The GM Runraycer was an experimental vehicles made in 1987.
IGeneral Motors entered the Sunraycer concept in a 1,950-mile electric-car race in Adelaide, Australia. When the Sunraycer won in first place, it proved that a solar-powered car could be a car for the future.
The one-seat, four-wheeled, teardrop-shaped Sunraycer was powered by 7,200 solar panels. General Motors entered the car in the race to develop and demonstrate technology in lightweight structures and materials, low-speed aerodynamics, high-efficiency batteries, lightweight engines, and solar cells.
Though nearly twenty feet long, the car, with aluminum tube and plastic skin framing, weighed only 390 pounds. It was propelled by a single direct-current engine weighing eight pounds.
The Sunraycer used bicycle tire technology and a technique for braking which returned energy back to the batteries. The left-rear wheel - the drive wheel - ran the drive motor as a generator when the driver released the accelerator, feeding energy back to the car's battery system.