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Kite Power: The Latest In Green Technology (thebulletin.org)

New submitter Dan Drollette writes: The solution to producing energy without contributing to global warming may be to go fly a kite. Literally. Researchers in Switzerland and Italy — high-altitude places where the winds are strong, steady and predictable — have been working on ways to generate electricity from kites that fly hundreds or thousands of meters high. The scientists already have a prototype cranking out 27 megawatts; they expect to have a 100-megawatt plant big enough to power 86,000 households. And they say that they can produce electricity for less that 4 cents per kilowatt-hour, which is better than fossil fuel. Plus, the kites look really cool (as does the "Darrieus rotor vertical axis wind turbine" at the base of the St Bernard Pass, on the Swiss side, which I've seen in operation in person).

103 comments

  1. Prior Art by Anonymous Coward · · Score: 4, Informative

    I think they forgot to google for the technology first: https://www.google.com/makani/

    1. Re:Prior Art by tempmpi · · Score: 4, Interesting

      Makani uses a completely different approach: They use a wind turbine to generate electric energy and just use a kite to get the turbine to 250m height, while the kites from switzerland are basically passive kites and the aerodynamic lift is used for generation of power. Makani could generate energy contiguously while this SwissKitePower approach would alternate between ascend and retraction phases and only produce power during ascend.

      --
      Jan
    2. Re:Prior Art by CanadianRealist · · Score: 1

      This sounds like approach SkySails uses. See from 1:50 in this video.

      They are the ones who make kites for large ships. (Shown at 4:20 in the same video.)

    3. Re:Prior Art by edtice1559 · · Score: 1

      I don't know whether there 100kW estimate was during the ascent stage or descent. I'm surprised it's generating during ascent. Would be easier to harness energy on the way down. But in any event, you could have two kites 180 degrees out of phase so to speak to ensure pretty continuous power.l

    4. Re:Prior Art by Anonymous Coward · · Score: 0

      A lot is discussed on this yahoo group
      https://groups.yahoo.com/neo/groups/AirborneWindEnergy/conversations/messages
      Looks like main participants on this forum have a dim view of makani

    5. Re:Prior Art by drewm19801927 · · Score: 1

      Soft kites have to be replaced quite often since the fabric wears out. SkySails can get away with it because the ships save more fuel than it took to manufacture the kite. It is cheaper to make them big, but that is offset by them being about 1/10 as aerodynamically efficient as a rigid wing.

  2. fast winds by the_Bionic_lemming · · Score: 1

    What happens if the wind stops? Do I get a free repair to my roof?

    --
    _ _ _ Go for the eyes Boo! GO FOR THE EYES!
    1. Re:fast winds by Waffle+Iron · · Score: 5, Funny

      What happens if the wind stops?

      The utility plant operators have to compensate by running backwards and pulling harder on the string.

    2. Re:fast winds by AHuxley · · Score: 2

      Depends on the size and scale of the project.
      "US army blimp wreaks havoc after breaking free from military facility" (2015/oct/28)
      http://www.theguardian.com/us-...
      "... dragging its 10,000 foot long cable behind it and knocking out power to thousands."

      --
      Domestic spying is now "Benign Information Gathering"
    3. Re:fast winds by amiga3D · · Score: 1

      If you put it all the way up into the Jet Stream it would be pretty steady.

    4. Re:fast winds by AmiMoJo · · Score: 1

      At the altitude they are using there will always be enough wind to keep the thing in the sky. The amount of energy generated might vary, but it won't fall down.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
    5. Re:fast winds by Iconoc · · Score: 1

      I was away from the computer when I heard about this. It is such a laughable event and yet I saw no American media coverage after minimal searching a week later. $2.8 Billion doesn't buy much anymore. I guess this seems like a good idea when you're spending someone else's money.

    6. Re:fast winds by Anonymous Coward · · Score: 0
      Here you can read about recovery phases for different variants of the airborne turbines: http://www.sciencedirect.com/s... None requires your roof. They also claim that:

      the problems that come along with conventional wind turbines - such as shade from the blades, accidents with birds, noise emissions, or impairment of the natural scenery - are negligible

    7. Re:fast winds by Rei · · Score: 3, Interesting

      That's part of the reason that blimps are increasingly going out of favor, in favor of hybrid airships. Hybrids are based on the concept of being aircraft (generally lifting-body aircraft) that get huge lifting areas via inflation (so that they don't need any real structural strength, and thus keep the mass very low), and use helium as the inflation gas, which partially (but not completely) lifts the craft. So you have the combination of huge lifting area and much of your weight compensated for, so it takes little energy to stay aloft (which can, for example, come from solar), and unpowered landings are perfectly safe. But because (for the same payload capacity) you don't need as big of a gas bag as with a blimp, they're not as vulnerable to crosswinds and thus not as likely to break free, as well as being much easier to land without being blown into power lines or whatnot.

      --
      He's the sort of person who would sell the Red Cross to Dracula.
    8. Re: fast winds by Anonymous Coward · · Score: 0

      Sorry, but the jet isn't stationary. It meanders with about a thousand miles variance. Sometimes missing even the US and Canada.

    9. Re: fast winds by Anonymous Coward · · Score: 0

      Wrong, the winds at all altitudes, varies. I remember reading the accounts of the explorer Hillery. The breeze on top of everest being low enough to take off their coats and still being warm. Other days they had to keep dressed even in the tents burried in snow.

    10. Re: fast winds by Anonymous Coward · · Score: 0

      That's if everything goes right. What if some hacker invades the system? Or Johnny fumblefingers is on his first pot of coffee and something don't work right? Or Terry Snapchat is selfieing when the power goes out and the controls go dead? Where does the kite go? Safeties in place? Rips apart in mid air, or drops on grandmas house?

    11. Re: fast winds by Anonymous Coward · · Score: 0

      It is VERY consistent during winter months over a band from North Africa to Korean peninsula.
      One can verify on the NOAA website.
      However, this is simulation results and much more data collection/studies at that level is required to get an accurate picture of the situation.
      Jeststeam winds are very interesting. Bill Gates has talked about it on his website a few months ago. Surprisingly he seems to suggest that people should look at it when he can himself sponsor a study. Going OT, but he seems to have earned all the passion that slashdot visitors have for him.

    12. Re: fast winds by Anonymous Coward · · Score: 1

      What if the control centre is hit by a car bomb from a terrorist group? What if the kite cable is hit by a meteor? What happens if the operator discovers that magic is real and summons a cavodemon that rips the cable drum to peices and the kite falls on his daughters teachers house? What if the kite gains sentience and decides to fly to Venus?

      You fucking moron!

    13. Re: fast winds by Anonymous Coward · · Score: 0

      It being a mountain range drastically impacts airflow. Far enough away from any solid surface the dynamics are different.

  3. Where is the prototype? by sectokia · · Score: 3, Insightful

    27Mw is no small prototype, but there seems to be nothing about it anywhere.

    1. Re:Where is the prototype? by gl4ss · · Score: 1

      they say turin.

      it's different company.

      27 is peak, so, it might not mean anything significant or it might. if it meant anything significant then that 'research' should already be self financing.. I would think.

      --
      world was created 5 seconds before this post as it is.
    2. Re:Where is the prototype? by Anonymous Coward · · Score: 0

      This "prototype" exists only on paper and the company "developing" it hasn't updated their page for years now: http://www.kitegen.com/en/ . It's one of the many vaporware projects the eco-industry creates to extort money from shareholders.

    3. Re:Where is the prototype? by Sir+Holo · · Score: 1

      27Mw is no small prototype, but there seems to be nothing about it anywhere.

      That's how it is with prototypes.

      This is why the word begins with the Latin root protos, meaning first or primitive.

    4. Re:Where is the prototype? by olau · · Score: 1

      In fact, the prototype they have actually built is "5kW average and 40kW peak": http://www.kitegen.com/en/prod...

    5. Re: Where is the prototype? by Anonymous Coward · · Score: 0

      AC got rekt

    6. Re:Where is the prototype? by Anonymous Coward · · Score: 0

      protos is Greek, not Latin. Not many words ending in -os are Latin, anyway :)

      https://en.wiktionary.org/wiki/proto-

    7. Re:Where is the prototype? by Sir+Holo · · Score: 1

      Ergh. Darn it! Yes, you're right. You win. :-P

  4. This has been around a while by Dasher42 · · Score: 4, Interesting

    This has been around a while; kites, windbelts, and laddermills were my area to cover for presentations when taking classes on sustainable energy in 2010, and they were a lot of fun. Anything that gives you an excuse to play footage of the Tacoma Narrows Bridge collapsing and demonstrating the awesome power of wind is pretty cool.

    Kites hold a lot of promise; they're far safer for wildlife than any turbine, even the large slow ones that don't deserve their bad rap, and they produce up to a third of a turbine's power given similar operating area, for a tiny sliver of the material cost. Solar's cool and all, but wind power has become surprisingly diverse in its options tailored for different environments, and is becoming more so.

    1. Re:This has been around a while by jandersen · · Score: 2

      Solar's cool and all, ...

      Speaking of which - it would potentially be worth putting solar panels on the sunny side of a kite.

    2. Re:This has been around a while by mystuff · · Score: 1

      Indeed it has been around for a while. I'm not sure who the inventor is but I know that Dutch Astronaut Wubbo Ockels conceived the idea for himself in 1995 and start filing patents, the first one being 1997. Here's a video with a prototype which was used to (partially) power the music at a Dutch concert some years ago. Strange that there is no mention of him in the cited article.

    3. Re:This has been around a while by hippo · · Score: 1

      > demonstrating the awesome stupidity of the Tacoma Narrows Bridge designers.

      FTFY

      (Actually that may be a bit harsh, ignorance may be a better word)

    4. Re:This has been around a while by Sir+Holo · · Score: 1

      Yeah, the bad rap that big wind turbines get is undeserved.

      Skyscrapers and power lines kill far more birds than wind turbines.

      And, y'know, I never heard anyone sling that mud at the idea of a Space Elevator. . . I wonder why.

    5. Re:This has been around a while by Anonymous Coward · · Score: 0

      Yes, and yet there are no commercial kite generating stations that I know of. Heck, there aren't even any pilot projects!

      Kite generators are not sufficiently controllable IMO. If the wind stops or just falls below the lift minimum, the kite falls to the ground, damaging the apparatus. It's a tension tether apparatus with a single attachment point, so you need a roughly circular anchor and control pad. If you cannot exclude people and structures from the area of potential ground impact you have liability issues. Natural structures (trees and mountains, mainly) act as fouling hazards.

      Proponents always carry on about how the wind gets stronger and more reliable with more altitude. While true they avoid talking about how, with increasing tether length, you get more operational control issues. If the tether is long enough you become a navigational hazard for aircraft, ultralights and all the rest. Your tether is not just the anchor and source of mechanical strength either. It must also be the power transfer mechanism, under any realistic design scenario.

      How do kite generators deal with lightning strikes? Storms? How do you launch and retrieve such a system?

      I've never seen even the beginnings of a realistic engineering design for such a system. All I've ever seen are trivial proofs of concept and not one of those actually generated any power.

  5. why not kite with turbine and rotors? by Anonymous Coward · · Score: 0

    it seems like if you can get the winds to drive rotors, that would be a more efficient way to generate power from high winds....

    1. Re: why not kite with turbine and rotors? by Anonymous Coward · · Score: 0

      Kites are simpler. It's a trade off between efficiency versus cost and complexity

  6. 3 eurocents per kWh by vikingpower · · Score: 1

    is dirt-cheap. Here in Austria, I pay around 18 cents per kWh for power that comes for 80% from wind and water plants. I guess this part of the country would have a potential comparable to that of Switzerland, due to comparable geography: a rather flat basin (of the Danube) with the Alps close.

    --
    Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
  7. One handed clap by invictusvoyd · · Score: 2

    The second (and perhaps less researched) approach is to minimize power utilization . It finally has to be a balance between clean power generation and efficient utilization .

    1. Re:One handed clap by dbIII · · Score: 3, Interesting

      Less researched?
      It's the road most followed.
      Even traffic lights have LEDs in them now. People who did not care about building insulation at all a few years ago have it. Roofs are being painted white. We could always do more but it is definitely not being ignored.

    2. Re:One handed clap by invictusvoyd · · Score: 3, Insightful

      The largest power consumers of the future are going to be developing countries like China and India . Not much is being done there.

    3. Re:One handed clap by umghhh · · Score: 1

      condoms for the poor of the world would do too.

    4. Re:One handed clap by Sique · · Score: 4, Interesting
      That's a common misconception. The birth rates are high only in regions with a long lasting, ongoing civil war, like Afghanistan, Somalia or Zaire. And that are places where you can't distribute condoms without being shot at sight.

      Most other countries have continously falling birth rates, even the so called poor ones. The average birth rate in the African countries for instance is close to 2.5 children per woman, not much higher than for instance the U.S..

      --
      .sig: Sique *sigh*
    5. Re:One handed clap by Lennie · · Score: 1

      One word:
      Airdrop

      --
      New things are always on the horizon
    6. Re:One handed clap by Barsteward · · Score: 1

      thats not quite true. if you have a look on this site, you'll find out more about how much china and india are really doing
      http://cleantechnica.com/?s=ch...
      http://cleantechnica.com/?s=india

      --
      "The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
    7. Re:One handed clap by invictusvoyd · · Score: 1

      The link says nothing about reducing power utilization.

    8. Re:One handed clap by Sique · · Score: 4, Informative
      Appearently (and supported by much demographic data), birth rates are not related to the availability of common contraceptiva. Case in point: The pill, introduced in 1963. The birth rate in the U.S. was already declining at the end of the 1950ies, before the pill became available. The birth rate in European countries was declining only five years after the pill became available. Thus while the pill was available nearly at the same time in the U.S. and in European countries, the beginning of declining birth rates was 10 years apart. The introduction of the pill and declining birth rates seems to be a classical case of correlation, but not causation.

      Thus back to airbombing people with the condom: It won't affect the birth rate. Birth rates decline in all countries with rising female education levels and better health care, wether you carpet bomb them with condoms or not.

      --
      .sig: Sique *sigh*
    9. Re:One handed clap by Whibla · · Score: 5, Informative

      Not much? Seriously?

      In the 2006-2010 five year plan the real improvements in China's energy usage came from two programs.

      Firstly, in the Thousand Enterprises Program the government forced China's top 1000 companies to completely rethink their energy use. They were told to monitor energy efficiency, and redesign, upgrade, and / or replace industrial equipment and software with the aim of becoming more energy efficient, reducing the amount of power they used without denting their productivity. The other program was even more drastic. Thousands of small, inefficient, factory units and assembly lines across the country were simply closed down.

      The above programs were so successful (a roughly 19% cut in their energy intensity) that they were extended and expanded for the current five year plan: smaller, inefficient units are continuing to close down, and the Thousand Enterprises Program has become the Ten Thousand Enterprise Program. Current indications suggest that China has met its target of a further 16% cut in their energy intensity.

      In addition, China has more installed wind power than any other country in the world, and has the second largest installed solar power capacity. I've also read that they (the Chinese government) are actively looking at new nuclear power plant designs as well as thorium salt reactor designs, which is a direct contrast to pretty much every single western government.

      If all this qualifies as "not much" I'm not sure what it would take to impress...

    10. Re:One handed clap by Barsteward · · Score: 1

      says a lot about non-fossil based power generation which is the argument for kites.

      --
      "The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
    11. Re:One handed clap by Anonymous Coward · · Score: 0

      The link says nothing about reducing power utilization.

      Well, if we are going to be all sanctimonious blowhard about it, neither did YOUR GP post.

    12. Re:One handed clap by thegarbz · · Score: 4, Interesting

      Even if China isn't exploring new fancy nuclear designs, they currently have 26GW of generation capacity, they are bringing a further 40GW online in the immediate future (plants already under construction many of which are nearly finished), and a further 50GW of generation capacity is already planned beyond that. That's a bigger push for CO2 free energy than a lot of other countries are currently making.

    13. Re: One handed clap by Anonymous Coward · · Score: 0

      Only one problem, with the led lighting. It has to be kept clean. Old fashioned lighting was self cleaning in snowstorms, led, because of the low heating, has to be cleaned. It's not fun to pull up on an intersection with red light cameras, and waiting five minutes for the clear spot, because the others keep running the light, because they cannot see it.

    14. Re:One handed clap by RicktheBrick · · Score: 1

      Build far enough underground and there would be little need for air conditioning. There would be no weather problems. Driving in tunnels would be far easier as there would be no pedestrians or wildlife. Even if the costs are enormous and it take centuries to justify the expense, the savings after that would be far more than the expenses. We just need to learn from Bertha in Seattle.

    15. Re:One handed clap by dave420 · · Score: 3, Insightful

      I guess you just like having someone to point to and say "well, they're worse than me, so I can continue being wasteful", as you clearly haven't spent any time looking for supporting evidence.

    16. Re:One handed clap by Anonymous Coward · · Score: 0

      Gee. If China's actual wind power generation surpassed that of other countries like the US the way the "capacity" has then something might be believed. Also Chinese coal use is continuing to increase. Mao called for more metal production and indeed China did it. You can still sometimes run across this metal in new products. It isn't steel. It isn't anything standard. It is terrible. So when there is a mismatch like declared capacity vs production then it looks like Chinese metal.

    17. Re:One handed clap by rocket+rancher · · Score: 1

      There is enough energy in, on, and above the planet to provide for current needs, and for projected needs into the arbitrary future. Wind, solar, geothermal, and nuclear sources of energy can be -- and are! -- deployed more and more as energy scientists and energy engineers find ways to get to them and exploit them. There is no scarcity of energy on this planet, there is only a lack of access. So asserting that we need to use all this energy efficiently is misguided at best, and really doesn't help with the real issue, which is access.

      Let me rephrase this, slightly. Protesting we need efficiency when there really is no scarcity is the same misguided idea behind using fiscal austerity measures to fix broken economies. Just like with energy, there is *plenty* of money out there. And just like with energy, the problem is figuring out how to get to all that wealth and redistribute it so that everybody can benefit from it.

    18. Re:One handed clap by Anonymous Coward · · Score: 0

      quote ====
      In addition, China has more installed wind power than any other country in the world, and has the second largest installed solar power capacity. I've also read that they (the Chinese government) are actively looking at new nuclear power plant designs as well as thorium salt reactor designs, which is a direct contrast to pretty much every single western government.
      unquote ======

      The use of thorium as a fuel is actively researched-developed in Norway ,the country having large deposits of the mineral.

    19. Re: One handed clap by Anonymous Coward · · Score: 0

      Plenty being done in China.

  8. Makani leading the field by drewm19801927 · · Score: 2

    Up until a year ago I was doing research in this field. Google/Makani is by far the closest to commercialization at utility scale. They are already on their 8th prototype, a 600 kW version. Nothing public is operating anything airborne in the Megawatts yet.

  9. Aeronautical Hazards by GumphMaster · · Score: 2

    I can see a lot of fun with aeronautical obstacle databases if this takes off in a big way. Essentially a power plant will need an airspace allocation up to 10000 feet AGL and a nautical mile or two across. Put a lot of these around a city and there are many aeronautical procedure designers that will certainly be cursing as they try to thread an aircraft safely between them.

    --
    Patent litigation: A doctrine of Mutually Assured Destruction... in which everyone seems willing to push the button
    1. Re:Aeronautical Hazards by paulatz · · Score: 2

      Flight restrictions, both permanent and temporary, are already quite common, there are a few websites that show maps of them (one relatively user friendly is http://tfrvisualizer.com/ ), checking where they are and avoiding them is part of the normal flight routine.

      --
      this post contain no useful information, no need to mod it down
    2. Re:Aeronautical Hazards by painandgreed · · Score: 1

      Flight restrictions, both permanent and temporary, are already quite common, there are a few websites that show maps of them (one relatively user friendly is http://tfrvisualizer.com/ ), checking where they are and avoiding them is part of the normal flight routine.

      Ok, but how often are they accidentally entered into anyway and how many consist of 10,000' high series of barrage balloons equivalents probably capable to bringing a plane down?

  10. the kites look really cool by Anonymous Coward · · Score: 1

    Yes, sure, for us it does. I am pretty convinced though that the folks living in the neighborhood of such a power plant will have a different opinion on that.

    The 27MW takes 9 kites flying at 10km altitude. That means a measly 100MW plant will consist of 33 kites. A 1GW plant requires ~330 kites.
    Nobody wants this in their neighborhood, just as everybody likes wind-power but nobody wants the windmill in his backyard.

    Also, the large scale introduction of kites, flying at 10km height, is going to be an issue for aviation.

    1. Re:the kites look really cool by Rei · · Score: 1

      Who wants any kind of 100MW plant in their backyard? 100MW is an awful lot of power. Doesn't matter how you generate it, it's going to have to involve some combination of extreme areas, extreme pressures, and extreme temperatures - otherwise the physics doesn't work. If you want it small, it's going to have to be high pressure and/or hot. If you want it low pressure and cool, it's got to be huge. This ignores all other potential issues with each given type of power plant...

      --
      He's the sort of person who would sell the Red Cross to Dracula.
    2. Re:the kites look really cool by Anonymous Coward · · Score: 0

      That "Not In My Back Yard" argument always applies, though. You'd prefer a 100MW coal power plant or 100MW natural gas power plant in your backyard too?

  11. More 'global warming' propaganda... by Anonymous Coward · · Score: 0

    ...from 'Climatedot'. Are you sick of it yet?

    www.wattsupwiththat.com
    www.climatedepot.com

  12. At least the passive kites do not produce the hum by Anonymous Coward · · Score: 0

    Is not the Makani version then as terribly noisy as the ground turbines?

  13. How does the power conversion work? by Anonymous Coward · · Score: 0

    It's not entirely clear how the power conversion works. Does the kite fly in big circles and that circling turns a ground-mounted generator via a gearbox?

    1. Re:How does the power conversion work? by Rei · · Score: 2

      If I remember this company's tech correctly, the wind drags it out, turning a generator as it goes. They then switch it to a low-drag mode and reel it back in. So it cycles between high power generation and low power consumption. The concept being that you'd have many of them so that you'd get continuous net generation.

      --
      He's the sort of person who would sell the Red Cross to Dracula.
    2. Re:How does the power conversion work? by jafiwam · · Score: 4, Interesting

      If I remember this company's tech correctly, the wind drags it out, turning a generator as it goes. They then switch it to a low-drag mode and reel it back in. So it cycles between high power generation and low power consumption. The concept being that you'd have many of them so that you'd get continuous net generation.

      Slow and powerful drag out is going to have a massive, complicated, and hard to maintain gear box to run a generator. Generators run at hundreds of RPM. This is the same problem with big wind turbines, making power into RPM in a gear box is hard. If you have a wind farm around, look at the ones that are stopped they'll have black stains on them where the gear box failed.

      On a tower, they are difficult to service.

      On a floating, bobbing, need to use a boat to get to, they are probably going to have to un-hook them and bring them to shore to fix.

      Those kite things are overly optimistic given the state of the gearbox technology used today.

    3. Re:How does the power conversion work? by Rei · · Score: 1

      Sounds a lot easier than for a large scale wind turbine, the RPM is surely much higher - even if you need to gear it up somewhat.

      --
      He's the sort of person who would sell the Red Cross to Dracula.
    4. Re:How does the power conversion work? by Anonymous Coward · · Score: 0

      The generators in the proposed system are on the ground, not the kites, AFAIK.

  14. A stupid idea from stupid people. by Anonymous Coward · · Score: 0, Insightful

    Sounds like an idea from a techie green person who has not actually worked in the power industry.

    You're going to use linear motion, convert it to rotational motion to spin a rotor in a generator and make electricity.

    Stupid and wasteful. Not to mention the hazard of losing your investment when one of these crashes.

    If you want to be smart figure out how to improve the steam cycle or cumbustion cycle most LARGE power plants operate off of. Figure out ways to improve your efficiency, cheaply. Refurbish old coal power plants into a combined cycle plant with an HRSG.

    You're not going to be generating electricity en masse (700+ MW plants) free of the steam or combustion any time soon. Unless you're okay with inefficiency.

    1. Re:A stupid idea from stupid people. by rogoshen1 · · Score: 0

      Designed by Italians, not Germans my friend. Inefficiency is a bonus.

    2. Re:A stupid idea from stupid people. by Anonymous Coward · · Score: 1

      "If you want to be smart figure out how to improve the steam cycle or cumbustion cycle most LARGE power plants operate off of."

      Spoken as someone who really and truly has no idea what has happened to date in the power industry, and who has no clue about the laws of thermodynamics.

      These processes have been optimized for decades. Thermodynamics defines the maximum efficiency of all cycles used in combustion and heat transfer. The cycles used to generate power are already operating very close, or at the very least as close as practicable, to these theoretical limits.

      This is why the power industry is so focused on load management. They cannot build any new power plants because government, and they cannot squeeze any more capacity out of existing generation because physics. So, the only thing left is to manage load.

    3. Re: A stupid idea from stupid people. by Anonymous Coward · · Score: 0

      Rotational? Like in a coal, gas or nuclear or hydroelectric plant? There might be some prior experience. And I do have experience in this area...

    4. Re: A stupid idea from stupid people. by Anonymous Coward · · Score: 0

      Carnot cycle limits steam cycle efficiency. The most recent plants are at this. So unless you propose repealing some if the laws of thermodynamics...

    5. Re:A stupid idea from stupid people. by Rei · · Score: 1

      Well... to some extent. You can always run hotter to be able to get more efficiency - for example, that's why coal gassification is more efficient than burning solid coal, you can run it very hot through a gas turbine. Also, recovery of heat once it gets to lower temperature differentials is often not done, so some new work is in making that more affordable, which is a big boon to resources that are fundamentally lower temperature (like geothermal). And of course pairing the two, high temperature cycles with low temperature cycles.

      Thermal generation tech does keep improving. But you're right, it's not easy, and there are limits.

      --
      He's the sort of person who would sell the Red Cross to Dracula.
    6. Re: A stupid idea from stupid people. by DuckDodgers · · Score: 2

      Since the anti-environmental types tend to be the pro-capitalism types, I ask the parent post writer to look at it this way: the biggest expense for a fossil fuel power generation plant is the fuel itself. So they have the best reason in the world to pursue maximum efficiency: profitability.

      So unless someone presents credible evidence the fossil fuel power industry has been intentionally wasting billions of their own dollars, we have to assume modern energy plant efficiency is pretty close to optimal for the technology being used.

    7. Re:A stupid idea from stupid people. by Anonymous Coward · · Score: 0

      OP here, that was my entire point: that we ARE at the lmits of the thermodynamic cycle. So unless something changes dramatically like changing your working fluid (Tried before but does not work very well.) or semicondcutor, things are going to remain the same. There is no magic unicorn to solve electricity generation. The steam cycle is over 200 years old and is quite well understood as you said.

      It is not going to change barring some 'break through' at scale in semi conductors or water chemistry.

      Electricity generation falls into 4 major camps:
      1.) Use steam to turn a turbine to turn a generator. (Generated by heat by nuclear criticality, combusting coal, fuel oil or an HRSG, or concentrated solar.)
      2.) Combustion. (Gas turbines)
      3.) Use fluid to turn something coupled to a generator. (Wind and hydro)
      4.) Photo voltaics

      Linear motion as in literally per the article "pulling string to turn a generator". I stand by my comment calling it "Stupid." A lot of Engineering goes into combustion turbine blades and fan blades, putting it on same footing as as pulling a wire coil wrapped around a shaft does not do it justice. Same same but different. (Really, you can't begin to compare the two. One method actually works to produce electricity. The other is garbage.)

      Last time I checked people don't make electricity by throwing a rock tied to rope wrapped around a generator off of a cliff.

    8. Re:A stupid idea from stupid people. by Anonymous Coward · · Score: 0

      Gas turbines aren't using the steam cycle as previously noted. Steam cycles are pretty well optimised.

    9. Re:A stupid idea from stupid people. by Anonymous Coward · · Score: 0

      They will look very chic and desirable, though.

  15. Re:At least the passive kites do not produce the h by Beezlebub33 · · Score: 2

    Actually, even more noisy and higher pitched. The Makani turbines are quite small but the kite is going very fast, so plenty of power, but the result being that the turbine are spinning like crazy.

    --
    The more people I meet, the better I like my dog.
  16. Re:At least the passive kites do not produce the h by Rei · · Score: 4, Insightful

    1) I've stood directly underneath a 1MW turbine in the middle of a large wind farm on a windy day. There wasn't much noise at all, just a light whoosh... whoosh... whoosh.... I don't know where this concept that wind turbines are "terribly noisy" comes from, but it doesn't at all match my experience.

    2) You're concerned with noise about something that's hundreds of meters up? What about kite-based systems that operate at thousands of meters up, would you be worried about noise from them too?

    --
    He's the sort of person who would sell the Red Cross to Dracula.
  17. Overly complicated? by Anonymous Coward · · Score: 0

    I don't know, sounds a little overly complicated to me. How many failure modes are there, micro-bursts, tangled wires, damaged kites, landing/ascent modes, improperly spooled wire, and I assume more. There definitely right, get away from the ground and the wind speeds usually go up and become more steady. But accessing them via this technique seems difficult to say the least.

  18. Re:Another case of un-intended consequences by Rei · · Score: 4, Informative

    The global wind resource is 72TW. You're going to have a hard time denting that. You might alter things locally - might - but not globally.

    And besides that... if any evil greedy megacorp wants to move into my valley and setup something that will rob the wind of its energy... Please Do! Seriously, someone should really work on wind turbines specifically designed to act as windbreaks, in a manner that can be affordably mass produced and deployed in lieu of traditional manufactured windbreak systems.

    (Before anyone says "just plant some trees..." I do, every year. They usually get killed by the weather, sometimes outright uprooted. I may have to start spending more time on each tree individually, encasing each one in its own individual PVC windbreak in addition to the broad rows of pallet windbreaks)

    --
    He's the sort of person who would sell the Red Cross to Dracula.
  19. Remaining Skeptical by Rob+Lister · · Score: 2

    Having read the article, I'm entirely convinced this is not scalable; we're not going to power cities with this. I'm not convinced it is not useful in some places at some times; small remote towns that don't have anything else would find it cheap and useful. It is clever. Assuming the wind blows [way up yonder] with great consistency, this has a lot of promise. My gut tells me you'll need to fly at least three to make it close to distributable; Like juggling. Obviously the more that are flying, the more consistent the result will be (as long as the wind keeps blowing). My gut is often wrong. Can any of you smart guys model this?

    1. Re:Remaining Skeptical by DuckDodgers · · Score: 1

      But consider, the power generation for a city is already massive. I'm trying to find a useful example and it's hard, but look at 2013 Rhode Island electricity use in 2013, http://www.eia.gov/electricity... - 7.8 million MWh purchased (if I'm reading the page correctly). That's for about a million state residents.

      So to pick a nuclear power plant at relatively random, the Braidwood nuclear plant in Illinois generates about 20 million MWh per year at a construction cost of $5.2 billion. To generate the electricity needs for Rhode Island, you need about 40% of its production capacity. That would cost 40% of the $5.2 billion, or about $2 billion. To pick a coal power plant at random, the colossal W.H. Sammis power plant also generates about 20 million MWh per year, and I couldn't find a construction cost but a recent retrofit cost $1.5 billion.

      $1.5 billion or $2 billion buys an awful lot of kites, and an awful lot of land to fly them over.

  20. Classified as Drones by Anonymous Coward · · Score: 0

    In the U.S. these are classified as drones, and have to be registered with the FAA, unless flown indoors.

    1. Re:Classified as Drones by Anonymous Coward · · Score: 0

      A vehicle tethered to the ground that has no power source of its own is not a drone by any stretch of the FAA's definition of "aircraft."

    2. Re:Classified as Drones by drewm19801927 · · Score: 1

      In the USA they are classified as buildings. They even blink at the top and bottom of their circular flight path so that they look like radio towers to airplanes. As such, they are not regulated as aircraft, and for better or worse, have freedom in how much systems redundancy they add, how rigorously their software is tested, etc... In Europe, similar systems (i.e. like the one from Ampys) are regulated as planes, and have to use all aircraft certified stuff.

  21. Re:Another case of un-intended consequences by Anonymous Coward · · Score: 0

    "The global wind resource is 72TW. You're going to have a hard time denting that. You might alter things locally - might - but not globally."

    We certainly made a dent in climate change by increasing the global CO2 concentration by just a few ppm, which is the entire argument for these stupid ideas.

    If you are going to argue against fossil fuels on the basis that even a tiny change has significant global effect, you cannot then deny that same argument against your kite-in-the-sky utopian nonsense.

  22. A stupid comment from a stupid person by Anonymous Coward · · Score: 1

    Linear motion, like the expansion of a gas, into rotational motion, like the spinning of a turbine?

  23. Re:Another case of un-intended consequences by Anonymous Coward · · Score: 2, Informative

    We increased forcing from CO2 50%. The power didn't come from our putting energy into the system, it came from stopping the sunlight leaving so quick. Hence your comparison is ridiculous and moronic.

    But it was the "best" you had, so you went with it.

  24. Cool looking? by NetNed · · Score: 1

    It looks like a parachute. How exactly is that "really cool looking"?

  25. I want one... by Anonymous Coward · · Score: 0

    ...and I will mount a 10 megawatt laser on it. Selfpowered!

  26. More band-aids instead of a real solution by Anonymous Coward · · Score: 0

    We need Thorium reactor technology, not works-sometimes solutions that make only tree-huggers happy.

  27. why not run it on gravity? by slashmydots · · Score: 1

    So wind blows in one direction for the most part and they want to use kites to generate power? Kites blow in one direction too. It takes energy to pull them back. That's why you don't make an unlimited magical energy generator that uses the power of gravity. Gravity pulls in one direction so eventually you have to lift the item against gravity. The same basic principal happens with wind and kites.
    So use that as a starting point and then look at the diagram of the ridiculously over-complicated kite system they somehow "invented" and compare it to a rotating wind turbine, one of the simplest machines ever created. I'll stick with the turbines, thanks.

  28. Re:Another case of un-intended consequences by Anonymous Coward · · Score: 0

    Actually, wind turbines *do* brake the wind, and do so quite effectively. The wind in the rotor plane is 2/3 v_0, in the wake it's at 1/3 v_0 and then picks up again after a few rotor diameters. v_0: speed of the 'undisturbed' airflow.

    Any system to reduce wind speed would have to deal with dissipating the resulting energy, proportional to v_0^3. So why not use it to generate electricity? :)

  29. The Japanese and many others have answer by dbIII · · Score: 1

    I keep on hearing this but it's a long ago solved problem. One solution is in Japan where horizontal traffic lights are used in the south but in the north they have vertical ones with large gaps in the shrouds designed to not get clogged up with snow.
    Just because your area has not bothered to solve it due to fragmentation of government services does not mean that they cannot solve it by simply buying the solution of of a catalogue!

    It's also like arguing that solar panels are useless due to snow buildup while ignoring that the majority of the world's population live in places where it does not snow at all.

  30. Re:Another case of un-intended consequences by Rei · · Score: 1

    Thank you for repeating my point.

    --
    He's the sort of person who would sell the Red Cross to Dracula.
  31. Re:At least the passive kites do not produce the h by Anonymous Coward · · Score: 0

    It looks like you are one of these skilled trolls, good at pushing their biased point by slight omissions, subtle strawmans, partial logic fallacies. Who make this site more and more shitty.

  32. Re:At least the passive kites do not produce the h by Lupu · · Score: 1

    1) I've stood directly underneath a 1MW turbine in the middle of a large wind farm on a windy day. There wasn't much noise at all, just a light whoosh... whoosh... whoosh.... I don't know where this concept that wind turbines are "terribly noisy" comes from, but it doesn't at all match my experience.

    I've held a megaphone in front of my mouth and spoken into it. All I heard was my own regular voice, therefore I don't believe they work as advertised. In other words, it's all about direction.

    I've also been visiting a house about 1.5km(1 mile) away from the nearest wind turbine, with the noise disturbance inside the house being at such a degree that I couldn't believe our government could let this happen. When the noise hits them, the residents can't sleep and neither would you in similar circumstances.

    The issue seems to be mostly coming from the low frequency noise forming from the air pressure of the wing hitting the tower after the wing has passed. It seems to be very directed - directly sideways of the turbine.

    Another contributing factor is weather. Certain conditions can cause noise that is emitted on a rising angle to curve back downwards. When these rare weather conditions are met, we've found people much father away complaining about the noise while the residents much closer had no issue with it.

    Often there's more going on than immediately meets the eye.