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Harvesting Energy in the Sky
withoutfeathers writes "The Economist magazine has an article on Flying wind farms. Mind you, we're not talking about ordinary, terrestrial windmills here. We're talking about actual airborne — up to 10km in the sky — wind farms intended to harvest the immense supply of energy in the jet stream. On the surface, the idea seems a little eccentric but, in fact, San Diego (California, US) based Sky WindPower has, apparently, thought their concept through pretty thoroughly and believes they can not only make this work, but do so profitably. The article discusses several other ideas for high-flying wind farming including a Dutch proposal to use pairs of kites to drive a generator."
Hope they tell the FAA before they put one up...
Somehow, putting up tons of windfarm hardware in the jetstream, strikes me as a great way to disrupt airtravel.
If we take the kinetic energy out of the wind and transform it into electrical energy, will this cause any problems? If we do so on a major scale?
Is it even possible for us to tap enough power from the jet stream (or other high altitude winds) to cause problems?
The SHPEGS project is an initiative to design and build a system that uses a combination of direct and indirect solar collection to generate electricity and store thermal energy in an economical, environmentally friendly, scalable, reliable, efficient and location independent manner using common construction materials.
I once had a similar idea: to pull energy right out of the air. Here's what I would do: separate a sealed chamber into two subchambers with a little door between them that could be opened. Have some kind of monitor determine *just* the right time to open it so as to increase the pressure in one side. When the pressure difference is large enough? Have one side expand against the other, drawing out useful work. End result? Both chambers have the same pressure *which is less than atmosopheric*! So to recharge, I just open it up to the atmosphere, and start over again.
:-/
Go, me, right?
After a few days of this, I woke up to find a severed horse's head in my bed. A note attached to it said. "You're depressurizing the atmosphere. Stop."
That settled it for me
Apology to Ubuntu forum.
Gather 3 wives and their mothers in front of these devices: output to be rated at MW/cup of coffee.
Take the 90-Day Challenge! http://rwmurker.bodybyvi.com/
"The Economist magazine has an article on Flying wind farms. Mind you, we're not talking about ordinary, terrestrial windmills here.
You're kidding? Flying wind farms aren't ordinary, terrestrial windmills? You learn something new every day!
There are shills on slashdot. Apparently, I'm one of them.
But what of Global Calming?
- Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.
It will be really sad when this idea comes crashing down... ;-)
StarTrekPhase2 - The Five Year Mission Continues!
Hey, lets put a bunch of aircraft up at 10km, with cables that tie them to the ground! Excellent idea! Why didn't anyone think of this before?
Oh, that's right - they did. They used them to prevent aircraft from flying over towns/cities/military targets (it sort of worked).
It also doesn't seem to make a whole lot of sense to stick a bunch of obstacles up in the jet stream. You know, where airliners tend to like to fly (at least when going west to east).
Oh, and doesn't the jet stream tend to be rather dynamic - as in, it's course often changes by hundreds or even thousands of miles?
Well since Global Warming is just a matter of too much energy in the system, maybe Global Calming would mitigate some of the weather pattern effects. (yes I know you being humorous)
We are all just people.
"Is it even possible for us to tap enough power from the jet stream (or other high altitude winds) to cause problems?"
No. The total power we could possibly harvest with systems like those in the article is not worth mentioning in the scale of the total energy in the jet stream. Windmills take a few percent of the energy of the wind that actually passes over them, wich would only be a tiny fraction of the wind in the jet stream.
You know what else tends to reside in the path of the jet stream? Storm systems.
I bet that these things would make excellent conductors for lightning. Take them down when storms approach and put them back up afterwards? Probably not feasible.
Then again, they would probably build up a heck of a static charge themselves just with the wind flowing over them.
Oh yeah, would ice build-up be a problem? Maybe not at the windmill itself, but on the tether, perhaps.
Seems to me there's a few (obvious) technical hurdles to address, first./p.
So don't RTFA (I haven't :) ), but make some estimate in your head of the total percent of the energy in the jet stream they could possibly harvest. I have some idea the scales involved and the efficiency of wind turbines, and in my wildest speculations I can't see how they are going to make even a tenth of a percent difference in the strenght of the stream. It's not going to be a problem.
Update: Just for kicks, I Read The Fine Article. In it, it is estimated that 1% of the power in the jet stream would power the entirety of human civilization. Not that you'd ever get that much, but again, not a problem.
This is a totally fucked up idea that has no hope of becoming reality. However, certain venture capitalists that have the ears of certain elected officials, retired milirary leaders, and recent political appointees think that this is certainly worthy of (1) government contracts, (2) earmarks in military spending bills, and (3) "grants" from the DOE, Military, and any other government agency that has a large amount of government gave-a-way cash to burn.
Thankfully, these cash infusions will allow technology companies to hire a least one full time patent attorney, with the goal of monopolizing any technology that could even be remotely useful to anyone else. Just in case the IPO doesn't make us billionaires.
Thank God that these guys are looking out for us and the environment through technology.
(nudge-nudge-wink-wink, Walmart's on board with this plan too - makes 'em look good and feel good)
The cable that is tethering it to the ground will be a hazard to aviation and all altitudes below the generator. Not only would the cable be very hard to see, but, unlike power cables and guy wires for antennas, it would also be hard to chart, since I imagine that the generator will move around quite a bit as the jetstream fluctuates.
Well, the technical hurdle is capturing the energy from a massive electrical discharge and then releasing it in a controlled form. You can't just send it through some super transformer to knock down the voltage because, even if you could, the voltage rise/fall time is so fast that the inductive impedance of the transformer would probably make it quite ineffective. Even if you could down convert the voltage of the lightning, you'd have difficulty building a device that could accept such a large inrush of current in such a short period of time. Direct application of the electrical energy is most likely out.
I would think that a solution for capturing this energy would reside in a less direct solution, such as dissipating the energy into a medium (i.e. specialized oil, or vaporization of a liquid) as heat, then using standard thermodynamic heat flow to mechanically spin a turbine or something. There's several forms of energy conversion in the whole process of something like that, but it would be done to better manage the storage and release of the captured energy.
Of course, the next problem is finding a relatively abundant source of atmospheric electrical discharge to make something like this economically feasible.
All 1.21 Jiggawatts of it!
It's a good thing it might be profitable, otherwise we would have to forget about the idea forever.
According to this public disclosure meeting in 2001, whereby high ranking government officials, very senior ex-military, black project staff, and ex-NASA employees pointed out... Zero point energy (aka. free energy) devices already exist, and have for decades, but are hidden by secret black project government programs due to the massive economic impact it would have on the world (i.e. no more need for OIL).
VIDEO: http://www.youtube.com/watch?v=uCLOIcFTSlE
It's time USA citizens wrote their congress men and appealed for all of these senior government etc officials to have a chance to testify under oath as they have promised to do. To date the disclosure project has over 400 such officials willing to testify. This is not wacko conspiracy theorists coming up with crazy theories... it's about the largest government cover up in the history of the modern world.
Adeptus.
PS. If the above is not enough to motivate you, think about how a world without burning fossil fuels would end the global warming impact nearly overnight! The evidence is simply overwhelming. See the video for yourself.
No trees were killed in the making of this post; however, many trillions of electrons were horribly inconvenienced.
By necessity, any generation of electricity is going to remove energy from our environment somehow. (In the case of fossil fuels, this is stored chemical energy, but it still came from somewhere.) Hydroelectric power, the big (and relatively environmentally friendly) energy producer where I live, requires a whole river to be diverted. This wind power proposal is more like sticking your toe into a fast-moving stream. It seems fair to assume (so long as we lack evidence to the contrary) that it is unlikely to have a significant effect (good or bad), and it would replace technologies with known negative effects.
Your argument seems to me no different than one which says we should not harness electricity from tidal changes because it contributes to tidal locking between the earth and moon. In both cases, the amount of energy likely to ever be extracted is only a very small portion of the total energy available.
You're right. We should stick to burning coal, firing gas, building dams, and fissioning radioactive materials. Those have all proven to have no unintended consequences.
I'd honestly be more concerned with global warming killing the jet stream than this. The jet stream is largely the result of low-altitude/surface-level thermal gradients (ie the equator to pole temperature difference). Given that most climate models predict the poles will warm significantly more than the equator, if they turn out to be correct I'd say that's far more troubling to the jet stream than a few big kites.
... what about the power transfer cable? I can't imagine a cable that can carry 10MW of juice over 10KM of distance could possibly considered a lightweight matter. This little helicopter contraption will need to generate power AND have enough energy to remain aloft under the weight of that cable. I think it's an interesting concept, but the solution to all our future power woes? Enh. While we're dreaming big, I'd be more interested in this Energy Island concept being built out.
I can see the protests now: "Not above my back yard".
"There is nothing nice about Steve Jobs and nothing evil about Bill Gates." - Chuck Peddle
Our planet is not necessarily overpopulated. The problem is the impact that those 6 billion or so are having. More specifically, the impact that a minority of those 6 billion are having.
Not true at all. While everyone likes to paint the Americans and other first-worlders as ruining the planet, the third-worlders are certainly doing their part as well.
Look at a satellite image of Haiti, and compare it to its neighbor Dominican Republic. Haiti is dirt-poor, but they're busy chopping down every tree on their side of the island, causing all kinds of problems with erosion and destruction of the marine environment offshore.
In Brazil, they're busily chopping down the rainforests to make way for agriculture. The rainforests are a huge carbon sink and change a lot of the CO2 in our atmosphere to O2, plus they have an enormous amount of biodiversity, with potential medicines waiting to be discovered there.
Pollution has become an enormous problem in places like China and Vietnam because of the rapid industrialization there.
It's not just resource consumption, but also resource management. At least the first-worlders have put some limits in place on pollution (especially the toxic kind, rather than CO2), which the third-worlders happily ignore in their ignorance.
The only way our planet could healthily support more people at a decent standard of living is for everyone to live peacefully in arcologies or other high-density utopian environments. The only way this will happen is if scientists can genetically modify all future humans to no longer be human: to not fight, to not be greedy or evil, to not be intolerant or force others to yield to their will, etc. Basically, we need to all act like ants, working only for the common good and completely ignoring any personal needs or wishes. Good luck with that.
Uh huh. Some guy named Gibbs had some. I learnt about it in college.
...the future crusty old bastards are already drinking the Kool-Aid.
Birth control well said. We first need to shoot every economist who still says that no growth is bad and then every idiot who calls me a Luddite. Reducing the population of worlds worst pest will do wonders to our world problems. (No I won't leave first but I do only have one child.)
Secondly taking energy out of the antmosphere is a great thing. The global warming (I there is such a thing because New Zealand has been cooling 0.9 degrees centigrade over the last decade)puts energy into the atmosphere and windmills take it out again. Hey it's energy recycling!
I'd be surprised if pilots are allowed to fly aircraft themselves in a decade from now. So avoiding a few lousy powerstations won't be a problem.
Icing? No problem. The cables are made of aluminium and as such not a great conductor. To keep the weight down these cables need to be thin hence they probably are going to be hot or at least warm anyway.
Weight? Yeah to total killer of this concept. There is no hope in hell they can build cables light enough to transfer energy to the ground while keeping the kite tethered. However, I can think of a variation of this idea. They could use the tether as a method to transmit rotational energy to the ground. A ground based pulley system and a 20 km long loop of fancy nanotube super light cable running as a chain between the airborne windmill and the ground. The generator remains firmly on the ground. This reduces the weight of the airborne system a lot while the power station can now stay aloft at very low wind speeds. Ow, bugger it. I made a picture. Here have a look,
http://vandinther.googlepages.com/home
I don't even think such a power station would need to be in the jetstream to function thanks to it's much lower weight. Of course if the cable breaks then you are uh... well actually no. The return cable can be just slightly longer. Breakage of the cable can be detected by a sudden reduction of tension on the drums and the return cable can immediately be locked in place while electronics adjust the rotors to reduce the tension to a minimum.
Falling to the ground is rather unlikely. If the unit can still be controlled, the best scenario is to just let it autorotate down and lay its cable down gently as it goes.
Sustainability and energy independence essay
Windmills take a few percent of the energy of the wind that actually passes over them, wich would only be a tiny fraction of the wind in the jet stream.
Even of the wind that actually passes through the area "swept" by the blades, the max it can harvest is about 59.3%. This is the "Betz Limit", the aerodynamic counterpart of the Laugher Curve of government revenue versus tax rates:
- Extracting power slows and deflects the air.
- Slowing and deflecting the air reduces the amount of moving air you can extract power from.
- Don't slow/deflect it and you get no power, stop it completely and you get no air - and thus no power. Zero at both ends, non-zero between. Somewhere there's a maximum.
- The maximum (for compressible fluids in free space) is where you extract 16/27ths of the energy from the air you affect (which is essentially the stream of air that passes through the area swept by the blades).
Real turbines can get very close to that, and most of the shortfall is a bit of energy left as rotation and turbulence in the wake.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
What are chances that the geographical areas where these contraptions are installed get hit by bad weather (i.e. typhoons, tornados, hurricanes, hailstorms, lightning, etc)?
They're in the jet stream. That's up at the TOP of the troposphere. The turbulent violence you're talking about happens further down - the top mostly just has winds, and the jet stream is already the worst of it.
Assuming the power station comes down in any uncontrolled fashion, and from the heights they are talking about and the strong jet stream winds they are dealing with, the power generation station could potentially travel many miles before it hits ground, endangering a very very large area below.
Now that would depend on the type of elevated structure. But most of them have acceptable failure mechanisms.
For instance: The four-bladed "helicopter" should auto-gyro nicely. If it loses its tether the blades keep spinning and keep providing lift - in the correct direction even. By transferring power from one blade to another as needed you can navigate it like a glider - even upwind, trading altitude for blade momentum as you drop. This lets you fly it to a landing area, landing vertically and quite gently, even without any additional power source onboard. Or find an updraft and soar until any crummy weather at ground level has moved on.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
"Perhaps you are neglecting the Butterfly Effect."
I am not. I have a degree in Mathematics in which I made a particular study of chaotic dynamical systems. I've written papers about the Butterfly effect; I've constructed physical models that demonstrate it. Let me tell you about the Butterfly Effect, so that you can refrain from bringing it up in discussions such as this in the future:
In a system which exhibits sensitive dependence on initial conditions (such as the weather), you cannot predict the details of long-term behavior (will there be a tornado in Iowa exactly 1 year from today) because tiny variations, well below what your measurement of the system could possibly account for (such as the breeze generated by the flapping of butterfly wings) will cause reality to drift further and further out of synch with your model until there is no resemblance on the detail level.
So the butterfly effect makes it impossible to ever predict what day it will rain months in advance, for example. But it does not prevent predictions about the aggregate, macroscopic behaviour of the system as a whole. In Meterological terms, long term weather prediction is impossible, but short-to-mid term climate prediction is easy.
Lets be ridiculously generous, and say this system takes a thousanth of a percent of the wind energy in the jet stream out. Is it reasonable to suppose this might cause significant changes in the world climate that will make a huge difference in its suitability for humans? No; it is not remotely reasonable. It's just not enough energy to make much difference.
Would it mean sometime in the future there will be a thunderstorm one day and not another? Absolutely. Whether you exhale the next breath you take slowly or forcefully means exactly the same thing; the minute difference in the velocity of a few thousand molecules of air your breathing pattern makes will eventually mean the difference in what day you get a thunderstorm.
The relevance of the Butterfly Effect in deciding whether to build this wind farm is the same as its relevance in deciding how forcefully to exhale your next breath. It means that the exact effect of either cannot be predicted, and that's it. It's not a reason to not do anything. (Well, except things like attempting long term prediction of weather detail.)
Hope that helps.
You're thinking of the Laffer Curve, and it's been mostly discredited in the economics world AFAIK
Interesting ideas, all, but access to the jet stream is a big deal requiring big bucks. I'm wondering about small projects.
When I was a kid, I got one of those big, plastic "bat" kites. (They were new on the U.S. toy market at the time, so that tells you how old I am.) I found it horrifically unstable, so I attached a tail made of torn cloth and other stuff. It was quite long and weighed several pounds, making the kite a pain to launch. Once it had gained some altitude, though, it was stable and pulled steadily. I ran out of kite twine, so I drove a stake in the ground and tied it off. Then I rooted around in the garage and found a giant spool of 100lb test fishing line. (Why we had it since it had been years since we'd lived near the Gulf Coast and gone offshore fishing, I didn't know.) I attached this new line to the kite string and let it play out. Quick as a wink, that kite was hundreds of yards high, just hanging there, pulling hard and steady. My older sis had a party that night and all the high school boys wanted to show off how manly they were, so they pulled in the kite for me. They had to work hard for over an hour, pulling it in as fast as they could, to get it to the ground. They were tired, sweaty, and pissed at me by the time they were finished.
I haven't thought about that episode in years. I wonder, though, if it would be possible to put up a fairly large kite to an altitude of just a few hundred yards and keep it aloft (semi-)long term with some sort of small wind generator hanging from it (I know that kite I launched in my youth could have held up 20 or 30 pounds, easily, once it was in the air.) and a small cable leading back to the ground. I live in a fairly mild climate and could pull it in if the weather got bad. I'm just wondering if this could produce enough energy to bank to some batteries that the exercise would be worthwhile.
I know lots of people have tried to go off the grid using power generated from small, often home-built terrestrial windmills. Because the wind at ground level is capricious, they need to feed big battery banks to tide them over the inevitable down time. I'm just wondering if putting a small windmill up at an altitude where air movement is more reliable could actually be a workable approach to the problem.
Of course, this is all just an unformed idea from someone who knows nothing about this stuff. For all I know, the wind at 1000 feet is no more reliable than the wind at ground level and that's why TFA is talking about getting up into the jet stream. Still, it's an intriguing idea to me.
So who wants to be the first to shoot it down?
(Yes, I love bad puns, too.)
What you said about the Butterfly Effect is correct but deals with the impact of small random fluctuations on a chaotic system. In this situation the planned alteration is highly non-random (a consistent reduction in energy potential of the jetstream), and the inevitable consequence of success is a gradual and significant increase in the magnitude of the change. The Butterfly Effect is not the correct model for non-random state changes of increasing magnitude.
In other words, the quoted person is thinking about a valid concern, but used the wrong model to express it. The concern is still valid however. Will our actions disturb a delicate balance in nature of which we are not yet aware? We just don't know. Experiments of this scope are not the ones that you want to go the wrong way, so I sincerely hope that this company and the government spends as much time determining how to calculate the limit of what we allow ourselves to pull from the jetstream as we do figuring out how to do it.