The Science Seminar Series: January 28, 2010
Solar Chimneys and Inflatable Vacuum Chambers: a new approach in renewable energy
Martech (The Center for Materials Research and Technology)
Department of Physics at Florida State University
Time: 4:00 -5:00pm
Solar chimneys, comprised of a "greenhouse", turbine, and chimney, are facilities for producing electricity from sunlight. A prototype facility operated in Spain from 1982 to 1989. For an efficient system, the chimney must be of extreme height. Thus the chimney constitutes the major construction cost of the design. A 1000-meter chimney of reinforced concrete, planned for Mildura, Australia, was estimated to cost $800 million. Despite attempts to reduce the cost, the project was finally canceled in 2009. The economics of solar chimneys remain difficult. We now suggest that the solution to these difficulties may lie in an apparently unrelated investigation, inflatable vacuum chambers. The idea dates back to 1921, possibly earlier. Some prototype "3-layer" structures were built in 1994 and instabilities were observed. In 2008, the speaker analyzed these instabilities theoretically and predicted that some "5-layer" structures would avoid these difficulties. Stable 5-layer structures have now been demonstrated. Such structures may have applications in airship design, aerospace, industry, transportation, and solar energy production. In this last potential application we find the connection with solar chimneys. Inflatable chimneys have been considered as an alternative to "brick-and-mortar" chimneys for the purpose of reducing weight, cost, and height limitations. The idealized inflatable tower is discussed. The need for compartmentalization, buoyancy, and moorings is established.