Solar chimneys are an excellent idea; they combine the best parts of solar and wind power to create reliable, environmentally friendly, cheap electrical power 24 hours a day. (See the links below for details... they really are quite nifty).
My idea is a variation thereof: one downside of a Solar Chimney is that in order for it to be practical, you have to create a big (huge!) skyscraper-like tower that rises a half- mile into the air. This is all well and good if you can afford to build one, but if you can't, no problem... just lie your chimney- chute down on the ground at the base of a mountain, and have it run up the side of the mountain to the top. Hot air will rise up the chute (diagonally), powering the turbines and generators at the top of the mountain.
This way is cheaper and easier to maintain than the traditional/vertical solar chimney, since all parts of the apparatus are close to the ground. As an added bonus, you can put in a ski lift next to it, and let people ride to the top and then rollerblade/skateboard/bike/innertube/raft down the inside of the chimney tube for a fun ride.-- Jeremi, May 19 2002 Solar Chimney description http://www.wired.co...,1282,46814,00.htmlWired article about a solar chimney being built in Australia [Jeremi, May 19 2002, last modified Oct 21 2004] Another article about solar chimneys http://www.gluckman.com/SolarChimney.htmlDescription of energy and water production benefits [Jeremi, May 19 2002, last modified Oct 21 2004] National Renewable Energy Laboratory's High-Flux Solar Furnace http://www.nrel.gov/lab/pao/highflux.html"The primary concentrator reduces the beam of sunlight to a 10-centimeter diameter and concentrates it to approximately 2,500 suns at the focal point. Special optical devices can be placed at the focus to significantly increase the concentration. Reflective secondary concentrators can deliver 20,000 suns; refractive secondary concentrators can achieve 50,000 suns." [phoenix, May 19 2002, last modified Oct 21 2004] Aerial view of a solar furnace http://rhlx01.rz.fh.../pictures/tower.jpg [phoenix, May 19 2002, last modified Oct 05 2004] Wikipedia on solar updraft towers http://en.wikipedia...Solar_updraft_tower [bungston, Oct 01 2008] Monument Valley http://www.navajona.../monumentvalley.htm [bungston, Oct 01 2008] big building atriums http://www.worldarc...view&upload_id=1771 [williamsmatt, Oct 03 2008] Not a bad idea, but baked to an extent (your links).
Now, the thought of combining fun and generating power strikes me as "Rafting the Grand Coulee Outflow" or something similar. Butter my buns!-- reensure, May 19 2002 Since the technology requires a great deal of stored solar energy (in the Wired article, the greenhouse is 6 square miles), and the ideal chimney would be vertical (which would put the 'greenhouse' in the middle of the mountain), put a solar concentrator at the top to focus sunlight on a heatsink at the bottom. An array of mirrors like those found in a solar furnace could replace the greenhouse itself.-- phoenix, May 19 2002 Phoenix, just as long as you use AOL cd's for your mirrors...-- RayfordSteele, May 24 2002 Leave it to a HalfBaker to find a use for those things.-- phoenix, May 24 2002 I suppose, if you can find a cliff that runs straight up for more than a half-mile. {...the ideal chimney would be vertical...} 'Course I could be wrong about the chimney.-- phoenix, May 24 2002 Interesting. Very often you find strong updrafts at the base of a mountain or cliff to begin with. Perhaps this chimney idea's not so bad.-- hyc, Jun 15 2002 How strong would the updraught be? Maybe riding UP harnessed to a kite would be the thing.-- sandfly, Jul 21 2003 The chimney doesn't need to be vertical: all that matters is the pressure difference, which only depends on the difference in altitude between top and bottom, not the verticallity itself. A non vertical chimney would be adding resistance by making the route longer and twistier than the ideal, but the simplified construction would definitely compensate for that: have you seen the Discovery Channel programmes about constructing 500-1000m tall buildings? Nothing built using that much concrete will ever solve any environmental problems-- Belfry, Dec 01 2004 For less visual impact and because vertical chimneys are better why not make them inside the mountain? What about combining those chimneys with those big road tunnels on The Alps?
At the same time you would take up all the exhaust pollution and save power on ventilation. The chimneys would have turbines up on the top and power cables would run down the chimney to power lights on the tunnel and possibly extra power could be added to the grid.-- Pellepeloton, Oct 04 2006 I was going to post this idea, but here it is gathering dust.
Specifically I was going to suggest the Navajo build these in Monument Valley. Many of the monuments go almost straight up for many hundreds of feet. They are surrounded by flat desert. A south face of one or more monument-type formations could host the chimney with the solar field on the valley floor below.
Instead of a massive custom cement chimney (as seems to be the accepted way of doing this) one could use a series of premade corrugated steel tubes. These are desert durable and would not be hard to camoflage for aesthetics. They would be easy to maintain and replace.
I assume the generator part would be similar to a windmill. These would do better that other desert windmills in that they would be enclosed - less variation, less windblown grit, no hawks. Windmills have optimal windspeeds. If there were a series of small chimneys one could close some down at night or on cloudy days to maintain windspeed for the operating windmills.
The Navajo have other advantages aside from an optimal location. There are other powerplants near Monument Valley and so wires are in place. The Navajo live in a first world nation (the US) with nearby energy markets. They are semiautonomous and so could get things like this done faster than other US governmental entities.
Monument Valley is a sacred place, but I cannot imagine the whole thing is so sacred that all you can do is look at it and think lofty thoughts. You gotta eat too.-- bungston, Oct 01 2008 The Wikipedia article has a link to a patent for a solar chimney built up a mountainside, but I can't find a date to see if it predates this idea.-- spidermother, Oct 02 2008 i'm just aghast to see wind towers in monument valley. what an awful imposition on their natural beauty. you know, using this same idea in recent buildings, particularly in difficult climates, mlarge atriums generate similar effects and could power at least local requirements. have a look at the link. Or, if you provided for ventilation spaces thru the facades of commercial towers, substantial air movement velicites could be achieved (although not large volumes). so the atirum working as collector would work better.-- williamsmatt, Oct 03 2008 This is an old thread, but building one on one of the arid slopes of Hawaii ought to be a good place for an investor to start. Maybe you could use the heat from the volcanoes to run it a night.-- RickRantilla, Dec 08 2014 random, halfbakery