Maryland-based Solar Wind Energy Inc has developed a hybrid solar-wind renewable energy technology which uses solar heat to generate wind that turns turbines.

At the center of the system, a 685 metre tall “Solar Wind Downdraft Tower”. A series of pumps carries water to the top of a tower, where it is cast across the opening as a fine mist. The mist evaporates in the hot, dry air. This cools the air, making it denser and heavier than the warmer air outside the tower. This cooled air falls through the hollow tower at speeds up to 80 kilometres per hour. When it reaches the bottom of the tower, the air is directed into wind tunnels that surround the base, turning wind turbines that are contained within the tunnels. The bulk of the water emitted at the top of the tower is captured at the bottom and recirculated through the system.