Humongous air-driven energy tower planned for U.S.-Mexico border

Plans are underway to build a massive new type of power generator in the southwestern corner of Arizona. Using evaporative cooling to create wind, it will deliver enough power for a medium to large-sized city with practically no effect on the environment.

The concept behind the so-called "downdraft energy tower" has been understood for decades, but until now nobody has taken on such a massive project. The principles are really quite simple, and are based on the fact that denser cool air will always sink while hot air rises.

At the top of the tower a fine mist of water is sprayed across the air to cool it, causing it to sink down the tower at a rapid speed. At the bottom of the tower the air escapes by passing through hundreds of wind turbines, generating massive amounts of electrical power as blows outwards.

The process is about 45% efficient, with losses resulting from the need to pump the cooling water to the top of the tower along with other thermal losses. Still, one tower can produce enough electricity for a city of one million, at a cost that's much lower than almost any other power source.

This all sounds great, but the one thing that all of the reports seem to be downplaying is the truly massive scale of the tower. 1,200 meters translates to almost 4,000 feet, or nearly half again taller than the tallest structure on Earth today, the gigantic Burj Khalifa. Comparing it to buildings closer to home, the tower will be more than twice as tall as Chicago's Willis Tower which is currently the tallest building in the western hemisphere. Clearly, constructing this thing is not going to be a minor undertaking.

Clean Wind Energy Inc., the company that wants to erect the tower, has already leased the land near San Luis, Arizona, and just received zoning approval for the project. Let's hope the zoning board didn't pull a Spinal Tap-style gaffe by confusing meters with feet, otherwise they're going to get a shock when this thing starts going up.

The video gives a basic overview of how this technology works. For some reason it kind of has the look and feel of a 1970s school science class film, but was actually made fairly recently by the Israeli scientists who have been developing the process.

Clean Wind Energy, via Treehugger

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