Slow Chat

Yeah a sign post saying “wrong way - turn back”.
I agree, it “looks” like a compelling design. Checks a lot of the right boxes. Unfortunately it also checks a few of the wrong boxes:

  1. The “vertical-axis-type” (in this case we can call it “cross-axis”) turbines,
  2. The rooftop mounting…
    To wind newbies, rooftop mounting “seems” like a no-brainer.
    Rooftop mounting indeed appears quite attractive.
    People, especially wind newbies, almost always like rooftop-mounting.
    Seasoned potatoes - er um I mean wind people, on the other hand, usually try to steer people away from rooftop mounting. As much of a slam-dunk as rooftop mounting seems like it should be, find one successful example.
    Just imagine - every newbie wants to use rooftop mounting, yet you can’t find a single successful example… Hmmmm…
    Well, it’s possible they all just ruin it with a cross-axis turbine, right?
    (Professor Crackpot always ruins any good invention by adding bad features - why? He’s nuts!)
    Then again look at the rooftop turbines installed at Logan Airport in Boston.
    Regular horizontal-axis rotors. Still didn’t work out.
    I think they were removed long ago.
    twenty years ago the big story was the new world trade center building would feature wind turbines. Paul Gipe and I both said “No it won’t”. Who was right?
    I had a rooftop turbine installed on a concrete block industrial building with steel framing.
    Worked OK, but even though it was mounted on rubber pads, the noise still permeated the building. Then the building owner made us take it down. A wood-frame house is like a giant acoustic guitar body. A wind turbine is like the strings. Any attempt to put a turbine on a house gets “wifed”. That’s when the wife says “take it down!”.
    I’ll wait to hear back after you’ve found the rooftop wind energy installation that is operating on a daily basis that everyone is happy with… Out of 7 billion people, there has to be one, right? Right???..

Fair point. No one wants a sleep deprived psychotic wife. That’s like being strung up by your nutsack. No guy wants that in his life. Quickest road to divorce and race to the bottom. Directed noise cancelling sound proofing still going to hard to sell. Even to the most determined of enthusiasts. If airports and former WTC decide nope. I wonder what spoiled it? Oh it noisy. It transfers too much vibration to the superstructure. like you said its a long list. Just a shame it don’t tick more boxes. As it would be more widely used. Or widely recommend. It has it challenges. If it can avoid being nuked by the wife’s of suburbia. The Viability goes up. By a factor of 4. Round where I am the neighbours would be the main problem. Envy or jealousy might do it in, in the end. It only take one of the to turn on you and problems. Over coming those hurdle would be the hardest part. Noise complaint and you have you local authority breathing down your neck. They are none too kind. Got some reading up to do if I find something i let you know.

SuperTurbine ™ has all the characteristics required to be installed on a roof. Multiple units can allow each unit to self-compensate for vibration.

Yes, it’s true. Just pointing out, rooftop mounting sounds like a slam-dunk, but so far has not worked out. In the case of the SuperTwin™ we installed, it worked OK, but the owner made us take it down before we got to the point of taking any data. I do not recall if it ever received any strong winds before we had to remove it. I think it was during the off-season.

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I had preached the false to know the true.

What I see here is one more case of “paralysis by analysis”, where people would rather sit around trying to figure out how to make everything into some complex math problem, often without really taking into account some of the most basic aspects of wind energy. Yes laddermill should have somewhere near zero tether drag compared to kite-reeling. I don’t see where that requires any math to figure out. Just one more reason why I’ve been disappointed that nobody ever built a laddermill after all that fanfare. I mean, if laddermill was not a good idea, then why did we celebrate Ockels in the first place? Just to keep the name laddermill for something else? I seems to me that immediate;ly degenerating into math-land rather than just building a crappy laddermill, then a better one, then a still better one, was the first mistake. Oh sure, rather than 100 wings going in a continuous loop, let’s just use one wing - it will be easier. Meanwhile we can sit around scratching our heads doing math problems to rationalize never building that first laddermill. As I’ve said from day-one, this field is pathetic in that nobody has ever even tried some of the simplest configurations. Oh well, some people would rather sit around at their computers trying to apply various mathematical formulas than get into a shop and build things. I’ve designed, built, and sold, many wind turbines, and a few AWE experiments, including generators and airfoils, and I don’t think my math has ever gone beyond simple arithmetic and knowing a few basic facts. You quickly get to the point where all you need is for things to “look right” and they work. I say “step away from the computer”. Cleanse your brain of all that debilitating math, get creative, use your hands, and get something running. You can do all the math you want, and you will miss one thing, and your machine will fly apart. That is when you start actually figuring things out.

Well doing mind experiments is way more effective use of time than building stuff. The analysis I just did gave some indications of where we would like to be heading.

You can improve incrementally, but if the physics are not sound, you can not prevail in the end.

No comparison to myself, but I read today that Betz did not produce a single physical device, still was hugely influential.

Paralysis exists, but this is not it. Also did I mention my day job involves building and flying AWE rigs? That does not prevent me from thinking about AWE physics, nor does it slow me/us down

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OK but if you are doing backflips on paper, to try to compare a kite to a wind turbine blade, and do not even take into account the fact that a generator is slowing the blades of a wind turbine, then what good is all that gibberish?
On the other hand, I did enjoy reading your links to Kitemill’s progress, and it seems like Kitemill is making decent gains, unlike most of the other kite-reeling efforts.

do not even take into account the fact that a generator is slowing the blades of a wind turbine

That was an error that was subsequently fixed. So if that ends the discussion over doing calculations over building stuff, you are not really having a fair conversation, rather just wasting time trying to win an argument

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Well good to correct it, but it’s just an example of people not understanding how wind energy even works at the simplest level, yet spending all day mathematically analyzing and postulating over stuff that either makes no sense, or leads nowhere. Out of all the papers written, presentations made, conferences had, in-depth analyses, CAD simulations, renderings, postulations advanced, etc., which one has turned out to yield any success? I’d take an ounce of focused effort that leads somewhere, over a ton of misguided busywork, handwaving, and happy-talk that leads nowhere.

Hi Doug, the difficulty is that a “crosswind” AWES is not intended to be only a wind turbine, but also a tethered drone flying in 3D in the end of a long tether, using a lot of artificial intelligence (AI). Mathematics are useful to improve the control among other things. One wrong equation and you end up with an AWES in your house.

47 posts were merged into an existing topic: More laddermill / spidermill ideas

I don’t see a great similarity. Kind of like a tricycle and unicycle are alike

I’m minded to agree with Pierre and Dave on this
It’s the ol fig5
And BTW… Please don’t reference unicycling into another aspect of AWES again :roll_eyes::joy:
It’s already a control theory
Ruins the sport for those of us who enjoy the practical

There are several variants of Payne’s patent figure 5 which describes two pulleys that are connected to the respective generators, and a tether connecting these two pulleys to the kite flying crosswind:

Kiteborne’s variant (on the video) where there are also two pulleys but only one generator.

I sketched another variant with two winches and two generators, one tether being stretched while the other tether being slack, and vice versa.

All these variants are discussed at What is possible with Payne's patent US3987987 figure 5?

I suggest that the currently discussed variant is also posted on the topic above.

I waded through 85 posts and nothing remotely similar. You seem to be making a point that this is an old idea when actually you have not understood what I was trying to convey.

I will accept maybe its an old idea, maybe even I have read about it then forgot. Its not terribly important, but please then just link to an exact match, dont send me to somewhere vague. Also if you dont want to join the discussion for any reason thats ok to. But saying «THIS WAS DONE» over and over just adds noise.

None of the «variants» you propose have similar functioning.

I stress; this is a pulley drive, not a pulling energy transmission. The kite position should be fixed in this design. It is «nothing» like Payne no 3.

Dave Santos, Rod Read and me find the same thing: it is reported to Payne’s patent figure 5. I have linked “your” system to other variants of figure 5.

“But saying «THIS WAS DONE»”: I did not say that, I indicated your design is a variant of figure 5, because that’s what it is.

Ok. Can you explain why you find that?

So I am glad we now agree that this design is a variant of figure 5.

Topic starter wants to discuss this idea, whether it is old or new. Beyond informing the reader the idea might be similar to other ideas, which can be done in a single post like Dave has done, the above discussion is off-topic.

Unclear title though I think, @tallakt.

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