Korea Tests System to Charge Electric Buses in Motion

South Korea is testing an inductive system that uses power lines embedded in the roadway to charge electric buses wirelessly as they travel along their routes, The Wall Street Journal reports.

The test in Gumi in southeastern Korea involves two specially equipped electric buses that operate on an existing 15-mile-long route. Each vehicle makes as many as 10 trips per day.

Developers say the system is 85% efficient in transferring power wirelessly to the big buses, thanks to technology that shapes and focuses the electromagnetic field created by wires in the road. The 100-kW system transfers power to an onboard battery that drives the rear wheels through an electric motor.

The 4.8-billion-won ($4.3 million) system requires buried charging strips in only 5%-15% of a bus's route. The technology, which was developed by the Korea Advanced Institute of Science and Technology, also can charge a motionless vehicle.

The Gumi test uses $581,000 carbon-fiber-bodied buses built by Korea's Dongwon OLEV Corp., which owns commercial rights to the system. The firm also has conducted shorter-distance demonstrations in Korea over the past three years.

Project engineers concede the system is prohibitively expensive at this stage of development. They estimate that mass production of the system's components could lower costs enough to result in a 14-year return on investment, according to the Journal.