The feasibility of electric air taxis: balancing time-savings and co2 emissions - a joint case study of respective plans in Paris

Abstract

This paper presents a comprehensive evaluation of the sustainability of Advanced Air Mobility (AAM) within urban and regional mobility infrastructure, utilizing Paris as a prominent case study. Driven by ambitious environmental targets, Paris aims to transform its transportation landscape into a cleaner, safer ecosystem. Collaborating with public and private stakeholders, the region has positioned AAM as a promising facet of future mobility, highlighted by the world’s first scheduled commercial electric Vertical Take-Off and Landing (eVTOL) air taxi service during the 2024 Olympic Games. The study’s main goal is to assess the energy consumption and CO2 emissions of AAM aircraft across typical flight missions, encompassing urban and regional routes. A comparison is drawn between eVTOL performance and conventional modes, such as cars, public transport, and helicopters. However, it is important to note that only direct connections were considered for these time-savings, and boarding and de-boarding times as well as delays were not accounted for in the flight duration. On urban routes spanning 50 km, eVTOLs offer noteworthy time-savings of around 23 min compared to cars and 22 min compared to public transport. Moreover, concerning specific scenarios, eVTOLs demonstrate substantial time-savings for regional routes of 300 km—averaging 76 min compared to cars and 69 min compared to trains. Regarding CO2 emissions, a contrast emerges between urban and regional contexts. Urban eVTOL operations are relatively less eco-friendly due to higher energy consumption, than electric cars. While multicopters consume 47% less CO2 than traditional helicopters, they surpass petrol cars by 13%, diesel cars by 19%, and electric cars by up to 256%. In contrast, for regional travel, Lift-and-Cruise 1 eVTOLs consume 77% less CO2 than average helicopters, 46% less than petrol cars, and 44% less than diesel cars, but emit 68% more than electric vehicles and 96% more than electric trains. In summary, while eVTOLs offer significant time-savings and CO2 reductions on regional routes compared to traditional helicopters and fossil-fueled cars. However, it’s essential to note that the comparison on urban routes compared to battery-powered vehicles and electric trains in terms of CO2(eq) kg/person requires the eVTOL to produce higher emissions due to the higher energy requirement, which depends on the specific operating conditions. To harness AAM’s full potential for Paris’s sustainability goals, policymakers, manufacturers, and researchers should explore diverse configurations, account for real-world operations, and seamlessly integrate eVTOLs into the broader transportation framework. This approach can pave the way for less emission, and more efficient urban and regional transportation futures.