Even as electric vehicles appear to be growing in popularity — witness the stunning sales for Tesla’s Model 3 earlier this year — there remains a persistent skeptical argument.
Yet a new study published in Nature Energy Monday by researchers from MIT and the Santa Fe Institute goes a long way towards addressing this concern. The new research, based on a vast data analysis of second-by-second U.S. driving patterns and other evidence, finds that in a surprisingly large number of daily driving cases, range anxiety may be overblown.
“What we found was that 87 percent of vehicles on the road could be replaced by a low cost electric vehicle available today, even if there’s no possibility to recharge during the day,” said Jessika Trancik, a researcher with MIT’s Institute for Data, Systems, and Society who was the study’s senior author.
Granted, even the remaining 13 percent of daily car energy use that exceeds a single battery’s capacity could be enough to drive lingering resistance to electric vehicle adoption — since nobody wants to find themselves out of power on the road.
Still, it’s hard to understate the importance of vanquishing this concern, incidentally — because aside from range anxiety, several other factors already tilt decidedly in EVs’ favor.
For instance, research has suggested that while there are a number of regional variations, it is currently greener to drive on electricity than it is to do so on gasoline, in terms of the resulting emissions.
The current study is a modeling exercise based on an enormous amount of very fine grained data. That’s necessary because precisely how much energy an electric vehicle uses — and thus, how quickly it depletes its battery — depends not only on the distance driven but other subtle factors like the ambient temperature, the time spent idling, how rapidly the driver accelerates, and more.
The study thus combined together hourly temperature data in different U.S. regions, survey data on trip lengths, empirical data on the fuel economy of different cars, and on top of all of that, GPS-derived data on the speeds of actual vehicles and how they vary on a second-by-second basis.
The study assumed a modestly priced electric vehicle — the 2013 Nissan Leaf – and daily charging overnight.
That 2013 model is worth bearing in mind – the study noted that over time, as vehicle batteries improve and become cheaper, ranges should continue to expand and the percentage of daily driving that can be accomplished on a single charge should only increase.
“Most trips can be made in an EV with current battery size,” wrote Willett Kempton of the University of Delaware’s Center for Carbon-free Power Integration in an accompanying commentary on the study, “and an even higher fraction could be made, if the battery size target set by the Advanced Research Projects Agency-Energy (ARPA-E) is met.”
A striking thing about the current study is that it actually didn’t find much regional variability in the key result – that about 87 percent of people’s daily car energy use can be accomplished on one charge of an EV battery.
“It really varies only from 84 to 93 percent across very different kinds of US cities,” Trancik said. “And so, that’s important because it means that there’s a high potential for electrification, not just in dense urban areas, but in sprawling cities.”
Granted, in real life, there are many limitations that prevent suddenly swapping out large percentages of current vehicles for electric ones.
Not everybody has access to charging a vehicle at night, for instance — consider apartment dwellers who park on the street, for instance. Moreover, even if we could get where we need to go on the average day with an electric vehicle, it’s still in the back of all of our minds that sometimes we need our car for a longer trip, too — like a vacation road trip.
Indeed, that’s one reason why the Obama administration recently laid out grand plans to greatly increase the number of charging stations across the country, to try to make faster, more frequent charging possible.
Trancik has not ignored potential logistical problems. For instance, on the longer trips, she says the research points to the need to develop a robust volume of car sharing for gas-fueled vehicles, so that people would know that those are available in a pinch for longer distances.
The study finds that the transition envisioned theoretically by the research would drastically cut emissions from the U.S. transportation sector. “If that 90 percent adoption potential was reached, then one could replace about 60 percent of gasoline consumption, but that would only reduce emissions about 30 percent, which is still a very significant number,” said Trancik.
Margo Oge, a former Environmental Protection Agency administrator who wrote a book on electric vehicles entitled “Driving the Future: Combating Climate Change with Cleaner, Smarter Cars,” praised the new study in a comment to the Post, calling it “elegant and insightful.”
“Perhaps the biggest hurdle we face with this new technology – as with any new technology – is consumer education about the benefits of EVs,” said Oge by email. “Unfortunately we don’t see the [automobile manufacturers] spending a lot of resources advertising EVs. The myth that will need to be dispelled is that they cost too much and that they cannot go far.”
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