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Classification Challenge
AWECS-classification schemes working folder
AWECS Classification Challenge Committee (ACCC)   
Most recent edit of page: Mo/da/yr: 10/24/2012

A classification allows a faster understanding of systems, advantages, and disadvantages according to systems' common main features, and that with a concise presentation. Studies of possible uses of systems will be easier. The joined presentation allows furthering insertion of other systems, corrections, and improvements of presentation. Links on websites or videos can be created. It would be interesting to keep steps before a conversion into PDF which could be a document for presentations towards organizations like NASA.  PierreB http://energykitesystems.net/AWECSclassification/PierreB/CLASSIFICATIONforAWECSbyPBnov2010.pdf    

Committee formation:
Meta-comment regarding committee formation:  WayneG suggests that there might be two committees:
1) One whose goal would be to pursue "People Friendly" Tethered Flight Technology to benefit everyone everywhere.
2) One for those that wish to pursue "People Targeting" Tethered Flight Technology to benefit some people at the expense of others
-- such as monitoring people that do not want to be monitored.     
WayneG, November 10, 2010.   
In a second round expression: "I think we need two committees. One for those who choose to develop Tethered Flight Technology to benefit mankind in general -- and only with those of like mind -- and only disclosing their knowledge with people of like mind. And the other for those that choose to develop Tethered Flight Technology to aid and assist any group that already has vastly greater military power than its opponents."
WayneG, November 11, 2010.   

Comment by JoeF on 12Nov2010:  I am happily struggling to hear Wayne; the last clause had to be wrestled before I understood; I here state what I believe to be an example that helped me understand the clause: say an AWECS worker P in Belgium has a set of opponents; those opponents may or may not have much military power; however those opponents stand in relation to other non-self groups; some of those groups may have military power greater than the opponents of Belgium.  I do not know of any opponent of Belgium, as I am not steeped in knowing such matters yet. But suppose that set of opponents is non-empty and we let that set be symbolized as set M. And let the the set of nations or groups that are not opponents to Belgium but have stronger military power than the military power of members of M be symbolized in the set designator O.    Then I am surmising that the second type of committee would hold P of Belgium and be choosing to develop TFT to aid and assist members of O. Why would one help those who are stronger militarily than one's opponents?   One's opponents want to do harm to oneself; those opponents might go gain the assist of more powerful militaries to injure oneself.  So, if one is willing to assist groups militarily more powerful than one's opponents, then one would consider joining the secondly mentioned committee. The tacit implication expressed, I am struggling, is that a member of the secondly mentioned committee would not be people-friendly and would not be wanting dominantly to benefit everyone everywhere. I am having difficulty with this matter because "everyone everywhere" includes those who might choose to harm others directly or indirectly.  So, I am urging that classification schemes be firstly neutral tools with the assumption that the tools    are like wheels and gears, potentially used unfortunately to hurt, but more importantly potentially useful for doing great good.  See a commentary by WayneG placed on a page on its own in this committee's folder. ]]

When forming the ACCC, I did not make Wayne's distinction; personally, I want to reach solutions that raise good for people in a manner that replaces systems giving less good; I would not want injustice to be tolerated in the process.  Classifications of AWECS might just be neutral tools that could be used for good or poor.   So, I do not know if ACCC is one or the other of Wayne's two choices or perhaps neutral to the bifurcation suggested; maybe the classification challenge could be met without having to decide what is being pursued relative to friendly factor. Of course, of the many possible classifications, some might be purposed for People Friendly, while some classification might be used in ways that deposit inequity. I have asked WayneG to clarify what he means by "monitoring" people, as such is yet unclear to me; he clarified that monitoring people has to do with collecting and analyzing information comprehensively by the use of airborne devices over countries and their people; that is as I understand from his note, which see JoeF, November 11, 2010.

Nominated-not-yet-accepted committee members, so far:   Dave Santos, David Lang, Wayne German (iff there is a "People Friendly" mission to a committee), Dave Culp, Richard Ruiterkamp,  

NOMINATIONS ARE STILL OPEN:  M2516 of Nov. 11, 2010.
October 19, 2010, e-mail to DaveS, JohnO, WayneG, AlexanderM, and PierreB: Rough outline started. PierreB has done some significant work on classification. See also our two methods files: see above for the two links.

Accepted their membership in ACCC:  Alexander Muzhichkov (AlexanderM or Alex Mu or AlexM), Joe Faust (JoeF), Pierre Benhaïem (PierreB), ________, ___________, ___________

Notes to protem secretary for the committee may be sent to JoeF:      Editor@UpperWindPower.com


See thread in group  M1739

Wiki goal, two main files. Develop other files on companies.

Terms of description of a given system.


Committee-member input original Secretarial redaction without intentionally changing substance Discussion spawned from the left two columns per row.

July 1, 2010   Working note re: Wiki

As co-founder of Ampyx Power, I am very interested in your extensive Wikipedia contributions on high altitude wind energy. There is however something that is missing in the structure of the wiki. Both the topic high altitude wind power and airborne wind turbine lack the theoretical structure as described in M. L. Loyd , J. Energy, vol. 4 - no. 3, 1980. In this paper Loyd deduces the theoretical optimum power production for stationary and moving tethered kites. In doing so he describes all the possible scenarios of tethered flight, with the exception of aerostats. As an example of this structure the differences in approach between Ampyx power, Joby Energy, Makani and other techniques becomes more transparent.

So I would like to propose to re-structure the wiki pages with the distinction of two varieties of airborne wind energy techniques: Aerostat (i.e.,  lighter than air platforms) and Aerodynamic variety (heavier than air). The latter category would then fall apart in three sub-categories: Static variety, Drag variety and Lift variety.

To demonstrate the use of this categorization Makani is working on an aerodynamic, drag power variety whereas Ampyx Power works on development of the aerodynamic, lift power configuration. To further clarify the different techniques, only in the aerostatic and aerodynamic static varieties will there be plans for high altitude wind energy (i.e. above 1000 meters altitude). In the aerodynamic drag and lift systems the maximum (and optimum) altitudes will be below 800 meters. As you might understand, this distinction is of importance to our project since a completely different set of legal/technological/social requirements are expected between turbines that aim for jet-stream deployment and low altitude aerodynamic varieties such as Joby, Makani, and Ampyx.

Dr. R. Ruiterkamp
Ampyx Power

  • Proposed in the note is this scheme:


    • Aerostat
    • Aerodynamic
      • Static
      • Lift
      • Drag


Commentary and actions relative to the suggestions on the left.
  • Lois or Loyd did not seem to cover free-flight AWECS.
  • Lois or Loyd did not seem to cover the free-flight tether holding kite at each end of the tether.
  • Loyd or Lois also both did not seem to face the free-flight AWECS systems that employ LTA compounded with HTA working kite.
  • There are methods that are compound wherein LTA parts compound with HTA parts.
  • Ampyx Power describes use of the groundgen Yo-yo method using rigid auto-piloted kites with a safety system monitoring the autopilot; this alternates power gain in downwind cross winding with low power cost in reeling-in low-angle-of-attack segment. The tether can be non-conductive.
  • The suggestion of "static" seems to miss that aerostatic and drag methods may indeed have dynamic tethering to take advantage of changing winds at various altitudes. Such dynamic tethering could also play in free-flight AWECS that may be aerostatic hybrids or not.
  • [ ] The two main wiki articles HAWP and AWT are to be examined with the committee of Pierre Benhaïem, Dave Lang, Dave Santos, Joe Faust, and others working on the "Classification Challenge" for AWECS.
  • The legal/technological/social environment is geo-politically variable and remains a sector of evolution.
  • The 800 m point is still being examined. Sweet spots for a particular precise AWECS may well be an envelope of altitudes that differ from the suggestion.
  • Proposed in the note is
    • Aerostat
    • Aerodynamic
      • Static
      • Lift
      • Drag
  • That simplified suggestion misses many systems and many alternatives.

Still working in committee on these matters,

Thank you,
Joe Faust

methods of airborne wind energy conversion systems


PierreB  on Nov. 10, 2010 enters matters for consideration:

A good scheme for classification should let contain all types of AWECS. Here is a trial for finding "determinants".

- A) fixed working station (most systems); B) mobile working station (ships with hydraulic turbine)
- A) I) groundgen; II) flygen; III) other place (example between flight member and ground).
- AI) a) reel-out; b) cyclic; AII)a) dynamic (ks)kite systems (Makani,Manual Flygen...) or mka)mixt kite-aerostat like Twind); b) static (aerostats like LTA or mixts like Magenn...)
- AIb) o) oscillating motion (Kitelab,OrthoKite...); c) carousel (KiteGen...);t) torsion (Serpentine with an airborne component)...
- AIa),AIb) and AIIa) 1) control near flight member; 2) control near the ground
- AIa1),AIa2),AIIa1),AIIa2) x) automatic control; y) human control; xpc) passive control;xca) control with avionics)...
With a schema of type tree reading is easier.


Here will be an effort of re-presentation of what is in the left column from PierreB on Nov. 10, 2010 by secretary JoeF: [effort session will be continued; not done, of course; pause]

A good scheme for classification should let contain all types of AWECS.
Here is a trial for finding "determinants".

  •  A) fixed working station (most systems)
    • AI) groundgen
      • a) reel-out
      • b) cyclic
        • AIb)
          • o) oscillating motion (Kitelab, OrthoKite...);
          • c) carousel (KiteGen...);
    • AII) flygen
      • a) dynamic
        •  (ks) kite systems (Makani, Manual Flygen...) or
        • mka) mixed kite-aerostat like Twind);
      • b) static
        • aerostats like LTA
        • mixed like Magenn...
      • t) torsion (Serpentine with an airborne component)...

    - AIa), AIb) and AIIa) 1) control near flight member; 2) control near the ground
    - AIa1), AIa2), AIIa1), AIIa2) x) automatic control; y) human control; xpc) passive control; xca) control with avionics)..

    • AIII) other place (example between flight member and ground).
  • B) mobile working station (ships with hydraulic turbine)
  • Notes:
    • Reading may be easier with a tree-type schema.

  • PierreB
Note: PierreB has published:   "A flygen is a configuration of AWECS with generator aloft."

Discussion: How will we handle an AWECS that has a generator aloft and a generator on the ground in the one system?  Bi-positioned generator?   JoeF, 14Nov2010.

Alex Mu on Nov. 11, 2010 puts on the table:

Really a quantity of AWECS types defined by multiplication of all variant that you mention in “Miscellaneous aspects of systems”, means 73*73=5329  or more. Many of them obviously are not realized and can be just in imagination of authors.

I suppose the main question is first in your list: “What work is being done?”. All kind of ideas about AWECS are like tiny brooks, but there are main let say “rivers” like Laddermill, Magenn,  and so on, that are already realized in any case. And they must be determining names in classification. There will be--in any case--some kind of natural selection. And only working (or at least tested) models have a chance to stay in history.

I suggest a classification like in nature, for example, webbed monkey. In our case is like Laddermill robot-controlled. This structure will be formed itself; we just can help it by discussions on forum. It means, that classification will be made not from theoretical sight but from sight of inventors. And I find it right because we make it for completely new sphere.

Other question is to collect and classify different means how to solve different problems. For example,
Decreasing weight of apparatus:
1. Fabric structure
2. Inflating with gas
Energy transmitting:
1. Alternate/reciprocal motion of tether
2. Common alternating electricity
3. High frequency electricity

Increasing of lift traction:
1. Cascade of kites
2. ….

Some methods can be described more detailed, other can be nominal. Most models has just one peculiarity and all other parts are taken from other models. Expediently to name a peculiarity but not all kind of it combinations.
Such classification will be also very useful for all inventors. Very observed. It will be exact what you search: not simple and not complicate.

I hope you understand what I mean and may be you find good in my reflections.

Have a good day

Alex Mu

  • We are finding good in your reflections, AlexMu.  Some translation fuzziness will be smoothed in time. 11Nov2010 JoeF
  • In hobby scale someday, thousands of variations will be explored and become part of history.   11Nov2010 JoeF
  • v

In 2004 Dave Lang put forward a classification scheme.    http://www.drachen.org/journals/a16/Using-kites-to-generate-electricity.pdf  


Some distinction therein: low-tech versus high-tech.  Then he constrained focus to power level range from "municipal to small domestic."
     He identified five methods of producing electricity:

  1. Ladder Mill
  2. Reel
  3. Fly Gen
  4. Buggy
  5. Sail

In the article, DaveL specifically  put aside bifurcations as to type of wing used in systems.       However, DaveL went further in the article to make a comparison even with a kind of metric over 12 parameters; the rating produced a best to least best  or "bad" scheme.

  1. maximum power potential
  2. scalability (ability to accommodate a range of power)
  3. practicality
  4. potential for autonomous operation
  5. manufacturing cost relative to return on investment
  6. prototyping cost
  7. complexity
  8. safety relative to design intent
  9. environmental impact
  10. accommodating wind variability
  11. probability of success when demonstrated
  12. probability of operational success


Commentary by committee members:
  •  Commentary by JoeF on Nov. 11, 2010:  2techs x 2ormore power levels x 5 methods=20 or more. Then upon the 12 parameters: 20 or more x12 parameters = 240 or more concerns.
L. Fagiano on a rough classification:

Altitude range: Boundary Layer vs Jet Stream
Lift type: Aerodynamic lift vs Aerostatic lift vs Rotorcraft
Generator position: Ground Level vs On Board

  • Altitude range
    • Boundary Layer
    • Jet Stream
  • Lift type
    • Aerodynamic lift
    • Aerostatic lift
    • Rotorcraft
  • Generator position
    • Ground Level
    • On Board


  1. Groundgen, rotorcraft, jet stream
  2. Groundgen, rotorcraft, boundary layer
  3. Onboardgen, rotorcraft, jet stream
  4. Onboardgen, rotorcarat, boundary layer
  5. Groundgen, aerostatic, jet stream
  6. Groundgen, aerostatic, boundary layer
  7. Onboardgen, aerostatic, jet stream
  8. Onboardgen, aerostatic, boundary layer
  9. Groundgen, aerodynamic lift, jet stream
  10. Groundgen, aerodynamic lift, boundary layer [KitEnergy]
  11. Onboardgen, aerodynamic lift, jet stream
  12. Onboardgen, aerodynamic lift, boundary layer
The objective of this system study is to assemble a complete picture of these systems to help establish a foundation for this future industry, and support the wide variety of concept approaches.  NASA, November 2010    
How does a particular AWECS use the THICKNESS opportunity of the air space?    
Mobility opportunity of mooring    
Strata opportunity of wing    
  • How might tethered aviation move people through the air? 
    • One big way is to have AWECS supply the electricity for e-PAVs.
    • Another is the free-flight methods
      • Gust mining
      • Dynamic soaring
      • Bi-kite free-tether dynamic soaring
    • Cable nets. Sail on the cables.
    • Kite-up launching followed by long glides partially sustained by PV and energy from AWECS at ground stations.


In Discourse, page 35.   Yr: 2010
by Joe Hadzicki and Dave Lang

Now let’s consider three main variables: lift
device, generator location, and flight path.

Generally speaking, three different types of
lifting devices are currently being used to
access higher altitudes:
1. Aerodynamic lift using kites or rigid
aircraft style wings
2. Aerostatic lift using aircraft similar to
3. Rotorcraft using devices not unlike

Generators are used to convert the motion
produced by the wind to electrical energy.
These generators can be carried on board
the flying device or located on the ground.

  • Lift device
    1. Aerodynamic lift using kites or rigid aircraft style wings
    2. Aerostatic lift using aircraft similar to blimps
    3. Rotorcraft using devices not unlike helicopters
  • Generator location
    1. Onboard
    2. Ground
  • Flight path
    1.  “reeling out/reeling in”motion
    2. “cross-wind” flying motion
M2960   Pierre B.    
Abbas Rezaey  aims at a classification scheme:
Introduction into Airborne Wind Energy Concepts

  1. Lighter than air concept 
  2. Lift and drag concept
          High drag coefficient concept (kits, hybrid kits…)
          High lifting coefficient concept (wing, laddrermill, system presented by sky wind power ) 
  3. Tower concept 
  4. Hybrid concepts

          High drag coefficient with lighter than air gas
          Low drag coefficient with lighter than air gas
          High drag coefficient with lighter than air gas with tower
          Low drag coefficient with lighter than air gas with tower