CAMBRIDGE, Mass.--The route to a less polluting car looks more like a multipoint intersection than a single superhighway, a panel of experts said on Wednesday.
The auto and fuels industries are in the midst of dramatic technological change, but it's still not clear how quickly which new technologies will be adopted.
Also unknown is whether consumers are willing to switch from traditional car ownership to the "transportation as a service" model where people share a fleet of clean cars dispersed around a city.
The EmTech 2008 conference, held at the Massachusetts Institute of Technology, put together a panel to discuss green transportation with Tesla Motors Chief Technology Officer JB Straubel, BP chief scientist Steven Koonin, and Ryan Chin, a student at the MIT Media Lab involved in the City Car and projects.
All of them agreed that there's a need to shift from today's fossil fuel-based transportation industry because of concerns over energy security and climate change. But it's unlikely that one single technology will displace the gas-powered internal combustion engine.
"You have to ask whether change will be revolutionary or evolutionary. If I had to bet, I'd say it will be evolutionary," said BP. "The most likely scenario is a plug-in hybrid with a very efficient engine powered by biofuels--with plausible technologies."
Koonin said that change comes slow to the auto and fuels industry and sought to dispel the idea that the world is running out of liquid hydrocarbons that can be used for fuels.
Getting access to conventional sources--natural gas and oil--is getting more difficult, but there is plenty of fossil fuel around for transportation in other forms such as oil shale, tar sands, and coal, he said.
BP, as well as some other incumbent oil companies, are investing in biofuels research. General Motors already touts having sold millions of flex-fuel cars that can run on gasoline or E85, a blend of ethanol and gas.
Like high-profile energy investoron Wednesday, Koonin said that biofuels have the potential to make a dent in the energy picture.
There are number of technological hurdles, though, to make ethanol sustainably, including enzymes to convert non-food plants effectively to ethanol.
BP is looking at other so-called advanced biofuels, including butanol, because ethanol is less energy dense than gasoline and is a corrosive, Koonin said.
Whither electric cars?
Transportation is also getting electrified. and said they intend to release extended-range electric cars, also called serial hybrids, by the end of 2010.
Tesla recently released the all-electric Roadster, a $109,000 sports car and said earlier this month that it plans to begin making an all-electric $60,000 sports sedan by the end of 2010. After that sedan, Tesla plans to make the "Model S," an all-electric car that's meant to be a less expensive family car.
One of the biggest barriers to electric car adoption is the cost that batteries add to the price of a car. But Tesla's Straubel said that trends point to greater use of electric cars for both political and environmental reasons.
"We can at least double the capacity of battery engines," he said. "We can make it quite competitive with the gasoline engine on the cost of operations basis."
He said that concerns over energy security tend to drive interest in electric cars, over environmental concerns.
Driving an electric car charged by a coal power plant does not offer much of an environmental benefit, he said. But, he said electricity in transportation offers the possibility of cleaner sources.
"Every year the grid is going to become less and less CO2-intensive. It's almost a guarantee," Straubel said.
What's the best policy?
Chin from MIT's Media Lab is pursuing electric vehicles, but in a very different form from anything that Tesla is developing.
The City Car and RoboScooter are concepts in shared transportation, where all-electric foldable cars and scooters would be placed in different places in the city, such as near subway stations or the airport. People would pick up cars or scooters by swiping a credit card and leave it at another charging location when they're done.
Tackling cleaner urban transportation is important because for the first time in history, more people live in cities than outside them and cities are expected to become more dense.
But for the shared clean-transportation model to take hold, people need to be convinced that having access to transportation is more compelling than owning a car in the city.
"Changing the mind shift from an automobile as a product--that you buy, use, and keep--to a service, that's very disruptive," Chin said.
Chin said that transportation policy should promote a diversity of technologies, rather than a single one.
BP's Koonin and Tesla's Straubel recommended higher mileage mandates in the form of Corporate Average Fuel Economy (CAFE) and a renewable portfolio standard (RPS)--which mandates that utilities generate a certain percentage of its electricity from renewable sources.
Also, putting a price on emitting carbon dioxide would help companies in the field, they said.
"We should raise the. We should set a floor on the price of gasoline," said Koonin. "That will drive innovation very rapidly...But I believe that's politically impossible."