The tower will be over there,” Davey says, pointing to a spot a mile distant where a 1,600-foot structure will rise from the ocher-colored earth. Picture a 260-foot-diameter cylinder taller than the Sears Tower encircled by a two-mile-diameter transparent canopy at ground level. About 8 feet tall at the perimeter, where Davey has his feet planted, the solar collector will gradually slope up to a height of 50 to 60 feet at the tower’s base.

Acting as a giant greenhouse, the solar collector will superheat the air with radiation from the sun. Hot air rises, naturally, and the tower will operate as a giant vacuum. As the air is sucked into the tower, it will produce wind to power an array of turbine generators clustered around the structure.

The result: enough clean, green electricity to power some 100,000 homes without producing a particle of pollution or a wisp of planet-warming gases.