Wikipedia
The Sunraycer was a solar powered race car designed to compete in the world's first race featuring solar-powered cars. This race is now called the World Solar Challenge. The Sunraycer, a joint collaboration between General Motors, AeroVironment, and Hughes Aircraft, won the first race in 1987 by a huge margin. The teams lead driver was Australian John Harvey, a driver with (at the time) nearly 40 years experience racing speedcars ( Speedway), open wheelers, sports cars and touring cars. Harvey was involved with the testing and development of the Sunraycer at the General Motors Proving Ground, Arizona.
The Sunraycer project started with a request from GM's Australian division to GM Headquarters to participate in the upcoming Solar Challenge. This race, to be held in Australia in late 1987 would feature purely solar powered cars. Roger Smith, the CEO of GM, was immediately interested in the idea and he agreed to fund a study to see if a solar powered car could be built within 10 months. Smith hired AeroVironment to do the study. A month later, AeroVironment engineers concluded that a highly competitive car could be built within the time available. AeroVironment, led by their famous owner/engineer Paul MacCready was given the contract to build what would be called the Sunraycer.
During the conceptual process, the constant goal was to create a very low-weight and ultra-low wind resistance vehicle. With this in mind, AeroVironment produced a design (resembling a futuristic streamlined cockroach) that proved to be very lightweight (only ) and created a very low drag coefficient (c: 0.125). Sunraycer was fast and capable of a top speed of .
A total of 8800 solar cells were manufactured and installed by a team, from Hughes Aircraft, which had a great deal of experience with photovoltaic cells used in the many communications satellites that they designed and built. At high noon, the car would generate about 1500 watts of power.
The engine was created for the Sunraycer by GM using a brand new electric motor based on Magnequench permanent magnets. This kind of rare-earth magnets were in 1983 invented independently by the GM physics department and Sumitomo Special Metals. Both companies discovered and eventually were using/commercializing two significantly different manufacturing processes for this material class. The GM concept was commercialized under the Magnequench brand. That new motor was lightweight and efficient motor; GM stated its motor efficiency was around 92%. In 2011 its constructor won the IEEE Nikola Tesla Award.
Aside from the driver, the single heaviest element in the car was the Hughes battery pack that utilized silver-oxide batteries. These batteries were included to provide extra power when passing trucks, to smooth out the performance of the vehicle, and because the race rules mandated driving only between the hours of 8 AM to 5 PM, but the cars were allowed to charge their batteries from sunlight even when they were not on the road. (So, the battery allowed driving during allowed hours even when the weather was overcast.)
The frame of the car weighed just 14 pounds. AeroVironment engineers made use of Kevlar for the shell of the car. The Sunraycer was tested through the spring and summer of 1987, and it had no problems. During the testing period, the team had the time to set a new world speed record with the Sunraycer, achieving a speed of from solar power alone (breaking the old record by 10 mph).