One major barrier to bringing electric vehicles to the masses is range anxiety — not the fear that you left the stove on at home, but the fear that your EV will run out of juice before you can get to the next charging station. But creative solutions are in the works. This week, South Korea debuted the world’s first electric road, 15 miles of city streets with underground cables that charge EVs parked or driving above — no plug-in stations necessary.
In the city of Gumi, two commuter buses will be the first to test the program, and the city plans to add 10 more over the next two years. Known as Online Electric Vehicles or OLEVs, the buses have batteries about one-third the size of the typical electric car battery. Extreme Tech explains how it works:
Exact details of the system are hard to come by, but we believe that the power is delivered by cables that are around 12 inches (30cm) below the road surface. The power is transmitted wirelessly via Shaped Magnetic Field in Resonance (SMFIR), a technology developed by the Korea Advanced Institute of Science and Technology (KAIST) that essentially runs 100 kilowatts of power through some cables at a very specific frequency (20 kHz in this case), creating a 20 kHz electromagnetic field. The underside of the bus is equipped with a pick-up coil that’s tuned to pick up that frequency, and thus AC electricity is produced via magnetic resonance. (Read: How wireless charging works.) Transmission efficiency is an impressive 85% thanks to the “shaped” part of the technology, which targets the electromagnetic field at the vehicle, so that less energy is lost to the environment.
Because the batteries are so small, only 5 to 15 percent of the road needs to be dug up and electrified. Once equipped with the technology, roads can sense when an EV is coming, and only then do their charging powers activate — increasing efficiency and sparing all the unlucky non-EV drivers from being exposed to radiation (but don’t worry, if you do happen to pass over a charged-up section of the road, the level of radiation emitted is within international safety standards).
If America’s legendary highway system went electric, we could drive EVs to our hearts’ content and never have to worry about running out of fuel. And just think how many jobs would be created by digging up 5 to 15 percent of the nation’s road surface. More than by building the Keystone XL pipeline, I bet.
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