Range anxiety is a common theme in arguments against electric vehicles, and it is a valid argument. But what if electric vehicles could drive…forever? Sounds crazy, but the idea of an in-road electric car charging system isn’t new. It is receiving a fresh look from researchers at Stanford University however, who want to use magnetic coupling to wirelessly charge EV’s as they drive.

The proposed design would transfer large amounts of energy via metal coils spaced about 6.5 feet apart. The design, in theory, could transfer up to 10 kW of electrical energy at a 97% efficiency rate. Very good numbers, in theory. Making it all work in the real world is the challenge though.

Stanford hopes to use resonant coupling to eventually lead to the development of an all-electric highway system. Resonant coupling uses two coils, one connected to an electric current that produces a magnetic field, causing the second coil to resonate. The magnetic resonance results in the transfer of electricity between the coils wirelessly. Several companies are working on bringing wireless charging to home garages, but this system would be built into the road themselves to provide charging on the fly.

In theory, this means that a highway with a wireless charging system could provide electric cars with an unlimited driving range. But while asphalt doesn’t interfere with the energy transference, the metal bodies of cars could, so more study and research is needed. But the potential here is huge…