DaveL,

Some time I must get around to finishing and publishing the spreadsheet
I did to prove what the best system is. The answer was totally clear so
I lost motivation to finish it off ready for the public.

Basically modern super-strong metals could conduct the electrical power
if you used a high enough voltage. The problem is the mass of the
turbines and generators is too great to lift economically.

Dyneema is so strong, cheap, fatigue resistant and safe that it comes
out as the clear winner at the moment. There are still plenty of
questions about how to best to use the tension in the dyneema tethers,
but storage considerations (and others) suggest a reel system.

Robert.

V3 basically teaches people how to build the turbines described in Hugh
Piggotts book. I have worked with one of them (Mark I think) to build a
turbine. Hugh lives in your neck of the woods. A self-built Piggott is
an economical way to make power in windy spots, but I think AWE could do
much better. Visventis aims to carry on and extend the self-build
philosophy.

Robert.

Rod,

It seems to me it is worth looking up a bit of history here. On 27th
April someone calling himself simon_0987 started a new wiki
http://airbornewindenergy.wikispaces.com/. I note that the site is still
there but Simon has not posted since 1st May. To save yourself the
wasted energy of reinventing the wheel it might be worth your while
looking at the site and Simon's posts to this group.

The Visventis philosophy is to promote hubs (real and virtual) with each
one having its own dedicated website which will be purely devoted to the
concepts that hub is working on.

Robert.

Just found a few links that may be new to the group about using kites as
anemometers. It is about the only application I can think of where
lighter than air concepts might be viable.

http://cires.colorado.edu/science/field/kites/
http://adsabs.harvard.edu/abs/1979WiEng...3..107B
http://adsabs.harvard.edu/abs/2010RScI...81g6104W
http://adsabs.harvard.edu/abs/1989TellB..41..196D

Finally here is a link to a whole PhD thesis from 1986 by S. Hobbs.
Plenty of maths and data for those serious about AWE.
https://dspace.lib.cranfield.ac.uk/bitstream/1826/918/2/sehphd2a.pdf


Robert.

DaveL'text can be also a first step fo making a comparison of ROI between AWE,but also between AWE and wind towers.A serious study can clarify the ROI and COP.

For now Reels (versus autogyro or kite flying crosswind) and Flygens (real wind, crosswind) schow some concrete results and perhaps comparable possibilies between them:the losses in electrical transmission and in propeller are compensated by the absence of cyclic recovering phase where electrecity is not produced but spent.The safety of ground-based generator is compensated by the simpler management of Flygen where only one configuration of flight is needed (excepted for lauching and recovering).Now it is difficult to see what is the best between them,but other means of conversion seems to be weaker and not proved or not calculated.

So we should make a comparison between better possible AWECS (Reel and Flygen and variants) and wind towers according to some criteria:

-Mass of materials (advantage for AWE);

-Reliability and maintenance (advantage for towers);

-Wear and Fatigue (see DaveL' post) (disadvantage for AWE);not enough resistance  in UV and other natural constraints (increasing by mechanical constraints) for fabric kites (only some months until new technologies in fibers allowed a great progress);tether for its different works as Dave Lang indicates; repercussion in turbine and kite respectively for Flygen or/and Reel in crosswind motion (for AWE) or big first investment in rigid wing;tether for autogyro-like (for jet-stream) being very long,its wear is also a serious field of cost.

-Wear and Fatigue (disadvantage for towers) of heavy components in quick motion (great rotor with great moment of inertia);

-Fatigue and expensive foundations (disadvantage for towers) due to the force on the whole tower.

But also:

-Little area of ground installations (advantage for AWE);

-Huge area above the ground (because of tether length no habitation being possible with perhaps an exception for AWECS harnessing jet-stream where the autogyro-like moves little or not) (disadvantage for AWE);

-Volume occupation (very high for AWE which must be implemented where it is possible to install no-fly-zone for planes,probably offshore);

-The power/front wind area (Betz output) with a great advantage for towers...

Now it seems that ROI and COP of actual wind towers are better than those of AWE,but the tendance can be reversed when  UV-resistant-high ratio lift/drag-lifetime 20 years-fabric-kites,or long-lifetime-long-tether (mainly in case of autogyro-like (for jet-stream)) will be available.

There is a great field of studies for universities;SkySails can also bring some experience about wear and real costs.Perhaps some players in the list (which Dave Lang) could also obtain some investments for producing some calculations.Indeed holdings like WOW SpA could make investments for such calculations before by far higher level investments making AWE work.After calculations we will have a better vue of what is lacking (principally in materials like Mark D.Moore (NASA) mentions).

PierreB

 

There can be a too long time before universities investigate real espected costs,ROI,COP in AWE.Nor such a study could be a precious tool to determine them,above all in comparison between AWE and towers.Such a study could be financed by the list and other investors,could receive an agreement from EnergyKiteSystems, AWEIA, NASA,ARPA-E...

PierreB

http://flygenkite.com  

The links in your post don't seem to work. I searched and can't find any reference to the superfluidity of UHMWPE or the 60 degree C number. The idea of it fascinates me but I can't find any good information.

Brian

-

Here's how concept comparison and product comparison work in wind energy:
A product is first shown to have a use. That is step 1, which we have not yet achieved in AWE.
For wind energy, uses such as grinding grain more economically than alternatives such as draft animals, verified early turbine designs.
So the first step is an AWE system or product that "does it better" than what else is available. What does "it" have to be? ANYTHING.

Then once you have products that are useful, people will buy them and install them and run them. Then you get to cost, performance, reliability, and longevity. Various schemes will emerge to make the product(s) reliable, using various means, at various costs. Slowly, the little things that go wrong with each product or type of product will emerge. The losers are self-eliminating, developing a bad reputation, while the survivors develop a good reputation.

Bit-by-bit, over a few years, wisdom begins to emerge: "this style of turbine seems reliable, but only if component X is case-hardened, or only if component Y is at an angle between N and M degrees..."
Over time, people and business using one type of turbine will have success, while others won't. Accumulated wisdom determines the continued direction of the art. What goes on, on this list, is SO FAR removed from that process, I'd have to say it is mostly only a wannabe effort, or a place where people can discuss their wannabe wishes that they even HAD an effort, which most do not. No amount of creating more and bigger bureaucracies or more complicated ways to talk about it will make a dent. Like Nike says "Just DO IT!"
:)
Doug S.

--

Yeah what I said as soon as I saw it: It's a piece of crap.
Of course I was going out on a limb there, telling what I saw as the simple truth. There were LOTS of press releases, by supposedly credible publications, saying it was good. I guess I had to have courage to stand up and say it sucked, eh? I mean in the face of all those "experts". We all saw many impressive renderings and photos. Government agencies like NASA and ARPA-E were top on the list of those regurgitating the Magenn P.R., if only in the form of using those Magenn images as their defining image of AWE.

That's like promoting Formula-1 Racing using an image of a wheelbarrow. But I GUESS that's understandable: It is evidence that this field (not industry), in its present state, is comparable to the wheelbarrow stage of development of wheeled vehicles in general, and Formula-1 Racing in particular. Yes it is that bad - NO real players, NO real products, NO contenders. People talking about turbines that require pilots to keep them in the air, just like a wheelbarrow needs a human to balance it! Yes truth IS stranger than fiction. All fantasy, all the time. And it IS a shame considering the extent of the resource and the number of supposedly "smart" people pursuing it.

Could this be evidence that those we assume are "intelligent" are merely automaton-like organisms, like we imagine bugs to be, functioning on instinct only? And that one instinct is to claim to be something called "smart", that remains yet undefined? I mean bugs build houses, farm for food, raise young - maybe bugs can figure out how to do AWE! Hey, It's a bug's life! I would do it but I have some other errands to handle today, and besides, it is too funny watching people talk endlessly about AWE, unable to DO anything about it, as though paralyzed. Very strange actually. "Help, I can't think my way out of a paper bag!" Gosh, this is just TOO Freakin' FUNNY! If I see one more 4-letter acronym pledge their undying devotion to pursuit of AWE, with no results, and really not even a plan of attack, I am gonna keel over from laughing! The only complete intelligent analysis I can offer is: "DUHHHH!" (With 10 exclamation points.) Have you tried enlisting the assistance of a kindergartener for guidance? One whose mind is fresh, not yet turned to mush?

Over the weekend I took couple hours to fabricate a couple of 8-foot diameter, counter-rotating gyrocopter/wind turbine blades. I think they weigh about a pound each. Not sure exactly what I'll build with them, but it DID cross my mind that what took me a couple hours and less than $20 in expenses, could easily have been a quarter-million-dollar project, starting with hiring people to write a grant proposal, then if funded, hiring a specialized aerodynamicist to design the blades, hiring a composites house to fabricate the blades, and a year or two later, having the same result: 2 blades ready for paint.

Said it before and I will say it again: Magenn merely takes the LEAST efficient type of wind turbine commonly built (Savonius) and makes it that much more expensive by filling it with helium. Not only can the numbers be shown (without the expense of building one) to be orders of magnitude from economical electrical power generation, anyone with any experience in wind energy could tell you at a glance, the Magenn apparatus would be severely challenged by anything but a light or medium wind. Survival of a storm would seem highly improbable.

So I say the answer to the question of what ever happened to Magenn is, it sucks (in its current form), and at some point people will realize that. Obviously some have. Real wind energy people have always known it sucked, from the first moment they saw it. Non-wind energy people are still discussing it, as though there were anything serious to discuss, and scratching their heads trying to figure it all out.

Maboomba!
:)
Doug S.

Yes understanding how to make power from the wind IS a good place to start. Rotating airfoils. Who knew? Most of the "issues" discussed on this list have been resolved decades ago, if not a century, or more. Even thousands of years, and I'm not even exaggerting.

Like people standing next to a freeway discussing how to get a proposed, hypothetical vehicle to move, bypassing the concept of a wheel as though it had already been disproven, or was somehow irrelevant. "Memory foam?" "A donkey?" "A donkey laying down on an upside-down treadmill that compresses air which drives walking legs?" Yup that is about how this list sounds to me. How to transmit power over a distance: covered: electricity. As long as one remains in denial of what is already known, one may pretend to be pursuing AWE without leaving your desk. Have fun.
:)
Doug Selsam

DaveL,

Like you point there are not evaluations from universities,but also probably not complete and enough credible evaluations from companies.For example if a cost like 0.03$ per kW/h (by far less than cost from wind tower) was proven or even only predictible, investments should be not something like 100 millions $ in the world but thousands times more.

At least a methodology could be realized for such evaluations.Then a complete study of only one element (for example wear of tether during reel operations) could be both an information and a prototype for further studies. 

PierreB

It is quite remarkable how success breads more success and failure tends
to follow failure. For the last 2 years Cambridge University has been
rated 1st in the world, so now, more than ever, it attracts the most
ambitions people from around the world. The result of that is that the
public can listen to lectures from world leaders in various fields
almost every day. Recently there have been a series of lectures on
graphene (single atomic layer thickness graphite). It was only
discovered a few years ago and those who did it have just received their
Nobel prizes. Yet in a short time amazing progress has been made. People
have discovered how to make it very cheaply and diodes and transistors
have already been fabricated with it. It shows fantastic promise;
computer chips 1000 times faster than silicon ones, diodes and
transistors to handle far more power etc. There are many barriers still
to cross but I was stunned at the speed of progress. Moore's law is not
about to stop any time soon.

You imply that every possible AWE system has been tried but a lot of
that work was done before the invention of materials substantially
stronger than nylon and kevlar and when computer chips were non-existent
or far more expensive than they are now. A local company, ARM, designs
the chips that go into 90% of mobile phones and they have far more power
than the first computer I used which filled a large building. Neodymium
magnets are only about 20 years old yet a Cambridge academic is talking
about making magnets far stronger. I believe they require
super-conducting temperatures but it still represents a potentially
significant step forward.

All these new developments mean we have to take a fresh look at AWE
tech. Structures in tension are still by far the strongest. The
difference is we can now use computer wizardry and power electronics to
control those structures while before we had to rely on making things
solid and stiff. If we can teach a human to fly a kite we can now
guarantee that a suitably qualified team could teach a robot to do it
even better. The robot can be made far stronger, and is can have quicker
reactions, which means it can fly a much more aerodynamic design that
would be too twitchy for a human.

Experimentation without the backing of a thorough theoretical
understanding is a waste of time. For this group to make better progress
it would have to form a team with division of labour. The theorists need
to predict which designs will work best. The practical people then need
to collect real results. That data gets fed back to the theorists who
modify their models and so on until a viable product emerges. Because
AWE has such huge advantages I do not think we will need many iterations
of that cycle to get there. Once a successful product is demonstrated
the billions of funding that Pierre talks about will start flowing.

At the moment I see 2 development routes with significant potential.
1) A minimal automation route rather like that taken by Skysails, but
using a reel in/out system. A large conventional soft kite is launched
and retrieved by some sort of robot arm and then controlled from the
ground by mimicking the techniques a human would use. As we learn to
compensate for the stretching of the tethers their length can be
increased to reach higher altitudes but initially tethers might only be
100m or so.

2) A fully automated design using a specialist much firmer and
aerodynamic kite, or dancing pair. Kite design will be instructed more
by modern model aircraft technology than kite history.

Once an AWE system is totally automated it becomes economical to make
them for the market that presently buys turbines in the 1 to 10kW range.
Farmers and remote communities of all types. Once people see the
potential of something in their own lives they will work to make it
happen. There are 2 billion people with inadequate power supply. That is
a huge potential work-force to write the software to automate those
kites.

Robert.

There is a danger of committing ourselves to the wrong road too soon if
we are not careful. For instance, say someone does a study on a certain
reel structure and concludes that the wear rate is too great, attention
gets pushed elsewhere. However, there are ways to keep wear down. One is
to have a large reel so that over the normal operating range there is
only one layer of rope on the reel. That cuts down rope on rope
abrasion. Another is to ensure that the tether is always under tension
and to control the kites in a way that minimizes change in tension. That
means there is less abrasion from the tethers stretching on the reels.
(Dancing pairs again?) Making sure the guide system lays the tether in
exactly the right place helps, and have a cleaning system included also
helps.

Recently I discovered that the shipping magnate Fred Olsen did an
assessment of AWE. (Another of those talks by a world leader in his
field.) He concluded that it was not ready to receive the 100's of
millions being thrown by the UK gov. at offshore wind power. How do we
convince him that he made too shallow an assessment?

Robert.

The sea-based version of the land-rail system. Not a reel-in-out, not a flygen.  

JoeF,

It looks like a promising scheme meeting three elements with potential of high convergence:kites (a system managing the train could be studied),sea,hydro-turbines.

PierreB

JoeF,

It looks like a promising scheme meeting three elements with high potential of convergence:kites (a system managing the train could be studied),sea,hydro-turbines.

PierreB

Totally agree with this sketch.
It's a simple integration of existing tech.
Could be more easily worked with a taller cable loop being pulled crosswind near the surface down to the bottom along and back.
The trick bit is moving the pulled cable around the central seabed tether, staying centred down wind.
A way of moving the cable around is to have the bouyed and (wedge / bruce) anchored pully point extents lifted as the kite travel shifts round with the wind. The cable crosswind length needs to be less than the normal reach of off wind travel of the kite... This balance can be achieved by paying out and reeling in the central tether to adjust for wind speed..Payed out for low wind in for high with faster end to end cycles.

The whole thing does however have the habbit of making a large ring mess on the seabed.

I had a very similar drawing a wee while back. But with turbines under the moving craft. Thus avoiding the need to shift the position of the cableway when the wind direction changes.

But better still I think is a held surface array of barges. (such as a muscle farm...)
Generator blades can spin their loops above (in air) and below (in the dense brine)

Also sea flora and fauna thrive on surface debris.

Or of course make seabed railway circular

Oh,
what about a circle of say 12 or more fixed tether floating barges with a loop of cable run around pulleys on their top.
A short tether from this pulley cable runs to a barge (kite board dynamics) with a kite controller.
As the barge moves cross wind it pulls the large radius cable reel around.

That's how to do it.

Here you go  a drawing and operation description

Dave S.:
Yeah but I was talking about generating electricity from the sky.
Sailboats etc. are great but not really AWE in the sense of the next advance in wind-generated electricity.

JoeF,

When I speak about reel-out-in efficiency,it is above all with regard to my precedent scheme http://youtu.be/OSWORXEy3tE 
which is a lever system with advantage of possible continuous power but the disadvantage of high strengths in the structure in the case of enough lever length providing complete conversion;such a scheme can be converted into a reel-out-in scheme.

Since it is expected high-scale AWECS will be offshore,a conversion with hydro-turbine is a pertinent way.

PierreB,
http://flygenkite.com

Maybe a little off topic but I have some articles by Moriarty on use of weather balloons as anemometers, some local guys were interested in cheap wind surveys. I'll stick em in the files section under an anemometer folder. And along those lines I proffer the 'easy anemometer' - wind speed thru angle of repose:

http://www.rutmans.org/jeremy/wind/easy_anemometer.pdf

the full video of my kite in partnership with SkySerpent :)
PM

I read this article today.
http://www.thebioenergysite.com/news/10081/jet-stream-cannot-contribute-much-to-renewables

It has been republished at many web sites. It seems to stem from this as yet unpublished paper.

http://www.earth-syst-dynam-discuss.net/2/435/2011/esdd-2-435-2011.html

I have not yet read the whole thing, but the gist seems to be that the jet stream will slow and or move if we extract power from it so we can't get as much from it as previously predicted. Even this lower estimate seems enough to go after. However IMHO the jet stream already moves to much to be a attractive target in the short term.

Brian

Basically what Miller & Kleidon have done is ask, 'what simplifying
assumptions can we make to make the potential of wind power look as
pathetic as possible'.

If you go to the interactive discussion link
http://www.earth-syst-dynam-discuss.net/2/435/2011/esdd-2-435-2011-discussion.html
and look at the comments by Kirk-Davidoff and Bergmann you will see that
there are many problems with the paper. Having reviewed this work I am
reassured that there is more than enough energy in the wind to power
everything we could want to do, and it will not cause significant
weather change by doing it. However, that is a hypothetical point
because solar power will share the major work-load with wind.

AWE in the jet stream is unlikely to ever be economically viable anyway.
Studies have shown that if we covered the land surface with turbines
reaching to a maximum of 200m they could generate all the power we use
today. If we limit ourselves to just 10 times higher using AWE out to
sea we need only use a tiny part of the total wind resource.

Robert.

Waves, thermals, plants, mountains, wheat stalks, animals, birds:  the entire set of objects on or near the surface of the earth is daily slowing the wind near the elements of that set of objects.  Then in the slowness there are pockets of slowed air that get heated; those pockets of heated air get released as bubbles of air or thermals; those thermals rise and slows the horizontal wind. 

Some support: 

In the paper: 

sorry... the link is here... :)
PM

The whole question seems premature. As Robert pointed out we can meet our entire energy demands many times over before we ever reach the jet stream.

Brian

1) For an expected massive application as new infrastructure making evaluations of wear of tether according to reel-out/in scheme (UV + abrasion during reel operations + different loads during power phase and between the point of changement out/in,in/out,_note Dyneema has a high resistance in UV and in traction,but a low resistance in abrupt changes of load),flygen or hydro schemes (UV + different loads during power phase).

Making evaluations of wear of fabric-kites,but also of rigid-kite by taking account of special tensions generated by tether configurations of flight which can be very different of free flight (like for usual planes) configuration.

If possible making evaluation of ROI (only in regard to cost and wear of materials) for the next ten years,then the further ten years (according to expected improvments of materials) etc.

2) The most important is making AWECS for a (even limited) commercial use which is not possible with non-AWECS.For example in a first time Robert's AWECS or mine's could be non-automatized and have applications like relief operations where wind access is not possible. 

PierreB  

Saving Germany's Whales from Wind Farm Noise - Spiegel Online.Wind towers,as solid constructions,are a great vector of vibrations which noise.The paper says that excessive noise is dangerous for whales and cetaceans and can cause their disappearance of the earth.A by far lesser noise is a forceful argument in favour of AWE.Such an argument could enter ROI study.

PierreB,

http://flygenkite.com  

Looks good Paolo!
:)
http://www.youtube.com/watch?v=x6V-6GsHzJM