Electric cars are poised to play a key role in mitigating climate change, but are often written off due to their limited driving range and infrastructure challenges. However, a recent study by Massachusetts Institute of Technology researchers reveals that nearly 90 percent of conventional vehicles on the road today could be replaced by electric cars without inconveniencing their drivers.
The study, published at Nature Energy, compiles GPS data from the National Renewable Energy Laboratory (NREL) and the National Household Travel Survey (NHTS). The combined datasets encompass millions of U.S. vehicle trips. The researchers showed that on the great majority of days that people follow their regular driving routines, their driving requirements could be met by electric vehicles (EVs).
“On any randomly chosen day, we predict that 87 percent of vehicles that are driven at any point could be replaced by an EV without needing midday charging,” said Zachary Needell, a graduate student who co-authored the study along with several colleagues working in the lab of Jessika Trancik, a professor of energy studies at MIT.
Putting more electric cars on the road, a process referred to as “electrification,” has the potential to dramatically reduce our carbon footprint. According to the study, transportation accounts for about 30 percent of U.S. energy use and nearly 35 percent of carbon emissions. Under the Obama administration, the U.S. is committed to reducing emissions by 26-28 percent by 2025. Electric cars are important to meeting these goals.
“[Electric vehicles] are the only form of personal vehicle technology widely available on the market that is capable of being clean enough to meet long-term carbon emissions goals,” Needell said.
Calming Range Anxiety
There are a number of challenges associated with greater electrification, not least of which is convincing drivers to deviate from what they’re used to. The range of most vehicles – that is, the amount of time they can run before needing to be charged – encompasses almost all personal vehicle travel. However, occasional long-distance trips create a problem.
“Even if in your typical day you only drive 30 miles, you’re used to being able to go on a five-hour road trip without having to change anything,” Needell said. “The question is whether people are going to be willing to modify their behavior a few days of the year if their primary vehicle meets their needs the vast majority of days.”
Improving the battery life of vehicles is one way to solve this “range anxiety,” but Needell says it’s important to think beyond range even as the technology improves and charging stations become more widely available.
“For climate change mitigation, it is important to develop technologies such that people have a convenient, desirable, low-carbon option to meet their travel needs,” he said. “One way to make EVs a more attractive choice is to offer increased range, as well as offering more convenient charging options, alternative modes [such as public transportation], or vehicle sharing for long-distance days.”
One way to do that is by building on steps people are already taking to increase sustainability. For example, in Boston, many people already use public transportation to get to work instead of driving.
“I think electrification of personal vehicles is going to be an important development in lowering Boston’s carbon footprint, but it’s important to think of things from a system-level perspective,” Needell said. “We don’t want to be incentivizing people to drive to work rather than taking the T.”
He says there’s a balance between integrating electric vehicles and having them dominate the system. “We’re not likely to solve the problem just by having really cheap electric vehicles with really good batteries. We should also pursue a cleaner electricity sector, smart development patterns, and investment in other modes in order to take full advantage of the opportunities presented by EVs.”
Developing the Grid
Greatly increasing the number of electric cars on the road suggests thinking about a sizable change in current electricity generation infrastructure, Needell said.
“Right now, the current contribution of electric vehicles to electricity demand is pretty small in the grand scheme of things, but if you start to imagine 20, 30, 40 percent integration, that starts to add up to a pretty significant amount of electricity coming from the existing grid,” he said.
Fortunately, the electric grid is getting cleaner as the U.S. shifts toward renewable energy, and the vehicles themselves are also becoming more economically viable.
“Purchase prices tend to be a little higher than conventional vehicles right now, but operating costs tend to be a lot lower,” Needell said. “I think there are going to be plenty of people out there who look at it as a general cost-benefit calculation.”
The study is an important first step towards greater adoption of electric vehicles, simply because it proves that can be done.
“What I find most interesting about this work is that it gives this really detailed picture,” Needell said. “There are a lot of different places to dive in and look at different kinds of problems.”
–Gwendolyn Schanker is a fourth-year journalism and biology major at Northeastern University. She is the current editor-in-chief of NU Sci, Northeastern’s student-run science magazine, and is also a freelance writer for Northeastern’s College of Science.
Photo credit: NCDOTcommunications — Flickr.