Energy Tower: Power for 15 Earths?
Researchers have designed a product that its inventors claim could easily produce between 15 and 20 times the total electricity the world uses today. Not only that, it could also be used as a desalination device and may be able to reverse the effects of global warming.
Those are pretty big claims, but the researchers from the Technion - Israel Institute of Science seem confident that the "Energy Tower" could be a major solution to the world's problems. They've been working on the concept since 1983, and together have spent more than 150 man-years researching, designing, testing, and analyzing.
As project founder Professor Dan Zaslavsky explains, the Energy Tower works on the basic principle of convection: hot air rises and cold air falls. The 3,000-foot tall tower, with a diameter of 1200 feet, would take advantage of the heavy falling weight of cold air.
Any kind of water - from a sea or drainage ditch - would be added to the top of the tower. The water would cool the hot air at the top, and the heavy cooled air would sink downwards, gathering speed as it falls, and would be used to power turbines at the tower's base. The turbines would be connected to a generator, which produces electricity.
Because it relies on the sun for hot air, the Energy Tower is considered a type of solar power. Due to the original hot air required at the top, the concept would work best in hot, dry climates. The team has identified regions in about 40 countries where towers could work, including in the Middle East, Australia, North Africa, California, and Mexico.
The researchers also predict that the project would be cheap - electricity generated from this method would cost just 2.5 cents per kilowatt-hour, which is less than a third of the cost of electricity in Israel today. It's also cheaper than solar, hydro-electric, and wind power.
Zaslavsky explains that the tower design could also be used for water desalination, producing fresh water at only half the cost of existing desalination technologies. The water reserves might be used locally for a number of purposes, including desert irrigation, the production of bio-fuels such as sugar, or for fish farming - an energy-efficient form of agriculture.
Finally, the Energy Tower might help the Earth cool itself, and actually reverse global warming. "Hadley Cell Circulation" is a natural process whereby the earth cools itself, but it mostly occurs only near the equator. But by cooling air around it, often in desert regions, the Energy Tower could expand the effects of this global cooling process.
While the researchers are confident in their technology, they're still waiting for investors to finance the project before taking the next steps, including building a prototype. But in the end, they hope that the Energy Tower could be the key to providing cheap energy for large populations.