Sunswift, a team of engineering students from the University of New South Wales, designed and built a car that holds the Guinness World Record for the fastest solar-assisted vehicle. In 2011, that car reached a top speed of 88 km/h (55 mph). The team hopes that its newest vehicle, eVe, will break a 20-year-old electric vehicle record for the highest average speed over a 500 km (310 mi) distance. The current record is 73 km/h (45 mph), and the Sunswift team is confident that eVe can beat that by a comfortable margin. For the record attempt on July 23, 2014, the car will only use a fully charged battery bank without help from its solar panels.
Aiming for a Practical Solar Electric Car
Speed vs. distance is one of the trade-offs with electric vehicles. Going fast increases drag, which decreases range. Many “novelty” solar cars are designed for high speeds while most commercial electric cars are optimized for long distances. The Sunswift team wants to create a practical solar electric car that can drive at sustained highway speeds while still providing a respectable range. Winning races and breaking records are nice, but Sunswift has a loftier goal: to revolutionize the car industry. Unlike the “spaceship” designs of the past, eVe is more conventional: a two-door, two passenger car that’s almost street legal.
eVe is powered by a Li-ion battery pack, an enormous bank of off-the-shelf laptop computer batteries, that drives a pair of custom designed motors with a staggering 97% efficiency. The motors were designed by the Australian national science agency, CSIRO. A solar array consisting of high efficiency flexible thin-film silicon PV cells provides up to 800 Watts of power on a sunny day. Regenerative braking replenishes the batteries, recovering up to 80% of the braking energy.
The car is capable of traveling 140 km/h (87 mph). Driving at highway speeds, eVe uses the equivalent power of a four-slice kitchen toaster. Its range is 800 km (500 mi) using the battery pack supplemented by the solar panels, and 500 km (310 mi) on battery power only.
The TeXtreme carbon fiber body keeps the car’s weight at a trim 300 kg (661 lbs). Its wheels are made of carbon fiber (front) and aluminum (rear).
The Sunswift Team
The multidisciplinary team includes students in electrical engineering, mechanical engineering, photovoltaic engineering, business, and economics. Some are PhD candidates, honours students, and co-op students at the University of New South Wales. Although their backgrounds are diverse, the students have several attributes in common: ambition, work ethic, vision, and a desire to make the world a better place.
While large automakers are working on their own electric vehicles, it’s students like these, with the freedom to innovate without the worries of quarterly profits, who will drive the future. That’s not to say that the team has carte blanche; they have corporate and academic sponsors who expect results, and their goal is to make a practical car that can be commercially produced. But corporations usually look at the bottom line above all else, which often stifles engineering creativity. Sunswift is more of a “think tank” that allows ideas to flow freely. The best of those ideas will make it to commercial vehicles, once the big automakers see their value.
Here’s a short video about the project:
Good luck, Team Sunswift!
Image and video: Sunswift/University of New South Wales
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