Saw a bit on this on the History Channel last night. Who knows? Might be the item. I imagine pilots wouldn't want to fly over it, though.

http://www.youtube.com/watch?v=cLIiGTZxH5s

http://www.youtube.com/watch?v=llHhaL6Hf7E&feature=related

http://www.math.purdue.edu/~lucier/The_Solar_Chimney.pdf

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1986 300SDL, 362K
1984 300D, 138K

Solar chimney, very simple and effective.

I saw the same program. You could actually see the reflected light from the mirrors as beams from the ground. Intense.

Hmm, that's the first time I've seen that. Sure is an interesting concept and seems simple enough.

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1980 300TD-China Blue/Blue MBTex-2nd Owner, 107K (Alt Blau) OBK #15
'06 Chevy Tahoe Z71 (for the wife & 4 kids, current mule) '03 Honda Odyssey (son #1's ride, reluctantly) '99 GMC Suburban (255K+ miles, semi-retired mule) 21' SeaRay Seville (summer escape pod)

I don't have the correct figures, I'm sure, but based on what I think I know: (they said the collecting circle at Enviromission's complex spanned 3 miles).

I believe they claimed 200 mgW. This would yield a generating capacity of 11 watts per sq. meter. Supposedly, the parabolic mirror plants yield 120 to 170 watts per sq. meter. But you have to double the area, for maintenance access, so it's then 60 to 85. I'm sure these numbers are barely ball park, if that.

The solar chimney would appear to be much cheaper to build and operate than the mirror plants, and more certain to generate power year round, as temperature differential is what makes it work.

I'm wondering how small a complex like that would be practicle. People are going to object to gynormous chimneys, a la the one in Aus. But maybe in the heart of South Dakota or Nevada, it would be a welcome attraction.

I once hung out by Lake Sevier, a mostly dry salt lake bed in S. Utah for a few hours, and there are some flat, desolate reaches round there. I could see a unit like this on the edge of the lake, taking in the water that feeds the lake annually, distilling it, and growing crops around the edges of the greenhouse, at least in the areas where the air flow has not yet picked up. I can only imagine it gets swift near the center.

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1986 300SDL, 362K
1984 300D, 138K

I remember reading about this sort of device in Popular Science, back in the late 70's/early 80's. Nice to see some one has put some more thought into it.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

It is elegantly simple. I like it.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Simple yes, but doubtful it is buildable as shown in the video.

Would prob need to be structural steel with a light weight aluminum panel skin with cross members and k braces on the interior every 12' rather than the guy wires they show every 1000' or so.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I was thinking the height might be a bit ambitious. It would be interesting to know how much of a factor the height of the chimney is. It's not going to make the air under the collector any hotter to any significant degree -- perhaps the higher it rises, the more velocity it gets -- and the air would be cooler the higher up you go which would increase the lift, I imagine.

Also, you'd want to get the hot air up enough so that it wouldn't influence the temp of the incoming air too much. Could be farfetched, but I wonder if a number of these operating in an area could influence weather in any way?

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1986 300SDL, 362K
1984 300D, 138K

The heat from the sun is still there, solar chimney or none. The chimney will by necessity remove heat, transferring it off the premises via electric power.

I think you've got two factors generating your wind speed. Temperature differential and pressure differential. When chimneys are shorter the pressure differential between the intake and the output is almost inconsequential, but the taller they are the more significant they become.

http://www.usatoday.com/weather/wbarocx.htm

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-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

The air under the glass will be heated a lot more than you imagine.

In my passive solar homes with sunspace collection, I have measured over 100 degree F air on a sunny february day with zero outside temp.

I was impressed.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Of course -- why didn't I think of that. 3281 feet elevation difference would count for something, for certain.

Doing the math, eviromission claims a wind speed of 49 feet/second -- about 30 mph at the fans. 32 turbines altogether, it's essentially a mostly guaranteed 30 mph wind for a large part of the day.

Here's another good link:

http://en.wikipedia.org/wiki/Solar_updraft_tower

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1986 300SDL, 362K
1984 300D, 138K

I don't think it'll work that way. The heat transfers itself off premises and electricity is the result. The air under the canopy would be around 150 at an outside temp of 86. At the top of the tower, the air would have to be a bit cooler.

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1986 300SDL, 362K
1984 300D, 138K