- Feb 14, 2012
Stanford envisions 'all-electric highway' that charges EVs as they go
The school says it's developing a technology that would allow electric-drive vehicles to be recharged as they're being driven down the road. The system involves magnetic energy being sent between metal coils placed in the road a few feet apart.
The process, called "magnetic resonance coupling," involves tuning the road coils and a coil at the bottom of a car to the same natural frequency, so that, when the road coils are charged with an electric current, they send electricity to the coil in the car, which then recharges a battery. Ultimately, Stanford researchers say they can develop what's essentially an electric highway that one of the researchers said may give an EV a higher charge after driving than before the trip started. Imagine that.
Obviously, such technology is a long way off being used by consumers, but the concept of wireless electric charging is a topical one because what's perceived by some to be the inconvenience of having to use a cord to recharge a vehicle. Indeed, global consumers may spend as much as $1.5 billion in wireless EV chargers by the end of the decade, Pike Research said in a 2010 study. Companies like U.S.-based Evatran and UK-based HaloIPT have developed in-ground wireless charging systems that allow EVs to be recharged by merely being parked on top of a charging system. Last week, Hertz said it would be the first rental-car company to test a wireless recharging system – made by Evatran – on its vehicles.
Moreover, an all-electric highway like the one pitched by Stanford would address the even larger issue of "range anxiety," since production EVs such as the Nissan Leaf currently provide for an official 73 miles of single-charge range. Last summer, researchers at Utah State University said they were able get get five kilowatts of electricity to jump an air gap of up to ten inches at 90 percent efficiency, implying that they were in the early stages of working on a similar "electric highway."