The University of Arizona's Steward Observatory Mirror Lab has produced the first prototype of a solar device that inventor Roger Angel hopes will eventually produce electricity from the sun at a price rivaling the cheapest fossil fuels.

Angel's design uses mirrors — 21 segments arrayed in a parabola on a lightweight aluminum frame — to focus the sun's light on a small solar cell.

Angel, the Mirror Lab's founder and director, said the device uses only about $200 worth of glass and eventually could be mass-produced for $1,500. At that price, the device would produce energy for $1 a watt, making it as cheap as coal-burning electrical plants.