--- In AirborneWindEnergy@yahoogroups.com, "roderickjosephread" <rod.read@...

OK Thanks for that interesting article on ropeways Bob.
It goes on for about 30 pages without mentioning the ropeways I'll be spending much of my winter riding: Chairlifts and Gondolas!

OK yes I found the part where electricity is generated:

"The most spectacular system, which has been tested in hurricane winds of 249 km/h, was built in 2007 for a Jamalco/Alcoa bauxite mine on Mt Olyphant in Jamaica (picture above). It is 3.4 kilometres long and has a vertical descent of 470 metres. The installation conveys some 1,200 tonnes of bauxite per hour from the mine to the processing plant, saving about 1,200 truck journeys per day and generating about 1,300 kWh of braking energy per day, which is fed back into the power network. The transport network thus doubles as a renewable energy plant."

The other example given says the cargo is lifted, but then talks about braking energy generating electricity. Let's be realistic: virtually any electrical machinery can generate some power when braking. Regenerative braking is a wonderful thing, and thee grid is a good place to put that power, but what power plant uses reels and cables for power transmission?

The economics are difficult to ascertain from such a brief article.
However I'd have to honestly guess that without the main use for transport of cargo, the electricity-generating portion would not be economical. In other words I don't think you are going to construct one of these for power generation alone and get 4 cent electricity, other than if you needed to brake the cableway anyway, if that brake happens to generate electricity, of course you are gonna use it.

Nonetheless it was a good answer, and an interesting article, strangely without much emphasis on the cableways millions of people ride every day for winter fun - ski lift! Let's go catch some air!

:)
Doug S.

OK Harry, take your example of Magenn.
Now let's say the machine is just barely able to lift its own weight. Also realize it turns slowly so any power will have to come down at low RPM meaning with high force. Seems to me the poor, tortured Magenn machine will only be able to produce a very minimal amount of power before it's pulling itself down from the sky! The power will be limited to what extra lift the machine has, times the speed of the cable, which we already know is slow. So instead of inventing a way to transmit power from the dubious Magenn system to the ground, you've invented a way to automatically lower (pull) the Magenn machine to the ground!

Now let's say we have a wind turbine flying in the air by aerodynamic lift. So it's using some of its power to stay aloft, like a gyrocopter. Similarly, it will only be able to transmit so much power through a clothesline on reels before that force exceeds its lift and starts pulling the machine down from the sky.

Something tells me there is a natural limit, similar to the Betz equation, whereby you can never get the full amount of even the Betz power in the wind using this method, since the cable is always traveling with the thrust force rather than sideways to it, kind of like a vertical-axis drag-based machine uses part of its energy to push the upwind side against the wind.

In our case, using a reel that wants to pull the turbine down out of the sky, a certain amount of energy must be expended to keep the machine from pulling itself down from the sky. That may be a large proportion of the available energy. (?)

Might be worth looking into a bit more.
:)
Doug S.

Did you get a chance to look at the drawing I posted yesterday Doug. Spinning kites pulling a skilift style line across the wind. Nothing really flying. Everything tied taught to earth.

There he is again, "the Nostradamus of AWE".
Sweeping pronouncements. Ultimate authority. Unlimited veto power. The final authority on all questions. (!)

OK Dave if you, and these multi-million-dollar players, are so on top of it all, why exactly IS Magenn a "leading" scheme? Why, if it's such a complete losing proposition, does NASA piggyback on Magenn's renderings? Why is Magenn shown in all the AWE PR? Doesn't ARPA-E, with all those "scientists" and millions of dollars, use it? Do real wind energy efforts show pictures of Savonius turbines? Could it be that these people are complete idiots on another Solyndra mission?

Why is a sideways barrel shape "terrible?" It's not the shape, it's because they use Savonius rather than Darrieus, which would be merely "suboptimal".
Oh and the main method all the big players are pursuing: reeling kites is now "just another brief historical phase". Why don't you call them up and tell them their next step?

Dave if you have ALL the answers, why not use that crystal ball and show us something workable beyond a toy for light winds that could briefly light an LED or two?

What I say about reeling pulling down on a machine that we are trying to keep up, applies also to pulsating pull. You know why you are talking about pulsating? Because as long as there is something that nobody wants to bother to build, including you, it can be talked about as though it's "the answer"

Build them and run them and see what the problems are. (Oh darn this is work!) Then you'll be on to the next phantasy like the dual-kite world-wandering system using microwaves to fry the populace - er um I mean "beam the power to power plants" (again, any economical examples?) that I heard another equally emphatic hypothesizer at the first ever AWE conference promote endlessly.

In wind energy there are knowns, ignored by newbies at their own peril. Magenn for example is popular because they actually built one and it can actually fly and so photos are available, yet it's a typical know-nothing newbie idea that ANY wind energy person can tell you sucks and not only that it sucks, but exactly WHY it sucks. All known. Why people are not building flying wind turbine is beyond me. I have plenty of designs that have NOTHING to do with Superturbine(R) and if I had even a spare day or two I could build them.

I think you and most of these "big players" are somewhere between lazy and completely asleep.

:) Doug S.

It can become a good design for AWE:small light turbines,high rpm,,scalability.

PierreB
http://flygenkite.com

Look carefully at the non-progress of reporters over AWE: 

--- In AirborneWindEnergy@yahoogroups.com, "Dan" <spiralairfoil@...

You covered pretty much everything Dave.
Keeping it simple like in this aero efficiency video...
http://youtu.be/4CdbBHzw8yQ
You're into physical efficiency leading to design which is more efficient than current popular wind gen tech. cool

I'm sailing on a 100yr old community dipping lug rig fishing yacht tomorrow. It's loose lines are no power match for a tight rig yacht. Yet it remains viable, has good wind range, stability, handling, it's an older design and it looks nice too. Aesthetics and other human factors will greatly influence the future of AWE.

I think that's partly why I'm using toys (when I get time in the loft!!!) The aesthetics are there, they are psychologically suggestive toward safety, fun, futures, growing, possibility, transformation, imagination...

Superturbine with wings inserted into a increasing elastic dia close to a ground based gen, Cant wait till I get round to making that tower of tubes.

Press releases, The journalists I know are bone idol with no time for investigation.
We could / should write state of research reports, stating heavily the future potentials with plenty of copy evidence ... and release them.

You mentioned wanting to be in a film about this, maybe you need a PR manager, a press officer, certainly a better camera and web presence organisation, tidier looking kites, but definitely keep the hoodie.

mar sin leibh

http://www.youtube.com/watch?v=JamIacRogRU&feature=share

While this is not a direct topic, it is.

Dan'l

Large flocks of untethered starlings, observed by young women in a canoe.

David Suzuki, science show host, speaks to the Occupy Vancouver assembly.  20 min. + 5 of supplements, very well done synopsis of the world situation and the inspiration for the Occupations.

OK Dave S., can you give me the formula for how much a non-buoyant wind energy system can weigh versus its swept area and how much that further reduces the amount of energy that the betz coefficient allows?
OK now how about the formula for how much more energy is lost (required to maintain altitude) if the power is transmitted by pull up a tether (pulling the AWE device downward), based on tether travel speed? Thanks.

Oh what's the matter? No formulae to offer? No carefully-thought-through Betz-like mathematical thought-experiment derivation? Gee Dave with all your omniscient pontificating, I would have thought you had all this figured out, but nobody has even looked at the basics. Even you. We have no basic formulae to even start from yet.

See, the fact is you DON'T answer my questions. Nobody has. I don't see that anyone even RECOGNIZES the main questions. Airborne wind energy is not even up to where regular wind energy was when Betz first put numbers to the point of maximum energy extraction from a given area.

Carry on with your edible paste, round-ended scissors, and construction paper. No you should not eat the paste!
:)
Doug Selsam

Nice example of someone actually building something simple and new that really works! The pilot and his family seem glad he survived.

I noted in the article that P.J. Shepard of SkyWindPower expressed her desire that Makani be successful. As a long-time (multi-decades) fan of the Shepard designs and concepts, I don't understand why Shepard SkyWindPower is not currently successful. I don't see any flaws in their overall approach, to at least have something in the air. Looks to me like SkyWindPower just needs some careful execution to make it happen.
Doug S.

***Thanks Dave you confirmed everything I was saying. Glad you stood up to the Magenn guy - I did not realize the promoters were serial scammers.
:)
-Doug S. ***

http://newsok.com/oklahoma-doctor-diagnoses-new-way-to-capture-wind-at-ground-level/article/3619759?custom_click=lead_story_title

he even uses the term super turbine - wonder where he got that?

Reminds me of FloDesign.
Next-Gen Wind - God even the name sounds just like all the other idiot monstrosities. I remember one called NexWind Energy - Alex Kollitz I think the guy's name was... he would never shut up til he finally went away with his multi-ton machine that could probably not even equal a regular 100-lb machine.

We've fielded the claims of these morons for years on the regular wind energy groups. They always come in guns-a-blazin' with their claims of superior performance, only to slowly disintegrate as reality sets in, and eventually slink away, tail between legs.

Let me use these money-wasting imbeciles as one more example. Here's the basic question in turbine design.
The goal in wind energy is:
a) How much material can you use to maximize the power through a small space?;
b) How little material can you use to maximize the power through a large area?;

The correct answer is answer b. (of course)
3000 years of working wind energy (that we know of) have taught us much, to be ignored at one's own peril.

:)
Doug S.

So do it and shut up.
You write far more than I can read.
Consider brevity. Consider substituting actions for words.

Your bungees are already in US 6616402

Given that a kite can't stay up without some tension on the tether, I don't see any problem with having that tension be on a moving pulley system.  The return line may double the weight, but it can serve as an overload preventer as well.  The power available will be the product of the available line tension times line speed.

Please see Fig. 98.
All roads lead to...
me.
:)

Thanks Bob for a concrete answer, to back up Dave S.' assertion that there's no fundamental math that has been ignored in the talk-talk-talk field of wannabe AWE.
Yet Bob's answer implies that a kite's weight is the LIMITING FACTOR on power output from a kite. He seems to say it is not a factor and you can get as much power as you want and seems to agree with Dave S. that my concerns for a formula are baseless. But a closer examination reveals that if your tether reel speed is limited, your power output will be limited by the tension in the tether times the tether reeling speed. This might in turn be limited by, say centrifugal force, air friction etc. So the weight of a reeling system would seem to be a limiting factor in power output, as would reeling speed of the tether. That's just off the top of my (pointed) head.

I'd like to propose a thought experiment in response:
Say you have a kite energy system that is barely able to keep itself aloft in a given wind due to its own weight. Say the tension on the tether varies between 0 lbs and 100 lbs. How much power can this device now transmit by pulling upward on a tether, steady-state? The answer might be close to zero, since any pulling upward on the tether by the device will tend to want to pull the device downward out of the sky.

Obviously there must be some maximum amount of power that can be pulled down from the sky by this method before the device itself is pulled down from the sky. The power would seem to be limited by whatever extra lift the device has (extra tension on the tether) times the tether's speed. So if we merely increase the tether's speed to an unlimited speed, can we then extract unlimited power from the tether? How does that unlimited tether speed affect centrifugal force at the spinning, circular reels? See what I mean? Some numbers could be put to all this. And what about that dreaded return cycle? Ya know, where you gotta give some of the energy back, or at least not make any power, as the system retracts? Personally, I prefer a steady-stae system without a retraction cycle but there's more fodder for requisite equations.

This is similar to the realization Betz and others had that a wind turbine slows the wind by extracting energy, and that there is a maximum level of energy extraction that can take place before you are slowing the flow so much that you have less energy to extract from that slowed flow. It's a case of effect/counter-effect, or action/reaction.

Anyway in all the press-releases from the big players, and in all the pontificating and 5-second, grainy videos from the peanut gallery, I have seen no such basic mathematical derivation that would indicate that any serious player has done the slightest amount of "on=paper" homework seen in normal engineering efforts.

:)
Doug Selsam

-

Technically, it is a video, and technically, it does show something.
I think you could do a little better job of video presentation, without getting into studio-level production quality.
Then again I have been wrong before. Coffee is a big business and some people like to grind their own. Good luck with your new device!
:)

Lights on tether are required for visibility of  the airline pilots.It is not a little challenge.Problems are:unwind and roll up tether in case of integrated lights ,and also what feeds the lights with electricity,a ground generator or a generator aloft with turbine (flygen scheme seems to be more advantageous) . I have a solution for both two problems.What are your ideas about it?

PierreB

http://flygenkite.com

 

--- In AirborneWindEnergy@yahoogroups.com, "Doug" <doug@...

Nice video.
Explains why I don't seem to care how much money I make.
That patent might as well be a coloring book.
It contains a teeny fraction of the wind energy ideas that come too fast to write them down. Superturbine(R) is just one concept of thousands. There are possibly great ways to do wind and AWE that nobody has ever contemplated. I'm talking about basic ways that have never been touched on or even anything close.
:)
Doug Selsam

I'd say your onto something. If the kite and/or it's line has to be lit, like either an airplane or a tower, then designing that lighting system is yet another engineering effort all AWE players will need to do. Having a separate company provide appropriate and proven lights just makes sense.

Brian

Tether visibility in AWECS?

JoeF,

"Will the tether report its position by calculation of top and ground point reports only?

Will the tether report its position from many markers along the tether? "

The tether being not immovable (excepted for Skywind Power for example) such a report should be difficult.

My idea is lighting is an additional (and compulsory) security since the aerial space should be forbidden for the complete (rather a shape of parallelepiped allowing the planes to continue their road without detour) volume aera from a permanent installation of AWECS, especially an AWECS-farm,according to all wind directions and the length of tethers.

If it is not the case,at least the quarter of said volume according to wind direction:a collision with a highly tense tether of AWECS can be more dangerous than with tether of aerostats.

PierreB