This Weird, Massive Tower May Be the Future of Energy in the U.S.

The news: The country's largest freestanding structure will soon start construction — and it's going to be a solar-wind tower. Projected to reach 2,250 feet, it will be considerably taller than other American landmarks like the 1,454-foot Empire State Building. Designed by Maryland-based Solar Wind Energy Tower Inc., the solar-wind hybrid facility just secured funding to build its first model, which is projected to stand near San Luis, Ariz., by 2018.

How it works: A network of sprayers emits a fine mist of water droplets over the upper lip of the structure; the mist subsequently evaporates, absorbing the ambient heat of the surrounding atmosphere (that's the solar component). The result is dense, cool air that rapidly flows to the bottom of the structure. The air reaches up to 50 mph by the time it hits the bottom, where it is diverted outwards through a series of tunnels radiating from the inside of the tube. Read More