Messages in AirborneWindEnergy group.                          AWES 26089 to 26138 Page 413 of 440.

Group: AirborneWindEnergy Message: 26089 From: joe_f_90032 Date: 6/16/2019
Subject: Re: Soaring Thermals by Passive Auxetic Control

Group: AirborneWindEnergy Message: 26090 From: dave santos Date: 6/16/2019
Subject: Re: New Multi-Line Ground-Anchor Design

Group: AirborneWindEnergy Message: 26091 From: dave santos Date: 6/16/2019
Subject: Re: Soaring Thermals by Passive Auxetic Control

Group: AirborneWindEnergy Message: 26092 From: joe_f_90032 Date: 6/16/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26093 From: dave santos Date: 6/16/2019
Subject: AWE's Weird Hidden GW Capacity?

Group: AirborneWindEnergy Message: 26094 From: benhaiemp Date: 6/16/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26095 From: joe_f_90032 Date: 6/16/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26096 From: benhaiemp Date: 6/17/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26097 From: dave santos Date: 6/17/2019
Subject: "Crash Landing" SIngle Skin Kites

Group: AirborneWindEnergy Message: 26098 From: benhaiemp Date: 6/17/2019
Subject: Re: "Crash Landing" SIngle Skin Kites

Group: AirborneWindEnergy Message: 26099 From: dave santos Date: 6/17/2019
Subject: Curtailing Bats for fast wing AWES?

Group: AirborneWindEnergy Message: 26100 From: dave santos Date: 6/17/2019
Subject: Re: "Crash Landing" SIngle Skin Kites

Group: AirborneWindEnergy Message: 26101 From: dougselsam Date: 6/17/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26102 From: dave santos Date: 6/17/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26103 From: benhaiemp Date: 6/17/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26104 From: Peter Sharp Date: 6/17/2019
Subject: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26105 From: dave santos Date: 6/17/2019
Subject: Re: Gipe'a AWES Testing Standard (quote and link)

Group: AirborneWindEnergy Message: 26106 From: dave santos Date: 6/17/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26107 From: benhaiemp Date: 6/17/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26108 From: tallakt Date: 6/17/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26109 From: tallakt Date: 6/17/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26110 From: benhaiemp Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26111 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26112 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26113 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26114 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26115 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26116 From: Santos Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26117 From: Joe Faust Date: 6/18/2019
Subject: BloombergNEF

Group: AirborneWindEnergy Message: 26118 From: Peter Sharp Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26119 From: Peter Sharp Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26120 From: dave santos Date: 6/18/2019
Subject: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26121 From: Peter Sharp Date: 6/18/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26122 From: Peter Sharp Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26123 From: Santos Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26124 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26125 From: Santos Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26126 From: Peter Sharp Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26127 From: Peter Sharp Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26128 From: Peter Sharp Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26129 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26130 From: Santos Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26131 From: joe_f_90032 Date: 6/18/2019
Subject: Re: Minesto News

Group: AirborneWindEnergy Message: 26132 From: Santos Date: 6/18/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)

Group: AirborneWindEnergy Message: 26133 From: benhaiemp Date: 6/19/2019
Subject: Tethered Vertical Axis Wind Turbine (TVAWT)?

Group: AirborneWindEnergy Message: 26134 From: benhaiemp Date: 6/19/2019
Subject: Re: Tethered Vertical Axis Wind Turbine (TVAWT)?

Group: AirborneWindEnergy Message: 26135 From: tallakt Date: 6/19/2019
Subject: Re: Tethered Vertical Axis Wind Turbine (TVAWT)?

Group: AirborneWindEnergy Message: 26136 From: tallakt Date: 6/19/2019
Subject: Re: Active Lift Turbine VAWT

Group: AirborneWindEnergy Message: 26137 From: dougselsam Date: 6/19/2019
Subject: Re: Minesto News

Group: AirborneWindEnergy Message: 26138 From: dougselsam Date: 6/19/2019
Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)




Group: AirborneWindEnergy Message: 26089 From: joe_f_90032 Date: 6/16/2019
Subject: Re: Soaring Thermals by Passive Auxetic Control
Group: AirborneWindEnergy Message: 26090 From: dave santos Date: 6/16/2019
Subject: Re: New Multi-Line Ground-Anchor Design
Attachments :
    Attached is a photo of the "Control Anchor" hardware tested. Sorry no test video; too often testing solo there simply is no extra had to work a phone camera.

    Better to just rig your own version of this simple power-kite control method and experience it for yourself.



     

    Ongoing kPower testing focuses on crosswind arch AWES using power-kites. This post covers a redesign of the pilot-in-command control-anchor-point, from where kFarm state-of-the-art left-off in 2014. That component was based on a steel fencepost between the PIC's legs, guyed to windward; safe but ugly.

    The new design reduces hardware to just the anchor, a pulley, and rope enough for running and reins. The pulley is used to take kite power while allowing control input, like is sometimes done in kite sports from a body harness. The kite's dangerous power is anchored off in the ground, with the pilot safely upwind holding the reins. 

    In testing at Austin's Oak Springs Soccer Fields yesterday, with a 7m2 NPW, the rig worked right away, but with a few moments of oversteering and some difficulty balancing the reins with no grip-reference knots, to be added in the next test. The kite flew perfectly until a line broke. When a power kite is solidly anchored it most develops monster crosswind power. The light 200lb-test lines were replaced with 500lb-test.

    Detail by detail, AWES power-kite practices are rapidly evolving around the world. This direct-control-from-anchor AWES method is claimed for the Open-AWE_IP-Cloud.

    Pictures of kPower's rigs soon; meanwhile see attached graphic of the Inuit Windsled, showing the same classic method, but attached to a mega-sled rather than kPower's AWES earth anchor.
      @@attachment@@
    Group: AirborneWindEnergy Message: 26091 From: dave santos Date: 6/16/2019
    Subject: Re: Soaring Thermals by Passive Auxetic Control
    Thanks Joe, and Hi to all the Hawks.

    Further notes. An auxetic soaring wing needs to tap some flight-energy to reapply as actuation-force. There is a delay relation between input signal and actuation, with a persistence or locking factor to actuation. Actuation should unlock once the input state abates. Slow quasi "memory foam" recovery of the metamaterial seems helpful.
    Group: AirborneWindEnergy Message: 26092 From: joe_f_90032 Date: 6/16/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)
    Pierre, have you found someone who expects Gipe to do independent testing of AWES?


    Group: AirborneWindEnergy Message: 26093 From: dave santos Date: 6/16/2019
    Subject: AWE's Weird Hidden GW Capacity?
    [finding messages in Draft file that do not seem to have mailed. please let me know if these messages are redundant]


    Every year power kite sports grow in popularity. Practicioners often buy kites as the fashions change, and remaindered kites tend to be in "like-new" condition. If we estimate a ratable average of 10kW for the larger kites, many a flier has around 100kW laying around in bags. 100 such fliers can have around 10MW of quiver stashed away. There is on the order of a few GW stashed away worldwide, especially including military surplus wings, and some surplus yacht sails adaptable to AWES.

    kPower's primary down-select in AWE is the power-kite at all scales, from hobby to ship kites. A handful of pulleys, lines, anchors, and a work-load are all that is needed to turn an out-of-style power kite into a power-plant for needy folks. It may even be  the most energy-needy folks, refugees of disasters and rural-poorest-of-the-poor populations, match roughly to the numbers of stored away kites. Reuse of these kites for AWES is even a research asset.
    Group: AirborneWindEnergy Message: 26094 From: benhaiemp Date: 6/16/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)
    Joe, have you found someone who expects P. Gipe to do not independent testing of wind energy systems?
    Group: AirborneWindEnergy Message: 26095 From: joe_f_90032 Date: 6/16/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)
    Yes. All the people I have ever met refrain from expecting Gipe to do independent testing of AWES.
    Group: AirborneWindEnergy Message: 26096 From: benhaiemp Date: 6/17/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)

    No, because Paul Gipe usually doesn't test AWES, but current wind turbines. So saying "...expecting Gipe to do independant testing of AWES" doesn't make sense.


    As I repeat DaveS wrote: "Gipe specifically invoked wind industry certification standards. Nobody thinks he's the person to provide independent testing."

    (https://groups.yahoo.com/neo/groups/AirborneWindEnergy/conversations/messages/26066), questioning his independent testing in regard to "wind industry certification standards', not in regard to AWES since he usually doesn't test AWES as I still repeat.


    I am still and still waiting for the document supporting his statement. 


    Group: AirborneWindEnergy Message: 26097 From: dave santos Date: 6/17/2019
    Subject: "Crash Landing" SIngle Skin Kites
    A rigid kiteplane must not crash; a parafoil "thumps" hard when it crashes, and can blow out cells; but an SS kite can "crash" at full speed and nothing damaging happens, its like dropping a rag harmlessly. SS Crash Landing is potentially a golden landing method, so simple compared to landing carefully.

    A kite pilot's trained instinct is to never crash a kite, so its an odd feeling to deliberately crash a kite. PL SS kites are shown crashing in a promotional video just to show nothing bad happens. Its possible that inherent SS virtues like crashworthiness, high turning rate, lowest-cost, highest-scalability, and so on, may prove to be decisive in future AWES shake-outs between competing wings.
    Group: AirborneWindEnergy Message: 26098 From: benhaiemp Date: 6/17/2019
    Subject: Re: "Crash Landing" SIngle Skin Kites
    Is the tether and the high power involved for AWES causing the concerns about crash risks?
    Group: AirborneWindEnergy Message: 26099 From: dave santos Date: 6/17/2019
    Subject: Curtailing Bats for fast wing AWES?
     Wind Power Industry concern for Birds and Bats has continued to grow. "Curtailment" is the jargon for mitigation measures. Again, faster more-aerobatic AWES wings present the greatest inherent danger to Birds and Bats, demanding the greatest mitigations. Its hoped by kPower that large slow kites will not present any serious danger to Bats. Slow kite wildlife advantage extends over conventional wind turbines, not just fast AWES.

    Thanks to New Forum for these links-

    https://www.windpowerengineering.com/business-news-projects/digital-issues/april-2019-issueintroducing-bat-friendly-wind-farms-thanks-to-a-safe-new-deterrent-device/

    Bat fatalities reduced by 67% at EDF wind farm




    Bat Conservation International was founded in Austin, Texas, where kPower is based, so we have a particular interest in the Bat, as "Bat Capital of the World".


    Group: AirborneWindEnergy Message: 26100 From: dave santos Date: 6/17/2019
    Subject: Re: "Crash Landing" SIngle Skin Kites
    High-Mass at High-Velocity is the formally regulated risk in Aviation.

    A tether is comparatively low-mass and only the part closest to a fast kite moves fast. Specific tether risks are mid-air collisions and dragging.



     

    Is the tether and the high power involved for AWES causing the concerns about crash risks?

    Group: AirborneWindEnergy Message: 26101 From: dougselsam Date: 6/17/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)
    As usual, it's amateur-hour at the yahoo AWE forum.

    Why discuss people and things you know nothing about, as though you have any info, insights, or ANYTHING to even say??   Think about this: WHO started this line of 100% ignorant conversation?  You get 3 guesses but only need one.
    Please consider:
    1) Paul never pretended to be testing to any particular standard for certification, just testing normally and reasonably, with "reasonably" being a concept certain people here will never understand.. 
    2) Here's a link to Paul's published list of turbines tested and when.  Does it look like he still tests turbines today, to you? 

    Also: Anyone can take a decent power-curve in a day (a few hours of good wind), with the results presented on a single page..

    Certified testing toward turbine certification has KILLED small wind because it turns into a politically-correct multi-year-long+, agonizing, expensive, highly-staffed process, with a ridiculous amount of documentation, calibrated instrumentation, people and agencies involved, with every anemometer and measuring device having to be "certified", "signed", "calibrated" etc.

    Most "small-wind" companies were put out of business once "certification" was required.  Even Jacobs went out of business, after failing certification testing.  I was offered to buy the whole company for the price of a single turbine.  Bureaucracy and certified testing killed small-wind.  They tried to apply too many "big", over-the-top, requirements to a naturally-small, inherently backyard industry.

    Here's an 80-page report of "certification" testing for the Windspire V-A turbine.  How much of your tax money do you think was wasted in this over-analysis?

    Looks like the manufacturer was already bankrupt by the time the report was even published.

    I sometimes joke, but I think it's true, that just the combined salaries and benefits of the small-wind bureaucracy is probably worth more than all the power produced by all the certified small wind turbines in the world.  Too bad they can't seem to measure the inefficiency of their own bureaucracy.  Reminds me of the saying from the Viet Nam war: "We had to destroy the village to save it."

    And you should probably be able to understand, it would not be possible to certify ANY current AWE system, because such a system needs to be installed then left to run for months unattended.  There is no provision in the certification protocol for "Sky-Monkeys" to be climbing around on rope-drive nets "for the honor" as one nutcase on this forum has insisted in his daily "future-news" blurting of ill-considered fantasy scenarios presented as fact.  Obviously, the need for even a single operator would ruin the economics, since even a MegaWatt turbine could barely pay the wages of a single, relatively unskilled employee opertor, if every cent earned by the turbine went toward that one employee's salary.

    Meanwhile, if anyone is interested in FACTS, my first two tries at being funded by The California Energy Commission were turned down because, as I was finally told, it named Paul Gipe to do the testing, for which his facilities and background were not deemed adequate.  Removing Paul's name from the proposal was the key to getting funded.  That was over a decade ago. 

    Doesn't mean there is anything wrong with Paul's testing of less-powerful machines, but they were right, and I'm glad they pushed me into using someone with a big enough tower, and with the background, ability, skills, and equipment, to do professional testing.  Name recognition is one thing, a specific skill set and proper test facility are another.

    Please realize the level of ignorance on this forum.  Most conversations here do not even START with any facts, let alone lead to any.  Most of what is said here is completely meaningless nothingness-vacuum, based on zero knowledge, or probably below zero: a negative quantity

    Meanwhile the king of ignorance on here, the prince-of-inverse-knowledge, a main inspiration for my concept of a "negative I.Q.", and we all know who that is, has had enough time to earn 3 PhD's in wind energy or engineering expertise directed there-toward, while instead the conversation continues to drift aimlessly in the abyss of no-knowledge at all - today it's about certification testing by a guy who doesn't even do certification testing, and never has.  One more case of the very topics of your conversation being dictated by someone trying to establish dubious credibility through name-association with people who have actual accomplishments, of which he knows nothing.   Duhhh...
    Group: AirborneWindEnergy Message: 26102 From: dave santos Date: 6/17/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)
    Gipe's own words remain reliable, that he does require durability certification for early AWE, only basic performance to a professional standard, as quoted. 

    Pierre did seem to imply Gipe might be someone to test AWES, which is a stretch. Gipe was in his own view primarily a specialized wind journalist. His HAWT testing was not as a career engineer, but as incidental experience and journalistic research.
     
    That's not as poor a grasp of the Gipe question as Doug paints.



     

    As usual, it's amateur-hour at the yahoo AWE forum.

    Why discuss people and things you know nothing about, as though you have any info, insights, or ANYTHING to even say??   Think about this: WHO started this line of 100% ignorant conversation?  You get 3 guesses but only need one.
    Please consider:
    1) Paul never pretended to be testing to any particular standard for certification, just testing normally and reasonably, with "reasonably" being a concept certain people here will never understand.. 
    2) Here's a link to Paul's published list of turbines tested and when.  Does it look like he still tests turbines today, to you? 

    Also: Anyone can take a decent power-curve in a day (a few hours of good wind), with the results presented on a single page..

    Certified testing toward turbine certification has KILLED small wind because it turns into a politically-correct multi-year-long+, agonizing, expensive, highly-staffed process, with a ridiculous amount of documentation, calibrated instrumentation, people and agencies involved, with every anemometer and measuring device having to be "certified", "signed", "calibrated" etc.

    Most "small-wind" companies were put out of business once "certification" was required.  Even Jacobs went out of business, after failing certification testing.  I was offered to buy the whole company for the price of a single turbine.  Bureaucracy and certified testing killed small-wind.  They tried to apply too many "big", over-the-top, requirements to a naturally-small, inherently backyard industry.

    Here's an 80-page report of "certification" testing for the Windspire V-A turbine.  How much of your tax money do you think was wasted in this over-analysis?

    Looks like the manufacturer was already bankrupt by the time the report was even published.

    I sometimes joke, but I think it's true, that just the combined salaries and benefits of the small-wind bureaucracy is probably worth more than all the power produced by all the certified small wind turbines in the world.  Too bad they can't seem to measure the inefficiency of their own bureaucracy.  Reminds me of the saying from the Viet Nam war: "We had to destroy the village to save it."

    And you should probably be able to understand, it would not be possible to certify ANY current AWE system, because such a system needs to be installed then left to run for months unattended.  There is no provision in the certification protocol for "Sky-Monkeys" to be climbing around on rope-drive nets "for the honor" as one nutcase on this forum has insisted in his daily "future-news" blurting of ill-considered fantasy scenarios presented as fact.  Obviously, the need for even a single operator would ruin the economics, since even a MegaWatt turbine could barely pay the wages of a single, relatively unskilled employee opertor, if every cent earned by the turbine went toward that one employee's salary.

    Meanwhile, if anyone is interested in FACTS, my first two tries at being funded by The California Energy Commission were turned down because, as I was finally told, it named Paul Gipe to do the testing, for which his facilities and background were not deemed adequate.  Removing Paul's name from the proposal was the key to getting funded.  That was over a decade ago. 

    Doesn't mean there is anything wrong with Paul's testing of less-powerful machines, but they were right, and I'm glad they pushed me into using someone with a big enough tower, and with the background, ability, skills, and equipment, to do professional testing.  Name recognition is one thing, a specific skill set and proper test facility are another.

    Please realize the level of ignorance on this forum.  Most conversations here do not even START with any facts, let alone lead to any.  Most of what is said here is completely meaningless nothingness-vacuum, based on zero knowledge, or probably below zero: a negative quantity

    Meanwhile the king of ignorance on here, the prince-of-inverse-knowledge, a main inspiration for my concept of a "negative I.Q.", and we all know who that is, has had enough time to earn 3 PhD's in wind energy or engineering expertise directed there-toward, while instead the conversation continues to drift aimlessly in the abyss of no-knowledge at all - today it's about certification testing by a guy who doesn't even do certification testing, and never has.  One more case of the very topics of your conversation being dictated by someone trying to establish dubious credibility through name-association with people who have actual accomplishments, of which he knows nothing.   Duhhh...
    Group: AirborneWindEnergy Message: 26103 From: benhaiemp Date: 6/17/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)

    "Pierre did seem to imply Gipe might be someone to test AWES, which is a stretch."

    No, Paul Gipe tests current wind turbines, and in an impartial manner for what I know.

    Group: AirborneWindEnergy Message: 26104 From: Peter Sharp Date: 6/17/2019
    Subject: Active Lift Turbine VAWT

    There is a breakthrough in VAWT technology called the Active Lift Turbine. It’s an H-rotor with non-pitching blades, but the blades produce a lot of extra torque using their high lift in the downwind direction, and they do so without moving downwind. It’s an amazing design that, at first glance, seems impossible. It may be the most efficient VAWT yet, and even more efficient than the best cycloturbine using computer-controlled blade-pitching.

    Efficient Active Lift is simple in concept but quite difficult to achieve. So I consider the design of the Lecanu Active Lift Turbine to be a brilliant invention. Since it doesn’t use blade-pitching, it opens the door to even more efficient VAWT with a wider Cp curve. For example, the Active Lift Turbine (an H-rotor) could include self-pitching Sharp Cycloturbine blades in place of its fixed blades.

    The published research findings are still somewhat ambiguous and incomplete, but large gains in the torque and the Cp seem to have been verified with simulations and by testing a model. But no photos of it, and no Cp curve is available yet.

    Here is the website for the Active Lift Turbine. See the animation of Version 3, which is currently the most advanced version. Note in the animation that the wind is coming from the left. Due to the relative motions, it takes some time to understand it. The off-center stationary gear is held upwind of the central shaft by a wind vane.

    http://www.cyberquebec.ca/_layout/?uri=http://www.cyberquebec.ca/normandajc/  

    ----------

    Some power kites make use of Active Lift, but not efficiently. Kite inventors might wish to think in terms of including efficient Active Lift. Long-pull power kites that fly across the wind at high speeds use Active Lift to produce their power, like a glider gaining altitude in an updraft. But because they move downwind while producing power from Active Lift, they forfeit about 2/3 of their available wind energy. So a problem for power kite inventors is to figure out a more efficient way to make use Active Lift. It may seem impossible. But if it can be done for a VAWT, then maybe it can be done for  power kites.

    In my opinion, Active Lift in VAWT has been around for a long time, but it was previously mostly a problem. A two-bladed VAWT will experience violent shaking if its rotor drag pulses resonate a natural frequency of the rotor-tower. The rotor drag pulses are due to the very high blade lift pulses acting in the downwind direction (Active Lift) twice each revolution. That’s why VAWT typically use 3 blades or, if two blades are used, the resonant frequencies must be carefully avoided, as is done for two-bladed eggbeaters.

    In 2012, I did a drawing of an Active Lift oscillating water-current pump and a friend submitted it to a contest. The piston pump sits on the bottom and uses a 2-bladed H-rotor on its side with the central shaft supported at both ends by vertical, oscillating pump levers. Buoyancy in the blades produces the return stroke. For the pump stroke, the very high rotor-drag pulses cause the rotor to move down current and downward twice each revolution. The pump can be used to pressurize reverse osmosis sea water desalination.

    I discovered that Active Lift explains the unusually high torque of the Sharp Cycloturbine at TSR which peaks at a TSR of about 2. When the upwind blade pitches, it rocks rearward and inward, so it pushes the support arms forward faster and farther than the blade. When the blade flips when heading directly away from the wind, the centrifugal potential energy stored when upwind is conserved. So the blade enters the downwind pass rocked fully forward (for that TSR). The blade’s center of mass then rocks rearward and downwind during the downwind blade pass while it pulls the rocking arm forward faster and farther than the blade. Both centrifugal force and Active Lift act on the blade downwind to increase the torque. The blade does not pitch too much in response to those high forces because the aerodynamic pitching force on the blade is 50% stronger than it is upwind. This is hard to understand without diagrams. Also, the center of pressure of the downwind blade moves slightly upwind during the downwind blade pass, which slightly increases the lift. But the center of mass moves downwind. The difference is due to the use of the rocking arm which connects to the blade near the leading edge. The center of mass and the center of pressure follow different arcs. At higher TSR, the blades pitch very little, so Active Lift no longer increases the torque. My guess is that at a TSR near 2, Active Lift increases the torque and the Cp max. by 10%.

    The Bird Windmill also makes use of Active Lift, which results in an eccentric orbit that is shifted in the downwind direction, but I’m not sure if it provides any additional power because the Bird Windmill doesn’t convert Active Lift directly into torque. What does happen is that Active Lift flattens the upwind blade pass, and that stores centrifugal potential energy in the blade. That energy is released during the downwind blade pass. The downwind blade pass produces a higher centrifugal pull-force because Active Lift adds to the centrifugal force and the release of the stored centrifugal potential energy. However, the TSR of the Bird blade is consistently only about 2, which limits the maximum power. The Bird Windmill’s value is due to it being extremely inexpensive to build.

    PeterS

     

     

    Group: AirborneWindEnergy Message: 26105 From: dave santos Date: 6/17/2019
    Subject: Re: Gipe'a AWES Testing Standard (quote and link)
    So now you seem to agree with the rest of us, that Gipe testing complex flying machines he knows little about, at his age, is not to be expected.
    Group: AirborneWindEnergy Message: 26106 From: dave santos Date: 6/17/2019
    Subject: Re: Active Lift Turbine VAWT
    Hi Peter,

    Great to see persistent inventive thinking in VAWTs.

    AWES applicability is likely to hinge on highest power-to-weight performance, for flight. Linear electrical generators tend to lower power-to-weight potential, and fluidic pumping begs the question of just what is pumped at altitude, maybe air down a hose (?).

    Let us know how specific AWES design concerns shake out.

    dave



     

    There is a breakthrough in VAWT technology called the Active Lift Turbine. It’s an H-rotor with non-pitching blades, but the blades produce a lot of extra torque using their high lift in the downwind direction, and they do so without moving downwind. It’s an amazing design that, at first glance, seems impossible. It may be the most efficient VAWT yet, and even more efficient than the best cycloturbine using computer-controlled blade-pitching.

    Efficient Active Lift is simple in concept but quite difficult to achieve. So I consider the design of the Lecanu Active Lift Turbine to be a brilliant invention. Since it doesn’t use blade-pitching, it opens the door to even more efficient VAWT with a wider Cp curve. For example, the Active Lift Turbine (an H-rotor) could include self-pitching Sharp Cycloturbine blades in place of its fixed blades.

    The published research findings are still somewhat ambiguous and incomplete, but large gains in the torque and the Cp seem to have been verified with simulations and by testing a model. But no photos of it, and no Cp curve is available yet.

    Here is the website for the Active Lift Turbine. See the animation of Version 3, which is currently the most advanced version. Note in the animation that the wind is coming from the left. Due to the relative motions, it takes some time to understand it. The off-center stationary gear is held upwind of the central shaft by a wind vane.

    http://www.cyberquebec.ca/_layout/?uri=http://www.cyberquebec.ca/normandajc/  

    ----------

    Some power kites make use of Active Lift, but not efficiently. Kite inventors might wish to think in terms of including efficient Active Lift. Long-pull power kites that fly across the wind at high speeds use Active Lift to produce their power, like a glider gaining altitude in an updraft. But because they move downwind while producing power from Active Lift, they forfeit about 2/3 of their available wind energy. So a problem for power kite inventors is to figure out a more efficient way to make use Active Lift. It may seem impossible. But if it can be done for a VAWT, then maybe it can be done for  power kites.

    In my opinion, Active Lift in VAWT has been around for a long time, but it was previously mostly a problem. A two-bladed VAWT will experience violent shaking if its rotor drag pulses resonate a natural frequency of the rotor-tower. The rotor drag pulses are due to the very high blade lift pulses acting in the downwind direction (Active Lift) twice each revolution. That’s why VAWT typically use 3 blades or, if two blades are used, the resonant frequencies must be carefully avoided, as is done for two-bladed eggbeaters.

    In 2012, I did a drawing of an Active Lift oscillating water-current pump and a friend submitted it to a contest. The piston pump sits on the bottom and uses a 2-bladed H-rotor on its side with the central shaft supported at both ends by vertical, oscillating pump levers. Buoyancy in the blades produces the return stroke. For the pump stroke, the very high rotor-drag pulses cause the rotor to move down current and downward twice each revolution. The pump can be used to pressurize reverse osmosis sea water desalination.

    I discovered that Active Lift explains the unusually high torque of the Sharp Cycloturbine at TSR which peaks at a TSR of about 2. When the upwind blade pitches, it rocks rearward and inward, so it pushes the support arms forward faster and farther than the blade. When the blade flips when heading directly away from the wind, the centrifugal potential energy stored when upwind is conserved. So the blade enters the downwind pass rocked fully forward (for that TSR). The blade’s center of mass then rocks rearward and downwind during the downwind blade pass while it pulls the rocking arm forward faster and farther than the blade. Both centrifugal force and Active Lift act on the blade downwind to increase the torque. The blade does not pitch too much in response to those high forces because the aerodynamic pitching force on the blade is 50% stronger than it is upwind. This is hard to understand without diagrams. Also, the center of pressure of the downwind blade moves slightly upwind during the downwind blade pass, which slightly increases the lift. But the center of mass moves downwind. The difference is due to the use of the rocking arm which connects to the blade near the leading edge. The center of mass and the center of pressure follow different arcs. At higher TSR, the blades pitch very little, so Active Lift no longer increases the torque. My guess is that at a TSR near 2, Active Lift increases the torque and the Cp max. by 10%.

    The Bird Windmill also makes use of Active Lift, which results in an eccentric orbit that is shifted in the downwind direction, but I’m not sure if it provides any additional power because the Bird Windmill doesn’t convert Active Lift directly into torque. What does happen is that Active Lift flattens the upwind blade pass, and that stores centrifugal potential energy in the blade. That energy is released during the downwind blade pass. The downwind blade pass produces a higher centrifugal pull-force because Active Lift adds to the centrifugal force and the release of the stored centrifugal potential energy. However, the TSR of the Bird blade is consistently only about 2, which limits the maximum power. The Bird Windmill’s value is due to it being extremely inexpensive to build.

    PeterS

     

     

    Group: AirborneWindEnergy Message: 26107 From: benhaiemp Date: 6/17/2019
    Subject: Re: Active Lift Turbine VAWT

    Hi Peter,


    Thanks for this description. Here is a link of Pierre Lecanu', Joel Breard', Dominique Mouazé' publication: https://hal.inria.fr/hal-01300531v1/document .

    Group: AirborneWindEnergy Message: 26108 From: tallakt Date: 6/17/2019
    Subject: Re: Active Lift Turbine VAWT
    Quite an amazing achievement to achieve those numbers on an «inefficient» platform like VAWT. If the numbers presented are actually correct and practically relevant.

    It show that the last word has not been said in windmills, and likewise not in AWE...
    Group: AirborneWindEnergy Message: 26109 From: tallakt Date: 6/17/2019
    Subject: Re: Active Lift Turbine VAWT
    To me this design is interesting for AWE, not because of an extra few % Betz limit, but because I see tether drag and then indirectly tether strength as a limiting factor for AWE. This design reels out when the energy harvesting is at its highest and so the practical loss og power compared to eg. Yoyo may not be very big.

    The same reason (tether drag) will probably favor vertically looping AWE (yoyo) to horizontal looping AWE based on this design. Because if you have a slightly long tether (100 meter for a medium sized rig) the power loss when flying upwind a 200 m diameter circle i expect to be significant, and you are probably only at 30 m altitude in doing so.
    Group: AirborneWindEnergy Message: 26110 From: benhaiemp Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT
    A patent is on https://worldwide.espacenet.com/publicationDetails/originalDocument?CC=WO&NR=2015107304A1&KC=A1&FT=D&ND=3&date=20150723&DB=EPODOC&locale=fr_EP# . The search report suggests the existence of a significant prior art. A deeper analysis would allow to detail the documents.
    Group: AirborneWindEnergy Message: 26111 From: joe_f_90032 Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT

    Pierre LECANU
    Joël BREARD

    TURBINE TELLE QU'EOLIENNE D'AXE ESSENTIELLEMENT VERTICAL A PORTANCE ACTIVE
    ====================================
    Perhaps near their beginnings of publication:

    From the circa 2007 period, one may trace some advancing points and claims from the two inventors.    Maybe their start:  FR0756928A


    ---------------------
    tag: type Darrieus  

    Group: AirborneWindEnergy Message: 26112 From: joe_f_90032 Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT
    Pierre Lecanu, Joël Bréard, Dominique Mouazé. 

    [HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not.]

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

    [[Recall: "Betz limit is based on an open disk actuator."  various]]
    Group: AirborneWindEnergy Message: 26113 From: joe_f_90032 Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT
    Operating principle of an active lift turbine with controlled displacement
    Pierre Lecanu, Joel Breard, Dominique Mouazé

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

    Group: AirborneWindEnergy Message: 26114 From: joe_f_90032 Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT

    Simplified theory of an active lift turbine with controlled displacement


    Pierre Lecanu, Joel Breard, Dominique Mouazé. Simplified theory of an active lift turbine with
    controlled displacement. 2016. hal-01300531v2
    ================================================
    Group: AirborneWindEnergy Message: 26115 From: joe_f_90032 Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT
    Put on critical thinking caps as their team is claiming: 
    "By combining a Darrieus-type turbine with a system for converting a alternative linear motion into a continuous rotating motion, the Active Lift Turbine has a superior performance than the Betz limit."

    What is one to think of such a claim?
    The claim as stated does not refer to channelized flow.  Tread carefully. 
    ===============================
    Group: AirborneWindEnergy Message: 26116 From: Santos Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT
    We understand such claims as by how Betz can be beat by turbines that harvest in depth along the wind axis, while Betz is merely a simplified disc assumption reflecting century old aerodynamics.
    Group: AirborneWindEnergy Message: 26117 From: Joe Faust Date: 6/18/2019
    Subject: BloombergNEF
    This topic thread could discuss BloombergNEF (BNEF) and its AWE opinions.
    See also: 
     

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

    The commentary below is by Massimo Ippolito.
    The paper he refers to is a paper for which he has a copy.   
    As yet, I have not found a copy of the paper except that copy sent in email to me. 
    ---------- Forwarded message ---------
    From: Massimo Ippolito m.ippolito@kitegen.com [kitegen]
    Date: Tue, Jun 18, 2019 at 8:11 AM
    Subject: [kitegen] BloombergNEF - KiteGen
    [[Note: the first signed notes are machine translated from Italian to English by a Google translation tool; see original, if in doubt.]]

    BloombergNEF has issued an information for investors on Airborne Wind in the annex

    They give KiteGen a leading role along with Makani and Ampix, for those who understand the subject knows that both Makani and Ampix have completely wrong the system architecture, so the document in a sense could be comforting but the absolute inability to distinguish the technologies is somewhat disappointing. 

    I replied with the following clarifications but unfortunately they kept the current version.

    I wonder what the ultimate purpose of BloombergNEF is because if these investors, who are also their customers, read the report in depth, they certainly do not come close to these projects. 

    Massimo Ippolito

    I have some issues regarding the content, as follow:


    page 1


    “five to ten years”


    This great length of time could imply that the research is not complete. That is not the case, since it has been thoroughly tested and specified. A fully-specified design of a special machine typically takes, without constraints, six months to set up production and another six months to rework the design and production of parts or components causing unreliable or out-of-specification results. The main hurdle is setting up the wide and diverse organization dedicated to the project, because in a new technology, each person involved needs to be retrained before again becoming a contributor; experience has taught it takes one full year. So my full and funding-unconstrained estimate is two years.

    The risk is that such a widespread opinion will delay full commitment at all levels of the chain, becoming a self-fulfilling prophecy. I have been fighting against this notion since 2016, when we completed the design, suffering exactly from the prophecy of IRENA, the EU and other major institutions that only guessed at such a number of years without a reasonable degree of insight.

    All the smart technologists we have met, after a comprehensive examination of the project,  at a certain point, have declared the glaring obviousness of the process and its outcome. This preventive acquisition of a reasonable understanding is missing in most independent evaluations.


    “costs continue to drop”


    As an early expert technologist in Photovoltaic (PV) and wind turbines, I have some difficulty in recognizing this statement as true.

    I.E., the recent Haliade-X 12MW requires a full investment of $400m. With a conservatively computed unit cost of $150m in batch production, excluding the BOS, that equates to $12.5m/MW, when turbines were typically priced around $1m/MW.

    Adopting the same tools and methodology to evaluate the KiteGen Stem, we obtain  $0.2m/MW; an advantage of 62 times, compared to Haliade without accounting for our doubling the Capacity Factor.

    Another issue occurs in the PV industry when it decided in 2009 to reduce the silicon refining process from solar-grade to upgraded-metallurgical grade, thus reducing the conversion efficiency to 14% of the top industry standard of 21% and halving the life of the cells with a major impact on users’ business plans. This was strictly a deceptive strategy, because the 25-year PV lifespan has already been commonly established for solar-grade silicon, but nobody has thought to recompute the LCOE with this new and obvious handicap.  


    Page 2          


    “developer claim capacity factors...”


    As per wind turbine installation, the expected capacity factor is computed in advance, before installation, because it isn't primarily a function of the turbine itself, but a function of the site. Analogously, for HAWT, precise mathematical and reanalysis tools are available and can be adopted by anyone, obtaining the same results. KiteGen early-on spent significant funds to independently validate such tools for HAWES.  I.E., we commissioned this work to KAUST. https://www.nature.com/articles/s41598-017-10130-6, or a new document about LIDAR measurement and our reaction.

    https://www.researchgate.net/publication/332422870_Interactive_Commentary_on_Improving_mid-altitude_mesoscale_wind_speed_forecasts_using_LiDAR-based_observation_nudging_for_Airborne_Wind_Energy_Systems


    Page 4


    “stationary bases are much more prevalent”


    As explained in our reaction paper to the ECORYS report, the stationary bases are but a step in the direction of the KiteGen Carousel. The modular nature of the Carousel can accommodate several KiteGen Stems in a ring, the advantage being a further dramatic improvement of the capacity factor, because there is no need to lose wind for aerodynamic activation (no operative/functional reel-out of the lines).


    “Fly-gen system show promise for higher capacity factors than ground-gen, ...”

    “Ground-gen Lower weight in the air, may allow for faster flight (linked to higher generation)”


    These two statements are in contradiction, because in both architectures the flight speed plays a quadratic role in energy production; the fly-gen is necessarily braked by the propellers so it flies at a slower pace, losing most of the power.


    Page 5


    “Tethers add both weight and drag to the system, which can decrease speed and thus electricity generation.”


    This is claimed by competitors, but isn't true. The tether weight is not significant because of the “figure-eight” path of the wing in airspace. The weight, 50% of the time, is favorable to the flight speed, (when the wing direction is toward the ground). The other 50% of the time could be profitably exploited to limit excess power by climbing inside the spot wind window, introducing the concept of potential energy accumulation, endo-phanic and exo-phanic paths in the airspace (direction of the lemniscate evolution).


    Also, tether drag is a non-issue.


    Tether drag doesn’t affect the wing speed or the system AE of Kitegen.


    The reasons are easily understood:


    During the tests, we pushed a wing at 2400m and 65m/s, observing no tether drag issues. This demonstrates KiteGen’s justification to reject the overly simplistic analysis based on some “system drag” idea that combines line and wing, appearing for the first time in the Loyd patent, the validity of which is limited to the domain of tethered aircraft (A) equipped with tails that drive and force their pitch.


    Thanks to in-depth research and simulation, it has been established that the drag of the line is irrelevant to wing speed and energy production. It is, instead, simply a geometric dynamic, conceptually affecting the path in airspace only of (B). Tether drag only limits the crosswind motion distance that can be achieved in one stroke, before the wing has to change direction. This is a feature that can be successfully exploited by the controls in order to extend the wind power spot.


    Issues related to transverse wave propagation on the line


    The wing is typically set to fly at 80 m/s. When the wing changes direction, a new displacement transverse wave acts upon the line, while the axial wave is running at 270 m/s. Such a transverse wave is slow, due the air mass added to the line’s linear density, taking several seconds to affect the entire line. Thus, the wing has the freedom to fly for a few hundred meters before line-bending changes its optimal angle toward the wind. The models adopted in literature expose an excessively tight time boundary, or even a “snapshot”, to track such behavior.


    Line drag is applied axially to the wing, the same effect that gravity has on gliders, that obviously never slows the aircraft. The force vector representing the drag of the lines binding the wing is only manifested axially, thus thrusting the wing as with gliders (above case, picture B).


    As Gustav Eiffel taught us, when the Reynold number of the segment of the line near the wing reaches an elevated value, a new effect called “drag crisis” takes place, greatly reducing it.


    The tether drag issue is speculation based on a fixed cylinder in a flow experimental setup, with a measured coefficient ranging between 1.2 and 1.5. The lines are light in specific weight, which means they are locally free to oscillate and rotate on the axis, dynamically losing air pressure accumulation. Thus, they cannot be compared to a typical fixed cylinder in a flow.

    Larger scales lessen the significance of the issue; this due to the line section and Reynolds surface ratio of the line section being the squared function of the diametre; the drag surface being linear, it is an advantage that grows dramatically with increasing scale.


    KiteGen’s scientific committee published an article trying to explain the limits and errors of the proposed models in the literature review; unfortunately, there being no skilled audience.

    https://www.researchgate.net/publication/323418613_The_largest_renewable_easily_exploitable_and_economically_sustainable_energy_resource


    Furthermore, in order to gain more flight freedom, KiteGen patented lines that were appropriately tapered in order to reduce the drag coefficient to 0.03, instead of the classic 1.2 of a cylinder immersed in a fluid, that the lines are immersed in as well. This patent applies to the domain of possible and potential future enhanced optimization of the technology.


    To repeat, as this is an extremely important concept, because the production of energy depends on the square of the flight speed. The line drag is not added to that of the wing, which remains free to fly at the speed of its glide factor or aerodynamic efficiency.


    This topic may require a lot of insight to be fully understood.


    Page 6


    “The idea is to avoid the inconsistency of ground-gen by flying the wings out of phase so that one is generating while the other is in recovery.”


    KPS is a very recent initiative and was looking for a little IP niche in which to work, circumventing KiteGen's IP, instead of collaborating under a licensing agreement.

    The KPS niche is to operate two kites together with a mechanical axis at the level of the lines’ reeling drums. This approach is highly impractical because the climbing kite needs a different reel-out speed and line tension, compared to the reel-in requirement of the kite in the recovery phase.

    This feature is currently state-of-the-art and is patented by KiteGen and is obtained with a farm interaction. Two (or better, three) separate KiteGen Stems can logically act in counter-phase (remote and parametric electrical axis) in order to provide a continuous supply of energy at farm level, not machine level, hence respecting also the distance requirements between machines and flying wings and their cones of optimum operational pertinence.

    A greater number of units in a wind farm lower the possible discontinuity of supply, cancelling the idea of a lower capacity factor.

    Currently, KPS, following my public criticisms, recognized the superior effectiveness of the electrical axis, changing the focus of their development. But the technological history was established, and KPS lost its claimed uniqueness.

    We find it quite surprising that these little reasonings do not develop in an autonomous manner into everyone's mind, but that is why it is necessary to explain and reiterate them, creating an almost embarrassing situation in the face of obvious facts.


    Page 7


    “Airborne wind does operate at higher heights than conventional wind, it is not high enough to obtain a radically better generation profile and is not as disruptive as it may appear based on power output alone.”


    This is another false notion circulating in scientific literature. We have observed that, due to the absolute originality and novelty of this concept, there is a lack of qualified peer review, and blatant errors have been propagated and transferred, undisturbed, from one poorly informed publication to another, with no-one critically re-analyzing their stratified assumptions.

    The Betz limit can meaningfully be applied to kites, since the area a kite moves in is generally very large, and the kite will only remove a small fraction of the wind energy passing through that area. Well before becoming aware of high altitude, or tropospheric, winds stronger and more constant than biosphere winds, KiteGen profitably addressed undisturbed wind flow exploitation at low Betz efficiency, that has since been revealed as a viable resource valued at at least three times the power that can be harnessed by a wind turbine under the same conditions. This feature alone was enough to establish the superiority of the concept and our strong commitment to develop it. This enabling feature is currently neither understood nor addressed in any current literature, despite its obviousness: The less we brake the wind,the more the resulting speed is higher. The power available is a cubic function of the wind speed. I.E., since a wind turbine only exploits a fixed window of wind, it needs to optimize the energy harnessed, looking for a compromise between braking effectiveness and residual wind speed.     


    “The drag on the tether (which scales linearly with length)”

    This statement is also a farfetched notion. It is not true that drag scales linearly, certainly not for KiteGen. We have a saturation effect that the line loses any additional geometrical effect of dynamic bending over about 3-400m of length.

    It is even sub-linear for Makani and Ampix architectures, because the line radial displacement of the line during extended flight follows a fourth-order function, exposing a hyperbolic cone of operation, so remarkably different line speeds.


    Page 9


    “Visual impact and noise emission”


    The flying wing is a dot in the sky, virtually invisible and, in the event of clouds, it disappears. The flight is always subsonic. The noise decay is a quadratic function, almost impossible to hear any noise coming from the wing at 1000m.


    “complicated to operate near populated areas”


    Here we know that this is a perspective mismatching, I.E., a 100MW farm needs only a few square km, or about 40 acres, including the safety zone containing the generators and the extended projection of lines and flying wings to the ground.

    The onshore farm is compatible with forestry and/or agricultural activities. The land purchasing cost for exclusive/primary use is about $120,000, while the tropospheric wind farm produces $20m./year of gross revenue.

    A matured machine installation can certainly afford the land for exclusive use.


    Pag 10


    “Shorter project lifetimes, cost levelized over less time”


    This statement is unjustified. The KiteGen stem is composed of two main sections:

    the flying section, composed of wing and lines, and the ground-gen, that is a giga-robot, including the arms, the alternators, the pulleys and the servo drive electronics.

    The ground-gen is machinery that needs ordinary routine maintenance with a typical lifetime of 60 years, similar to hydroelectric power plants.

    The flying section has a shorter life; the endurance tests we performed suggest about one year, but there is only about 800 kg of material involved, to be considered a consumable, like the grease for the bearings.

    To make a comparison, we need 200 kg of natural uranium or 4000 tons of coal to produce the same energy equal to KiteGen’s 800kg flying consumables (lines and wings).


    “Higher cost of advanced materials”


    The same, it is a very small quantity of material.


    “Longer and more complex permitting process”


    This isn't a concern for the project, because suitable installation sites are widely available, including flight restrictions already in place. The demonstration of the incredible wealth provided by cheap energy and the solution to several epochal problems will globally pave the way to further installation sites.


    Page 11


    KiteGen didn’t adopt a soft wing. Instead, it is alone in the scenario, based on a semi-rigid wing, certainly not Enerkite or EWIND that are flat wings, hence totally rigid in order to maintain the shape under traction.


    Page 12


    “The M600 is a 600 kW rigid wing model with a 26 meter wingspan.”


    We do not feel comfortable giving power indications without providing the wind speed or the specific power density.

    M600  requires 4kW/m2 for nominal power instead the KiteGen Stem  0.5kW/m2



    Pag 15


    “This so-called  ‘valley of death’ is a critical period for technology startups.”


    This sentence certainly conjures up a fascinating image, but it does not correspond to the reality of a highly innovative and very high-potential development process, since those who lead it are already aware of the necessary work and difficulties. So, you have to proceed to milestones, which for KiteGen was to start demonstrating that the concept exists and produces energy and has been totally successful. Precisely, this experimental success has been so significant that it has triggered hundreds of initiatives around the world which have largely become informal competitors, but now, due to their delay, seriously lag behind in the deep understanding of the subject.


    The next milestone was to choose the dimensional size of the generator and conduct all the theoretical and technological research to substantiate the product and its feasibility at the required scale, and this process was also successful and accumulated value, mainly in IP and know-how.


    In the end, the detailed design of the machine started with the creation and validation of the components, putting enough hay in the farmstead to have an accumulated, safe, demonstrable and spendable value.


    Now it is the turn of batch production to start on a precise and reliable industrial plan, which can be accepted by, and shared with, suitable and interested partners. So, if there was a “valley of death” it was certainly confined to the first milestones. Now it's a simple matter of good engineering practices, good relationship and good industrial agreements.



    Posted by: Massimo Ippolito <m.ippolito@kitegen.com

    .__._,___
    Group: AirborneWindEnergy Message: 26118 From: Peter Sharp Date: 6/18/2019
    Subject: Re: Active Lift Turbine VAWT
    Attachments :

      Hi JoeF,

      Yes, this doesn’t make sense. However, it’s a translation from French to English, and that might be a cause of confusion. They calculated that the “Betz” limit for VAWT is a Cp of .61. Others have calculated up to .64, depending upon the flow model that is used. But even so, a Cp in excess of .593 is quite unlikely because it is too close to the “Betz” limit for VAWT. So this claim requires an explanation or clarification or correction.

      PeterS

       

      From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
      Sent: Tuesday, June 18, 2019 8:36 AM
      To: AirborneWindEnergy@yahoogroups.com
      Subject: [AWES] Re: Active Lift Turbine VAWT

       

       

      Put on critical thinking caps as their team is claiming: 

      "By combining a Darrieus-type turbine with a system for converting a alternative linear motion into a continuous rotating motion, the Active Lift Turbine has a superior performance than the Betz limit."



      What is one to think of such a claim?

      The claim as stated does not refer to channelized flow.  Tread carefully. 

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

      Group: AirborneWindEnergy Message: 26119 From: Peter Sharp Date: 6/18/2019
      Subject: Re: Active Lift Turbine VAWT
      Attachments :

        Hi Tallak,

        Here is an example of a VAWT that could be carried aloft by a pilot kite, while operating in a vertical looping orbit, and incorporating Active Lift. It should work as a short-pull power kite, but the TSR is limited to 2, which is not fast enough for very high power. I’m trying to improve the pitch control to raise the TSR, but no luck so far. This is the vertical orbit version of the horizontal orbit Bird Windmill -- a single-blade, unbalanced, cycloturbine that uses centrifugal force to pump water. In the video, the tethers are 1/8” shock cords.

        https://www.youtube.com/watch?v=ekO8f2a1Hcs  

        PeterS

         

        From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
        Sent: Monday, June 17, 2019 11:47 PM
        To: AirborneWindEnergy@yahoogroups.com
        Subject: [AWES] Re: Active Lift Turbine VAWT

         

         

        To me this design is interesting for AWE, not because of an extra few % Betz limit, but because I see tether drag and then indirectly tether strength as a limiting factor for AWE. This design reels out when the energy harvesting is at its highest and so the practical loss og power compared to eg. Yoyo may not be very big.

        The same reason (tether drag) will probably favor vertically looping AWE (yoyo) to horizontal looping AWE based on this design. Because if you have a slightly long tether (100 meter for a medium sized rig) the power loss when flying upwind a 200 m diameter circle i expect to be significant, and you are probably only at 30 m altitude in doing so.

        Group: AirborneWindEnergy Message: 26120 From: dave santos Date: 6/18/2019
        Subject: Peter Sharp's Looping Arch (reposting video link to new topic)
        kPower also tested this looping-arch configuration a few years ago, with similar impressive results shared on the Forum. Its effectiveness owes in large part to DS boost in the surface wind gradient, that conventional VAWT motion does not exploit.

        I like how the kitesurfer in the video does not really know what to make of this strange new kite wing sharing the same beach.




        Group: AirborneWindEnergy Message: 26121 From: Peter Sharp Date: 6/18/2019
        Subject: Re: Active Lift Turbine VAWT
        Attachments :

          Hi Tallak,

          Darrieus rotors have inherent flaws, primarily dynamic stall, which makes them not very efficient. But the best research cycloturbines are now as efficient as the best HAWT.

          In addition, VAWT can make use of additional techniques to increase their power. If rotor tipping and paired counter-rotation are used together, the increase in power can be as much as 50%. So if the original VAWT is an efficient cycloturbine with a Cp of .50, the resulting power from adding those techniques would be equivalent to a Cp of .75. That is way beyond what is possible for HAWT.

          Theoretically, VAWT are almost twice as efficient as HAWT. If the VAWT is extremely wide relative to its height, and more than a kilometer in diameter, the wind will have time to mix and speed up again after passing through the upwind blades and before reaching most of the downwind blades. So the VAWT will function like two wind turbines, even though it is only one turbine. This design is not necessarily practical, but it does show that VAWT could be, theoretically, almost twice as efficient as HAWT, with a Cp in excess of 1.0.

          More important than the Cp is the breadth of the Cp curve. That is because something like 30% to 40% of the energy in the wind can be contained in gusts. Gusts typically come from a different direction, and the angle can be as large as 30 degrees. When a gust hits a turbine, that lowers the TSR. So the turbine needs to be able to adjust instantly to the changes in the velocity of the wind so as to increase the torque and accelerate the rotor RPM. Some cycloturbine VAWT can be especially good at that as compared to other wind turbines. An efficient cycloturbine can capture something between 20% and 35% more energy annually than a Darrieus rotor. (Darrieus patented a cycloturbine, but it was not efficient because it used collective, cyclic pitching, which is not accurate.)

                    It is possible and probably practical to combine Active Lift, blade-pitching, rotor-tipping, and paired counter-rotation. So I agree with you that the last word in windmills has not been said. However, I do not agree that VAWT are an inefficient platform to build upon. They are proving to be more varied, more versatile, and more powerful than was initially assumed. But they are not yet cheaper and more durable than HAWT. I am confident that will happen.

                    So, in my opinion, AWE inventors might benefit from understanding and possibly adopting some of the advances in VAWT technology.

          PeterS

           

           

          From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
          Sent: Monday, June 17, 2019 11:16 PM
          To: AirborneWindEnergy@yahoogroups.com
          Subject: [AWES] Re: Active Lift Turbine VAWT

           

           

          Quite an amazing achievement to achieve those numbers on an «inefficient» platform like VAWT. If the numbers presented are actually correct and practically relevant.

          It show that the last word has not been said in windmills, and likewise not in AWE...

          Group: AirborneWindEnergy Message: 26122 From: Peter Sharp Date: 6/18/2019
          Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
          Attachments :

            DaveS,

            I’m surprised to hear that you built and tested this design. You never mentioned that to me previously. Please show me what you did and when you did it.

            You are mistaken about this concept benefiting from dynamic soaring (DS). This concept does not rely on DS. It will function the same when there is no wind gradient. In fact, given that cycloturbine blades produce more lift and thrust when advancing into the wind than when retreating from the wind, this concept should work better when there is no wind gradient. Since the solidity ratio is so low, the downwind lower quadrant is the one that produces the most thrust. That means that a large wind gradient should reduce the power rather than increase the power.

            So perhaps you did something different. I’m interested in seeing what you did in case you discovered something.

            PeterS

             

            From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
            Sent: Tuesday, June 18, 2019 11:42 AM
            To: Yahoogroups <airbornewindenergy@yahoogroups.com

            Group: AirborneWindEnergy Message: 26123 From: Santos Date: 6/18/2019
            Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
            Yes, this was tested with Ed Sapir by kPower around 2015. LeBreque is related prior art. DS ridge-soaring gliders are very similar.

            It takes a bit of patience to datamine old work folks missed. We used an EPP foam RC wing in our case, but often use Coroplast too, for quick wings.

            Expect the hidden mountain of prior kite art, as specific topics recurr. Prior art is always jumping up on everyone in AWE, so we get used to it.
            Group: AirborneWindEnergy Message: 26124 From: joe_f_90032 Date: 6/18/2019
            Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
            Peter Sharp commented:

            "It will function the same when there is no wind gradient. In fact, given that cycloturbine blades produce more lift and thrust when advancing into the wind than when retreating from the wind, this concept should work better when there is no wind gradient."

            Slight minor note: Peter, we probably cannot have it "same" and then at change "better."    : )      

            It will be neat when the the wing is tested  up in high free air (thus little to no wind gradient) to compare with when tested where the wing goes in gradient at about a foot off the ground.    And alter the variable of the reacting springy poles as opposed near rigid side holds for further informing. And further: profiling of flight radius relative to arch tether length. Fun. 
            Group: AirborneWindEnergy Message: 26125 From: Santos Date: 6/18/2019
            Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
            Part of the DS wind gradient effect is the arrow of gravity, with potential energy stored at the top of pattern, and kinetic energy at the bottom.

            The looping arch thus works distinctly set horizontal in gradient wind vs set vertical.

            We have spent many happy hours working these details out.
            Group: AirborneWindEnergy Message: 26126 From: Peter Sharp Date: 6/18/2019
            Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
            Attachments :

              DaveS,

              It is unfortunate that you didn’t keep a record of your experiments. They might have had some value.

              I just explained to you why DS is not similar, yet you repeat your statement. How strange. The operating principles are different. A cycloturbine VAWT on its side does not operate like a DS glider.

              LeBreque is not prior art. His patent application was in 2008. I sold versions of my kite before I retired in about 2000, which placed the invention in the public domain and made it not patentable as of one year later. So his patent is post art, not prior art. If his patent were challenged, it could be easily invalidated as “obvious to someone practiced in the art” (patent office language). I was willing to let Lebreque commercialize his invention if he could. But his design has drawbacks which make that unlikely. He didn’t take the concept far enough.

              PeterS

               

               

              From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
              Sent: Tuesday, June 18, 2019 1:42 PM
              To: AirborneWindEnergy@yahoogroups.com
              Subject: RE: [AWES] Peter Sharp's Looping Arch (reposting video link to new topic)

               

               

              Yes, this was tested with Ed Sapir by kPower around 2015. LeBreque is related prior art. DS ridge-soaring gliders are very similar.

               

              It takes a bit of patience to datamine old work folks missed. We used an EPP foam RC wing in our case, but often use Coroplast too, for quick wings.

               

              Expect the hidden mountain of prior kite art, as specific topics recurr. Prior art is always jumping up on everyone in AWE, so we get used to it.

              Group: AirborneWindEnergy Message: 26127 From: Peter Sharp Date: 6/18/2019
              Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
              Attachments :

                JoeF,

                I think what I said is clear. But since you don’t find it so, and even perceive a contradiction, I will try to clarify. The way that it functions does not require a wind gradient. If there is a wind gradient, its effect will be negative, if anything. But as you can see in the video, it still functions in spite of the steep wind gradient between the top of the orbit and the bottom of the orbit. The negative effect is small, if any. So, if anything, it would work a little better without a wind gradient. Does that clarify for you?

                PeterS

                 

                 

                From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
                Sent: Tuesday, June 18, 2019 2:20 PM
                To: AirborneWindEnergy@yahoogroups.com
                Subject: RE: [AWES] Peter Sharp's Looping Arch (reposting video link to new topic)

                 

                 

                Peter Sharp commented:

                "It will function the same when there is no wind gradient. In fact, given that cycloturbine blades produce more lift and thrust when advancing into the wind than when retreating from the wind, this concept should work better when there is no wind gradient."



                Slight minor note: Peter, we probably cannot have it "same" and then at change "better."    : )      



                It will be neat when the the wing is tested  up in high free air (thus little to no wind gradient) to compare with when tested where the wing goes in gradient at about a foot off the ground.    And alter the variable of the reacting springy poles as opposed near rigid side holds for further informing. And further: profiling of flight radius relative to arch tether length. Fun. 

                Group: AirborneWindEnergy Message: 26128 From: Peter Sharp Date: 6/18/2019
                Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
                Attachments :

                  DaveS,

                  Sorry, but if you two happily worked out the details, you got them wrong. My kite does not work like DS.

                  “The looping arch thus works distinctly set horizontal in gradient wind vs set vertical.” This “sentence” has no clear meaning. Please translate into a clear statement of what you mean.

                  PeterS

                   

                  From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
                  Sent: Tuesday, June 18, 2019 2:29 PM
                  To: AirborneWindEnergy@yahoogroups.com
                  Subject: RE: [AWES] Peter Sharp's Looping Arch (reposting video link to new topic)

                   

                   

                  Part of the DS wind gradient effect is the arrow of gravity, with potential energy stored at the top of pattern, and kinetic energy at the bottom.

                   

                  The looping arch thus works distinctly set horizontal in gradient wind vs set vertical.

                   

                  We have spent many happy hours working these details out.

                  Group: AirborneWindEnergy Message: 26129 From: joe_f_90032 Date: 6/18/2019
                  Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
                  Thanks, Peter. Excellent clarification.
                  Group: AirborneWindEnergy Message: 26130 From: Santos Date: 6/18/2019
                  Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
                  Peter, we know this kind of turbine does not require the wind gradient, just as you insist, but our analytical contribution is that gradient boosts power, and you were testing in a real gradient.

                  Also be relieved that we did document kPower's version, it just takes time to locate old Forum sources. Some folks seem to think a few days is too long to recall the right keywords and find time to complete the search from tend of thousands of posts. But we always persevere.

                  There is vast prior kite art documented, to constantly rediscover.


                  Group: AirborneWindEnergy Message: 26131 From: joe_f_90032 Date: 6/18/2019
                  Subject: Re: Minesto News
                  Group: AirborneWindEnergy Message: 26132 From: Santos Date: 6/18/2019
                  Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
                  See reply in separate post. We did document well, and we know looping does not require gradient, and also know the DS boost from gradient. 

                  Being able to consider complex mixes of kite factors is our special power here. 

                  Note that towing this rig would avoid gradient, and make the lack of DS boost measurable.
                  Group: AirborneWindEnergy Message: 26133 From: benhaiemp Date: 6/19/2019
                  Subject: Tethered Vertical Axis Wind Turbine (TVAWT)?

                  Hi Peter,


                  Tallak asks on https://forum.awesystems.info/t/yoyo-awe-based-on-vawt/606/8?u=pierreb : "Could it be that there are feasible options for short tether AWE on a tower?".


                  I ask the same, knowing the challenge is keeping the tension of the tether during the whole rotation (360°), knowing the flight window of a stunt kite is lesser than 180°, and knowing the wind window can be about 270° in sea, using a boat with its drift (point of sail on 

                  https://en.wikipedia.org/wiki/Point_of_sail#%2Fmedia%2FFile%3APoints_of_sail.svg).


                  Thanks,


                  PierreB



                  Group: AirborneWindEnergy Message: 26134 From: benhaiemp Date: 6/19/2019
                  Subject: Re: Tethered Vertical Axis Wind Turbine (TVAWT)?
                  Hi Peter,

                  Some precision: the arms carrying the blades would be replaced with tethers. Something like this 

                  Thanks,

                  PierreB
                  Group: AirborneWindEnergy Message: 26135 From: tallakt Date: 6/19/2019
                  Subject: Re: Tethered Vertical Axis Wind Turbine (TVAWT)?
                  Yup. The last one (Aerogenerator) would be similar to my thinking except with variable arm length and pitch on the wing, along with tethers instead of the arms.

                  I think this stuff would only be feasible on a short tether. From my experience at kitemill I would gather pitch control would be a lot easier with a tailed wing. _IF_ I were to experiment with this, I would probably start out with a model sailplane rather than just a wing, and probably also with a single attachment point at the bottom of the body. I would have an electrical motor at the tether to give the rig most flexibility.

                  But even before I came to that point, we should eb able to simulate such an aircraft quite easily, and then optimize the flight path and tether lengths before actually building something in AFK (away from keyboard)

                  :)
                  Group: AirborneWindEnergy Message: 26136 From: tallakt Date: 6/19/2019
                  Subject: Re: Active Lift Turbine VAWT
                  Thanks for you replay, both very good and also very interesting. It seems the mass of the kite/wing is an important element to accumulate energy so that wind energy is harvested along the whole loop. For upwind, you get an increase in speed, and downwind, you can "reel out" downwind to recover energy from kite speed while still having enough "grunt" to keep the kite going until next upwind stroke. In this cycle, sometimes wind energy will have to be stores as kinetic energy in order to keep the rig running... at least these are som e very initial thoughts.

                  Group: AirborneWindEnergy Message: 26137 From: dougselsam Date: 6/19/2019
                  Subject: Re: Minesto News
                  It would be nice if the Minesto news were ever about how much power they are contributing to a grid, rather than how many millions of future grant money they can say will be paid to them in the future.


                  ---In AirborneWindEnergy@yahoogroups.com, <joefaust333@...
                  Group: AirborneWindEnergy Message: 26138 From: dougselsam Date: 6/19/2019
                  Subject: Re: Peter Sharp's Looping Arch (reposting video link to new topic)
                  Funny how you demand exact quotes with a link, from others when discussing your previous posts, but can't even find your own.
                  I think I've shown the search function on this group does not even work properly at all.


                  ---In AirborneWindEnergy@yahoogroups.com, <santos137@...