While searching the net I found an article at Inventorspot.com that I find very interesting and it appears to be environmental safe. Not only can this tower provide us with enough energy to produce between 15 and 20 times the total electricity the world uses today, but may also be able to reverse global warming by cooling off the Earth.

Picture by inventorspot.com
Researchers from the Technion – Israel Institute of Science are quite confident that the “Energy Tower” could be a major solution to the world’s problems. They’ve been working on the concept since 1983 with more than 150 man-years researching, designing, testing, and analyzing. The Energy Tower works on a 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.
Water would be added to the top of the tower which would cool the hot air at the top, and the heavy cooled air would sink downwards, gathering speed as it falls, and this would be used to power turbines at the tower’s base. The turbines would be connected to a generator, which produces the electricity.
The Energy Tower is considered a type of solar power and will 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 team has believes that the cost of electricity generated from the Energy Tower 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.
Professor Dan Zaslavsky, project founder, 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.
While the researchers are confident in their technology, they’re lack of financial capital to finance the project has placed their work at a stand still before taking the next steps, including building a prototype. They hope that the Energy Tower could be the key to providing cheap energy for large populations.