Despite their limited driving range, electric vehicles could easily meet the needs of about nine in 10 car owners and bring about a meaningful reduction in the greenhouse-gas emissions causing global climate change, a new study found.
Researchers from MIT and the Santa Fe Institute published their four year-long study in the journal Nature Energy this week. The study amassed an enormous amount of data on millions of trips made by drivers across the U.S. The data included a highly detailed set of second-by-second driving behavior based on GPS data, and another broader, more comprehensive set of national data based on travel surveys.
What the researchers found is that the driving range requirements of nearly all consumers could be met by EVs, and the vehicles could do it at a cost no greater than that of conventional internal-combustion vehicles.
Additionally, a large-scale replacement of combustion-engine vehicles would be sufficient to meet the nation's stated near-term emissions-reduction targets for personal vehicles, which makes up about a third of the nation's overall greenhouse gas emissions. A majority of greenhouse emissions come from privately owned, light-duty vehicles.
"Roughly 90% of the personal vehicles on the road daily could be replaced by a low-cost electric vehicle available on the market today, even if the cars can only charge overnight," said Jessika Trancik, an associate professor in Energy Studies at MIT's Institute for Data, Systems and Society (IDSS).
Deeper emissions cuts would be realized if power plants decarbonized -- moved away from fossil fuels such as coal -- over time, the researchers noted.
Even after many advances in EV technology, EVs continue to suffer criticism over initial retail prices and range anxiety, or the fear that they hold insufficient power to complete longer trips.
Range anxiety has been a key focus of EV makers such as Tesla Motors. Last year, Tesla founder and CEO Elon Musk announced an over-the-air software upgrade to the entire Model S fleet that not only tracks charging station locations but alerts drivers when they're out of range of those stations.
"This is an issue where common sense can lead to strongly opposing views," Trancik says. "Many seem to feel strongly that the potential is small, and the rest are convinced that is it large.
"Developing the concepts and mathematical models required for a testable, quantitative analysis is helpful in these situations, where so much is at stake," she adds.
Those who feel the potential for EVs is small cite the premium prices of those available today, such as the highly rated, but expensive, Tesla models, and the still-limited distance lower-cost EVs can drive on a single charge, the research found. The lack of available charging infrastructure in many places, and the much greater amount of time required to recharge a car compared to simply filling a gas tank have also been cited as drawbacks.
The researchers, however, found that the vast majority of combustion-engine cars on the road consume no more energy in a day than the battery energy capacity in affordable EVs.
The data was represented by a scenario in which people would do most of their recharging overnight at home, or during the day at work. For such trips, the lack of infrastructure was not really a concern.
Vehicles such as the Ford Focus Electric or the Nissan Leaf — whose sticker prices are still higher than those of conventional cars, but whose overall lifetime costs end up being comparable because of lower maintenance and operating costs — would be adequate to meet the needs of the vast majority of U.S. drivers.
"The adoption potential of electric vehicles is remarkably similar across cities," Trancik said, "from dense urban areas like New York, to sprawling cities like Houston. This goes against the view that electric vehicles — at least affordable ones, which have limited range — only really work in dense urban centers."