuration, with a retrofitted parallel configuration achieving 17.6 % fuel savings. The study emphasizes the importance of a collaborative approach to research and development, promoting a pathway for achieving substantial environmental benefits in regional air travel.