The future of electric vehicles could soon come charging down the road – in more ways than one – with composites playing a key role. At a Logan, Utah, test track, researchers from Utah State University are exploiting the strength and wireless transparency of GFRP while experimenting with recharging moving electric vehicles. The goal is to solve a problem that’s kept electric vehicles to a small fraction of total car, truck and bus sales despite some clear advantages.
“An electric vehicle with a city-range battery is quite economical. The total cost of ownership is on the order of half that of an internal combustion engine vehicle,” says Regan Zane, a Utah State University electrical engineering professor and director of the Center for Sustainable Electrified Transportation (SELECT), which manages the quarter-mile test track. “But that vehicle won’t meet your needs unless it can get you from city to city.”
Some batteries in high-end electric vehicles, such as the Tesla Roadster, remain charged for more than 200 miles. But the average electric vehicle can only travel 40 to 100 miles on a single charge. Plus, a complete charge can take several hours.
Studies and modeling show that more than 80 percent of the time, drivers travel less than 40 miles, Zane says. That makes an inexpensive electric vehicle practical – most of the time. Those occasions when drivers need to travel further distances could be better handled if there was some way to recharge the battery periodically while in transit. That’s why researchers at Utah State are looking at in-road, wireless recharging.
There are a variety of ways this could be done. One is to bury the recharger in a trench under the road, which protects people from potential exposure to high voltage electricity. It also enables recharging independent of the weather and results in a roadway that doesn’t look much different than a standard one.
Wireless recharging can be accomplished via electric fields, magnetic fields or a combination of both. Faculty at Utah State are experimenting with a magnetic approach at the test track, while faculty at SELECT partner University of Colorado Boulder are evaluating capacitive coupling with electric fields. According to Zane, the test track needed a material for trench covers that was transparent to any of the wireless recharging options housed below the track. The trench covers also had to be strong, since many tons of metal would routinely roll across them. Finally, trench covers had to be easy to remove so that the recharging systems could be changed out between experiments.