As soon as automakers hear about tougher fuel economy rules, they start concocting new ways to cut vehicle weight.
That time-honored tactic becomes even more important in electric vehicles, where cutting weight reduces the need for expensive battery power. That's why BMW is getting into the carbon-fiber business.
On July 7, BMW broke ground on a carbon fiber plant in Moses Lake, Washington, in the United States. Joerg Pohlman, BMW's top official at the plant, says BMW believes it has solved the dilemma of carbon fiber: superb lightweight material but way too expensive for most vehicles.
BMW and its partner, SGL Automotive Carbon Fibers, will make industrial-grade carbon fiber, which costs about $10 per pound (about 8 euros for almost half a kilogram), rather than the high-end, even more expensive stuff in Formula One racecars, which costs about $25 per pound. But using industrial-grade fiber, plus careful reuse of scrap and cheap hydroelectric power, will cut the cost drastically, Pohlman says.
"We worked on that intensely with SGL," Pohlman says. "We're talking about slashing it, bringing it down to one-quarter of the cost [of high-end carbon fiber]."
Initially, at least, the project's carbon fiber will go solely to BMW's small Megacity Vehicle EV due in 2013. Keeping vehicle weight -- and battery requirements -- down was critical to the business case, he says. A 10 percent weight reduction allows for at least a 10 percent reduction in battery size, Pohlman adds.
"That was absolutely crucial for the battery-electric vehicle," he says. "The lighter the vehicle, the greater the amount of range with the same battery pack."
Pohlman predicts broader use of low-cost carbon fiber: "This is really just a first step that we're taking with the Megacity Vehicle."