Wednesday, June 9, 2010
ChargeCar - Steel City Project Puts Electric Cars in Charge of the Commute
For the team at Carnegie Mellon University, which is designing cars to get residents to work without burning a pint of gas or even wasting an electron, the future of electric cars is Pittsburgh.
Designers of the ChargeCar project say that instead of selling pricey new vehicles, they want to create a kit that makes it easy for local auto shops like Wichrowski's to convert a gasoline car to run on electricity.
"There's a bunch of machine shops running idle in Pittsburgh," said Illah Nourbakhsh, a robotics professor at CMU and a co-director of ChargeCar. "There's a ton of shops that can do that kind of thing. There's mechanical know-how in this town like no other that I've seen."
Electric-car conversions have been available for decades, whether through small, independent companies or engineers tinkering in their garages. But ChargeCar is likely the first effort to gut a gasoline car and redesign it for a single purpose: the perfect commute.
When Nourbakhsh and his colleagues looked at how Pittsburghers drive, they found that most trips are about half a dozen miles. Some zoom along the highway, while others plod past stop signs and red lights. Some drive on flat roads; others climb or coast down the city's hilly terrain.
The team reckoned a battery, combined with a gadget called a supercapacitor and controlled by software, could make most of these miles electric-powered, at a price Pittsburghers could afford.
Fiddling and fact-finding
ChargeCar's latest projects sit in a former gas station across the street from Carnegie Mellon. One is a 2006 Honda Civic: Over the next month, the team will convert it into a short-range, all-electric car. Wichrowski's mechanic will lend a hand and advise on how to make such conversions as simple as possible for other auto repairers in Pittsburgh.
The other car in the garage feels more like an airplane. From the outside, it looks like a common Scion xB; surrounding the cockpit, though, are scores of dials and gauges.
The car is an experiment.
As Nourbakhsh pulls onto the road, he points to wobbling needles and flashing numbers on the computer screen. This car is powered by a battery and a supercapacitor, and these gauges are constantly crunching numbers: how much juice is left, how much power is flowing, how hot the battery is.
He switches between using the supercapacitor and the battery. He tries each one on hills, up and down. When he slows at a red light, he can choose which device he wants to charge up.
As the professor fiddles, the team is learning important facts about the most efficient way to power an electric car.
The reason has to do with how batteries work -- and a major technical challenge for automakers.
Batteries are good at storing energy, but they degrade if they have to take on, or release, too much power too quickly. To deal with that degradation, automakers stuff cars with larger batteries, but that adds cost and weight.
Unlike batteries, supercapacitors are built for abuse: They can take a huge charge and discharge, thousands of times, without losing a step.
They're not so good at holding a charge, Nourbakhsh says, so the team decided to pair one with a battery.
Those Pittsburgh hills and traffic lights? They become energy savers.
"When you're stopping, all the current gets dumped into the capacitor, therefore saving the energy so that you can reuse it, rather than going into the battery, because putting it into the battery costs battery life," he says.
As the argument goes, if one knows exactly how someone drives, it's possible to come up with the perfect-size battery and supercapacitor for that driver.
A $10,000 price tag
Nourbakhsh and his team are at work on a computer program that can predict where a driver speeds up, hits traffic and pauses for doughnuts -- all to make a battery system that's the perfect size.
Over time, this program could even learn more about the driver, firing up the capacitor or battery at precisely the right times to get her to work.
Nourbakhsh says a regular battery may cost $8,000, but adding a $1,000 capacitor to handle the sudden charges means the battery doesn't need to be as big, so the combo may cost only $2,000.
The total price of conversion? ChargeCar is targeting a $10,000 tag.
Article Courtesy of NYTimes