This was my original idea as it relates to the post in the "other:space" section... called "Super Deep Space Hubble"
If you could Collect and reflect energy using giant inflatable solar collector/deflector/reflectors... whatever you want to call them...
It would save a HUGE amount of money to produce solar fields, and it would have no giant impact on the surrounding ecosystem I can think of... easy to build and easy to take down... cheap to replace and energy efficient...
Your average "joe smoe" could produce alot of energy at low maintinance cost and investment...
what do ya think...-- oxygon, Dec 17 2001 Baking... http://www.delphion...ils?pn=US05893360__Sorry to let the air out of your solar balloon [Worldgineer, Oct 04 2004, last modified Feb 20 2008] Baking... http://www.metaeffi...ion-in-funding.html$21M investment in solar balloons. [Worldgineer, Feb 20 2008] How would an inflatable structure manage to keep a concave parabolic shape? It wouldn't be at all good at reflecting light to a focus, especially if you factor in wind and the lack of rigidity.-- pottedstu, Dec 17 2001 That's the cool part!-- phoenix, Dec 17 2001 let me define what I mean...
the blow-up lens would have one half of the lens shape silvered on the outer rim and have transparent center and the opposite half of the balloon would be silvered in the center and transparent outer rim... creating a huge cheap variable shape parabolic lens... You would need to secure it too a variable base to focus the suns energy onto a heat tank of group of solar cells...
I probably should have included that...-- oxygon, Dec 17 2001 [admin: oxygon, at the halfbakery, you can go back and re-edit your text after posting it. There is a text box containing your idea's text right below the normally printed text; edit that and press OK to change summary, name, or text of your idea.]-- jutta, Dec 18 2001 Two fishbones and four annos in over a year; why? This is a _fabulous_ idea for a solar heater.
Solar heating is impractical in most applications, because the dish is too large, heavy, expensive, etc.
As I understand it, this idea would be for a balloon, silvered on one (parabolic) side which would internally focus light rays to a point on (or outside) the other side. All the cost and structural issues have been solved at once.
It really won't matter about the optical performance of this system, because you could have many, many balloons (or a tubular balloon).
A tubular balloon could have a heat-conductive, blackened water pipe at the focal point of the sun's rays. This concentrated heat source could be used for heating, or even powering a stirling engine or similar*.
* I don't think we'd necessarily want to use a collector tower, as the optical precision fould have to be increased. Nor would we want to have a system that depends on high temperatures (i.e. a steam turbine) because that could melt the balloon.
One further application I have thought of could be in the use of solar cells in areas with a low solar energy density. This low cost system could be used to amplify the solar rays to an optimal level for PV generation.
This idea needs a croissant: Bravo!-- FloridaManatee, Mar 11 2003 I agree. Great idea. Looks like it's been at least half-baked in a patent (see link), but it's an idea I hadn't heard of until now.-- Worldgineer, Mar 12 2003 The other day I heard of a semimar talk about membrane lenses from some JPL/NASA guys of the of the Interferometry and Large Optical Systems Section.
The "half-silvered side" concept is grand. Another good concept is if both sides were transparent and the device could be used as a lens. The inherent problem with this is that the film of ballon and the filling of it with air does not lend itself to much magnification. Its all about the index or refraction of the material... inflating a ballon with water would make a really neat lens.
Im just adding some baking to a good idea. For posterity...-- bobbo, Mar 23 2003 This seems a good idea. Actually, the NASA is investigating on inflatable fresnel lenses for spaceship solar concentration.
I vote for it.-- rpardell, Sep 02 2003 Ground based huge red blood cell looking thing. Make it clear and let it collect heat greenhouse style. Then pump the air out into ducts and into homes. Some sort of heat exchanger. Make the bottom black. Throw a couple of hundred cables over it and winch them down to squeeze the air out. I would expect the temp would get well over a hundred degrees. It would be flat by the end of the night. Then open an end facing into the wind and fill it back up again.
On cloudy days it would make one hell of a moon walk party. Still a little hot on the feet though : )-- clafever, Jan 21 2004 Worked a little on the inflatable space lense thing a few years ago. Several tubes, fashioned as rings, were placed inside each other, with the larger inflated size as the larges diameter, and the smaller on the inside. When you inflate them all, you can attach a reflective material on one size, and it will form any mirror shape you like. Will try a text diagram, but not sure you get the idea. Imagine a cross section like this:
Oo..oO
Then imagine them as circles with a reflective layer attached on the top side. The idea is patented, but doesn't mean you couldn't use it as a license.-- azmatsci, Jan 21 2004 I recently saw an inflatable solar still for water purification for hikers - it floats on a pond and packs down into your backpack.
Good idea - should be simple to implement. I especially like the tubular variant.-- BunsenHoneydew, Jan 24 2004 Existing Plant: Some concentrators are built like a drum: A cylinder with two membranes on each side. If you pump out air, the membranes form a spherical concentrator. A spherical concentrator is similar enough to a parabolic one within certain limits. One of the membranes is reflective coated and casts the light to a Stirling engine.
Let's get back to your balloon idea: It could store enough hot air to fly by itself, at least during day. This exists, but only as toys.
Most of the balloon being transparent and the lower side mirror-shaped would require the heat receiver being in the balloon. Its position would have to track the sun, since the focus is not in the middle of the balloon (assuming a spherical concentrator). The balloon will be MUCH larger than the drum described above (assuming a spherical concentrator).
The idea with the partially coated double reflector (if I got it right) would require a very flat balloon.
NASA's JPL (Jet Propulsion Lab) does much nice research. Worth a link.
Water purification not only profits from heat, but also from concentrated UV radiation.-- stonux, May 08 2004 Why bother with iflatables. A more compact, low-profile solution would be collapsible, foldable reflectors that work like umbrellas.-- eilathean, Jul 04 2004 (see link)-- Worldgineer, Feb 20 2008 I like the inflatable idea; in fact, it mirrors my own concept for "tethered", helium-filled mega balloons equipped with flexible photovoltaic upper skin.
Some of the tethers would serve as helium balancing line conduits (i.e., semi-rigid synthetic gas distribution tubing, inside hollow, engineered "wire ropes").
Other tethers would serve as power transmission conduits, delivering the solar-generated DC power to earth-based AC convertor and power distribution hub.
Other tethers would serve as data transmission or communications wiring bundle conduits.
Since these tethered mega balloons would be large scale deployments, i.e., each inflated photovoltaic balloon would expand to an area in the "square-miles" size range; they could be strategically placed over the polar ice cap to "shade" the ice cap and slow down glacial melting.
Nanosolar (http://www.nanosolar.com/) is working on flexible "printable" photovoltaic film collector substrate/grid/matrix; I believe the technology is very close to being viable for something like this mega-balloon collection setup.
Obviously, much engineering needs to be done, including the actual balloon construction, materials and manufacture; the massive foundations that would be needed to keep the balloons safely and securely tethered to Earth; keeping the balloon in a stable position at high-altitude (needs to be high enough to collect sunlight 24/7/365); helium-balancing system for above position control and stabilization; hollow, flexible, extra-strong tether "conduits"; balloon deployment methodology (large scale size and length of tethers means large scale deployment project); and more.-- w1z111, Jun 06 2008 random, halfbakery