Recharging EVs while you drive

Electric vehicle drivers of the future might not need to plug in to charge their batteries — and they may not even need to stop.

Projects underway in Florida, Indiana, Michigan and Utah are testing a technology that would charge vehicles as they move along special road surfaces.

The basic idea is similar to those employed by wireless charging stations, or even wireless phone chargers, said Nadia Gkritza, a professor at the Lyles School of Civil Engineering at Purdue University in West Lafayette, Ind. Coils installed in roadways circulate a high-frequency current to generate a magnetic field. Receivers on the vehicle pick up that energy, allowing it to charge the battery or power the motor directly, she said.

Purdue has partnered with the Indiana Department of Transportation and the Aspire Initiative, an engineering research center funded by the National Science Foundation, to develop the technology. The program is also working with German startup Magment, which has developed a magnetizable concrete that researchers hope will allow for efficient charging of high-powered, heavy-duty trucks.

"We don't advocate for 100 percent roadway electrification," Gkritza said. "But we feel there are points where it would be useful: to support charging deserts where we don't have a lot of EV charging stations, and specifically for long-haul freight trucking."

The Purdue project is one of several wireless roadway charging projects underway in the U.S. Aspire researchers are working on versions of the technology in Florida and Utah. (Aspire is based at Utah State University and includes research labs around the country and at partner universities including Purdue, the University of Colorado Boulder and the University of Texas at El Paso.)

The Michigan Department of Transportation also announced a project this year, with plans to build a mile-long stretch of road with wireless charging capabilities in Detroit by 2023. That project is being spearheaded by Israeli startup Electreon.

"As we aim to lead the future of mobility and electrification by boosting electric vehicle production and lowering consumer costs, a wireless in-road charging system is the next piece to the puzzle for sustainability," Michigan Gov. Gretchen Whitmer said in a news release.

The Indiana project is in a test phase, with plans to build a quarter-mile-long stretch of public road with charging capabilities in the coming months, a spokeswoman for the state's Department of Transportation said.

Purdue's Gkritza said researchers' long-term goal is to expand to a 1-mile test bed on a stretch of Interstate 70 in Indiana, depending on the results of various pilot programs. By 2030 or 2035, the goal is to have stretches of roadway of up to 10 miles capable of charging vehicles.

Tallis Blalack, managing director of Aspire, said researchers are working on more than just the wireless charging technology, saying vehicle-to-infrastructure communications will be critical to implementing such systems.

Vehicles need to be able to effectively tell the road charging system what type of vehicle it is and whether the driver wants its battery to be charged, Blalack said, and if so, to provide payment information.

"All of that information is going to be exchanged, and it needs to be secure," he said. "As we think of this at scale, it means I'm going to be driving through different electric utilities, and I'm going to cross state lines, which are going to have different taxes. It's going to take us a long time to build out, but we're working on the research to make that happen."

Wireless charging could be especially effective for long-haul truckers, who have to drive through parts of the country that might not have many charging stations, Blalack added. The technology also holds great potential to improve EV access for those with disabilities, since the driver would not need to leave the vehicle to charge up, he said.

"If we do this right," Blalack said, "we can drop the costs of transportation for everybody."