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Utah to deploy electric bus that needs no plug

A Utah State University spinoff company thinks it has found a way to cut the cord and recharge electric transit buses through a wireless boost from charging pads embedded in concrete, in hopes of revolutionizing road travel.
Graphic of wireless power transfer
Demonstration by Energy Dynamics Laboratory, of Utah State University Research Foundation, a WAVE partner, of how wireless power transfer would work on a car.Energy Dynamics Laboratory / Utah State University
/ Source: The Associated Press

A Utah State University spinoff company thinks it has found a way to cut the cord and recharge electric transit buses through a wireless boost from charging pads embedded in concrete, in hopes of revolutionizing road travel.

The concept has been around for a century, and for years, wireless power transfer has been used in some consumer devices and in factory power strips. Now the technology has been engineered for vehicles. With a seamless charging system, transit buses could use radically smaller batteries for a big weight savings, solving other problems that have held back the electrification of vehicles.

"We solve the battery problem," said Wesley Smith, chief executive of WAVE, which stands for Wireless Advanced Vehicle Electrification. "All of the components that make this application viable for vehicles are coming together."

His fledgling company is the beneficiary of a $2.7 million federal grant that will supply one shuttle bus and cover engineering costs for an electrified bus route on the University of Utah campus in Salt Lake City. The Utah Transit Authority obtained the grant.

The technology was perfected by Utah State's Energy Dynamics Laboratory, which stands to share in any profits. WAVE hopes the Utah demonstration will spur sales to transit agencies around the country.

The company is also working on a demonstration project for Park City's diesel-powered shuttle system.

U.S. Transportation Secretary Ray LaHood announced the grant Nov. 17 for the University of Utah's project. Smith believes he can persuade the school to convert all of its diesel- and natural gas-powered shuttle buses if the first magnetic-induction bus proves reliable.

A year from now when the project is ready to go, the University of Utah could be the first in the nation to use a transit bus that tops off its battery charge by merely sitting for a few minutes over a magnetic conductor embedded in pavement.

The Energy Dynamics Laboratory has improved on the energy transfer of magnetic induction so much that electricity can jump a 10-inch air gap — from charging pad to bus — with a loss of only 2 percent of the energy, Smith said.

Because the shuttle bus will travel a short circuit, it can use a small battery that can be recharged frequently, which takes two to four minutes, he said.

That translates into an 85 percent weight savings over conventional battery packs for plug-in vehicles, which have to draw on their power for an entire day before recharging becomes practical, Smith said.

The secret is frequent and quick charging, a concept that could be extended to a futuristic highway where all vehicles become electric and draw energy continuously from the pavement without having to stop for a recharge.

Getting there would take an enormous investment in new infrastructure, however — highways would have to be ripped up for installation of wireless power strips, Utah Transit Authority spokesman Gerry Carpenter said.

For that reason, the UTA doesn't see magnetic-induction working for transit buses on a larger scale anytime soon. And the technology isn't affordable enough for a trolley line the UTA plans to start building next year in the Salt Lake City neighborhood of Sugarhouse. That trolley will use conventional overhead wires for power, Carpenter said.

The charging pad WAVE plans to install at the University of Utah is no larger than a dinner plate, with a matching receiver plate on the underbelly of the bus.

The pad will be embedded in pavement at the light-rail station at the school where the bus will idle several minutes before picking up rail passengers for a quick shuttle through the heart of the campus.

The charging pad will be unaffected by snow or rain and is safe enough for someone to touch or walk on without getting zapped, Smith said.

Still, one of the remaining engineering problems is calibrating the charging pad correctly so it wouldn't affect a person with a heart pacemaker who happens to fall chest-first on top of it, Smith said. Very low voltages can alter a pacemaker's rhythms.

Utah officials hope the new technology turns into a commercial success.

"It is always a proud moment when university technology is recognized for its potential in the marketplace," said Stan Albrecht, president of Utah State University.