This is more on the vortex energy idea. A prototype small solar tower operated in Manzanares, Spain. This concept is solar collectors generate the heat that starts a vortex "tornado" inside the tower that turns the electricity generating turbines. The advantages are having a never ending source of energy, no mining, processing and hauling nuclear fuel or coal, no need to de commission towers in just 40 years like nuclear power plants, no danger in polluting the environment from operation. M

Giant solar tower could power the future

Project could generate enough electricity for 200,000 homes

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Giant solar tower could power the future - LiveScience - MSNBC.com

updated 10:35 a.m. PT, Wed., July. 2, 2008

A new energy concept called a solar tower could generate enough electricity for 200,000 homes. Looking like a giant smokestack, it would release no noxious fumes — just sun-heated air.

Demonstrated more than 20 years ago, the basic design calls for solar collectors to warm the air near Earth's surface and then channel it up the tall central tower. Turbines placed at the bottom make electricity from the updraft.

"It's a combination chimney, windmill, greenhouse," said Kim Forté of EnviroMission Limited in South Melbourne, Australia.

EnviroMission has designed a kilometer-high solar tower (0.62 miles) and is now looking at possible sites in the southwestern United States.

Solar-stack

The solar tower is an updated version of a solar chimney — a centuries-old technique for providing ventilation to a home by creating a natural updraft from sun-heated air.

The physics is also similar to the atmospheric vortex engine, where a man-made tornado funnels warm air up into the sky. Even though this vortex could extend higher than a solid structure, only the solar tower has been demonstrated to work, Forté said.

Up, up in the sky
The company's plan is not only to build stronger, but also taller. This allows for a greater temperature difference between the ground and the top of the tower, and this difference makes for more powerful suction up the chimney structure.

The optimum configuration is an 800- to 1,000-meter tower (twice the height of the Empire State Building) surrounded by a greenhouse canopy 1.5 miles (2.5 kilometers) in radius on the ground.

"It is a sizeable footprint [on the land], but with the rising cost of carbon fuels, it's becoming more commercial," Forté said.

On a sunny day, the air at the top of the tower would be 70 degrees Fahrenheit (20 degrees Celsius), whereas the air in the greenhouse could reach 160 degrees Fahrenheit (70 degrees Celsius). As this hot air escapes up the tower at 34 mph (15 meters per second), it spins 32 turbines that generate up to 200 megawatts of electricity.