Prospective LCA of Future Propulsion Systems for Aviation: A Fuel Cell Based Auxiliary Power Unit

Abstract

According to the Air Transport Action, aviation accounted for roughly 3.5% of total anthropogenic climate impact in 2020, with expectations for this percentage to increase due to escalating demands for commercial flights. Consequently, there is a need to reduce the environmental impacts of aviation in the long term and to assess the environmental performance of novel and lower-emission propulsion technologies. The project EXACT of the German Aerospace Center (DLR) investigates different aircraft concepts aiming for sustainable commercial flights. One conceptual aircraft involves employing gas turbines fueled by hydrogen for propulsion, while fuel cells generate electrical power for onboard and ground operation auxiliary functions. Although this technology has shown success in small-scale applications, challenges persist, that need to be addressed until the technology reaches maturity and becomes competitive. These challenges can be technology specific (e.g. high efficiency and low mass) or context specific (e.g. electricity mix, global economy, policies, etc.). Focusing on the manufacturing phase of the fuel cell-based auxiliary power unit, we conducted a prospective life cycle assessment (pLCA) guiding with background scenarios by 2050. Thus, the main contributions and key findings of our study are: • To depict the prospective methods to model the foreground system (fuel cell system). • To describe the methodology to couple the foreground system with prospective elements of integrated assessment models (IAM) scenarios such as IMAGE and REMIND. • To identify which sectors in the IAM scenarios has a significant impact on the fuel cell manufacturing process by 2050. • To evaluate and analyze the environmental impacts during the manufacturing phase of the future fuel cell system considering prospective foreground and background LCI data.