Electrified roads could power vehicles, say researchers

Researchers in South Korea have developed a way to charge electric vehicles on the move by embedding magnetic components in the road that can inductively charge vehicles passing over them.

The system, developed by scientists at the Korea Advanced Institute of Science and Technology, is designed to increase the range of zero-emission electric vehicles including buses and cars, while cutting down on battery size.

It uses the same kind of electric charging technology sometimes found in electric toothbrushes, which allows a device to charge without requiring direct contact between metal elements.

Instead, inductive charging uses an electromagnetic field, which brings two magnetic elements close enough together that they can transfer energy wirelessly without any contact.

The South Korean pilot project uses strips of magnetic material embedded a few centimetres under the surface of the road that then react with sensor-driven magnetic devices underneath vehicles. As the vehicles pass over the strips, they receive a micro-charge.

Inductive charging has been investigated by electric car developers in the past, but critics have maintained that it is currently too inefficient to be of much use.

However, the researchers insist that the charges provided by their system are efficient enough to have a significant effect on the range and battery size of a vehicle.

They suggested that batteries could be a fifth of their conventional size when used in conjunction with the technology, helping to make electric vehicles lighter while significantly increasing their range.

The university already has four prototype buses using the technology on its campus, according to reports from news agency Reuters, and hopes to have the technology embedded in roads in Seoul, the South Korean capital.

However, at a cost of $353,500 (£237,000) per kilometre of road, the technology does not come cheap.

This modern take on the tram is one of a number of electrified road proposals under development. A US-based firm is also working on a vehicle known as the Tritrack, a proposed dual-mode car that travels at slow speeds when on the road, accelerating when on an electrified monorail system.