Pessimism v. Optimism means nothing. If wind energy works well in next future for offshore HAWT but not for AWE,it is all the same a good thing for renewable. AWE has two ways to contribute in wind energy: as a component for a sea/groundborned system, and as a whole system. The winning design (if it exists) should look simple and obvious, as the current design of HAWT. So forget the style of a kite linked to four pulleys whereas six supplementary ropes run under twelve other pulleys acting a swivelling tray linked to a secondary element allowing alternating right and reverse AoA... Forget also obviously non-workable elements like (for kites) passive-control, being good for kite-art or even for some energy production but only for some hours, like kite-pilot (how do you launch both kite-pilot and power kite ?!), and above all fancy conversion systems like flipping with no possible production but maybe with some applications within kite-art as funny AWES.Please DaveS forget also Heidegger: for you conversion in wind energy is already difficult to understand, and Heidegger is also very difficult to understand. Forget also numerous futile arguments: a good system speaks by itself and is easily understood.

The serious teams like DELFT, Makani, Ampyx, Windlift, etc..., by making a very good job, show kite systems have serious problems like moving tethers on great areas. My idea is these designs are not enough AWE specific: kite + turbines, kite + reel system etc. AWE design should look simple and recognizable, not a juxtaposition, and of course not an accumulation of devices to correct devices to correct other devices... So it is possible to deduce the tether must be stationary, both lift and crosswind power being assumed by rotation. So AWE winner could be a sort of gyrocopter with specific features making it light and huge.

PierreB

Rod, 

     I am not confident that I have captured the description just given; here is a draft of a first round interpretation of the description:   (thanks for any correction or redirection)

http://www.energykitesystems.net//DRAFTDRAWS/DRAFT001.jpg

A start sketch: 

http://www.energykitesystems.net/Structures/AftToTether/AftToTether001.jpg

Even such seemingly most simple structure has infinite variations; which among the variants will solve some need important to someone? 

Still have to work on getting the driver kites skinnier but this is showing some promise.

Want to tie it all to only work on an outer tether set too.

Last years and yet now, said crosswind kite systems (yoyo and flygen) were studied in first as most promising schemes. But some deeper analysis shows problems like moving tethers over a huge area, like non optimized both swept area and worked area, like also irregularities of power (see on videos on http://flygenkite.com ) and losses, probably stresses in both tether and wing, the motion being not as natural as rotor motion. These problems can be qualified as inherent problems: with a tether in nanotube, with some improvements, the problems will stay, making such schemes non economically viable with regard to HAWT. So the tether and also the flying member should be stationary, crosswind motion being assumed by the blades like for a HAWT or a gyrocopter, the swept area being optimized. But actually such autorotating kites are too heavy and are able to fly with more than 6 m/s wind speed, making it not (yet) viable. Is an inherent problem or a problem of engineering? If some features make gyrocopter able to fly with 2-3 m/s wind speed by producing energy on the basis of half swept area with correct Betz ratio, AWE will have a foot into viability.

Are searchers making crosswind systems in some organizations like Delft or Makani newbies or Crackpot? Of course no, there are fine searchers making optimized job about all components, from active-controle to aerodynamics, the chosen solutions being actually better; but without enough taking account of the difference of inherent problems and problems of engineering, or more probably having not yet the possibility for that.

So the (for the moment) non-viability of AWE makes possible all ridiculous theories with futile arguments like I cannot prove them (but I assert 3 times/week as basis for Mega-Giga-Watt-Scale) but you cannot prove they do not work; makes possible the perpetual false confrontation enters Doug and DaveS, Doug posing correct technical (comprising about SuperTurbine(R)) and historical assertions and fine analysis about correlation between them, but without convincing enough due to interferences with qualifications of newbies and Crackpot, and also sentences like "all roads go towards SuperTurbine(R)"; and DaveS collecting both false technical directions by promising the world with fabric and string ,and hair-splitting under appearances of skill. So the "match" between Doug and DaveS is finished for a long time: of course  Doug was the winner. 

So concerning a tethered AWE I propose studying different features for a lighter gyrocopter-like. All people for it is welcome for a real cooperation, even DaveS with his high qualities of dynamism. Please DaveS make good science! Stop with F-B-E (flipping Böse-Einsten), stop promising the world with Mothra-Arch which is even not an AWES (where is the conversion system?), only a kite being able to fly in prevailing winds, only a basis for funny "Kixel" AWES, please return to correct schemes like yours in www.energykitesystems.net/KiteLab , please listen to Doug more instead arguing and arguing.

PierreB 

Rod, 

    One target direction might be missed if the "taut" downline is taken for granted; one target is to obtain robust negative kiting to give the down tension with little dependence on simple mass for the tautness. It costs to keep mass aloft. Negative kiting gives variable tautness for downing whereas once mass is accepted the downing cost of that mass for itself is constant, not variable. Ultralight tactics are encouraged to obtain robust substantial negative lift that would be variable and correlate with wind variation.     The lead ball is just part of an exploration, not intended to be central giver of tautness in the main target exploration.   We keep the mass of a sled kite low to win flight in low-speed winds; similarly in negative kiting one target is to keep the mass low so that positive-lifting systems (kite system or bridge, etc) have less work to do to carry the constant mass of the negative-kite system. 

Best, 

JoeF

JoeF,

Thanks for precisions. I think in an helicopter-mode like SWP ,being able to be launched by itself, and being stationary during power phase. Some targets: different designs for decreasing the weight and increasing scalability, towards an use also for low (100-600 m) altitude, high altitude becoming later.

PierreB

Autorotating-blade flygen (HAWT) with aloft-generated electricity sent to ground via electrical conductor by Dave Santos many years ago; shown item is in an AWES Museum in Low Angeles inspiring others to our field. Pierre just placed a link to a page holding this photo:

"Los Angeles"   

spelling correction, not "Low"     ;)

Clarifying an incomplete explanation on SWP; rather SWP is not a gyrokite when it is powering as a helicopter with a hung power-giving conducting tether; but when such power is not being used, then it enters a gyrokite mode. In total, SWP is a hybrid that shares captive helicopter life and also gyrokite life; two phases; if the SWP releases the tether during special choice, then the resulting glider would be a gyroglider, unpowered, but perhaps still generating some electricity during the glide down, if it so chose (gliding might occur better if no electricity was being mined during a glide during a recover or landing operation).    SWP is welcome to comment. 

~ JpF

Clip and interpretive captions: (others may add caption comment). 

Clarification of a caption:

The "brace to allow knee action" is also formed to hold the torque for use by the generator only and not to twist the main tether.   DaveS might caption this matter better. 

~JpF

Notice that the rig shown may be trained in two ways: 

1. Repeat branches off the main tether for unit HAWTs. 

2. At a branch multiple ultralight blades may drive the shaft, a tactic known well from early patents and also forwarded by Doug Selsam in later years; Doug's patent does give some citing to some early multi-rotor patents, but not all. 

Note that such system generally fits Pierre's stable-position advice.

Note that such stable-position training may be repeated to form farms both left and right and area-filling downwind of first line of trains. 

Note that the system may be scaled also by blade length. 

Provision of lift by the lift system may be supplied by single-wing or trains of multiple wings. 

Electricity made aloft may be routed into separate or unified tethers. Some treatment of the electricity may be done aloft, if needed or chosen. 

Note that electricity made aloft need not be the only way to transfer the HAWT energy mined; rather, driven loops per several published research instruction might be employed; such loop transferred energy then may be converted on the ground to electricity or used directly.  Note that ganging such loop-carried energy may be a tactic to drive central electric generators on the ground. 

~ JpF

Doug asked about the "AWES Museum in Los Angeles, California"   ." Where is it?  What are their hours?  How many exhibits do they have?  Why do I not find it using Google?"   

Here is the entry in the AWES Glossary:

==================================

AWES Museum is in an embryonic stage without open hours. Direct visits are not permitted; some items are shown in visits at exterior venues.  Los Angeles, California. Founded by K.I.T.E.S.A. Holdings are objects, papers, books, and digital records. Stewardship of most of the matter is by EnergyKiteSystems and shared to the world online.  Others may enter items for the collection by e-mail or URL reference or by postal mail arranged with the curator.   

=========================

Note: Google will eventually get wind of AWES Museum.

Underwater "divers" partially inform on topic; however mass challenge for topic is quite apart from the mass use in underwater divers that are paravanes or water-"flying" kites.   

Here is a photo of Dave Santos' Underwater Kite Museum

http://www.energykitesystems.net/DaveSantos/KiteLabUnderwaterKiteMuseumDaveSantos.jpg

(high resolution image)

The design from SWP could evolve towards  www.energykitesystems.net/Beaujean/index.html  ,a rotating design with huge diameter but using "small" blades and no hub. In such a design, some inherent problems in AWE can be topped: (for crosswind kites) moving tether, hazard from both a single unity and a farm, non-controled whole swept area...; (for helicopter-mode) the low ratio area/weight. But a huge work in engineering is needed to reach such a system by making also feasible elements. In the end a huge work in engineering to reach a viable AWES is better than inherent problems after realization.So to make a viable AWES, it is better to imagine the whole system without (or with little) inherent problems and evaluate needed engineering to make it from small to utility-scales. But sometimes it is not so easy to make a difference between inherent problems and problems of engineering. http://wheelwind.com is an attempt where the rotor is also seaborned, but conversion makes an _inherent_ problem due to generator in tip blades. So I study other possibilities. Note that SuperTurbine (R) is also a possibility but only (for an utility-scale and according to me) in a light semi-rigid structural configuration allowing a greater diameter for the tower-shaft without excess of weight and drag, that by latticework structure (fig.32 of Selsam's US2002192068). Indeed tethered configuration making it too difficult to launch, too dangerous due to the risk of contact between rotors, too heavy to fly in a correct angle, and not being able for a correct transmission by torsion.

PierreB

Precision: "(for helicopter-mode) the low ratio swept area/weight."

Pierre B

Thanks for this - I watched the video with my mouth gaping - also - an RF quote is always a pleasure for the sane and rational amongst us.

DougS, 

       You are invited to see the different rooms that are always open 24 hr per day. Visitors are welcome to most of the museum's rooms. You have been visiting one of the rooms almost daily, this room: AirborneWindEnergy  where access is open to you and others in the world for viewing shares, discussing technical matters, etc.  

The AWES Museum exists and is growing by the contributions of many people. The collections are kept in various rooms both online and offline; the offline rooms are open by appointment with the curator. Some of the collection goes mobile and is presented by the museum at various exterior venues for show-and-tell-and-discuss sessions.    You and others are invited to increase the collections for sharing. 

Here is a dated snapshot of the AWES Museum front room: