Australian company EnviroMission ^[1] is in the land acquisition and site-specific engineering phase ahead of building a massive solar tower in the Arizona desert—and “massive” may even be an understatement: the 2,625-foot tower will be twice the height of the Empire State Building upon completion, automatically making it one of the tallest buildings in the world.

That tremendous height is not merely for bragging rights. Thanks to the temperature differential between the ground and the air thousands of feet above it, solar towers actually become more effective the taller they are. It works thusly: Solar towers make use of a massive greenhouse area of solar tiles at ground level (in Arizona, the ground can reach temperatures of 104° F); the heated air, which naturally wants to rise, is funneled through a centrally located tower, with turbines at the tower’s base powered by the passage of heated air. However, the cooler the air at the top of the tower—ambient temperature drops by about 33 degrees for every 328 feet above the ground—the more powerfully the tower sucks up the hot air at the bottom, which translates to more power through the turbines. Also, because the tower works on temperature differential rather than absolute temperature, the design is suited to a number of different climates.

The gigantic, zero-emission solar tower will have 200-megawatt power generation capacity, with enough for 150,000 U.S. homes per year. Once built, the tower is expected to produce energy with almost no maintenance requirements for more than 80 years.

Read more at Gizmag ^[2].