But it won't just be electric cars that replace today's internal combustion-powered models. It could be hydrogen-powered versions. It could be those with natural gas powertrains.
It doesn't really matter. The key is "and," not "or." Because all that does matter is that we move forward; break the inertia.
That's according to University of Michigan professor Lawrence Burns, who pondered the future of personal transportation aloud here at the 2012 ARPA-E Energy Innovation Summit.
THE NEXT ERA OF PERSONAL MOBILITY
During a panel that included ExxonMobil's Michael Ramage and Ford's John Viera, Burns -- who also serves as director of Columbia University's Program on Sustainable Mobility -- explained that we face a "transformational opportunity" to move from the mechanical automobile, developed some 125 years ago by Karl Benz, to an electrical one.
It's a massive challenge: there are more than a billion cars on the road today worldwide, he said.
"Is [this situation] sustainable in terms of safety? Energy? Congestion? Parking? Environment? Infrastructure? Even equality?" he asked. "My wife asked me to take her somewhere expensive this summer; I think I'll take her to a gas station."
Sure, we can continue to evolve the internal combustion engine and incrementally make it better. But in the grand scheme of things, the situation is "still largely unsustainable," he said.
The future, then, is one filled with cars powered by internal combustion, hybrid powertrains, electric powertrains, fuel cells and other means.
Not one, mind you. All of them. Together.
"All of this is important," he said. "To sit around and debate which one is better, I think, is premature."
For the United States, natural gas dominates the outlook.
"It looks like we're going to have low-cost, plentiful natural gas for a long while," Burns said.
There are three things the U.S. can do with its natural gas reserves, he said:
- Compress it for compressed natural gas-powered vehicles;
- Burn it to create electricity for electric vehicles;
- Reform it into hydrogen for fuel cell vehicles.
Americans need to embrace all options, Burns said. Natural gas remains a non-renewable resource, and some of these methods are more energy-efficient than others.
"If we get myopic and excited about just compressing and burning, [we're wasting our resources]," he warned. "It might not be the most sustainable thing we can do."
For example, if the U.S. sought to get its road transportation off OPEC oil by 2025, it would take:
- 5.9 quadrillion BTU of natural gas for CNG vehicles;
- 3.3 quadrillion BTU with battery electric vehicles and fuel-cell electric vehicles.
If the U.S. only used natural gas vehicles to accomplish that goal, it would take 80 million of them -- 30 percent of 2025's fleet and 40 percent of sales between 2013 and 2025.
"Yes, there's plenty of natural gas. And yes, we can use it in the road transportation sector," he said. "The challenge is getting to these vehicles."
Despite the hurdles, if the U.S. seeks to transition away from oil, natural gas remains a strong contender, because it does not suffer from the intermittency that wind and solar inherently carry with them.
"Natural gas might be the best thing to happen to renewables," he said.
Which is why it's going to take a diverse portfolio of "energy pathways" and overall systems integration for the U.S. to achieve its goal of energy independence.
"At the end of the day," he said, "the only solutions that scale to where it matters are the ones that consumers want."
NEXT STEPS -- AND BEYOND
But if you really want to look to the future, consider one in which the driver is entirely obsolete.
Driverless vehicles are compelling, Burns said. That's why he advises Google on its experiments with the technology in California.
"I became convinced at [General Motors] that driving is a distraction," he said. Driverless cars are far less likely to crash, of course -- but just as important, they would be much lighter, since they would do away with the hardware needed for manual operation.
They would use less energy to go distances. They would be cheaper to manufacture. It's not unthinkable to make vehicles tailored to purpose: short-haul driving, duty or long-haul trips.
"Why are we driving around a 4,000-lb. car?" he asked. Simply, there's no need for an all-purpose vehicle in a driverless world.
The intersection of future, then, is no longer one with traffic lights and concrete dividers but instead a broad expanse where each vehicle has a specific space-time capsule.
The U.S. can lead this charge, Burns said. It can be a world leader if it works to get the "mobility Internet" platform necessary for driverless operation up and running.
"There's plenty of raw energy and technology out there," he said. "[Slow adoption] is due to a lack of integrated systems" -- and the inertia of the installed base.
Driverless cars offer better mobility at radically lower cost, he said. Anything else is just wasteful.
"I'm an engineer by nature. Some see the glass half full. Some see it as half empty. I see the glass being twice as big as it needs to be."