Kevin Bullis

A View from Kevin Bullis

Daimler Tests Cordless Electric Vehicle Chargers

The inductive chargers could make charging more convenient.

  • December 6, 2011

Having a few electric vehicle charging stations here and there isn’t a big deal. But if they ever become common in cities, they’ll be an eyesore, with their long, tangled black cords clumped onto their sides or sprawling across parking spaces to the outlet on the side of a car. Charging stations could also be a tempting target for vandals.

A much more elegant solution would be to bury inductive chargers under parking spots, a concept that Daimler has started testing. The chargers could be invisible and protected from vandals. And they could make charging easier—just pull into a parking spot, and the car can start charging.

Daimler, along with Conductix-Wampfler, a company based in Germany, has only recently started testing cars equipped with the inductive charging coils. But the initial results look positive.

The system is 90 percent efficient, which isn’t as good as charging with a cable, but is better than some other inductive charging systems. The companies say that when you count efficiency losses within the car, the system is almost as good as plugging in.

Daimler has modified a E-Cell plug-in hybrid concept vehicle like this one to allow it to charge without having to plug in. So what will we call plug-in hybrids now?
Credit: Daimler

In initial tests, after two or three practice runs, drivers have been able to successfully park their cars so that they’re centered over the charging coils.

An object detection system is supposed to avoid the potential problem of the buried coils heating up a piece of metal left on the road. The prototypes are based on a wireless charging system developed for electric buses that has been operating since 2003.

It will be interesting to see how the cost of the system compares to conventional chargers, and whether it will still be necessary to install a post for communications gear, to allow drivers to pay for the charge with their credit cards, for example. Ultimately, cities will have to decide whether the better looks and convenience are worth the sacrifice in energy efficiency.

The company WiTricity is developing chargers that could be more convenient still, charging efficiently at distances greater than is allowed by inductive charging. We featured the technology as one of our 10 Emerging Technologies of 2008.

Become an MIT Technology Review Insider for in-depth analysis and unparalleled perspective.
Subscribe today

Uh oh–you've read all five of your free articles for this month.

Insider Premium

$179.95/yr US PRICE

More from Sustainable Energy

Can we sustainably provide food, water, and energy to a growing population during a climate crisis?

Want more award-winning journalism? Subscribe and become an Insider.

  • Insider Premium {! insider.prices.premium !}*

    {! insider.display.menuOptionsLabel !}

    Our award winning magazine, unlimited access to our story archive, special discounts to MIT Technology Review Events, and exclusive content.

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

    First Look. Exclusive early access to stories.

    Insider Conversations. Join in and ask questions as our editors talk to innovators from around the world.

  • Insider Plus {! insider.prices.plus !}* Best Value

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus ad-free web experience, select discounts to partner offerings and MIT Technology Review events

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

    Access to the Magazine archive. Over 24,000 articles going back to 1899 at your fingertips.

    Special Discounts to select partner offerings

    Discount to MIT Technology Review events

    Ad-free web experience

  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning magazine and daily delivery of The Download, our newsletter of what’s important in technology and innovation.

    See details+

    What's Included

    Bimonthly home delivery and unlimited 24/7 access to MIT Technology Review’s website.

    The Download. Our daily newsletter of what's important in technology and innovation.

You've read of free articles this month.