N
nexium
Guest
The first medium scale tent type solar power tower is under construction in Austrailia The chimney is to be one kilometer tall (With perhaps a dozen windturbines in holes near the bottom) so it will be very costly. I could not find details on the one square kilometer transparent tent = greenhouse, but it will be stressed conciderably by the hot air, plus rare 70 knot winds will likely total the tent. How do you clean and make repairs to the center of a one square kilometer tent without walking on the roof? <br />It is expected to produce about 100 megawatts = 100 watts per square meter which is inferior to photovoltaic panels, unless the 100 megawatts is average day and night, winter and summer. Taller than one kilometer improves the output power. <br />In my opinion, performance can be doubled by putting the chimney at the top of a steep North or NW facing cliff, and building most of the transparent tent on the side of the steep cliff. Construction cost, and cleaning cost would be higher, but land is often very cheap on the side of a steep cliff. The verticle rise in the tent is added to the chimney heigth, but more important, the sun's rays will pass through the transparent tent, closer to verticle on the average. Collecting rain water will be simplified on the side of a steep cliff. 10,000 tons of water on the roof will distroy the tent. Sandstorms will degrade the transparency. <br />A variation, that might be practical, is to build the green house over an existing road that climbs a South or SW facing mountain (in the northern hemisphere) Vehicles would have a strong tail wind on sunny afternoons reducing the ammout of fuel need to reach the top. Decending vehicles would face a head wind which would reduce break wear. Ice would be melted off the pavement on sunny afternoons even if the outside temperature was 0 degrees f. Exhaust fumes might be a problem near the top espcially near sunrise when the flow of air would stop then reverse for an hour or so. Neil