1987 GM Sunraycer

In 1987, General Motors entered the Sunraycer concept in a 1,950-mile electric-car race in Adelaide, Australia. 7,200 solar panels powered the one-seat, four-wheeled, teardrop-shaped Sunraycer. 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. When the Sunraycer won first place, it proved that a solar-powered car could be a car for the future.

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 drive wheel's left-rear wheel ran the drive motor as a generator when the driver released the accelerator, feeding energy back to the car's battery system. The Sunraycer used bicycle tire technology and braking technique, which returned energy to the batteries.

Source: Concept Car Central