The University of Michigan and Ford released a study of the environmental sustainability impacts of flying cars.
Flying cars are formally known as electric vertical takeoff and landing aircraft, or VTOLs.
The study said they wouldn't be suitable for short commutes, like seen in The Jetsons, but they could play a role in sustainable mobility for longer trips.
According to the study, several companies around the world are developing VTOL prototypes. Flying cars would be especially valuable in congested cities, or in places where there are geographical restraints, as part of a ride-share taxi service, according to study authors from the University of Michigan's Center for Sustainable Systems and from Ford Motor Co.
"To me, it was very surprising to see that VTOLs were competitive with regard to energy use and greenhouse gas emissions in certain scenarios," said Gregory Keoleian, senior author of the study and director of the Center for Sustainable Systems at U-M's School for Environment and Sustainability. "VTOLs with full occupancy could outperform ground-based cars for trips from San Francisco to San Jose or from Detroit to Cleveland, for example," he said.
Researchers found that for trips of 62 miles, a fully loaded VTOL carrying a pilot and three passengers had lower greenhouse gas emissions than ground-based cars. Emissions tied to the VTOL were 52 percent lower than gasoline vehicles and 6 percent lower than battery-electric vehicles.
Akshat Kasliwal, first author of the study and a graduate student at the U-M School for Environment and Sustainability, said the findings can help guide the sustainable deployment of VTOLS.
"With these VTOLs, there is an opportunity to mutually align the sustainability and business cases," Kasliwal said. "Not only is high passenger occupancy better for emissions, it also favors the economics of flying cars. Further, consumers could be incentivized to share trips, given the significant time savings from flying versus driving."
The U-M and Ford researchers used publicly available information from these sources and others to create a physics-based model that computes energy use and greenhouse gas emissions for electric VTOLs.
"Our model represents general trends in the VTOL space and uses parameters from multiple studies and aircraft designs to specify weight, lift-to-drag ratio and battery-specific energy," said Noah Furbush, study co-author and a master's student at the U-M College of Engineering.
"In addition, we conducted sensitivity analyses to explore the bounds of these parameters, alongside other factors such as grid carbon intensity and wind speed," said Furbush, who is also a member of the U-M football team.
The Nature Communications paper is titled "Role of flying cars in sustainable mobility." Once published, it will be available here.
