It may look like an Ikea reject, or something from outer space, but according to George Hansel, a freshman physics major at the Massachusetts Institute of Technology and a member of MIT's solar car team, the school's new solar car is a dream ride. He raves, "It drives beautifully. It's fun to drive and quite a spectacle."
MIT recently pulled the wraps off its latest solar car, which it plans to enter in the World Solar Challenge, a one-of-a-kind week long race held every year in the Australian outback. MIT's car shows some real power, offering speeds of up to 90 MPH. And while unlikely to be coming to a dealership in the next several decades, the school is pushing the latest electrical automotive systems and solar research, which should help to power up the next generation of hybrids and electric vehicles, as well as fueling new utility and solar electronics developments.
Technology from the World Solar Challenge indeed has a way of finding its way into real-world offerings. General Motors' Sunraycer, which it built with AeroVironment and Hughes Aircraft in 1987, smoked the competition in the race's first year. And today, the upcoming Chevy Volt, which GM is betting its future on, is the Sunraycer's direct decedent.
Jon Bereisa, a longtime member of GM's advanced-propulsion team and key engineer on the Volt project states, "The unexpected success of the Sunraycer made GM leadership take notice as to what might be technologically possible. 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."
The Sunraycer project was transitioned to the Impact concept car, which then became the EV1. Despite the EV1's 2003 demise at the hands of a GM crushing crew, the legacy lives on in the Chevy Volt.
For MIT, legacy is equally important. The 2009 competition will mark MIT's 10th car. MIT, which competed against GM in the inaugural race, is hoping to sweep the competition this year with its new design, which it has named Eleanor. The team had to do extensive redesign work due to rules changes in the competition which require the solar cars to have drivers sitting up, rather than reclining, as in past designs.
Despite this obstacle, the team's finished product has a mere 0.11 drag coefficient, compared to a drag coefficient of 0.29 for the current Toyota Prius, or 0.195 for the EV1. The car features 6 square meters (64.5 square feet) covered in 580 silicon solar cells from Sun Power. The cells generate approximately 1,200 watts -- about enough power to run a hair dryer or a couple of desktop computers.
However, in the new solar car, that's enough juice to propel the car with a passenger at speeds up to 90 MPH. The power is stored up in a 6-kilowatt-hour advanced battery pack from Genasun, which features 693 lithium-ion cells. The battery weighs about 32 kilograms (about 71 pounds) and could give the car enough juice, without solar input, to fuel a trip from Boston to New York. A hub-mounted motor drives the lone rear wheel. Two other wheels are unattached to the motor and provide balance.
Why the three wheel design, you ask? MIT's Hansel describes, "A three-wheel vehicle simplifies suspension design. It's also traditional."
The vehicles body is built from a chrome-moly steel frame. This frame is wrapped in carbon-fiber-and-Kevlar paneling to deliver a top half body weight -- with solar cells -- of a mere 40 pounds. In total, with the battery, the car weighs just under 500 pounds.
The new car will cruise through the Australian desert at a steady speed of approximately 55 MPH.
Will the drivers take it faster, up to the 90 mph maximum speed? Some serious limitations apply. The car's stiff suspension and hollow body will likely start to shake as it reaches high speeds, creating a rumble that can alarm even seasoned drivers. Describes Mr. Hansel, "Our previous car, Tesseract, was very fast. It was taken up to 85 mph before the driver got terrified. You reach the driver limit before you reach the motor limit."