Electric Car Electrified By Electric Road While Driving

One of the biggest obstacles to widespread acceptance and usage of electric vehicles (EVs) is range. American motorists are simply reluctant to buy an automobile that they can only drive for 100 miles at a time. This “range anxiety” is compounded by two other elements: The charging infrastructure in the U.S. is still in its infancy, meaning there just are not that many places to juice up; and charging an EV requires a pretty substantial investment of time—sometimes up to eight hours. This makes a long road trip in an EV next to impossible.

But what if there were alternatives? What if we could continually charge an EV while were were driving it? What if we never had to worry about charging stations? What if our highways were the charging stations?

highway ev charging

image via Stanford University

That’s just what Stanford University researchers may have just discovered. The scientists say they’ve designed a high-efficiency charging system that uses magnetic fields to wirelessly transmit large electric currents between metal coils placed several feet apart. The long-term goal of the research is to develop an all-electric highway that wirelessly charges cars and trucks as they cruise down the road.

The new technology has the potential to dramatically increase the driving range of electric vehicles and eventually transform highway travel, according to the researchers. Their results are published in the journal Applied Physics Letters.

“Our vision is that you’ll be able to drive onto any highway and charge your car,” Shanhui Fan, an associate professor of electrical engineering, said in a statement. “Large-scale deployment would involve revamping the entire highway system and could even have applications beyond transportation.”

The wireless power transfer is based on a technology called magnetic resonance coupling. Two copper coils are tuned to resonate at the same natural frequency—like two wine glasses that vibrate when a specific note is sung. The coils are placed a few feet apart. One coil is connected to an electric current, which generates a magnetic field that causes the second coil to resonate. This magnetic resonance results in the invisible transfer of electric energy through the air from the first coil to the receiving coil.

MIT researchers have created a spinoff company that’s developing a stationary charging system capable of wirelessly transferring about 3 kilowatts (kW) of electric power to a vehicle parked in a garage or on the street. Fan and his colleagues wondered if the MIT system could be modified to transfer 10 kW of electric power over a distance of 6.5 feet—enough to charge a car moving at highway speeds. The car battery would provide an additional boost for acceleration or uphill driving.

Here’s how the system would work: A series of coils connected to an electric current would be embedded in the highway. Receiving coils attached to the bottom of the car would resonate as the vehicle speeds along, creating magnetic fields that continuously transfer electricity to charge the battery.

To determine the most efficient way to transmit 10 kW of power to a real car, the Stanford team created computer models of systems with metal plates added to the basic coil design.

Steve Duda lives in West Seattle, WA with three dogs and a lot of outdoor gear. A part-time fly fishing fishing guide and full-time writer, Steve’s work has appeared in Rolling Stone, Seattle Weekly, American Angler, Fly Fish Journal, The Drake, Democracy Now! and many others.

    • Davisdairycow


    • Anonymous

      No mention of the efficiency. I suspect the power conversion figure is no more than 20%, which means a lot more power needs to be generated somewhere else.

      • Pete

        The researchers report transfer efficiency of 97 percent at short distances. (Pete Danko, EarthTechling)

    • Anonymous

      No mention of the efficiency. I suspect the power conversion figure is no more than 20%, which means a lot more power needs to be generated somewhere else.

    • Gstrickland77

      sounds like it might generate cancer too

      • Pete

        We didn’t have time to get into it in the story, but thenpossible health effects were mentioned in the Stanford press release about thisnresearch:nnn”The researchers also want to make sure that the systemnwon’t affect drivers, passengers or the dozens of microcomputers that controlnsteering, navigation, air conditioning and other vehicle operations.nnn”‘We need to determine very early on that no harm isndone to people, animals, the electronics of the car or to credit cards in yournwallet,’ saidu00a0Sven Beiker,nexecutive director of the Center for Automotive Research at Stanfordn(CARS).u00a0 Although a power transfer efficiency of 97 percent is extremelynhigh, Beiker and his colleagues want to be sure that the remaining 3 percent isnlost as heat and not as potentially harmful radiation. (Pete Danko, EarthTechling)

    • Creelme

      The coal fired generators would hummmm away and puff away to make the electricity! Unless we use Nuclear and pray for no leaks. I know why don’t we use natural gas , oh wait that puts out CO2. Gee that leaves gas and fuel oil. Well that’s not good to convert energy from one source to another to another because some is always lost in the form of heat. Foolish idea to use electric cars no matter how you do it, unless we invent Fusion and we haven’t done that yet. Don’t put the horse before the cart.