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Step 1: Install solar power plant on a hill near a city. This plant should be the solar collector type, but with solar reflectors aimed at the city, rather than the sun.
Step 2: Give everyone in this city a lump of a material that hardens. Could be as cheap as clay. Include instructions on how
to stick a piece of this lump to their roof together with a CD aimed to reflect light at the hill (doesn't matter what time this is done - on average many CD's will be aimed at the hill).
Soon you'll have a shining silver city with abundant power.
(thanks, [Rayford] for inspiration)
Helios helper
http://www.halfbake...dea/Helios_20helper Similar idea to power the world with AOL CD's. Looks the same to me. [Laughs Last, Oct 04 2004, last modified Oct 05 2004]
MSCAoD
http://www.halfbake...rray_20(of_20Doom!) The next level [Worldgineer, Oct 04 2004, last modified Oct 05 2004]
A forum post
http://www.ecolivin...le/messages/57.html Someone has tried this in New Mexico [ooys, Oct 04 2004, last modified Oct 05 2004]
Physics Problem
http://zebu.uoregon...strok/sunstrok.html Solar reflector physics problem, with formulae. [sehrgut, Oct 25 2005]
Helios Helper
Helios_20helper Helios Helper: a home solar concentrator using AOL CDS. [sehrgut, Oct 25 2005]
[link]
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I note that AOL's latest ads spoof themselves, with people making artwork out of AOL CDs, etc. |
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I like the idea. I saw a guy make a Tesla turbine using about a dozen of them. I tried it and it worked. Maybe there's something there :)
Maybe I'll try a hot water heater out of them. There are also lots of other sources for free cd's. I know my father in law gets about 20 a year from GM Parts updates. Good luck! |
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Would you not need to steer the CDs to account for the moving sun? |
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Every hour or so you have to go up on the roof and readjust your CD. |
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[krop] That would be ideal, and much more efficient. But it would require little motors and a few other components that are more expensive than clay. With this idea we fight inefficiency with a very large supply of material. |
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Just have each city block set thier cds up at diffrent defined times. That way the concept stays cheap but there are always some cds hitting their mark. |
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Yes, and housing near the plant have low rent and come with sunglasses. |
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Wow. That would hurt your eyes. |
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Since AOL has strategically flooded every home with more then one of their precious CDs, everyone could place roughly 12 CDs each perfectly calibrated for a different hour of the day. Thus, eliminating the need for adjustment. |
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Sorry to go on and on but it's fun. Just trying to contribute. to the meham. I'm sure some of yo uhave tried this but here goes. |
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If you put two of them back to back and use a 5" diameter 1/8" cross section oring between them then put a bolt or whatever in the middle pulling the two centers together you would have a quasi spherical surface. More conic than anything. Try this sometime. You'll be amazed at the heat you can get. |
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I know of coarse this would require near perfect tracking because you would have a smaller beam but hey if a bug flew in front of it near its focal point... well...zap...smoke...poof : ) |
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I made a whole bunch of these using about 100 surplus lids from containers that were about 4" in diam. and 1/2 inch deep. Just drilled a hole in the center, set the cd on the open end, put a bolt and fender washer through the cd then the lid and a nut on the back. Adjustable focus too. Not a mirror of coarse, I'm an astronomy equipment manufacturer. I put a bunch of these on a board all focused within about a 4-5 inch area and fried my fence rather quickly. Have fun. |
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Now I know what we can do with all of the out of date satallite dishes in mobil home parks and out on farms. No insults intended. Just glue cd's to them and poof there's your sterling engine reflector. |
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Also surplus perfectly mirrored hard drive discs work great too. |
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[claf] Thanks for the input, but it looks like your comment would be much more helpful in [Laugh]'s link. Having any kind of curve in the MACSCA implementation would not do at all - you'd disperse the light far before it reaches the power plant. |
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It is nice to know that CDs reflect infrared light well (//You'll be amazed at the heat you can get.//), as I was hopeful but not sure CDs are as reflective in that specrum as they are in the visible spectrum. |
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I'm happy just sticking with coasters... but my cups do that for me :( |
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You could maybe arrange the mirror CDs so that for most of the day they point in different directions, then at a particular time of day (maybe only one day a year) they all focus at a particular point. Like Stonehenge, except using CDs instead of megaliths. And with focussing. |
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I think the issue with doing this on earth would be the distance spread vs. atmospheric losses in the power transmission, limiting the total output. The amount of land area needed to have a few CD's on everyone's roof is likely to be too large a distance in the outlier houses for there to be any more gain. |
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Interesting about AOL CD's and IR rays. Makes me want to revisit my AOL roofing shingle idea. Might have a melt problem, though. |
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I love the irony of using Stonehenge as the ultimate earth-based alien ship destructo-laser. We and our ancestors will have come full-circle. |
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For some inexplicable reason this idea is doing much better in the voting department than my own.
Things that make you go Mmmmhhh. |
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Yours was different. This idea's doing much better than my Rainforest Fruit, if that helps you feel better. |
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It takes some of the edge off. (+) btw |
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(sorry for churning, but I realized I've never linked to the MSCAoD (link)) |
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Don't apologize for a churn - there's a lot of good ideas some folks've never seen, and this brings 'em up faster. |
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I seem to remember an Asimov's novel where a pack of soccer fans fry the referee using a lot of silvered
booklets covers (not CD's of coarse). |
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- you mean the short story "Case of
sunstroke" by Arthur C Clarke. |
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You are Korrect. Thanks, Hippo. |
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Baked to some extent, or it sounds like
it, but I can't find any more than the
reference in a forum to my [link]. |
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[fin] That's wonderfully evil. See my MSCAoD idea (link) for an even closer comparison. |
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[oo] Cool, I hope Ray continued his/er project. |
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We have this gigantic field of mirrors at the Almeria desert powering an experimental smelting facility, and when at standby they focus on the air in front of the tower, and the air just....burns, that's the word for it.
I imagine it's the dust in suspension getting hyper-hot.
But you see this x-tremly bright point hanging in there and it takes a little to realize what it is. |
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I tried this on a backyard scale... cds aren't anywhere near as reflective as mirrors, you're losing a lot of efficiency. Of course if the scale is large enough it doesn't matter as the cds are free + |
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I drew a neat design for a table lamp with a central column of stacked CDs, and a T5 fl. tube through the center hole. I like this solar concentrator idea better. |
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[elhigh] Your lamp intrigues me. T-5's are considered too bright for direct illumination, and CDs might spread out the light and therefore the intensity. Of course, the shape of the CD may act as a lens and, well, blind you. |
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[World], the focal length of any optic effect the CD might have would be measured in millimeters, and not many of them. The light from the tube shouldn't be too bad. BTW, the base of this thing would weigh several kilos; that much solid plastic for the base gets pretty heavy. |
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[BigGibbyG], your idea is getting closer
to what is necessary, but the main
problem with this idea is that each
household is contributing, at any given
moment, the energy collected by a
single CD, 120mm diameter (here
discounting the center and rim of the
CD, which are non-reflective), giving a
reflective area of about 0.0113 m^2.
This results (see "Physics Problem" link)
in 11 watts of power being reflected
from each CD. So, assuming an
impossible, 100%-efficient solar plant,
each citizen is contributing 11W of
electricity. Which means, of course, that
each citizen can run a small fluorescent
bulb (provided they don't try to turn
them on at the same time). |
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For this to work, each citizen would
have to have nine reflectors trained on
the station for each 100 watts of power
they use, at any given moment. Also,
even those closest to the station would
need on the order of one reflector per
ten or fifteen minutes per 11W, and
those farther away would need one
reflector per five minutes to even one
minute. |
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If you went with the tracking system, it
might actually be more financially
feasible, since you would not need the
everlasting multiplicity of reflectors, but
merely one reflector per 11W. Well,
considering real-world efficiencies, let's
say in the light-to-steam-to-turbine-
to-generator energy transfers, we're
able to capture 2.5W per 11 (a best-
case scenario), we'll need 25 reflectors
per 100W used. |
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Another loss is, as [eulachon] pointed
out, the diffraction resident in the CD
(since it's not a smooth reflector, but
rather a reflective diffraction grating).
Say we can extract one watt of
electricity per CD, and we'll be being
optimistic. |
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--Pointed out on Helios Helper by
[stonux], CD polycarbonate does not
hold up well to solar UV. |
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One watt? Wonderful! That's a watt that you had to burn oil/coal/nat gas for before. This is an absolutely free watt contributed by something that would have been added to a landfill anyway. |
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The real insight of this idea is not in the technical details, but in the idea that when you get A LOT of people doing one thing, that large quantity of small efforts can result in a big thing. If one solution is technically 100 times less efficient than another solution that is 1000 times more expensive, you're still 10 times ahead. (And the cost is very spread out.) |
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Nice one Worldgineer. I like the scale of this one. it
would work best with a solar chimney/tower power plant -
there's several multi-MW ones in existence, or I like the
inflatable half-baked one. Fixed mirrors could work ok
spread over a very large area. |
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Another AOL CD use would be to combine the inflatable
'parabolic' reflector idea (can't remember who posted that
but it's here somewhere) with papier-mache and AOL CDs:
Big balloon, cover part of it with AOL CDs, then papier-
mache, then deflate = cheap solar collector for solar
stoves and so forth. |
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An interesting aside: There's a whole generation of people who will have no idea what this idea is about. |
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Has it been 7 years already (well, almost)? Luckily this idea still works, using old scratched cds or dvd or bluerays or whatever it is the kids use these days. |
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