Recharge while you roll | Electric car manufacturers take one step ahead

Plug-in electric cars like the Nissan Leaf and Chevy Volt are trying to enter the U.S. consumer marketplace and making its place. In the meantime automobile manufacturers are thinking of making cars that can recharge itself while moving on the road to its destination by eliminating time consumption at the recharging garages. This technological advancement looks promising because it will change the usual way of locating a garage for fueling-up the car. 

People are very happy with the idea of recharging their cell phone and other gadgets on the move but as far as the notion of plugging in a car while on a journey is not so common in fact it’s primitive. 

‘Immobile’ wireless charging 

" It’s now a universally accepted idea for all the car manufacturers that customers don’t want to plug-in their vehicles and recharge them by going to fuel-in garages. So they are thinking of offering something that make their customers happy by saving their time at stations and plugging in time, like wireless, hand free charging.”says David Schatz, director of business development and marketing for WiTricity Corp. in Watertown, Mass., which is a manufacturer of wireless chargers for cell phones and other gadgets.With WiTricity's system, a consumer would not have to park his or her car straight on a charging mat, let alone deal with cords. If the vehicle is within the range of the system, the energy will flow into the car battery without any cords-wireless. 

The method depends on a principle called magnetic resonance coupling. The charging device, made of a coiled wire with capacitance plates on either end, uses electricity to generate a magnetic field that resonates at a specific frequency. Just as an opera singer can shatter a wine glass by singing the right note, the emanating coil transfers energy only to a receiving coil that resonates at the same frequency. Magnetic resonance coupling is thought to be safer than other methods of wireless charging because the intensity of the field can be increased without affecting other, non-resonant objects nearby. 

The technology, created at the Massachusetts Institute of Technology four years ago, may finish in this fashion , in the coming cars soon. WiTricity last year joined with major automobile component supplier Delphi Electronics on a demo car, and Mitsubishi Motors recently settled to work with WiTricity on groundwork research. 

"Go-ahead wireless" charging 

Other scientists are taking wireless charging to the next step: designing cars that can charge while on the highway. Dynamic charging would help to eradicate the fear that drivers might have of being stuck on the road with a dead battery, often referred to as "range anxiety." 

A team at the University of Michigan–Shanghai Jiao Tong University Joint Institutein China is testing a sample electric vehicle (EV) that would use a similar resonant coupling system to charge. Instead of setting up refueling stations inside garages, however, the researchers suggest chargers should be installed in the road itself, so cars could juice up on the go. Because electricity in this situation would be universal, cars could abolish heavy batteries, using super capacitors to store energy. 

Super capacitors could be an ideal storage device for fast, frequent charging, as opposite to the slow, hours-long process used by many of today's plug-in vehicles.Chengbin Ma, an engineer at the institute, sees this setup as perfect for a fleet of electric buses, because they have guaranteed stops where the energy could be delivered for longer periods of time. 

Ma and colleagues have built a coffee can–size prototype vehicle that "can really move and stop for wireless charging automatically," he says. The next steps are to finish a go-kart–size one-seater EV prototype, boost the system's power, and perfect that car's on-the-move recharging. 

Super "Giant"Capacitors 

On the contrary, super capacitors still have some practicalproblems that need to be ironed out. "I don't think there's anmassiveexpectancy for them," says Brett Smith, co-director of manufacturing, engineering, and technology at the Center for Automotive Research, an Ann Arbor, Mich., nonprofit that studies the auto industry. "I think they will potentially be a lesser cost [than batteries], but they aren't robust enough. They don't do what the industry needs them to do yet." Smith says that no matter how far the new advances have taken this technology, it will be a decade before it appears in mass-market cars. 

As for placing chargers in the roadbed, that technology is "fascinating, and very expensive," Smith says. In cities the infrastructure will likely be built sooner because there's "an incredible need for traffic and pollution controlling," or at least more than in suburban and rural areas. Still, "people are complaining about the infrastructure cost of putting in a charging station," he says. Larger infrastructure enhancements will be an even tougher sell. 

Some Challenges  

In addition to the cost, the big drawback of both Ma's and WiTricity's technology is distance. The car's receiving coil still needs to be fairly close to the charger's emitting coil. WiTricity'sSchatz says an optimum distance is roughly 12 to 18 centimeters. Ma's system has similar limits: At about 50 centimeters away from the charging station, power transfer dropped to almost nil. Supporters argue that a trade-off in efficiency is worth it for the benefit of not having to use a physical plug. "It's a small loss compared to when you plug in a vehicle, but a gigantic gain in ergonomics, or ease of use," Schatz adds. 

Notwithstanding the challenges that wireless charging poses for both car makers and drivers, the notion is gaining momentum. Audi introduced a wireless-charge concept car that is half race car and half sedan, called simply the Audi Urban Concept, at the Frankfurt Motor Show in September. Toyota recently announced an contract to work together with WiTricity in developing its resonance wireless charging technology. Likewise, BMW and Siemens are joining hands to develop inductive charging stations for ultimate use by taxis. If such improvements continue at this stride, a future with cordless electric cars may not be too far down the road.