Students pray for sun this week at Shell Eco-marathon in Houston

Some Rice University students will break out their fancy new wheels this weekend, but not for Beer Bike.

The 16-strong Rice crew will compete with 138 other teams for bragging rights to the most futuristic, energy-efficient car on the road, whether powered by gas, alternative fuels, electricity or the sun. The competition will take place in downtown Houston on a 0.6-mile track laid out around Discovery Green.

The Rice Solar Car Team formed a year ago and raised more than $80,000 from various sources, including a generous gift from Rice alumni Burton ’56 and Deedee ’56 McMurtry. The project picked up steam, so to speak, in the mechanical engineering class of the team’s adviser, Andrew Dick, an assistant professor of mechanical engineering and materials science.

The result was a vehicle, RSC1, pieced together over the weekend at Ryon Lab and the Oshman Engineering Design Kitchen. It is the culmination of a year’s work that saw students choose an unusual design that breaks with the form factor of previous solar cars.

“The biggest thing that drove this design was our time constraint,” said Duncan College sophomore Allison Garza, co-president of the club with Hanszen College sophomore Joseph Song. “Having only three months to design and build a car brought some innovative approaches.”

 

Kerry Wang, a Duncan College senior, will pilot the lightweight car this week. He worked primarily on the power system and will get the thrill of experiencing the 18.8-percent efficiency the solar panels will provide.

Make that “solar panel.” The top of the car will effectively be one panel, pieced together from 174 small, square units laboriously wired together by hand and set into a 1.3-by-3.5-meter frame that will serve as a solid solar roof.

“This is our first car, and we wanted it to stand out in some way. So we went for creativity,” Garza said, noting the team did extensive research on other solar cars. “There are two heavily used designs: You have the bubble canopy, which is a flat car with a bubble on top (for the driver’s head); then you have the manta-ray design, which is sleeker and usually has a shield where the eyes peek through.

“We were thinking, ‘What can we do to maximize solar-array space while still being innovative?’ So we’re the first solar car that has the driver completely underneath the roof. We’ll lose a little bit of aerodynamics, but going 18 miles an hour doesn’t add a lot of drag.”

 

The competition requires that the vehicle weighs no more than 140 kilograms, or a little more than 300 pounds, including the carbon-fiber frame and two battery packs that total about 8 pounds. With the driver, who must weigh at least 100 pounds in accordance with the rules, the car will top 400 pounds.

“Most car bodies take a good five to six months to fabricate,” Garza said. “Kerry came up with a design with panels that fit into each other like a puzzle. So instead of taking months, we spent 20 minutes putting it together. It will probably take us a day to seal it with carbon fiber tape.”

The Eco-marathon is not a traditional race: There will be no head-to-head competition on the track around the downtown park. Competitors must maintain an average minimum speed of 15 miles per hour as they try to squeeze every last drop of energy out of their limited fuel. The teams are expected to take their cars for 10 laps around the track, a total of six miles, within 15 minutes.

If the days are cloud-free, Wang said, fuel won’t be an issue. In fact, a good solar car will hit the finish line with more power than it had at the start. “(Solar cars) are the only cars that produce energy,” Garza said. “Technically, if ours is very efficient, we could produce more than we use.”

 

Wang said the primary 5.8-pound lithium polymer battery stores enough juice to run the course twice with no input from above. “Having more capacity means the battery’s more efficient at lower power, because less is lost to heat dissipation,” he said.

Song said the team didn’t expect to qualify for such a large competition in so short a time, and he thanked the team’s sponsors and donors for making it possible. “With their support, team members of all disciplines and backgrounds have been able to experiment in a unique setting,” he said. “All of this trial and error has led to the creation of our first car.”

The club’s real draw, Garza said, was the chance to contribute to what she sees as the future of transportation, however impractical current solar cars may be.

“Besides getting to do a really cool engineering project, I also feel it helps the environment, in some sense,” she said. “Maybe one day in the next 10, 20 years we might come up with a technology that will revolutionize the way cars are built. That’s exciting to me.”

Dick sees another benefit. “One of the original ideas for the solar vehicle was to also have it serve as a platform for new technologies developed at Rice,” he said. “We’d like to take advantage of that for the vehicle, but also to showcase researchers. That’s one idea for the future.”