As interest in electric vehicles (EVs) grows, President Joe Biden is pushing for a national EV charging network in his proposed infrastructure bill. The expansion is part of an effort to increase the viability and use of EVs. It seeks to add a half million charging stations by 2030.
Experts say the nation has to find ways to create more effective and convenient charging options to meet the needs of long-distance drivers. Sites along major highways, with easy access and amenities for travelers are being considered as locations. Charging stations would provide universal DC fast chargers that are capable of getting drivers back on the road in approximately 20-30 minutes.
Meanwhile, researchers out of Cornell University have been working to develop a technology that would allow drivers to charge their EVs while they are in motion by implanting wireless charging infrastructure into US roads. Khurram Afridi, an associate professor of electrical and computer engineering at Cornell, says it will be about five to 10 years before the project could be ready to be rolled out to major roadways, but he has been encouraged by recent experiments.
“Highways would have a charging lane, sort of like a high occupancy lane,” Afridi noted. “If you were running out of battery you would move into the charging lane. It would be able to identify which car went into the lane and later send you a bill.”
Afridi sees wireless charging as the best way to eliminate drivers’ fears regarding charging stations and running out of battery. There are currently about 1.8 million battery-powered cars on U.S. roads, but only about 100,000 charging plugs for them at around 41,000 public locations.
The science behind Afridi’s project dates back over 100 years to Nikola Tesla, the inventor who used alternating electric fields to power lights without plugging them in. Afridi’s technology would embed special metal plates in the road that are connected to a powerline and a high frequency inverter. The plates would create alternating electric fields that attract and repel a pair of matching plates attached to the bottom of the EV.
In recent years, people have been looking at wireless charging for phones, but overall, those efforts have fallen flat as the hardware has proven expensive and often unwieldy. Wireless charging has failed to take off because tech companies have been focusing on magnetic fields, instead of electric ones, which require bulky, expensive hardware and use more energy than they provide. Afridi says.
Afridi’s team at Cornell has already made several advances and can power vehicles with up to 18 centimeters of clearance from the road, which accounts for most EVs. The group has also created technology that allows the vehicle to gain full power when passing over the charging plates (which would be embedded several meters apart) even if they are not fully aligned.
The biggest hurdles for the project have been finding and creating components able to conduct the high levels of electricity needed to power vehicles, as well as switches that would be able to operate at the high frequencies required for efficient charging. The infrastructure necessary for the charging lanes would require a massive overhaul of major US roadways, but Afridi said one approach would be to electrify busy highways and major cities first. The metal plates would also be useful for charging at stop signs and traffic lights.