CO2 emissions from electric flying cars: Impacts from battery specific energy and grid emission factor

Electric flying cars are attracting global attentions considering their ability to provide high-efficiency point-to-point transportation. However, there is a lack of understanding on the environmental impacts from electric flying cars. In this study, by modeling flying processes and sizing components of flying cars, the well-to-wheel CO2 emissions from electric flying cars are estimated. The results show that when assuming battery specific energy of 200 Wh/kg and grid emission factor in China's context, CO2 emissions from 100 km-range-capacity electric flying cars are 66 g CO2/passenger-ground km eq., 11% and 62% higher than those from on-road internal combustion engine vehicles and battery electric vehicles. With battery specific energy increasing to 400 Wh/kg and 600 Wh/kg, CO2 emissions can be reduced by 39% and 45%. Reduction in grid emission factor further contributes to emissions reduction, with emissions from electric flying cars lower than those from on-road internal combustion engine vehicles in multiple regional and temporal grid contexts. For electric flying cars with longer range capacities, more aggressive battery and grid improvements are needed to find breakeven with on-ground vehicles. This study justifies the critical roles next-generation batteries and clean power grid play in leveraging the development of electric flying cars, and calls for joint efforts from the government, industry and academia.