Across a variety of urban landscapes, most US drivers could perform their daily personal vehicle trips using an electric vehicle, according to new research by SFI External Professor Jessika Trancik and colleagues.
The scientists evaluated the energy requirements of millions of personal vehicle trips across US cities to determine whether motorists could perform their daily driving using battery electric vehicles, without having to recharge. They found that 87% of vehicles on the road could be replaced by electric vehicles -- a number that is "remarkably similar across dense and sprawling US cities, from New York to Los Angeles and Houston," perhaps surprising when the varying driving habits and urban environments are considered, Trancik notes.
Replacing internal combustion engine vehicles with electric vehicles for these trips would reduce gasoline consumption by 60 percent and emissions by about 30 percent with the current electricity supply mix.
Even with substantial battery improvements, however, other kinds of car engines will be needed to cover those days with the highest energy consumption. This need may persist for some time, even with expanded charging infrastructure, Trancik says. This highlights the importance of car-sharing of conventional vehicles to enable the electrification and decarbonization of transportation.
The paper is getting widespread attention because its results might help alleviate "range anxiety" -- the fear that relying on an electric vehicle might leave a motorist stranded far away from a charging station -- by helping drivers predict and plan for days in which they might exceed their vehicle's battery charge.
But the paper suggests some interesting implications beyond that most practical interpretation, Trancik says.
Some of the most interesting findings, she says, are new fundamental insights about how people are consuming energy in cities. A substantial literature exists on the relationship between gasoline consumption and the density of cities, in which less dense cities are found to have higher gasoline consumption.
"Interestingly, though, we find that for those cars that are on the road, a similarly large number in each city could be replaced by a limited range electric vehicle without exceeding the batteries’ charge," she says. "So, although the tendency to own and use a car varies across cities, for those that do drive they are driving similarly in this way."
One novel idea that underpins this research is the benefit of evaluating patterns of energy consumption in order to inform technological innovation — in this case electric vehicles and mobile energy storage.
"While there are numerous studies of behavior in cities, there is limited work in this area on how technology matches up with peoples needs and how improved technologies would fare" — an approach she calls a "kind of humanist technologist's approach" to clean energy development.
Read the article in Nature Energy (August 15, 2016)
Read the article in The Washington Post (August 15, 2016)
Read the article in MIT News (August 15, 2016)
Read the article on MSN (August 16, 2016)
Read the article in The Boston Globe (August 18, 2016)