Here's one way you could charge electric cars in the future. A South Korean city is testing electric buses that get their charge from cables buried underneath the road.
The cables create magnetic fields that a device on the underside of the buses converts into electricity. (In principle, they're like enormous versions of the induction power that charges toothbrushes and smartphones wirelessly.) The charging works both while the buses are driving and when they're sitting still.
Right now, there are two of the buses and they run back and forth along a central city route that's about seven miles long, or 15 miles round-trip. The Gumi government plans to add 10 more so-called OLEV (Online Electric Vehicle) buses by 2015, according to the Korea Advanced Institute of Science and Technology. Electrical engineers at the institute developed OLEVs.
Other specs from the institute include that the electromagnetic field that the cables create is weak enough to be safe for pedestrians, according to the institute. The cables also switch on only when they detect that OLEV buses are passing over. Five percent to 15 percent of a roadway needs to have cables in it for the buses to run.