The Jetsons’ jet-set lifestyle has long inspired engineers and agitated environmentalists—what about a flying car instead of gas-guzzling vehicles?
Alas, we still don’t have the joy of a Jetson lifestyle to replace our carbon emitting ground-based transportation. But we’re inching closer to a future of flying cars with Vertical Takeoff and Landing aircraft, or VTOL for short.
The aircraft works by taking off and landing like a helicopter, and flying like an airplane between destinations. By combining the two, VTOLs eliminate the inefficiency of flying with a lighter weight while maximizing speed.
Currently under development by companies around the world (including big names like Chrysler, Airbus, and Uber), the VTOL has the potential to, at the very least, make short-distance air travel easier and more common.
But researchers at the University of Michigan have been wondering whether we can improve on flying cars. It’s one thing to have a vehicle that flies, it’s another if it’s still inefficient and environmentally detrimental. If we replace our ground-based travel with these aircraft what with the impact be on the environment? And how will they compare to cars?
Researchers partnered with Ford and compared an electric VTOL to both electric and gas-powered cars. They found that as cool as a VTOL is, it’s only sometimes more energy efficient. For trips longer than 100 km (62 miles) a “flying car” fully loaded with one pilot and three passengers outperforms a gas or electric car carrying the U.S. average occupancy (which is 1.5 people). In this very specific window the emissions are 56 percent lower than gas vehicles and 6 percent lower than electric vehicles.
For trips shorter than 100 km, however, the VTOL is less efficient than any ground-based car. That’s because it requires a lot of energy to lift the airplane off the ground.
“What we’re saying is [the VTOL is better] if you’re heavily congested, have geographic constraints, indirect routing, if you don’t have roads, or if you have to go a long distance,” Gregory A. Keoleian, director of the Center for Sustainable Systems at the University of Michigan, told The Daily Beast.
However, Keoleian notes that while the VTOLs would be more environmentally friendly in these specific circumstances, it’s important to understand the context of the study. The researchers only looked at cars; they didn’t compare the flying vehicles to the efficiency of trains or buses. And they didn’t look at the efficiency of helicopters that are currently doing all the work of short air-based travel.
“We don’t want people to shift from an efficient transit mode like rail to a VTOL that’s not going to help the environment,” he said. An aerial taxi, when rail isn’t available, he says, might ultimately be the most useful version of these flying vehicles because they are the most efficient when they are at full occupancy.
“And the other factor that’s important is vehicle miles traveled,” he added. “The more miles, the more emissions, the more energy used. So it’s also very important that new technology innovations don’t make transportation so convenient that people live further from work. We want to avoid sprawl. We need to reduce miles traveled.”
Keoleian noted that there are several companies looking at ways to turn the use of these vehicles into a business and “what we would hope is that they are going to be deployed in very strategic applications that could help accessibility but more importantly reduce environmental impact. The transportation sector is responsible for 28 percent of greenhouse gas emissions, the largest sector. Cars are 60 percent of that.”
When VTOLs finally hit the market they are going to be luxury vehicles that will be accessible only to certain, wealthy, customers. Considering that these folks are currently likely using helicopters for the types of trips that they could accomplish with a VTOL, it’s possible in the end that replacing that mode of transportation will electric aircraft will have a net environmental benefit overall.
Still, it doesn’t look like the flying car is really ever going to truly be the transportation of the future—at least not for the masses. If we really want to find energy-efficient ways to get around, says Keoleian, “maybe we should be investing more in mass transit.”