On August 31, 1955, William G. Cobb of the General Motors Corp. (GM) demonstrates his 15-inch-long “Sunmobile,” the world’s first solar-powered automobile, at the General Motors Powerama auto show held in Chicago, Illinois.
Cobb’s Sunmobile introduced, however briefly, the field of photovoltaics–the process by which the sun’s rays are converted into electricity when exposed to certain surfaces–into the gasoline-drenched automotive industry. When sunlight hit 12 photoelectric cells made of selenium (a nonmetal substance with conducting properties) built into the Sunmobile, an electric current was produced that in turn powered a tiny motor. The motor turned the vehicle’s driveshaft, which was connected to its rear axle by a pulley. Visitors to the month-long, $7 million Powerama marveled at some 250 free exhibits spread over 1 million square feet of space on the shores of Lake Michigan. In addition to Cobb’s futuristic mini-automobile, Powerama visitors were treated to an impressive display of GM’s diesel-fueled empire, from oil wells and cotton gins to submarines and other military equipment.
Today, more than a half-century after Cobb debuted the Sunmobile, a mass-produced solar car has yet to hit the market anywhere in the world. Solar-car competitions are held worldwide, however, in which design teams pit their sun-powered creations (also known as photovoltaic or PV cars) against each other in road races such as the 2008 North American Solar Challenge, a 2,400-mile drive from Dallas, Texas, to Calgary, Alberta, Canada.