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DOE Pulse
  • Number 452  |
  • November 16, 2015

EV charging habits revealed

INL releases most comprehensive study to date on EV usage and charging.

INL releases most comprehensive study to
date on EV usage and charging.

While America’s love affair with the internal combustion engine is not showing any signs of slowing down, plug-in electric vehicles are finding their way into the marketplace. But the big question is, “What is it going to take to see plug-in electric vehicles embraced by the public?” To give automakers, government planners and the public an idea, at DOE's Idaho National Laboratory has released the most comprehensive study to date on plug-in vehicle usage and charging patterns.

Drawing data from five different projects between early 2011 and the beginning of 2014, study partners installed more than 17,000 charging stations around the country and tracked the charging habits of more than 8,000 plug-in hybrid and all-electric car drivers. EV owners and businesses were given incentives to participate, with DOE installing Level 2 chargers in homes and company parking lots wherever it could obtain written consent to monitor use over three years.

In all, EV and hybrid drivers in this study put roughly 125 million electric miles on their Nissan Leafs and Chevrolet Volts in 2011, 2012 and 2013.

Among the findings: although people will leave home or work to fill their cars and trucks with gas, with electric vehicles it’s exactly the opposite. Most EVs are charged at home or at work rather than at public charging stations. And while public charging stations are going to be essential to widespread acceptance, they won’t need to be as ubiquitous as gas stations.

“This kind of stands the gasoline station model on its head,” said Jim Francfort, project manager in INL’s Advanced Transportation Group.

While it generally takes five or 10 minutes to fill a car or truck with gas, electric vehicles using 110V AC can take up to eight hours to charge. Fast-charging stations, which use 480V DC, can still take up to half-an-hour to impart a full charge.

Therefore, it makes sense that a commuter is going to find it a lot easier to drive his EV to work if there is a charging station in the company parking lot. The INL analysis showed that drivers who could charge at the workplace did so more than anywhere besides their home.

“Most people don’t need charging everywhere.” Francfort said. “Any 110 outlet is charging infrastructure.”

Where charging was fast, public stations were popular — as long as the price was low. Also, perception figures prominently with public charging, Francfort said. Putting DC fast charging stations along interstate corridors can encourage people to take longer trips, even if they don’t need to stop and charge.

“They know it’s there if they need it,” he said

With no tuneups or oil changes, less engine wear and tear, fleet owners will probably embrace EVs ahead of the public. “Fleet owners understand,” Francfort said. “They’re interested in the bottom line. Over the life of the car, an EV is going to cost you less.” – by Nicole Stricker

Submitted by DOE’s Idaho National Laboratory