Large glass coil, shaped like a tightly wound spring spiraling upwards. Air inside is heated, and thus rises, shooting out the top & sucking air in the bottom. At the top is a turbine to create electricity. For a small one I'm thinking maybe a 1m diameter tube, mabe about 3-5 meters high, but they could be any size really. Placed in the desert these suckers would get mighty hot.-- simonj, Mar 17 2004 Solar tower http://www.popsci.c...2543,396386,00.htmlGoogle also Solar Chimney Manzanares Spain [kbecker, Oct 04 2004, last modified Oct 21 2004] Solar chimneys are in the oven. See Mountainside Solar Chimneys in the list above.-- FarmerJohn, Mar 17 2004 Unless the glass coil adds a special twist this is baked (link).-- kbecker, Mar 17 2004 Nice link [kbecker]-- Mungo, Mar 17 2004 [kbecker]Yeah, the twist is that it doesn't have to be twice the height of the Empire State Building (see link)-- simonj, Mar 31 2004 random, halfbakery