Energy from High-Altitude Kites 288
maddmike writes "High altitude kites could produce energy equal to some power stations at a comparable cost without polluting. The technique uses a thing dubbed a 'Laddermill' - a chain of kites attached together to create a loop in the sky more than 5 miles long."
Feasable? (Score:1, Interesting)
how? why?-Air pollution. (Score:2, Interesting)
More surface area. The overall thing I'm worried about is the upcoming pollution of the airspace. Kind of what happened to outerspace.
Tension in the wire (Score:4, Interesting)
Also what will happen if the cable snaps. They worry about the kite, what about the heavy cables falling and destroying things down here.
With these cables how are they going to fly the kite from the ground ? Will they use turbines from the military planes to blow air ?
Anyone has more information about it ?
-a
Global Stasis? (Score:4, Interesting)
instead of wind-power (Score:2, Interesting)
Five miles high (Score:4, Interesting)
This means the cable is actually ten-plus miles long. I don't remember my differential equations from twenty years ago, but I do know that as the cable gets longer (goes higher), the amount of weight supported increases. So half the loop is a five mile strand going up, and the other half is five miles of cable coming down. It sure seems like the weight on the top kites would be extraordinary. Do we have carbon-fiber cable yet?
And what happens when lighting hits it? Didn't Tesla manage some stunning current with a structure less tall than this?
Re:degrees (Score:5, Interesting)
Reminds me of something I saw when I was a kid. My dad and I were fishing off the coast of Cape Cod. The boat we were in was a 23' center console with twin 135hp engines. If memory serves me (this was some 25+ years ago) the boat would do about 40mph on a flat calm. Anyway... There was a good stiff breeze, good for sailing, kight flying, etc. At one point not too far in the distance we saw an orange kite flying in the sky. It was one of those $1.99 plastic things you can buy in any toy store. Well it didn't take us too long to realize that nobody was flying the kite because they'd have to be in the water given its location, and there weren't any other boats in the area. We decided to investigate (the fish weren't biting) so we headed towards the kite at full-throttle. It took us about 45 minutes but we eventually caught up with the kite. The string had apparently snapped or whoever was flying it had let go of the string. Enough string was dragging in the water to create just enough drag to keep the kite aloft, and the kite was dragging it through the water at a pretty decent speed. If the boat wasn't as fast as it was we probably wouldn't have caught the kite. We figured it could have made it all the way to Europe in a week or so if we let it. (Makes for a good story anyway) But it ended up in our closet instead.
I suppose as long as the kites in this ladder-thingy are designed properly they would continue to fly upright. But unless they have enough drag (like the string in my little tale) I'd suspect that the wind would just blow it out of the sky if the line were to break.
The numbers don't add up... (Score:3, Interesting)
Re:Lots of possible problems. (Score:2, Interesting)
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lds
Re:Five miles high (Score:4, Interesting)
The other problem is that the cable would have to, at a minium, support something on the order of 20,000 psi. The only way to offset that would be use hellium or some other lighter-than-air gas in the sails. However, then you have to put this thing under stress in order to generate the power, so were back to the 20,000+ psi range. Steal is pretty much out. What sort of fiber/metal/ceramic are thinking of?
And what of wind shear??? (Score:2, Interesting)
How is this better than a wind turbine? (Score:3, Interesting)
If height is the issue, then why not have a tethered blimp hoist wind turbines? You could even cover the top of the blimp with flexible solar panels and have a high-flying hybrid system and you don't have worry about bombing people with a giant bicycle wheel if the wind died. If the weather gets bad just reel the blimp in.
Use the pancake rotor types, carbon composite blades, you could make some pretty high production turbines that were light enough to be raised by a blimp. Some kind of frame and the tether could double as the transmission cable.
back issue (Score:2, Interesting)
A lone genius move out into an arid southwest desert and quickly bulldozes out an underground home. He then feeds one end of a roll of sheet plastic into a jig that turns it into a very long tube.
After attaching some wire our genius somehow flies the entire (mile long?) tube up into the sky like a kite, and fastens the bottom end to a rig on the ground.
The air near the earth being relatively warm rushes up the tube, stiffening it. The resulting current turns a fan blade, powering an electrical generator.
Condensation along the inside of the tube constantly trickles down and provides all the water our hero needs.
I think he gets the girl.
same principles for "space tethers" (Score:3, Interesting)
Several orbital experiments have been tried. I recall one time mechanical problems prevented full unwinding of the cable. Another time the cable shorted and burnt apart from a power surge. I suspects these bugs will be eventually fixed by the engineers.