Solar Cells Info

Petoskey Grad key part of Solar Car Team Challenge

By Ryan Bentley News-Review Staff Writer
Tuesday, January 2, 2007 1:17 PM EST
source:
http://www.petoskeynews.com/articles/2007/01/02/news/local_regional/news1.txt

Momentum, a project of the University of Michigan Solar Car Team, is shown during the 2005 World Solar Challenge race in Australia. The team will enter a new solar car, Continuum, in the 2007 WSC race. (Courtesy Photo/David Hancock). In preparing for a car race across Australia this fall, Petoskey resident Garrick Williams and his teammates will try hard to make the sun shine on their entry. Given their vehicle’s power source, the U-M Solar Car Team’s need for sunshine is quite literal.

Williams, a U-M junior and the son of Keith and Karen Williams of Petoskey, is strategy director for the solar car team. He and others in the team’s strategy division will analyze the race route and likely weather patterns in hope of maximizing the solar car’s potential in this year’s World Solar Challenge. The strategy group also works closely with the team’s engineering division to ensure optimal vehicle performance.

This is Williams’ third year of involvement with the solar car team, a non-profit organization which normally includes 100 to 200 U-M students depending on the time of year. In previous years, he’s played key roles in vehicle aerodynamics and engineering for the team. “It’s neat to be able to work on a project when you get to see something through the entire design and build phases,” said Williams, a 2004 Petoskey High School graduate who’s now majoring in aerospace engineering.

The last solar car built by the Michigan team, Momentum, took first place in the 2005 North American Solar Challenge race which ran from Texas to Alberta — the fourth national championship for a U-M solar car. Momentum later placed third in the World Solar Challenge in Australia. Under prime conditions, the car could log more than 400 miles in a racing day and post average travel speeds of more than 60 miles per hour.
* For this October’s World Solar Challenge — the North American race has been delayed until 2008 because of a sponsorship cut from the U.S. Department of Energy — the U-M team is developing a vehicle called Continuum. Williams will take the fall semester off from classes and travel to Australia to assist his team in the competition.

The race will follow an 1,800-mile route from Darwin, on Australia’s northern coast, through the Outback to Adelaide on the southern coast. “The road’s pretty straight, pretty flat,” Williams said. “It’s a good place to do this.” The U-M team and its competitors will have to adapt to some changes in the rules for this year’s race. Previously, the team could cover as much of the car’s 1.8 meter-by-5 meter roof with solar cells as they wished. But now, the solar cell area will be limited to 6 square meters. Rather than having the driver lay down while operating the vehicle as in the past, the rules now require a sit-up cockpit on the car — which can add to the drag on the vehicle.

“The most important thing is knowing your vehicle’s systems really, really well,” Williams said, “so you know if it’s going to take 1,450 watts or 1,500 watts to do something.” The solar cells power an electric motor — which is set up in a “pancake” configuration connected directly to the drive wheel — capable of producing 2-5 kilowatts of energy, or a couple of horsepower.

On the U-M team, student leaders typically handle the decision-making for solar-car projects, though faculty sponsors are regularly available to provide advice. Including operations, one of the team’s solar car projects typically costs more than $2 million. The team has hundreds of sponsors, including firms in the automotive, aerospace, energy and computer fields as well as individuals.

Williams said it would be very difficult to develop a solar car suited for everyday transportation, noting that limits on solar cells’ ability to harness the sun’s energy require the vehicles to be extremely lightweight and efficient. U-M’s solar cars make use of materials normally used in aerospace applications, like carbon fiber for the chassis, he added.

Still, Williams noted that solar car development has brought some technological advances which have carried over into other products, like regenerative braking.

This system recaptures kinetic energy that would otherwise be lost to heat as the vehicle brakes and stores it for future use. It’s commonly used on today’s hybrid cars.

A more realistic application for solar energy in real-world vehicles might be the use of solar cells to supplement another electric power source, Williams added. Williams’ interest in the solar car team was first triggered when he attended a U-M recruiting event while still in high school. After he obtains his bachelor’s degree, he’d like to pursue graduate study in aerospace engineering at Michigan and eventually work in a field like aircraft or spacecraft design.

Based on his experience with the solar car team, Williams said he’ll likely pursue an aerospace job that allows for some hands-on involvement with projects rather than one that’s performed exclusively at a desk.

On the Web

The University of Michigan Solar Car Team has a Web site at www.engin.umich.edu/solarcar.

Details about the World Solar Challenge which the team will compete in this fall in Australia are available at www.wsc.org.au/2007.