Electric roads offer a new future for tires

Tokyo – Tire technology is at the heart of an innovative approach to powering electrical vehicles (EVs), which is currently being developed in Japan.

While EVs are emerging as a ‘green’ alternative to traditional combustion engine-powered designs, the batteries used to power them limit the continuous running distance from one charge and can take a long time to recharge.

To overcome these limitations, scientists at Toyohashi University of Technology and Toyota Central R&D are developing a promising ‘electric roads’ solution for powering EVs capable of running unlimited distances.

The technology employs high-speed inverters to convert energy from power lines into radio frequency (RF), which is applied to a balanced metal track embedded under the surface of the road. Vehicles pick up the RF voltage via electrical capacitance between the metal and a steel belt installed inside of the tires of the EV.

The team, led by Masahiro Hanazawa at Toyota Central R&D labs.and Takashi Ohira at Toyohashi University say their experiments have they demonstrate the feasibility of energy transfer from the road to a running EV.

If this energy transfer could be increased to tens of kW on motorways, then in the future it may be possible to drive via this feeder system as far as you want without concern about battery discharge problems, the team has stated.

At the Ceatec Japan technology fair in October 2014, the researchers demonstrated the technology: using the current generated in the metal belts and wires within the tires to power a small electric cart.