Last Updated Feb 26, 2010 1:46 PM EST
A Virginia-based company, Evatran, is in field trials with a product called Plugless Power that will enable hands-free EV charging. Evantran plans to have it on the market in the fourth quarter of 2010, which is the same time many electric cars--including the Chevrolet Volt, Nissan Leaf, Fisker Karma and Think City--go on sale. The concept for the device is fairly simple, and based on the 100-year-old principle of inductive power transfer that is at the heart of the $25 million utility transformer business for MTC Transformers, Evatran's parent company.
"Simply put, electrical current flowing into a primary source causes current to flow into a secondary source," Evatran says.
According to Rebecca Hough, director of sales and marketing at Evatran, "We see a lot of problems and inconvenience with plug-based systems. So our system depends simply on proximity between the charger and the car."
Each EV would be equipped with a vehicle adapter made for that model. The driver then pulls into an equipped parking space, and aligns the lip of the car over the concrete barrier at the end of the space. The adapter at the bottom of the car will be just a quarter to half an inch from the barrier, allowing the power transfer. When the adapter is over the charger, a light goes on in the Plugless Power tower sitting next to the barrier, and the car automatically begins charging. "It's easy," said Hough. "Our main tenet is convenience. In our field trials, a 65-year-old woman did it on the first try."
An obvious challenge for any such system is the different ride heights of cars and trucks. To get over that hurdle, Evatran is working with a Colorado company, Synchroness, which is charged with getting Plugless Power ready for the market. Synchroness researched the heights of upcoming models and concluded that the system should be able to accommodate 90 to 99 percent of EVs likely to be on the road next year. Monster trucks aren't likely to be eligible, but Big Foot and its ilk are not likely to ditch fossil fuels anytime soon.
For field trials, Evatran is working with the Town of Wytheville, Virginia, where the company is based, as well as with local businesses there including Smokey's BBQ and Counts Pharmacy that will install the system in parking spaces. Next month, Evatran will take delivery of three Wheego Whips (small neighborhood EVs made in Atlanta), a Current from Electric City Motors and a Zenn.
Probably the biggest barrier to widespread Plugless Power adoption is the plug-equipped competition from such major charging players as Better Place, Coulomb and AeroVironment. In a long process involving the Society of Automotive Engineers, the five-pin SAE J1772 charging plug was standardized--eliminating what would otherwise be a confusing morass of non-standard hardware.
On the other hand, Plugless Power's system could be standardized from the outset, and quickly adopted by EV manufacturers.
But some EV advocates have caveats. According to Paul Scott, vice president of advocacy group Plug In America, "I think it's kind of silly, to tell the truth. Not that it doesn't have applications, but if they think people will like EVs more because you can drive over a spot in your driveway and charge, saving you the arduous task of having to (gasp!) plug in your car, then they don't understand the nature of the American people I grew up with. Most of my friends are perfectly willing to spend the three seconds it takes to physically plug in the car."
Scott also claimed there is a minor loss of power in inductive charging. "This is not inconsequential to those of us into hypermiling [getting the most range possible]," he said. To be fair, however, Scott's friends are probably really dedicated to EVs. The casual user could prefer just aligning his car in a parking spot, with no messy plugs to deal with.
Graphic: Plugless Power