Thursday, July 3, 2008

A Giant Solar Tower for the Future

There is a new energy concept called a solar tower that can generate electricity for 200,000 homes. It does not release noxious fumes, only sun-heated air. The concept has started 20 years ago and basically it involves solar collectors to warn that air near earth’s surface and then channel it up the tall central tower. Turbines are placed at the bottom to make electricity from the updraft. EnviroMission has designed 0.62 miles-high solar tower (1 kilometer) and is looking for suitable sites in the southwestern United States.

This solar tower follows the concept of a solar chimney, a technique to provide ventilation to a home by creating a natural updraft from sun-heated air. The physics is similar to the atmospheric vortex engine, where a man-made tornado funnels warm air up into the sky.

The optimum configuration is around 800 to 1000 meter tower surrounded by 2.5 kilometers radius greenhouse canopy on the ground. It needs to be tall so it has great temperature difference between the ground and the top of the tower, which will make more powerful suction up the structure.

The solar tower is less than one tenth as efficient as solar cells in converting the sun’s energy into electricity, but its materials are much cheaper. A report showed that 200-megawatt solar tower only costs 10 cents per kilowatt-hour or approximately a third of the electricity cost from solar cells.

This news was taken from How a Giant Solar Tower Could Power the Future.

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