MIT Unveils 90 MPH Solar Race Car

MIT's latest solar race car might look like a funky Ikea table with a hump, but don't laugh. It'll do 90 mph and is packed with technology that may end up in the hybrids and EVs the rest of us will soon be driving.

The university's Solar Electric Vehicle Team, the oldest such team in the country, unveiled the $243,000 carbon-fiber racer dubbed Eleanor on Friday and is shaking the car down to prepare for its inaugural race later this year.

"It drives beautifully," said George Hansel, a freshman physics major at the Massachusetts Institute of Technology and a member of the team. "It's fun to drive and quite a spectacle."

Eleanor is slated to compete in the tenth World Solar Challenge, a seven-day race across nearly 2,000 miles of Australian outback.

Vehicles competing in the endurance race may look hopelessly impractical, but the competition is a test bed for batteries, motor technology and power-management systems that may eventually appear in hybrids and electric vehicles. Like Formula 1 and other big-budget motor sports, the solar challenge helps develop some of the vehicles we see in showrooms.



"It pushes the technology from the books to real life," said Spencer Quong, senior vehicles analyst with the Union of Concerned Scientists. "It opens the industry's eyes to how to build a more efficient vehicle."

Like, say, the Chevrolet Volt range-extended EV, the forthcoming electric car that General Motors has all but bet its future on.



The Volt is a direct descendant of the Sunraycer solar car General Motors developed with AeroVironment and Hughes Aircraft in 1987. Sunraycer smoked the rest of the grid in the inaugural World Solar Challenge, raising quite a few eyebrows back in Detroit.

"The unexpected success of the Sunraycer made GM leadership take notice as to what might be technologically possible," said Jon Bereisa, a longtime member of GM's advanced-propulsion team who is now working on the Volt. "It finished the race across Australia a full three days ahead of its competitors, powered by an electric motor that consumed as much power as a hair dryer, at speeds up to 45 mph, and the solar-powered batteries were still fully charged."

GM execs were impressed enough to greenlight the Impact concept car, which became the groundbreaking EV1 electric car. GM famously killed the EV1 in 2003, but the car lives on in the Volt, which is slated for production by the end of next year.

"One might say sunlight and solar started a bright idea after all," Bereisa said.


MIT's solar team entered its first race in 1987, and Eleanor is its 10th car. A change in the rules requiring drivers to sit upright instead of stretching out makes Eleanor taller than earlier cars but no less aerodynamic. The team spent six months designing the body before fine-tuning it in Ford Motor Company's wind tunnel. The result is a super-slippery drag coefficient of 0.11, making Eleanor more aerodynamic than a Toyota Prius, the EV1 or even the super-slick Aptera 2e electric car.

Aerodynamic efficiency is paramount to extending battery range, especially when you're dealing with batteries charged by the sun. Eleanor features 580 silicon solar cells manufactured by Sun Power.

They cover six square meters (about 64.5 square feet) and generate 1,200 watts — enough to run a hair dryer or a pair of desktop computers. The juice is stored in a 6-kilowatt-hour Genasun battery pack comprising 693 lithium-ion cells. The battery weighs 32 kilograms (about 71 pounds) and provides sufficient range — even without sunlight — to get the car from Boston to New York. Propulsion comes from a 10-horsepower hub-mounted motor driving the lone rear wheel.

"A three-wheel vehicle simplifies suspension design," Hansel said. "It's also traditional."

Everything is packaged in a chrome-moly steel frame wrapped in carbon-fiber-and-Kevlar bodywork. The car weighs just under 500 pounds, and the top half of the body weighs just 40 pounds — with the solar cells.

Racing across Australia will require more than getting in, buckling up and mashing the accelerator pedal. There's a tremendous amount of strategy involved, with careful consideration of everything from road conditions and terrain to the weather forecast. Maximizing efficiency and range is the name of the game.

"You've got to go 2,000 miles, you've got specific hours you can drive and you've got a fixed amount of energy in the battery," said Spencer Quong, the Union of Concerned Scientists expert who is a member of the Team New England solar race team.

That's not to say Eleanor can't get up and go. She'll run all day at 55 mph, and although no one's put the pedal to the metal yet, Hansel says the math suggests Eleanor is capable of 90 mph.

Not that anyone will push her that hard. With their stiff suspensions and hollow bodies, solar race cars tend to resonate like drums at high speeds, creating a rumble that can be disconcerting in the driver's seat.

"Our previous car, Tesseract, was very fast. It was taken up to 85 mph before the driver got terrified," he said. "You reach the driver limit before you reach the motor limit."