One of the most promising ideas for extending electric car driving range is to install wireless charging features into city streets. The city of Gumi, South Korea recently launched a pair of electric buses wirelessly charged through the roadway, and if the initial tests go well, this could pave the way.
The Korea Advanced Institute of Science and Technology developed the inductive charging system, called the Online Electric Vehicle (OLEV) platform. This system has already deployed it on trams at the Seoul Grand Park amusement center and buses around the KAIST campus. The city of Gumi now has the pair of buses running a 15-mile route, and hopes are high for this initial test.
Inductive charging uses magnets to pass electricity through the air, and it essentially allows for electric cars to drive an unlimited range…at least until the road chargers run out. It also allows for much smaller on-board batteries, lowering weight and battery costs. A network of in-road electric chargers, on a city-scale, could eventually save municipal governments millions in fuel costs.
The Gumi system achieves an 85% charging efficiency rate with a 6.7-inch gap between the road and battery, and the charging points make up only between 5% and 15% of the route, so installation costs wouldn’t even be that high. The points only activate when a compatible vehicle drives over it. This is a similar model to the capacitor buses being tested in China, recharging buses quickly at regular intervals at each stop.
Of course deploying such a system in Korea, where half the population inhabits one city, is more likely than here in the much larger U.S. A more likely wireless charging solution will be like the kinds being developed by GM or Infiniti, which will charge parked cars without ever plugging, making refueling far more convenient.
But it also isn’t out of the realm of possibility to one day imagine a cross-country electric highway, charged by solar power, with autonomous semis and cars hauling goods and people non-stop on a constant electrical current.