As a high school senior, Kevin Grace rebuilt the engine and the transmission of a 1994 Camaro to race on drag strips in Fayetteville and Rockingham.
The car was loud, uncomfortable and broke down frequently. It was also fast, Grace remembered with a broad grin.
The mechanical engineering student is still a gearhead, but he has been spending a lot of his time at N.C. State University with electric motors. In the past four years, he has taken apart and tested electric motors at a lab on NCSU's Centennial Campus in Raleigh. About two years ago, he said, exotic designs and materials started to show up in the lab.
The motor testing lab is part of Advanced Energy, a nonprofit that has pursued energy efficiency for two decades. NCSU engineering students can work in the lab and gain hands-on experience, if they're willing to graduate a year late. Grace, 25, liked the work so much, he now manages the lab - even though the full-time job has further delayed his graduation.
"It's not quite as exciting as driving 100 miles per hour down the racetrack," he said. Still, electric motors pack some surprises.
Working quietly and often out of sight, they have long been the workhorses of industrial automation, turning ventilation fans, moving factory conveyor belts and powering compressors. They help wash and dry laundry, cool and heat buildings and warm up food. There would be no renewable energy without electric motors on wind turbines and solar cells.
In cars, electric motors lower seats, open windows, position mirrors and help steer. One of the attractions on the International Geneva Motor Show, which opened March 4, is a Porsche 911 fitted with electric motors on the front axle to boost acceleration.
U.S., Chinese and Japanese carmakers are also looking under the hood to replace internal combustion engines. Electric motors are up to four times more efficient and emit no greenhouse gases.
But fully electric cars are far from the perfect green alternative. Coal, essential to U.S. power generation, is a fossil fuel just like oil. Energy storage and, therefore, driving range are limited by today's battery technology.
Fully electric cars are also pricey. The 2010 Tesla Roadster costs about $130,000, five times as much as the Mazda Miata, which has a cabin of comparable size. The 2011 Nissan Leaf, the first mass-produced electric car, is expected to cost more than $35,000 and is scheduled to become available later this year.
"The fully electric car is for early adopters - the techie, the greeny who has the disposable income," said John Malinowski, senior product manager at Baldor Electric, an electric motor manufacturer in Fort Smith, Ark. Malinowski is skeptical that electric motors will replace internal combustion engines in cars.
"It'll be part of the solution, but it won't be the solution," he said. "We're still going to rely on fossil fuel-powered vehicles."
Whatever the contribution of electric motors will be, there's a chance Grace will check it out first at Advanced Energy's testing lab.
Motors make up only 10 percent of Advanced Energy's annual revenue, said Kitt Butler, Grace's boss, "but in terms of impact, the work we do with motors is dramatic."
Home to the only independent lab in the U.S. that can test electric motors to federal standards, Advanced Energy plays a role in regulating new technology. Already, the lab tests whether electric motors from 1 horsepower to 200 horsepower meet minimum efficiency performance standards that took effect in the late 1990s. The standards will stiffen by the end of the year.
Size of the motors and materials used to build them are important in efficiency testing. That's why Grace and the other students in the lab take motors apart.
Grace supervises up to two engineering students. Their job includes testing engines for efficiency by mounting a motor on a test stand and hooking it up to a dynamometer, a device that provides resistance and allows for measurements of how much mechanical energy the motor produces.
A test can last less than a minute or take all day. The lab has tested as many as 10 motors simultaneously.
Generally, the heavier an electric motor, the more efficient it is, Grace said. "The more material you use, the lower the energy losses."
Most electric motors are stationary, and weight doesn't matter. New technologies are cropping up precisely because weight does matter in a moving car. New technologies make electric motors light and small enough for a car but energy efficient at the same time.
Without those new technologies, the conversion of electric energy to mechanical energy depends on a magnetic field that is set up by the power flow. A metal cylinder in the motor starts spinning and creates the mechanical energy that can move objects. More material makes a traditional electric motor more efficient, because it increases conductivity and less of the electrical energy is lost.
Thicker copper windings and a bigger steel core can produce electric motors that turn as much as 94 percent of the electric energy going in into mechanical energy coming out. Less material makes for lighter and cheaper motors, but energy efficiency also drops. The Advanced Energy lab has tested motors with less than 1 horsepower that were only 20 percent efficient, Grace said.
The rules of physics that determine energy efficiency pose a challenge to car makers: how to design an efficient electric motor that fits in a limited space and doesn't make the car too heavy or too expensive.
That's why the Advanced Energy lab started seeing electric motors with exotic designs and materials about two years ago.
"The motors look very different from what we were used to seeing," Grace said.
They come with external electronic controls or magnets made from rare earth metals with magnetic properties. Grace expects to see more of that in the future.
Testing the new technology has piqued his interest in owning a fully electric car, especially one like the Tesla Roadster. For now, though, the Roadster is out of his price range, he said. The 2005 Pontiac GTO he drives will have to do.
