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Energy from High-Altitude Kites
Posted by
michael
on Sun Jan 02, 2005 06:30 PM
from the sky-dragon dept.
from the sky-dragon dept.
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."
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The altitude isn't... (Score:3, Funny)
Are your crazy!? (Score:5, Funny)
Re:Are your crazy!? (Score:5, Funny)
Well, at least we'd be moving back in time so we'd be able to fix it.
Parent
Hey Ben... (Score:3, Funny)
Re:Hey Ben... (Score:3, Insightful)
"You know what that is? It's Patent infringment, thats what that is!"
Re:Hey Ben... (Score:3, Funny)
Probably something that never made into his diary:
"*Zzzzzzttttt* Shityaaaaaooo! Fuck this energy experiment. Let some losers hundreds of years in the future try this crap instead. I'm done with kites."
Article skimpy on details ( as usual ) (Score:5, Insightful)
I'd like learn more, but the article is not very helpful.
Re:Article skimpy on details ( as usual ) (Score:5, Informative)
Side note. Kinda funny how it is being developed for high altitude in the Netherlands.
Parent
Official Website (Score:3, Informative)
http://www.laddermill.com/
or, for that matter, do a Google search for "laddermill":
http://www.google.com/search?q=laddermill
Now how hard was that?
Re:nothing new (Score:5, Funny)
The industrial world has a vested interest in maintaining itself and not destroying itself or us: If there is no civilization or people to buy goods and services, then money and soon power (as in power of the people, not nuclear power) go bye-bye.
It's simplistic and misses all those pesky nuances, but true.
Now, whether or not the industrial world _knows_ how to maintain itself and not destroy us... THAT's another question...
Parent
Re:nothing new (Score:3, Insightful)
[On smoking]
Ishmael: You should try to quit. They say its bad for your heart, your lungs. It quickens the aging process.
Roy: Who's done more research than the good people at the American Tobacco Industry? They say its harmless. Why would they lie? If you're dead, you can't smoke.
Re:nothing new (Score:3, Insightful)
I'd say at least in the USA, we have a long way to go before we hit the bottom.
As long as you have access to other countrie's resources.
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)
Re:Global Stasis? (Score:3, Funny)
I know! Let's all just DIE! (Score:5, Insightful)
So when I see possible energy solutions like this one, it makes me rack my brains to think what excuse will these NiMBY folks use THIS time? Thanks so much for 'global stasis'. I can see the lawsuits now...
I vote for moving the coal plants in CT that feed Nantucket down near the Kennedy Compound. You might as well get them closer to where the HOT AIR is generated...
Parent
Re:Global Stasis? (Score:3, Insightful)
Wind is not finite or depletable.
Wind is constinuously generated by the sun's differential heating of our planet.
As the air warms, it expands and rises. As it cools, it contracts and falls down.
We will never have "global stasis" and it would be hella difficult to globally impact the weather system.
Global warming exists because gases travel and diffuse throughout the entire atmosphere.
Windmills are fixed.
Slowing down the wind a little bit here and there does not immediate
Difficult but could be promising (Score:5, Informative)
The former problem is essentially a strength vs. weight problem that even high tensile lines made of dyneema won't solve easily (above 400/500m, a 6m parafoil can very well sit there and refuse to climb with standard lines).
The latter problem introduces a problem of angle, since the line becomes curved under the wind drag, which makes the section right under the kite more and more vertical as it climbs, which in turn "flattens" its incidence angle and reduces its lift. It's always possible to modify the incidence on the ground to compensate, but takeoff can get dicey then. And of course, the wind drag on the line also tends to pull the kite down, and it's not negligible with a lot of line up.
So yes, it should be possible to use kites to generate power, but there will have to be a great deal of electronic magic to regulate everything, down on the ground and up in the air, if high altitude flying is to be more than stunts performed by enthusiasts on good days with (semi-)controlled conditions.
Trains beat single kites (Score:5, Informative)
The record, set back in 1969, is 10,830 m abg. So the 30,000 ft mark has already been surpassed.
The single kite record stands at around 13K feet.
Parent
Links for the lazy (Score:5, Informative)
"Equal to some power stations"? (Score:5, Insightful)
What they were saying was equal was the cost, not the total output per kite.
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:Five miles high (Score:5, Funny)
that's called free extra power
Parent
Re:Five miles high (Score:3, Informative)
There is a good picture at http://www.ockels.nl/Introduction.htm [ockels.nl] (from http://www.laddermill.com/ [laddermill.com], which somebody else posted).
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?
Parent
More trouble than its worth (Score:3, Insightful)
The nice thing about some of the other alternative power systems is that they tend to be smaller scale and are backed up by the power grid or some other form of generation. If you have a 100MW kite system, it would be such a substantial source of power that providing a backup to it when there is no wind or the cable breaks, will not be trivial.
Jerry
http://www.syslog.org/ [syslog.org]
Re:More trouble than its worth (Score:3, Funny)
And if they install some along the US/Mexico border as the article suggests then there's also drug-smuggling aircraft.
This just in... The city of Dallas was plunged into darkness when a kite was struck by a cocaine-laden aircraft.
Very short on details (Score:3, Insightful)
Re:Very short on details (Score:3, Funny)
I can just see the engineers standing slackjawed as they watch their kites go awol. Gee Herb, I thought it was your job to tie the string.
I think that the Europeans... (Score:5, Funny)
(ducking)
Can't see the wood for the trees... (Score:5, Informative)
Have a look at some of the plans and protoype pics of this behemoth, and it becomes clear (if not in the article) that the intention is for the ladder to be ground-originated, not just ground-anchored. This means the kites are travelling up from the ground to 5 miles and back again. The volume occupied by such a structure - especially one as non-static as this - would be monumental, not to mention the massive safety margin required to have more than one in operation within a few miles of any other ladder.
So if we're looking at 400 ladders to generate enough to power a city, we're look at a good 3000+ square miles of land if we're to be sure that no ladder is to collide with another. Not practical on any scale, I suspect.
Now if we're to be sure the things don't come down every time there's a spot of bad weather, we are looking at getting them up above the common cloud-cover atmospheric strata. In that case, why the hell not just use bigger kites, no ridiculous ladder-arrangement, and use the kite-wing surface-area to convert solar-energy? If the kites are well-engineered and -controlled enough to be able to operate in such a stringently unified fashion, I'm sure the same technology could be used to keep solar-kites in the air. True, the strain on the cables would be even greater if they have to be reliable electrical conduits as well, but that's really only one of several major flaws in this project.
Frankly, we'd be better off burning drug-addled research-scientists as fuel. They're renewable, at least.
Let's go fly a kite... (Score:3, Funny)
This idea is not new (Score:4, Informative)
The idea of tethered high altitude wind power generation has been around for a long time. The people behind Sky Wind Power Corporation (http://skywindpower.com [skywindpower.com]) have been developing their technology since 1979.
They do not use kites but a tethered electrical generator, like a helicopter with 2 fifteen foot rotors and no cabin. The documentation on their site seems to cover a lot of questions that would come up here, especially about the tether etc.
It is just sad to see another australian inventor having to go overseas to try and get their idea noticed.
The numbers don't add up... (Score:3, Interesting)
Re:The numbers don't add up... (Score:3, Informative)
How about outsourcing our power? (Score:5, Funny)
A person can generate about 1/4 horsepower with an excersize bike. Given the daily rate for unskilled labor in many countries now, we could simply rig up a giant wheel like what Conan the Barbarian pushed around as a slave in that clearly prophetic movie.
Given the cost of building a nuke plant, then running it, getting rid of the waste, (hiding it really well for a really long time), and cleaning up after it -- it would be cheaper per kilowatt to simply have a bunch of low paid people push giant logs around in a circle.
The economics are outstanding. Its great excersize, and the power companies would be incented to provide health care at the same time. It provides plenty of jobs for unskilled labor, and could quickly be set up in the lowest income countries.
All in all, its a win-win. Best of all, it doesn't suffer from the one drawback everyone is clearly afraid to speak about with wind-power, which is the potential for slowing down the rotation of the earth! Clearly a danger if ever there was one. Why, if we slowed down the earth, and there was no centrifugal force apposing the gravity of our planet we would all be crushed! Oh the horror.
Wouldn't an autogyro be better than kites? (Score:4, Insightful)
Given that all the down kites, and the up kites below the level of high winds are dead weight, wouldn't it make more sense to just put a big tethered autogyro or 10 on the cable instead, and drive a generator from the prop rotation? This would eliminate the dead weight, replace the unstable kites with fail-safe autogyros that land gently naturally, and changes the requirement for a flexible cable that can cope with extreme tension for a requirement for a weaker less flexible cable that can transmit electricity, which should be easier to produce.
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.
Yet another diversion (Score:3, Insightful)
There was a similar idea to this about 20 years ago, called a "Lift Translator". It got goverment money. It made the cover of PopSci. It went precisely nowhere because it didn't work. This one's likely to work just as well/badly.
No-one I know in the wind energy industry thinks this 'laddermill" is remotely credible.
80,000 kites, 40 square miles (Score:3, Insightful)
"A few hundred"? That's at least 200, so we're talking about a minimum of 80,000, 27-foot kites, for a single large city. Then consider that each of these trains will be 5 miles long, and swaying in the wind. That means they need to stay some distance away from each other. My guess would be that half a mile between them (that's only 1/10th the length of a train) wouldn't be overly conservative. For a 14*14 installation (196 trains) that means just over 40 square miles (more than 25,000 acres) for a single installation. Sure, you can let some cows graze inbetween, but still. Somehow this whole scheme seems a little... impractical...
Re:Air Hazzard. (Score:4, Informative)
The Laddermill would only be flown where aircraft are banned. One such area is the zone along the US-Mexican border, where high-flying balloons fitted with radar are used to combat drug traffickers.
It's not even slashdotted. Yet.
Parent
Lots of possible problems. (Score:3, Informative)
As far as the balloons on the border, here is an example from the descriptions on the appropriate aeronautical charts (referring to the few balloons on the border) -
CAUTION UNMARKED BALLOON AND CABLE TO 15000 FEET IN R-6317
The entries for the few other sites list alitudes of 14000 or 15000 feet. The chart doesn't say that aircraft are banned, but most
Re:how? why? (Score:3, Informative)
It differs from regular windmills in that you should have read the article.
Re:Feasable? (Score:3, Informative)
Re:Feasable? (Score:5, Informative)
Parent
Re:Without polluting... (Score:3, Insightful)
"Professor Ockels says a few hundred of the installations, each requiring some 400 kites with 27ft wingspans, could generate enough electricity to supply the needs of a city the size of Seattle. The cost would be similar to that of generating power with polluting fossil fuels."
At a few hundred per city... that is a lot of kites..
Then you have to find the places to put them...
"The Laddermill would only be flown where aircraft are banned. One such area is the zone along the US-Mexican bo
Re:Ben Franklin (Score:3, Insightful)
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.
Parent
Re:Worlds Larget Lighting Rod (Score:3, Funny)
Heck, I figure you could get about 1.21 gigawatts easily.
Re:Superficially, this sounds like crackpot (Score:3, Informative)
What, never heard of biogas?