Charging Electric Vehicles While on the Move

Researchers at Stanford University recently built on MIT’s experiment where they powered a light bulb more than 6.5 feet away through thin air using magnetic resonance. They set out to develop a similar system that could deliver even more power. Specifically, the researchers wanted to transmit 10kW wirelessly which would be enough power to propel an electric vehicle down the road at highway speeds. They used computers to experiment with the optimal design for a system that could effectively transfer 10 kW to a moving car. They found that a source coil with a 90-degree bend atop a metal plate could transfer the necessary power to an identical coil equipped to a vehicle 6.5 feet away. They achieved a transfer efficiency of 97 percent which is much higher than other wireless systems, and believe that they can eventually reach an even higher efficiency by adjusting the design a bit more. The electrically-charged coils would be embedded into the asphalt of the road. The coils would transfer the power to the electric vehicle as it drives over them which continuously charges the battery. Such a system would allow the vehicle to travel very long distances without having to stop and recharge. Theoretically, the range would easily be greater than any liquid-fuel powered vehicle and the driver would never have to plug their car in to charge it.

With the computer simulation showing encouraging results, the Stanford researchers now plan to move on to a laboratory and perform real-world driving tests. They have even filed a patent for their wireless charging system. The research team has also started working with the engineering department to begin looking at the problems related to designing roadways with these coils installed. Of course, they also need to determine that the magnetic system is safe to use in a real world environment and will not result in radiation harmful to humans or electromagnetic interference that could affect vehicular electronics. Nevertheless, the technology is exciting and could allow electric vehicle owners to drive almost indefinitely and never have to recharge.