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Low Mass Mill

Because what goes up must come down...
  (+8, -1)
(+8, -1)
  [vote for,

The biggest problem I see with wind power is that:

A) the wind is way up there in the air and gets (much) slower as you approach the ground

B) anything that you lift way up into that good wind can fall / fly a long way and...

C) if it is heavy, it's going to do a lot of damage when it hits the ground.

So I'm more interested in windmills that use light-weight cloth type materials.

I've been turning over in my mind a sort of dirigible with sail "wings" that would be turned about its axis by the sails and use a single mooring line looped over a pulley at the nose. It would pull up on one side of the line and let out the other. On the ground, the pull up side of the line would turn a pulley on a generator. The "let out" side of the mooring line would run over a pulley some distance from the generator side which would be spring loaded to maintain tension on the loop.

The point here is that the heavy bits, such as the generator, are on the ground.

The killer on that design is how you keep the thing from turning in the air and tangling the lines, while at the same time allowing it to turn into the wind. It may be acceptable to moor it to two or three points and not allow it to turn at all. Most large windmills do not turn and are simply set facing the prevailing wind.

James Newton, Jun 27 2006

Rather poor drawing http://techref.mass...86/wind/FLYMILL.JPG
I messed up the direction of the wings and added a 3rd tether to compensate [James Newton, Jun 27 2006]

Blimp mounted windmills Highaltitude_20windfarm
What became of [FloridaManatee]? [bungston, Jun 27 2006]

Other interesting wind mills http://techref.mass...other/windmills.htm
[James Newton, Jun 29 2006]

(??) The ladder mill http://www.laddermill.com/
Another sort of light weight, generator on the ground mill. [James Newton, Jun 29 2006]

Hullaballoon Hullaballoon
Any excuse to link to this one. [spidermother, Jun 29 2006]

Kite pump Kite_20pump
An idea which uses varying angles of attack to change the pull on the line, and then pump water. [Ling, Jul 03 2006]

A real world blimp turbine http://www.magenn.com/
It's still half-baked, though. [goldbb, Apr 06 2009]

RotoKite, http://www.youtube....edded&v=p7ilG78cBLg
not the same at all, but related [James Newton, Nov 02 2012]

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       Bun for the illustration alone.
normzone, Jun 27 2006

       A blimp mounted windmill. Or something like it, since you seem to want to make the whole blimp spin - not sure how that is better than a regular blimp with a windmill tail. There are windmills mounted on everything else in the HB but my search could not find windmills on balloons. Have bread!   

       (later) - found it. Actually right next to this idea in the category.
bungston, Jun 27 2006

       The pully system sounds troublesome. Most LTA craft rise and fall with the temperature. Why not use a universal joint or two instead, with a light weight shaft leading to the ground?   

       OK, so the shaft is heavier, and you'd need some sort of retractable length in it somewhere, but that's minor compared to the troubles of the belt twisting, sinking, stretching, dragging on the ground...
ye_river_xiv, Jun 28 2006

       [bungston] I was trying more for the "no generator way up high" as the point of this idea than for the "wings on a blimp / balloon / whatever." Putting wings on a blimp is only in the idea because it was the only way I could see to put the generator (any everything else with significant mass) on the ground.   

       [ye_river_xiv] maybe a carbon fiber shaft? There was an idea somewhere to put a batch of small props on a long shaft with the generator on a little raft in the ocean. I wonder if the carbon fiber shaft could be light enough to do no serious damage and still be long enough to get up in the high wind.   

       Another point on all this is legality around suburban homes. I can't build a tower in my back yard, but I can fly a kite... Now if that kite happens to be pulling up a line on one side and letting out a tail on the other...
James Newton, Jun 29 2006

       [JN] (Puts down hammer) I can't do what now?   

       Of course, a tethered Hullaballoon could also work.
spidermother, Jun 29 2006

       Don't you just hate all those regulations, [spidermother]? I have a tree that the bees love. You can stand under it and it sounds like a high voltage power line buzzing. And that tree is perfectly legal for me to have in my back yard; with all the thousands of bees flying in and out from it, over my neighbors back yards... But I CAN NOT have a bee hive. That would be dangerous. /eye roll/   

       I have exotic birds (don't say chickens) in the back yard. But no one complains, 'cause of the free eggs. And the city hasn't come down on my yet... 'cause they have an exemption for exotic birds as pets.   

       But I can't drill a well for water, nor can I keep goats, and so on.   

       But, damn it, I can fly a kite... Can't I?
James Newton, Jul 03 2006

       I wonder if one could modify this to take advantage of the fact that wind is not usually steady - even when strong, there are gusts.   

       In this scheme, the kite line is under tension from a spring mounted device on the ground. When the wind slackens, the line is reeled back. On gusting, the line is paid out. The line moving out rewinds the spring and also turns a wheel to generate the electricity. I envision the kite bobbing back and forth at the end of the line.
bungston, Jul 03 2006

       I think the fact that this thing floats solves the issue of line tension. You would need a basic flexible joint on your transmission line so that the only change would be in the angle that the line is at relative to the ground.(think like a windsock on a pole accept the pole is very thin and flexible and that the windsock floats which keeps it up in the air. Also a set of foils on the lower part of the transmission line(a short distance from the blimp) will help offset the weight of the transmission line. When the wind dies down the blimp will just float straight up and wait until it picks up again. On windy days the blimp will get pushed down somewhat but will still have suffcient lift to stay in the high velocity airstream.   

       For a transmission line I would think you could create a bundled, twisted or braided carbon Nanotube type cable, with a spiral shaped casing(kind of like a sash cord or bicycle brake cable). This would create a very lite, very strong cable that rotates within a case that counteracts the twisting forces of the Blimp. It might also be self Lubricating.   

       (edit) On second thought you realy would not need a sheath, if the cable was attached direct to the blimp you would need only to attach the base to a transmission plate and the thing would work. The key is a transmission line that is very rigid and would not bend up and kink. Probabaly something more like a ridgid pipe than a line.
jhomrighaus, Jul 03 2006

       Yes, I was thinking along the same lines: use the main anchor cable as a twisting transmission cable, too.
Ling, Jul 03 2006

mecotterill, Apr 04 2009

       [+x10] sorry I saw this only now!
pashute, Aug 12 2011


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