A few states are testing induction road-charging networks to power electric vehicles as they're driving using coils embedded in the pavement.
On two short stretches of road near downtown Detroit, Michigan transportation officials hope to make history.
Over the next two years, they plan to embed technology in the pavement that can charge electric vehicles while they’re being driven. The wireless system will be the first U.S. test of so-called inductive charging on public roadways, according to the Michigan Department of Transportation.
“We’re the auto capital. We continue to push technology advancements,” said Michele Mueller, a senior project manager at the agency.
In some other states, including Florida, Indiana, Pennsylvania and Utah, officials also plan to test inductive charging on public roads in the next several years.
“This is a great solution to a problem we have today of how to get to zero emissions,” said Tallis Blalack, managing director of the ASPIRE engineering research center headquartered at Utah State University, which focuses on electric vehicle infrastructure. “If we do this correctly, we can decrease the costs of transportation for everyone.”
Electromagnetic inductive charging is common in everyday life — setting a mobile phone on a wireless charger uses similar technology. On roadways, coils embedded in the pavement transfer magnetic energy to a receiver mounted beneath an electric vehicle to wirelessly charge its battery.
Eventually, wireless road systems could extend electric vehicles’ battery range, reduce the idle time required to recharge batteries and allow freight trucks to transition to electric by making it possible for them to use smaller, less expensive batteries, say proponents of the technology. They envision inductive charging along sections of highway across the country.
Drivers would use a phone app or vehicle control to choose whether to accept a charge from a road’s coils. Users would pay for kilowatts the same way they do at an EV charging station, though the system would be free to drivers during test pilots.
Blalack said the biggest challenge in getting to zero emissions nationally is figuring out how to move the 70% of freight that is now transported by truck.
Without an inductive charging system, it would cost an estimated $150,000 to put EV batteries into each long-haul electric semi, he said. Those batteries would weigh 20,000 pounds, a quarter of a truck’s payload. Charging truck batteries that large would require megawatt chargers to fast charge them, he added.
Inductive charging would eliminate the need for such heavy long-range batteries, Blalack said. Smaller truck batteries would require fewer natural resources to manufacture and would cost only about $15,000.
“We can reduce the cost of transportation for everybody if we have the infrastructure in place,” he said.
Blalack said his center estimates that it would require about $30 billion a year to develop induction road-charging networks in some regions across the country by 2035, primarily on interstate highways.
“It seems like a lot of money, but you’re talking trillions of dollars to buy batteries for long-range vehicles,” he said. “It’s significantly cheaper for us to invest money in infrastructure than build out all these vehicles with long-range batteries.”
Some states already have experimented with wireless in-road charging, but it’s been on test tracks or at private facilities, rather than on public roads, according to Blalack, whose center is collaborating on wireless in-road charging pilots in several states.
The 2021 federal Bipartisan Infrastructure Law requires $5 billion to be distributed among every state, the District of Columbia and Puerto Rico to help build a network of EV charging stations available every 50 miles along federally designated highways. But that money isn’t meant to be used for induction charging road pilots.
States are using their own money to test inductive charging or are relying on companies that make the technology to share the cost.
In Michigan, transportation officials have partnered with Electreon, an Israeli company that develops wireless charging infrastructure, and plan to start testing by fall of 2023 on a quarter-mile stretch near the renovated Michigan Central Station, which Ford Motor Co. plans to make the centerpiece of a so-called mobility innovation district southwest of downtown. Officials will be outfitting an electric shuttle with the wireless receiver.
In 2024, the state will install the technology on a three-quarter mile stretch of a busy commercial street near downtown. A Detroit Department of Transportation electric bus will carry the receiver, as will a group of electric delivery vehicles, which also will be able to charge their batteries on static pads at certain spaces along the route, officials said.
Michigan is spending $1.9 million in state money for the $6 million project, according to Mueller. Electreon is picking up the rest of the tab.
Mueller said the goal is to understand the benefits and challenges of induction road charging networks and how they might work for public transit, passenger cars and commercial vehicles. Another aim is to reduce drivers’ “range anxiety” and decrease demand on the electric grid.
“If you can use inductive and static charging, then once you get home, you won’t have those peaks of everyone charging their EVs at once, so you won’t get spikes on the grid,” she said. “This will level off demand throughout the day.”
In Indiana, the state Department of Transportation and Purdue University are working on an inductive charging project that could power heavy-duty trucks on a state highway near the university in West Lafayette. Officials hope to start constructing the system in fall 2023, according to Blalack, whose center is collaborating on the project.
In Florida, the Central Florida Expressway Authority is planning a similar project for all vehicles on about a mile of the Lake/Orange Expressway near Orlando, a new roadway under construction that is scheduled for completion by 2026. The pilot will cost about $10 million.
In Utah, the ASPIRE center is working with the Utah Inland Port Authority in Salt Lake City on a project that will test high-power charging technology using electric trucks that move cargo from containers at the railyard to local distribution warehouses.
And the Pennsylvania Turnpike Commission wants to install the technology on 3 to 5 miles of a planned section of road near Pittsburgh on the Mon/Fayette Expressway, though the final site hasn’t been selected, according to Keith Jack, the turnpike’s director of facilities operations. The agency hopes to launch the project between 2026 and 2030.
Jack said officials first want to test medium and light cargo electric vehicles on the road, so no date has been set for when inductive charging would be available for public use. He noted that he’s a big supporter of using inductive charging rather than plugging a vehicle into an outlet.
“If you have to drive 600 miles, most EV vehicles don’t have the capacity to do that. You’re going to have to stop for 20 minutes and do fast charging,” he said. “If I’m going from here to Indiana, I’m not going to stop six times for 20 minutes. We’re trying to make long-distance travel easier.”
The turnpike hopes to use power generated from its own solar fields at maintenance facilities and service plazas to electrify portions of the induction roadway in future projects, Jack said. It already has one solar field in operation and six others planned.
“If we can produce the energy on the right of way or our maintenance sheds, we can apply it into the road,” he said. “As we transition to EVs, we have to think about the relationship we have with energy — where we make it and where we’re going to use it.”