Imagine a world in which a vehicle is refueled with the ease of E-ZPass: hands free, no credit card swiping, a completely background transaction.

Andy Daga, chief executive of Momentum Dynamics Corp., has built his Malvern, Pa., company around the concept of a wireless recharging system for electric vehicles in which energy is transferred from a panel embedded in the pavement, through the air, then into an EV.

Daga said the system is similar to a wireless recharger for a cellphone, though it transfers energy in far bigger volumes.

"This is really revolutionary, to automatically operate fast-charging systems that nobody needs to interact with," said Daga. "Your vehicle will automatically charge itself without thinking about it."

Until the company can develop a network of wireless chargers embedded into parking lots and roadways, Momentum Dynamics is focused on serving a market of large electric vehicles such as municipal buses that follow a circuit and return repeatedly to the same location.

"We make incremental charges along the way," said Daga. "That bus can then have unlimited range."

Not everyone shares Daga's conviction that wireless charging is the technology that will give EVs the market breakthrough the industry desires. EVs are about 1 percent of the U.S. vehicle market.

"Wireless charging isn't as efficient as battery swapping or a corded solution," said Scott Shepard, a senior energy research analyst with Navigant Research.

However, for people who need a boost along the way, it could be an option.

At Link Transit municipal bus terminal in Wenatchee, Wash., a Momentum system provides five-minute top-up charges to an electric bus before it departs on its next scheduled circuit. The Regional Transit Authority in Howard County, Md., in suburban Baltimore, also has a system.

Without the en route wireless charges, Wenatchee's electric bus would run out of juice before the end of the day, said Todd Daniel, the agency's maintenance and technology manager. Thwe wireless charger means the bus can stay in service for a full 16-hour day.