Messages in AirborneWindEnergy group.                          AWES 24008 to 24058 Page 372 of 440.
Group: AirborneWindEnergy Message: 24008 From: dave santos Date: 10/9/2018
Subject: Winged Ropedriving in the Sky at Mach .8, XC (>1000km); how cool wou

Group: AirborneWindEnergy Message: 24009 From: dave santos Date: 10/9/2018
Subject: Topological Lyapunov Stability as AWES Passive Control Paradigm Iden

Group: AirborneWindEnergy Message: 24010 From: dave santos Date: 10/9/2018
Subject: Re: Water launch at its fullest in kitefoiling

Group: AirborneWindEnergy Message: 24011 From: tallakt Date: 10/9/2018
Subject: Re: more kite golden-age man-lifting history

Group: AirborneWindEnergy Message: 24012 From: dave santos Date: 10/10/2018
Subject: Re: more kite golden-age man-lifting history

Group: AirborneWindEnergy Message: 24013 From: dave santos Date: 10/10/2018
Subject: AWE in Paris 2024 Olympics (kitesurfing finally accepted)

Group: AirborneWindEnergy Message: 24014 From: dave santos Date: 10/10/2018
Subject: Multi-Winch Aerotowed XC Loops (incl. horizontal crosswind laddermil

Group: AirborneWindEnergy Message: 24015 From: Peter A. Sharp Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24016 From: Pierre BENHAIEM Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24017 From: dave santos Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24018 From: dave santos Date: 10/10/2018
Subject: AWES Air-compression Gas Turbine Hybrid (PeterS)

Group: AirborneWindEnergy Message: 24019 From: dave santos Date: 10/10/2018
Subject: EU CORDIS page on Skypull

Group: AirborneWindEnergy Message: 24020 From: dave santos Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24021 From: Peter A. Sharp Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24022 From: Pierre BENHAIEM Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24023 From: Peter A. Sharp Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24024 From: dave santos Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24025 From: dave santos Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24026 From: dave santos Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

Group: AirborneWindEnergy Message: 24027 From: dougselsam Date: 10/10/2018
Subject: Re: Spanish windmills going Airborne - Now what, Don Quijote?

Group: AirborneWindEnergy Message: 24028 From: joe_f_90032 Date: 10/10/2018
Subject: Re: EU CORDIS page on Skypull

Group: AirborneWindEnergy Message: 24029 From: joe_f_90032 Date: 10/10/2018
Subject: Re: EU CORDIS page on Skypull

Group: AirborneWindEnergy Message: 24030 From: joe_f_90032 Date: 10/10/2018
Subject: Re: Minesto News

Group: AirborneWindEnergy Message: 24031 From: dougselsam Date: 10/11/2018
Subject: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24032 From: dougselsam Date: 10/11/2018
Subject: New Patent receives more press coverage

Group: AirborneWindEnergy Message: 24033 From: Pierre BENHAIEM Date: 10/11/2018
Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24034 From: Pierre BENHAIEM Date: 10/12/2018
Subject: Re: New Patent receives more press coverage

Group: AirborneWindEnergy Message: 24035 From: dougselsam Date: 10/12/2018
Subject: Re: New Patent receives more press coverage

Group: AirborneWindEnergy Message: 24036 From: Peter A. Sharp Date: 10/12/2018
Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24037 From: dougselsam Date: 10/12/2018
Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24038 From: dave santos Date: 10/13/2018
Subject: Re: New Patent receives more press coverage

Group: AirborneWindEnergy Message: 24039 From: dave santos Date: 10/13/2018
Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24040 From: dave santos Date: 10/13/2018
Subject: Paper on "Loitering" AWES

Group: AirborneWindEnergy Message: 24041 From: Peter A. Sharp Date: 10/13/2018
Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24042 From: tallakt Date: 10/13/2018
Subject: Re: Paper on "Loitering" AWES

Group: AirborneWindEnergy Message: 24043 From: joe_f_90032 Date: 10/14/2018
Subject: Re: Paper on "Loitering" AWES

Group: AirborneWindEnergy Message: 24044 From: benhaiemp Date: 10/15/2018
Subject: Re: Keeping Drag Force in Play

Group: AirborneWindEnergy Message: 24045 From: dave santos Date: 10/15/2018
Subject: Re: Keeping Drag Force in Play [1 Attachment]

Group: AirborneWindEnergy Message: 24046 From: dave santos Date: 10/15/2018
Subject: KPS Kiteplane? (IMechE coverage)

Group: AirborneWindEnergy Message: 24047 From: benhaiemp Date: 10/15/2018
Subject: Re: Keeping Drag Force in Play

Group: AirborneWindEnergy Message: 24048 From: dougselsam Date: 10/15/2018
Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

Group: AirborneWindEnergy Message: 24049 From: benhaiemp Date: 10/16/2018
Subject: Low-technology approach

Group: AirborneWindEnergy Message: 24050 From: joe_f_90032 Date: 10/16/2018
Subject: Wind inflow modeling for Airborne Wind Energy Systems

Group: AirborneWindEnergy Message: 24052 From: dougselsam Date: 10/16/2018
Subject: Re: Low-technology approach

Group: AirborneWindEnergy Message: 24053 From: dougselsam Date: 10/16/2018
Subject: Re: Sway turbine websites

Group: AirborneWindEnergy Message: 24054 From: Pierre BENHAIEM Date: 10/16/2018
Subject: Re: Sway turbine websites

Group: AirborneWindEnergy Message: 24055 From: Pierre BENHAIEM Date: 10/16/2018
Subject: Re: Low-technology approach

Group: AirborneWindEnergy Message: 24056 From: dougselsam Date: 10/17/2018
Subject: Re: Sway turbine websites

Group: AirborneWindEnergy Message: 24057 From: Pierre BENHAIEM Date: 10/17/2018
Subject: Re: Sway turbine websites

Group: AirborneWindEnergy Message: 24058 From: dave santos Date: 10/17/2018
Subject: Re: Keeping Drag Force in Play [1 Attachment]



Group: AirborneWindEnergy Message: 24008 From: dave santos Date: 10/9/2018
Subject: Winged Ropedriving in the Sky at Mach .8, XC (>1000km); how cool wou
Consider ~500mph DS glider wing equivalents flying 10km high, as beads on power-kite-quality super-polymer UHMWPE line sections 10km long. Just 200 gliders on the line could comprise a rope-drive loop 1000km long. How much power could be transmitted by this "toy-based" idea? Somewhere about 100kW, on just one moving power kite line, efficiency depending on distance drag loss and energetic cost to maintain the flying mass aloft. This idea might scale to GW-class, with the largest ropes and gliders.

Yes, there are tricky challenges, like just how to drive and tap the ends. But we can already sketch out some obvious details. Call them "line-planes" or "line-foils" to hold the tensioned line level, and it makes sense to rig the line axially in the chord, in the direction of motion. no empennage needed, just wing. If the wings could flip, the loop could be aerotowed with both sides flying the same direction, then one side flips to start the loop mode.

This is a specific conceptual extention of Culp's Flying Rope and Bolonkin's gliders-on-a-loop. The basic concept is suited for prototyping by very cheap simple means. A single horizontal pumping line, with simple shunting wings to eliminate line-sag, would test basic viability. Direct experimental comparison could be made to a line drive supported by towers with pulleys. The small leap here seems to imagine the amazing operational capability; that a GW-class powerline could be put up anywhere over long distances, in hardly more than an hour, and then be maintained indefinitely.

What better means to bring power fast to a disaster? Could millions of flying lines in the sky power the world? Lets hope so.
Group: AirborneWindEnergy Message: 24009 From: dave santos Date: 10/9/2018
Subject: Topological Lyapunov Stability as AWES Passive Control Paradigm Iden
Active Control theory in AWES engineering has tended to rely on maths like Markov decision process (MDP) or Moving Horizon Estimation (MHE), processed digitally. On the other hand, Passive Control (like CB's latest AWES demo and countless other cases) have no digital control to program algorithmically. The absurd result has been for scholars to disregard the toy kite flight solution of evident cybernetic embodied-cognition, for lack of sufficient math. Its proposed here that the Control Lyapunov Function is the right stuff.

Building on Van Veem's formal chaos identification of kite flight, we identified Lyapunov functions as predictive of kite stability. We then explored topological stability physics to find our kite control lines to be topological control inputs. Connecting-the-dots finally brings us to the Control Lyapunov Function, or "Topological Lyapunov Stability" if you will, as best-yet formal Control Theory for how staked-out, tailed, and/or otherwise stabilized classic kites fly.

It gets even better. Active MHE (and MDP) methods are mathematically known, "not optimal, in practice (MHE) has given very good results when compared with the Kalman filter and other estimation strategies." [WP] Its the tricky estimation processing step in a high dimensional state-space, plus sensor "soda-straw" data and actuation saturation errors, that ensure suboptimality. On the other hand, embodied Topological Lyapunov Stability has no estimation requirement, no sensor/actuator error that is not self-correcting.

In the most exotic interpretation, this is topologically robust macroscopic-phonon-based analogue-quantum-computing. If this system identification is somehow wrong, an AWES kite and its WECS payload still flies somehow, so someone please explain it better.

https://en.wikipedia.org/wiki/Control-Lyapunov_function
https://en.wikipedia.org/wiki/Optimal_control
https://en.wikipedia.org/wiki/Lyapunov_optimization
https://en.wikipedia.org/wiki/Moving_horizon_estimation
https://en.wikipedia.org/wiki/Markov_decision_process
Group: AirborneWindEnergy Message: 24010 From: dave santos Date: 10/9/2018
Subject: Re: Water launch at its fullest in kitefoiling
A few further details about this video, which is rather typical of the ongoing wonders in kite sports. The kite is an experimental design with fewer cells but stronger cloth, which also retains ram-air pressure better. The design goal was "90% of the performance of a race kite at 50% of the price", and reviewers agree the goal was met. The Kite Itself handles very easy on the water, filling quickly with wind. There are whiskers in the LE. The kite pro in the video is particularly trying to popularize wet launch, as one of the first practicing the new capability. Packing up the kite in the water is part of the operational innovation. The odd foil-board missing rear wing in the video seems a new trick, to remove the sharp awkward rear wing when walking in and out of the water, as I only see missing wings in beach crossing photos, not in action or product photos.

All in all, kite sports are evolving at lightning speed. The Power Kite Forum is a churning monster site of technical discussion. There are hundreds of kite and equipment reviews by hundreds of wizards writing an arcane tongue. I have never seen such ferment in a hacker culture, although HG-PG forums have the same tech rush. These are mainly adrenaline freaks desperately trying to boost their high by any means, rather than classical engineers. So they seem oblivious to AWE, except as they have mastered it for themselves. They do not keep secrets, because everything about a kite is tangible, and there is plenty wind for all. One can learn more about AWE at this site than anywhere except JoeF's monstrous archives-

http://www.powerkiteforum.com/
Group: AirborneWindEnergy Message: 24011 From: tallakt Date: 10/9/2018
Subject: Re: more kite golden-age man-lifting history
Lifting people could be useful for skydivers.
Group: AirborneWindEnergy Message: 24012 From: dave santos Date: 10/10/2018
Subject: Re: more kite golden-age man-lifting history
Hi Tallak,

We have considered kite-based skydiving would be great also, and have explored the possibilities, including using the wind to ferry jumpers up along a fixed kiteline ("kite messenger" cableway). We have elite BASE jumpers ready to go as soon as anyone provides them the platform. This would be as radical an innovation as how kitesurfing greened/displaced waterskiing.

Beyond that, some of us would like to live on kites, and the chute would be a safety backup. As Baden-Powell noted, there is a death-zone too low to even BASE jump safely (~10-50m). We have also pondered flying habitat design based on climber's portaledges, with fast egress and minimal snag-risk. The field is called Aerotecture, and AWE is the natural combination. Join the Aerotecture Group, if you have a special interest in developing this path to the sky,

daveS
Group: AirborneWindEnergy Message: 24013 From: dave santos Date: 10/10/2018
Subject: AWE in Paris 2024 Olympics (kitesurfing finally accepted)
Marina de Marseille, actually. Seeing racing parafoils finally dominate over LEIs in race photos; and foil-boards have supplanted planing-boards.

https://www.surfertoday.com/kiteboarding/14327-world-sailing-confirms-kiteboarding-in-the-paris-2024-olympic-games
Group: AirborneWindEnergy Message: 24014 From: dave santos Date: 10/10/2018
Subject: Multi-Winch Aerotowed XC Loops (incl. horizontal crosswind laddermil
A question posed yesterday was how to drive winged XC power-loops (wings on a rope) at ~0.8 Mach. The problem is that there is no feasible bull-wheel drive fast and big enough.

A neat solution seems to be to multi-winch/reelgen aerotow of the XC loop to power it. At each end of the XC loop would be a kite carousel much as KiteGen and others envisioned. Rather than being a stand-alone WECS, the carousel would be the power-drive or PTO at each end of the loop. The aerotow kites would fly up from the carousel and grab the loop, to either drive or tap it. A nearby kite-farm/gas-turbine hybrid could power the drive. The intital detail problem was how to fast re-extend reeled-in tow-lines, but it became clear that the tow-lines could re-extend passively by riding the loop around the end bends, while paying-out. The tow-kites would then drop the loop on one side and glide over to grab the other side, again ready to tow (drive) or be towed (tap).

This is also a promising solution to horizontal ladder mills running crosswind, where both ends of the loop are PTOs. An XC loop might power itself when the wind happened to be crosswind.

This is hopefully not too wild a scheme, based on existing aviation similarity-cases, where aerotow tethers are routinely taken up or dropped. Its merely a numeric extrapolation of known methods that would both be fast enough and big enough to drive winged XC loops.

Open-AWE_IP-Cloud
Group: AirborneWindEnergy Message: 24015 From: Peter A. Sharp Date: 10/10/2018
Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
Attachments :

    Hi Dave S,

              OK, so you would use jerker lines or rope pulleys from all of the kites to spin a single shaft, and then connect that shaft to the gas turbine’s generator using an over-running clutch. So the gas turbine needs to be capable of operating over the whole range of zero power up to full power, and it needs to be capable of modulating its power very quickly to compensate for the wide variations (zero to full power) in power from the kites.

              However, gas turbines lose a lot of efficiency if they operate at less than full power. In this case, the gas turbine would be operating very inefficiently at roughly an average of half power most of the time. The greater the capacity factor of the kite farm, the greater the inefficiency of the gas turbine. That means a lot of excess CO2 emissions. That seems self-defeating. So it’s not clear how you intend to save fuel and minimize CO2 emissions. You might even end up consuming more fuel than just using the gas turbine alone without the kites. How did you resolve that dilemma? Please show me your calculations?

    https://www.energy.gov/sites/prod/files/2016/09/f33/CHP-Gas%20Turbine.pdf  

              It seems to me that there might be a simple fix to this serious inefficiency problem: Use the kite-powered shaft to spin the gas turbine’s compressor via an over-running clutch. That way, energy from the kites reduces the fuel needed to spin the compressor, which consumes about half of the gas turbines power. And the gas turbine always operates at maximum efficiency. That saves the most fuel and eliminates the most CO2. The heat of compression could then be used to produce steam for the steam turbine of a combined cycle gas turbine.

    ------

              However, there are siting problems to contend with as well. For example, offshore kites seem incompatible with a gas turbine/kite combination using direct mechanical coupling because the jerker lines or pulley lines would have to extend many miles to shore where the gas turbine was located, or a gas line would need to extend many miles out to sea to a floating gas turbine. How did you resolve that problem? Similarly, finding a land location suitable for both a kite farm and a gas turbine seems limited to rather few locations. How did you resolve that problem?

              Let’s assume that the kite farm and the gas turbine plant can’t be in the same location, which would probably be true in most cases. If the gas turbine is a larger, combined cycle turbine (the residual heat from the burned gas is used to make steam for a steam turbine on the same shaft) compressed air produced by kites could be fed to the gas turbine to reduce fuel consumption, and the heat of compression can be used to create steam for the steam turbine. Compressed air (250 psi) can be transported over long distances fairly cheaply in pipe lines, and doing so provides a means of storing energy.

    But high temperature heat is not usually transported over long distances in pipe lines due to the problem of insulating the pipes. So maybe it would make sense to use the heat of compression to make steam for a steam turbine located at the wind farm, and then only the electricity from the steam turbine would be transported. The water would be recycled. Solar energy could also be captured on the kite farm to create steam directly. Or, both the heat of compression from wind energy, and from solar heating, would be used to heat salts as used on a solar concentrator farm, which also provides short term energy storage. Then the salts would be used to produce steam on demand, 24/7, for the steam turbine.

    ----

              But it seems to me that the most sensible alternative is to use kites and/or wind turbines (preferably Sharp Cycloturbines or Bird Windmills) to generate heat directly and store it in molten salt. Producing the heat is cheap, and storing it is reasonably cheap. Then use the heat to make steam for a steam turbine to generate grid electricity on demand. This system provides energy storage and eliminates the need for a backup gas turbine. It’s also compatible with solar heating where possible.

    Based on preliminary experiments, I believe that the heat can be generated very cheaply using T-shaped stirring rods in a container of BBs or the equivalent, lubricated with a little high-temperature silicon oil. The resistance force can be regulated to match the power from the wind energy source by simply raising or lowering the stirring rods because lowering them greatly increases the resistance due to the increase in pressure due to depth. The efficiency of the conversion of mechanical energy to heat is close to 100%. The BB container can be relatively small and can be located inside of the container of salt to minimize heat losses. The heat is generated primarily by a momentum exchange rather than by friction. The BBs will gradually deteriorate due to friction, thus forming a soup of powdered steel, which should work about as well as the BBs. Diced, thin steel rods could be used instead of BBs, or machine shop metal filings could be used instead of BBs.

    PeterS

     

     

    From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
    Sent: Tuesday, October 09, 2018 10:58 AM
    To: yahoogroups <airbornewindenergy@yahoogroups.com

    Group: AirborneWindEnergy Message: 24016 From: Pierre BENHAIEM Date: 10/10/2018
    Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

    Hi Peter,

     

    Great post. Please can you detail your solution by using a schema? 

     

    PierreB

     

     

     

     
    Group: AirborneWindEnergy Message: 24017 From: dave santos Date: 10/10/2018
    Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
    No PeterS,

    We studied the hybrid idea out rather better than you guess, including having our own career power-plant pros to consult with. We know that major power plants have multiple turbines (and some gens have two turbines, either matched, or one major one, and one "pony" unit, to adapt output). Its standard practice to bring them up or down individually to match demand, and count on such means for hybrid operation. We have never naively imagined throttling a turbine outside its optimal range. It is possible to throttle-back moderately in a wind boost mode under high load demand. Despair at the workability of direct kite hybrid is premature. There is enough promise in the direct hybrid idea to compare it with your indirect scheme (plus heat-of-compression) of adding air-compression, for the same hoped-for benefit. Consider estimating the capital cost of the your compression storage upgrade, compared to direct hybrid operation cost estimates.

    We also know how to be as super flexible in principle with kite power as experts can, including potentially tapping useful power high while surface wind-turbines are idle (like common AM calm inversions at surface while wind above forms a nice LLJ). Let the kite side of the hybrid be the most flexible source.

    I am sorry there is too much past Forum discussion to repeat here, but at least it lives in archive form for anyone who searches. Just be aware how much you might accidentally presume others do not know about subjects they spent years and thousands of messages exploring. Thanks for any added insights we surely missed,

    daveS
    Group: AirborneWindEnergy Message: 24018 From: dave santos Date: 10/10/2018
    Subject: AWES Air-compression Gas Turbine Hybrid (PeterS)
    This thread is for PeterS to detail his kite-power/gas-turbine air compression-based hybrid, as requested by PierreB. on-topic.

    My questions to PeterS regard rough capital-cost per unit-energy and heat-of-compression handling.
    Group: AirborneWindEnergy Message: 24019 From: dave santos Date: 10/10/2018
    Subject: EU CORDIS page on Skypull
    Group: AirborneWindEnergy Message: 24020 From: dave santos Date: 10/10/2018
    Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
    Replying to some of PeterS specific concerns and ideas-

    - Aviation pros on AWE are convinced kites can be part of normal controlled airspace, even over cities, especially under NextGen capability. FAA's own experts are not concerned that AWE will be a menace, nor do they think AWE might not be workable. Non-experts tend to fret about airspace for AWE.

    - Transmitting power over ropeways a few miles is long established art; we will depend on this method as needed.

    - Many rural power plants already have large enough land foot prints for easy AWE hybrid use. Many coal plants (like Fayetteville, TX) are in their own strip-mine. Some get converted to gas turbines, to leverage location and grid connection. These are low-hanging fruit for kite-hybrids, even if the high-hanging fruit is out of reach.

    - Adding storage by compression, heat, cryogenic, fuel-cycles, etc. adds a huge cost layer, best if avoided. AWE dependent on added systems will be slower to develop.
    Group: AirborneWindEnergy Message: 24021 From: Peter A. Sharp Date: 10/10/2018
    Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
    Attachments :

      Hi Pierre,

      Which solution is the one that interest you?

      By “schema”, do you mean a diagram?

      At present, I think that heating a tank of salt using a friction heater inside of it is the best way to store wind energy, and then use a steam turbine to produce electricity on demand. That is what some large solar-concentrator plants do; they heat a tank of salt and then use the heat to drive a steam turbine. The conventional objection to using wind turbines to heat salt is that mechanical energy is a higher grade form of energy than heat, so it shouldn’t be wasted. It should be used to drive a generator directly in real time. But that technology ignores the problem of wind energy intermittency, so it requires gas turbine back-up and CO2 emissions, which greatly increases the total grid system cost once wind energy supplies a large proportion of the energy.

      I also mentioned using wind energy to partially or wholly directly-power the compressor stage of a gas turbine (assuming the gas turbine could be located on a wind farm for kites or wind turbines).

      I also mentioned storing compressed air to feed into a gas turbine to make the gas turbine more efficient.

      PeterS

       

      From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
      Sent: Wednesday, October 10, 2018 11:46 AM
      To: AirborneWindEnergy@yahoogroups.com
      Subject: RE: [AWES] Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

       

       

      Hi Peter,

       

      Great post. Please can you detail your solution by using a schema? 

       

      PierreB

       

       

       

       
      Group: AirborneWindEnergy Message: 24022 From: Pierre BENHAIEM Date: 10/10/2018
      Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

      Hi Peter,

      By "schema" I mean a schema, particularly a schema of the over-running clutch within the other elements like the kite-powered shaft, the gas turbines etc.:"  It seems to me that there might be a simple fix to this serious inefficiency problem: Use the kite-powered shaft to spin the gas turbine’s compressor via an over-running clutch. That way, energy from the kites reduces the fuel needed to spin the compressor, which consumes about half of the gas turbines power. And the gas turbine always operates at maximum efficiency. That saves the most fuel and eliminates the most CO2. The heat of compression could then be used to produce steam for the steam turbine of a combined cycle gas turbine." Thanks.

       

      PierreB

       

       

       

       

       
      Group: AirborneWindEnergy Message: 24023 From: Peter A. Sharp Date: 10/10/2018
      Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
      Attachments :

        Hi DaveS,

        Your answer was non-responsive. You did not explain why it would be better to use wind energy to drive the generator of a gas turbine rather than the compressor.

        PeterS

         

         

        From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
        Sent: Wednesday, October 10, 2018 12:50 PM
        To: AirborneWindEnergy@yahoogroups.com
        Subject: RE: [AWES] Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)

         

         

        No PeterS,

        We studied the hybrid idea out rather better than you guess, including having our own career power-plant pros to consult with. We know that major power plants have multiple turbines (and some gens have two turbines, either matched, or one major one, and one "pony" unit, to adapt output). Its standard practice to bring them up or down individually to match demand, and count on such means for hybrid operation. We have never naively imagined throttling a turbine outside its optimal range. It is possible to throttle-back moderately in a wind boost mode under high load demand. Despair at the workability of direct kite hybrid is premature. There is enough promise in the direct hybrid idea to compare it with your indirect scheme (plus heat-of-compression) of adding air-compression, for the same hoped-for benefit. Consider estimating the capital cost of the your compression storage upgrade, compared to direct hybrid operation cost estimates.

        We also know how to be as super flexible in principle with kite power as experts can, including potentially tapping useful power high while surface wind-turbines are idle (like common AM calm inversions at surface while wind above forms a nice LLJ). Let the kite side of the hybrid be the most flexible source.

        I am sorry there is too much past Forum discussion to repeat here, but at least it lives in archive form for anyone who searches. Just be aware how much you might accidentally presume others do not know about subjects they spent years and thousands of messages exploring. Thanks for any added insights we surely missed,

        daveS
        Group: AirborneWindEnergy Message: 24024 From: dave santos Date: 10/10/2018
        Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
        --------------------------------------------
        Group: AirborneWindEnergy Message: 24025 From: dave santos Date: 10/10/2018
        Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
        I am responding, PeterS, it just was not quite the response you demand. Its not claimed here that one or the other scheme can be known as "better", without a full examination and testing. Be patient in seeking response, I have to run to a meeting.

        You and Pierre please make new topics when you find your selves in new subjects, as best you can.
        Group: AirborneWindEnergy Message: 24026 From: dave santos Date: 10/10/2018
        Subject: Re: Review of Kite/Gas-Turbine Hybrid Concept (redirected topic)
        "Use the kite-powered shaft to spin the gas turbine’s compressor via an over-running clutch."


        Note- Most gas turbines of interest have compressor stage and combustion turbine stage on the same shaft, so kite driving the shaft drives the whole in proportion.
        Group: AirborneWindEnergy Message: 24027 From: dougselsam Date: 10/10/2018
        Subject: Re: Spanish windmills going Airborne - Now what, Don Quijote?
        Chris:
        What model and brand of lifter kite were you using for that video?
        It seemed to fly in a stable manner, without requiring a tail.
        DougS
        Group: AirborneWindEnergy Message: 24028 From: joe_f_90032 Date: 10/10/2018
        Subject: Re: EU CORDIS page on Skypull

        SkyPull

        Domenico Chianese​
        Co-founder​
        President of the Board
        -----------------------------------------------
        Nicola Mona​
        Co-founder 
        Chief Executive Officer
        ===============================
        Aldo Cattano​
        Co-founder 
        Chief Techical Officer
        ============================
        Marcello Corongiu​
        Co-founder 
        Chief Operation Officer
        =========================
        Edgar Van Nunen​
        Chief Financial Officer
        ========================
        Claudio Micheli​
        Control Systems Engineer, Pilot
        ==========
        Alberto Bettelini​
        UAV Manufacturing and Pilot
        ========================
        Sandro La Marca​
        Electromechanics
        =========================
        Alex D'Agosta​
        Press
        ========================
        Laurie Jego​
        CFD Stagiere
        =============================
        Group: AirborneWindEnergy Message: 24029 From: joe_f_90032 Date: 10/10/2018
        Subject: Re: EU CORDIS page on Skypull
        Group: AirborneWindEnergy Message: 24030 From: joe_f_90032 Date: 10/10/2018
        Subject: Re: Minesto News
        Group: AirborneWindEnergy Message: 24031 From: dougselsam Date: 10/11/2018
        Subject: "Dark Side of WInd Power" - new article: Bloomberg
        I knew it I knew it I knew it.  And I've probably said so here. 


        Oh, you mean all the "smart" people were wrong, and all the stupid people were right?  Again?  (except me, of course... wink)  By the way, remember "Eggs, not as bad as we thought!"?

        Environmentalists tend to be driven by emotion more than science, (even though they imagine the opposite), so it was pretty-much expected that they'd only be able to look at one factor at a time while demanding we power our whole planet with wind power.  I've been saying all along, the push for more windpower to "fix" the climate, by environmentalists, will last until they start looking at how slowing the winds affects climate. 

        The poles are nature's air conditioner for the planet, but that requires winds and ocean currents to cycle the fluids from the equator to the poles and back.  If you block the winds, you slow down the heat exchange process, just like if you restrict the flow in the radiator hoses of your car, your engine temp will increase. 

        For example, the wind turbines in the Mountain pass at Palm Springs must by definition slow the wind going through the pass.  That wind is Southern California's air-conditioner.  So nobody mentions that the same wind turbines that charge money for you to run your air conditioners are also super-charging their own market by making it hotter every afternoon. 

        I guess, with all the hype, in the fog of battle, none of the "Scientists" noticed that taking energy from the wind slows the wind.  Ya think?

        Hmmm, but I thought climate scientists had all this stuff figured out!  I mean, what about their "models"?  Oh, you mean the models that said it would be 5 degrees hotter by now?  That all coastal properties would be underwater and no snow would ever fall again in DC after 2015?  Those models?

        Anyway, being the fountain of prescience that I can sometimes be, I've been expecting this all along.  Well, ya know...  This will affect wind energy and ocean current energy, once the official geniuses figure out that the ocean currents may be even more important than the winds for keeping things cool by helping to average out the temperature from Poles to Equator, and that taking energy from ocean currents slows circulation. 

        I'm sure you've already heard about "the melting" injecting fresh water into the Northern Atlantic, possibly affecting the "conveyor belt" of the gulf stream, dipping Europe back into a glacial cycle, which may mark the transition to mass panic over "cooling", which has historically had about a 30 year cycle of warming vs. cooling panic.

        Imagine this: Just as we now ask hydrocarbon-burning power plants to sequester their CO2, soon they'll be requiring windfarms to re-accelerate the wind again, when they are done using it.  Luckily we have SUPERgeniuses here on this very forum to figure out how, so I'm not worried. I mean, considering all the stuff they've figured out so far, especially lately, re-accelerating the wind after using it should be relatively easy.

        Now, as with any panicked "we just woke up and realized the world is going to end" statements by scientists, we have to take this with a grain of salt.  For example, how do they know there isn't some compensating effect?  If they slowed the wind, and a temperature differential is enhanced, that should make the winds stronger again.  And the extra heat of all those air-conditioners running should also accelerate the wind.  So, run your AC overtime to fight global warming.  Make a bonfire.  Anything to create heat.  Also, slowing the winds would prevent some warm tropical air from reaching the poles, slowing the ice melt, so that would be good, right?  (Is anyone noticing that there are so many inter-related variables, combined with "things we don't know", and "aspects we've never considered", that predictions are difficult, if not almost certain to be wrong?
        Group: AirborneWindEnergy Message: 24032 From: dougselsam Date: 10/11/2018
        Subject: New Patent receives more press coverage
        New Patent for offshore wind floating foundation receives more press coverage:
        Group: AirborneWindEnergy Message: 24033 From: Pierre BENHAIEM Date: 10/11/2018
        Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg

        See this study on the topic: http://iopscience.iop.org/article/10.1088/1748-9326/aae102/meta: "Observation-based solar and wind power capacity factors and power densities" Lee M Miller and David W Keith. 

        See also GIEC report on http://report.ipcc.ch/sr15/pdf/sr15_spm_final.pdf , page 19/33, recommending increasing nuclear until 6 times.

         

        PierreB
        Group: AirborneWindEnergy Message: 24034 From: Pierre BENHAIEM Date: 10/12/2018
        Subject: Re: New Patent receives more press coverage

        Hi Doug,

         

        Please what is your advice about https://www.youtube.com/watch?v=jyl4DecxwGE , also on http://www.sway.no/index.php?page=166 ? Sway' downwind turbine is like a ballasted floating bottle, with a single tension leg. It looks to be far lighter (thanks to tension leg instead of catenary moorings) and cheaper than other floating turbines.

         

        PierreB

         

         

         

         
        Group: AirborneWindEnergy Message: 24035 From: dougselsam Date: 10/12/2018
        Subject: Re: New Patent receives more press coverage
        Hi Pierre:
        A ballasted floating tube - that is what our new patent covers, so it would also cover this "Sway".  I guess someone could poetically call it a "floatiing bottle".  Same basic idea.

        "Sway" seems interesting, with some clever creativity, but I doubt if you'll ever see it as illustrated.  It just has that "wa-wa-wah" flavor.

        When wind energy developers talk of downwind rotor orientation relative to a tower, they usually go to a 2-bladed rotor, rather than a 3-blade rotor..  The tower wind-shadow beats on the blades in either case, which is why such a configuration is not used on land or anywhere else, despite many attempts.

        When a blade is traveling at 160 mph, it hits the tower wake almost as a solid object.  The resulting concussion reverberates throughout the entire structure.  People sitting at their desk fooling around with their computer know nothing of any of this.



        New Patent receives more press coverage:

        North American WindPower Magazine:

        WindPower Engineering and Development Magazine:

        USWINDLASBSLOGO3at25%.jpg
        SelsamLogoScan2at25%x25%.jpg know nothing of any of this.


        ---In AirborneWindEnergy@yahoogroups.com, wrote :

        Hi Doug,

         

        Please what is your advice about https://www.youtube.com/watch?v=jyl4DecxwGE , also on http://www.sway.no/index.php?page=166 ? Sway' downwind turbine is like a ballasted floating bottle, with a single tension leg. It looks to be far lighter (thanks to tension leg instead of catenary moorings) and cheaper than other floating turbines.

         

        PierreB

         

         

         
        Group: AirborneWindEnergy Message: 24036 From: Peter A. Sharp Date: 10/12/2018
        Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg
        Attachments :

          Hi DougS,

          What did you know?

          https://www.aweablog.org/fact-check-no-wind-turbines-not-cause-climate-change/ 

          https://www.awea.org/Awea/media/Policy-and-Issues/Harvard-article-response.pdf 

          PeterS

           

          From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
          Sent: Thursday, October 11, 2018 7:33 AM
          To: AirborneWindEnergy@yahoogroups.com
          Subject: [AWES] "Dark Side of WInd Power" - new article: Bloomberg

           

           

          I knew it I knew it I knew it.  And I've probably said so here. 

           

           

          Oh, you mean all the "smart" people were wrong, and all the stupid people were right?  Again?  (except me, of course... wink)  By the way, remember "Eggs, not as bad as we thought!"?

           

          Environmentalists tend to be driven by emotion more than science, (even though they imagine the opposite), so it was pretty-much expected that they'd only be able to look at one factor at a time while demanding we power our whole planet with wind power.  I've been saying all along, the push for more windpower to "fix" the climate, by environmentalists, will last until they start looking at how slowing the winds affects climate. 

           

          The poles are nature's air conditioner for the planet, but that requires winds and ocean currents to cycle the fluids from the equator to the poles and back.  If you block the winds, you slow down the heat exchange process, just like if you restrict the flow in the radiator hoses of your car, your engine temp will increase. 

           

          For example, the wind turbines in the Mountain pass at Palm Springs must by definition slow the wind going through the pass.  That wind is Southern California's air-conditioner.  So nobody mentions that the same wind turbines that charge money for you to run your air conditioners are also super-charging their own market by making it hotter every afternoon. 


          I guess, with all the hype, in the fog of battle, none of the "Scientists" noticed that taking energy from the wind slows the wind.  Ya think?

           

          Hmmm, but I thought climate scientists had all this stuff figured out!  I mean, what about their "models"?  Oh, you mean the models that said it would be 5 degrees hotter by now?  That all coastal properties would be underwater and no snow would ever fall again in DC after 2015?  Those models?

           

          Anyway, being the fountain of prescience that I can sometimes be, I've been expecting this all along.  Well, ya know...  This will affect wind energy and ocean current energy, once the official geniuses figure out that the ocean currents may be even more important than the winds for keeping things cool by helping to average out the temperature from Poles to Equator, and that taking energy from ocean currents slows circulation. 

           

          I'm sure you've already heard about "the melting" injecting fresh water into the Northern Atlantic, possibly affecting the "conveyor belt" of the gulf stream, dipping Europe back into a glacial cycle, which may mark the transition to mass panic over "cooling", which has historically had about a 30 year cycle of warming vs. cooling panic.

           

          Imagine this: Just as we now ask hydrocarbon-burning power plants to sequester their CO2, soon they'll be requiring windfarms to re-accelerate the wind again, when they are done using it.  Luckily we have SUPERgeniuses here on this very forum to figure out how, so I'm not worried. I mean, considering all the stuff they've figured out so far, especially lately, re-accelerating the wind after using it should be relatively easy.

           

          Now, as with any panicked "we just woke up and realized the world is going to end" statements by scientists, we have to take this with a grain of salt.  For example, how do they know there isn't some compensating effect?  If they slowed the wind, and a temperature differential is enhanced, that should make the winds stronger again.  And the extra heat of all those air-conditioners running should also accelerate the wind.  So, run your AC overtime to fight global warming.  Make a bonfire.  Anything to create heat.  Also, slowing the winds would prevent some warm tropical air from reaching the poles, slowing the ice melt, so that would be good, right?  (Is anyone noticing that there are so many inter-related variables, combined with "things we don't know", and "aspects we've never considered", that predictions are difficult, if not almost certain to be wrong?

           
          Group: AirborneWindEnergy Message: 24037 From: dougselsam Date: 10/12/2018
          Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg
          Hi Peter:
          What I've always known is, at some point, there would be a push-back on wind energy and ocean current energy, based on the idea that they slow the cycling of fluids to the poles and back, in the extreme case, and cause localized heating, at a less sensationalized local level of concern.  Either way, slowing nature's air conditioner is the theme.
          Do I believe it to be true?
          Well I think it's true there must be some effect.
          Palm Springs can reach 120 degrees on a hot day.  Ocean winds blow in every afternoon "trying" to cool the desert.  Block those winds and it's probably that much hotter upwind, downwind, and in, Palm Springs, where almost nothing grows as it is, unless it is irrigated, or a palm near a spring.
          But as I've mentioned, there could easily be mitigating effects too.

          Like I've said, the whole system is SO complicated and inter-related, I'm not sure ANYONE really has a handle on it.  In fact I'm pretty sure they don't.  The main factors could be things nobody has even thought about yet.  Imagine trying to figure out exactly what will happen next with some icy-surface dirt-ball with a molten core, spinning in front of a blowtorch on a winter night.  Good luck.  Example: the new idea that a lack of sunspots could allow more "cosmic rays" (McParticles) to hit earth's atmosphere, causing a "cloud-chamber" effect, making clouds, blocking sunlight, lowering temps.  Then again clouds at night raise temps.  BTW, Did you know CO2 lowers the amount of total solar radiation hitting Earth?  Most people don't.  Nobody ever mentions it because nobody thinks for themselves, but rather we mostly just repeat talking points strategically spoon-fed to us.
          Group: AirborneWindEnergy Message: 24038 From: dave santos Date: 10/13/2018
          Subject: Re: New Patent receives more press coverage
          The Sway concept does embody Doug's patent claim, just as hoe notes, but as Norwegian prior art a decade or so older that has been tested at fairly large scale.

          What this case seems to represent is that the US Patent system now routinely grants patents without close examination, pocketing the fees. As for "press coverage", many sites function on click-bait content and traffic, and careful fact-checking is not part of the biz model.

          Good Luck to Doug in his ongoing inventive practice. The race to define and perfect the future of wind power goes on, and no telling who might first get there.
          Group: AirborneWindEnergy Message: 24039 From: dave santos Date: 10/13/2018
          Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg
          The actual dark side of wind power is energy-inequity, where wealthier populations with high per-capita energy consumption enjoy it, and the poorest do not. We expect the business press, including Bloomberg, to obsess over anything affecting fossil fuel profits. Fossil fuel addiction remains the bleakest path. Destroying the planet with too much wind power, as Doug warns about, is a far more remote risk. CristinaA is our top expert theorist of AWE climate impacts, and she is resolutely optimistic, based on the data. Its our mission to explore AWE rather than fall for "dark side" click-bait alarmism.

          AWEA response to the Harvard study is mild, as the actual calculated results are small potatoes- that surface turbines might increase local temperature some fraction of a degree, when the real crisis is global increase of several degrees. This particular effect does not necessarily apply to AWE operating at a much higher altitude, nor kites reflecting away heat and providing shade. Our general consensus has been that upper wind will be part of a basket of green energy solutions, and that greener more efficient lifestyles are the top urgent solution.

          The idea that environmentalism is more "emotional" than raw capitalism is suspect. Environmental values may in fact be the more rational path than the shrill "greed is good" ideology, as environmental risk proves existential. In fact, the most prosperous countries invest the most in meeting environmental concerns, not because they are more emotional, but because they rationally choose a better environment.
          Group: AirborneWindEnergy Message: 24040 From: dave santos Date: 10/13/2018
          Subject: Paper on "Loitering" AWES
          This very preliminary paper contributes an AWES term-of-art, "Loiter"; for staying aloft in transient calms. KPS is the close industry partner to this work-

          Flight Phase Control Strategies for Airborne Wind Energy Systems

          John Warnock, David McMillan, Samuel Tabor
          University of Strathclyde, Electronic & Electrical Engineering Department, Glasgow, UK

          KPS, Glasgow, UK
          john.warnock@Strath.ac.uk

          http://iopscience.iop.org/article/10.1088/1742-6596/1102/1/012020/pdf
          Group: AirborneWindEnergy Message: 24041 From: Peter A. Sharp Date: 10/13/2018
          Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg
          Attachments :

            DaveS,

            Well said. Thank you.

            PeterS

             

            From: AirborneWindEnergy@yahoogroups.com [mailto:AirborneWindEnergy@yahoogroups.com]
            Sent: Saturday, October 13, 2018 1:23 PM
            To: AirborneWindEnergy@yahoogroups.com
            Subject: RE: [AWES] "Dark Side of WInd Power" - new article: Bloomberg

             

             

            The actual dark side of wind power is energy-inequity, where wealthier populations with high per-capita energy consumption enjoy it, and the poorest do not. We expect the business press, including Bloomberg, to obsess over anything affecting fossil fuel profits. Fossil fuel addiction remains the bleakest path. Destroying the planet with too much wind power, as Doug warns about, is a far more remote risk. CristinaA is our top expert theorist of AWE climate impacts, and she is resolutely optimistic, based on the data. Its our mission to explore AWE rather than fall for "dark side" click-bait alarmism.

            AWEA response to the Harvard study is mild, as the actual calculated results are small potatoes- that surface turbines might increase local temperature some fraction of a degree, when the real crisis is global increase of several degrees. This particular effect does not necessarily apply to AWE operating at a much higher altitude, nor kites reflecting away heat and providing shade. Our general consensus has been that upper wind will be part of a basket of green energy solutions, and that greener more efficient lifestyles are the top urgent solution.

            The idea that environmentalism is more "emotional" than raw capitalism is suspect. Environmental values may in fact be the more rational path than the shrill "greed is good" ideology, as environmental risk proves existential. In fact, the most prosperous countries invest the most in meeting environmental concerns, not because they are more emotional, but because they rationally choose a better environment.
            Group: AirborneWindEnergy Message: 24042 From: tallakt Date: 10/13/2018
            Subject: Re: Paper on "Loitering" AWES
            I believe this document does not describe what loitering is. I belive the term loitering is a goot term though.

            Tallak Tveide
            [Employee at Kitemill AS]
            Group: AirborneWindEnergy Message: 24043 From: joe_f_90032 Date: 10/14/2018
            Subject: Re: Paper on "Loitering" AWES
            an airborne powered loiter phase

            a grounded waiting phase

            wind-speed measurement uncertainty

            launch-and-land policy

            Laddermill, a tiered kite-based AWES 

             ground-generating AWES 

            cut-in wind speed

            loiter phase
            optimal loiter time
            airborne loiter policy

            flight phase control policy

            the utility of airborne loitering of an AWES

            intermission

            parasitic costs

            intermission, launch, generate (may be fly-gen or pumping), loiter, land, grounded (may go to launch or intermission)

            determining true optima of policy parameters.
            Group: AirborneWindEnergy Message: 24044 From: benhaiemp Date: 10/15/2018
            Subject: Re: Keeping Drag Force in Play
            Attachments :

              I remember the interesting Chinese AWE project.

              As a parachute (I experimented http://www.brookite.com/kites/air-bear-kite-and-parachute.html) can be quite large, such a low-technology project would be promising if the used film (or fabric) is cheap and resistant enough and has a long life. A drag power kite is not also requiring as for the holding of the shape: the film or fabric wear is less problematic as for a lift power kite.

              A company or some studies for a parachute-like reeling groundgen?


              PierreB

              		   @@attachment@@
              Group: AirborneWindEnergy Message: 24045 From: dave santos Date: 10/15/2018
              Subject: Re: Keeping Drag Force in Play [1 Attachment]
              We see drag as a working part of max force by a power kite. There is no pure drag AWES, since some lift is required to stay airborne; the Chinese varidrogue case depended on the lift of its pilot-lifter; it was not a pure-drag concept. Kite fabric lasts just as long in lift or drag mode; exceeding max-load of the fabric and UV are what most shorten useful life. There are wear factors of flogging or abrasion, and a drogue dragging on the ground without being lifted would not last long.

              Another critical problem "keeping drag force in play" as an AWES basis is reeling dependence. A power drogue WECS would require a parasitic upwind reel-in cycle, with the further complication of cyclic furling and re-inflating the drogue. This is another way of seeing "crosswind-power" as our engineering ideal. Another clarification is that AWES load-demand always expresses as drag-forces, so no drag-free AWES option even exists. As KiteShip first determined, a ~3/1 L/D ratio is typical of any power-kite in its working-load state, the drag component is essential.

              There are many interesting traps in trying to down-select the most competitive AWES architecture. Broad comparative testing of both good and bad ideas can best settle differences of opinion, but someone has to actually produce losing ideas for fly-off testing, or the market eventually just settles on whatever works. All this is review of past analysis.
              Group: AirborneWindEnergy Message: 24046 From: dave santos Date: 10/15/2018
              Subject: KPS Kiteplane? (IMechE coverage)
              KPS has been a soft-kite venture, but now we see them betting on an airbeam-based rigid-wing kiteplane design, according to coverage by the Institution of Mechanical Engineers. All previous AWE ventures who gave up on the soft-kite in favor of rigid wings found themselves in engineering limbo, since there is no proven kiteplane able to fly safely and reliably to a far-longer payback, and rigid structure scaling is severely limited by cubic-mass-penalty and fixed average wind velocity.

              The probable winner in KPS's fickle wing selection is SkySails, holding firm in the proven soft ship-kite design space. If, as kPower predicts, the ship-kite derivative will be the winner of large-scale AWE R&D, the high-profile kiteplane ventures are running out of luck.

              http://www.imeche.org/news/news-article/let%27s-go-fly-a-kite-how-airborne-wind-turbines-on-drones-and-kites-could-take-off


              The article also has Dr. Harrop predicting next year as the historic market entry of AWES product (at ~30kW), overlooking both existing small products and future true-utility-scale products.
              Group: AirborneWindEnergy Message: 24047 From: benhaiemp Date: 10/15/2018
              Subject: Re: Keeping Drag Force in Play
              Attachments :

                As the present topic is about Drag Force, as the initiation message mentions a "diameter-play parachute", mentions also that "A simple drogue develops almost pure drag force..." the reader is informed enough that we write about kite power using mainly drag force.

                Then specifying every time that a kite has some lift component is not useful as generally a kite flies.

                Beside it a parasail-like can fly by itself without any kite pilot. See the holes in the low part of the toy kite on the toy http://www.brookite.com/kites/air-bear-kite-and-parachute.html.

                Moreover the consequences of film or fabric deformation can be higher for a high L/D ratio wing. By the same sails regatta can have a shorter lifetime. 

                The figure 4 of the attached patent represents a depower system that can be efficient.

                An advantage is the possibility of the production of an electric current that is more regular than that achieved by crosswind kite dealing with different cosines within the flight window.


                PierreB

                 

                		   @@attachment@@
                Group: AirborneWindEnergy Message: 24048 From: dougselsam Date: 10/15/2018
                Subject: Re: "Dark Side of WInd Power" - new article: Bloomberg
                "Destroying the planet with too much wind power, as Doug warns about, is a far more remote risk."

                I was noting that I've always expected that, eventually, someday, OTHERS would "warn about" this, not warning about it myself.  The actual opinion I expressed was that the system is too complicated to jump to any such conclusion.  I was warning about the warners, not to be confused with being one of them.  I would prefer if my name is used here, it would not be used to misrepresent my statements.
                Group: AirborneWindEnergy Message: 24049 From: benhaiemp Date: 10/16/2018
                Subject: Low-technology approach

                As AWE R&D go towards several directions, we favor a low-technology approach.

                A single-skin 1.3 kg and 16 m² glider as shown on http://www.paraglidingforum.com/viewtopic.php?t=92469  can become a robust basis for a crosswind or rotary AWES. The fabric can be far heavier in order to achieve AWE requirements of which a lifetime high enough.

                PierreB
                Group: AirborneWindEnergy Message: 24050 From: joe_f_90032 Date: 10/16/2018
                Subject: Wind inflow modeling for Airborne Wind Energy Systems

                Wind inflow modeling for Airborne Wind Energy Systems

                September 2018

                DOI: 10.13140/RG.2.2.20725.83685

                Conference: EAWE PhD seminar 2018

                Project: AWESCO - Airborne Wind Energy System Modelling, Control and Optimisation

                Markus Sommerfeld

                Curran Crawford


                Markus Sommerfeld

                University of Victoria

                Department

                Institute for Integrated Energy Systems at the University of Victoria (IESVic)

                Research information

                4 Publications       0 Citations


                Curran Crawford

                University of Victoria

                Department

                Department of Mechanical Engineering

                Research information

                127 Publications       938 Citations


                Note:  eawe   :: European Academy of Wind Energy 
                Group: AirborneWindEnergy Message: 24052 From: dougselsam Date: 10/16/2018
                Subject: Re: Low-technology approach
                I'm asking, if people use the term "we", they say who they mean by it.
                It often seems to be used like an animal puffing up its fur, trying to look bigger than it is.
                As in, to imply a broad consensus of agreement over what is really just a solitary opinion.
                Turn the "w" upside-down and "we" turns into "me"...
                Also, I'm not sure how anyone can call this PG "low technology" since it is the latest, newest technology in PG.  Seems like there's a serious PG injury around here every few weeks.  PG's: great until they "let you down".
                Group: AirborneWindEnergy Message: 24053 From: dougselsam Date: 10/16/2018
                Subject: Re: Sway turbine websites
                Pierre:
                I googled Sway turbine and found myself at a completely different, yet similarly formatted Sway website http://www.swayturbine.no/ for a completely different idea, not floating, no guy wires..  Both sway websites seem to have stopped updating in 2012
                Group: AirborneWindEnergy Message: 24054 From: Pierre BENHAIEM Date: 10/16/2018
                Subject: Re: Sway turbine websites

                It is another design with a "large diameter permanent magnet ring style generator".

                 

                PierreB

                 

                 

                 

                 
                Group: AirborneWindEnergy Message: 24055 From: Pierre BENHAIEM Date: 10/16/2018
                Subject: Re: Low-technology approach

                Doug,

                 

                I am a little sorry for this parodic style message.

                 

                PierreB

                 

                 

                 

                 
                Group: AirborneWindEnergy Message: 24056 From: dougselsam Date: 10/17/2018
                Subject: Re: Sway turbine websites
                Yes Pierre, the renderings show a large-diameter PMA.  GE is promoting a 10 MW direct-drive PM machine for offshore too.  The big turbines are starting to copy the small turbines these days - direct-drive using no gearbox.  Less wear.  The GE machine tries to decouple the rotor blade reaction forces from the rotation of the PMA.  Smart.  The sway rendering purports to do the opposite, making the PMA rotor part of the blade rotor.  Sway's rendering heads toward the Honeywell turbine fiasco configuration.  Bad direction to go.  Well they apparently had their fun.  The difference between these concepts?  Experience.
                Group: AirborneWindEnergy Message: 24057 From: Pierre BENHAIEM Date: 10/17/2018
                Subject: Re: Sway turbine websites
                Group: AirborneWindEnergy Message: 24058 From: dave santos Date: 10/17/2018
                Subject: Re: Keeping Drag Force in Play [1 Attachment]
                We (the AWES Forum) have long explored drag as a surprisingly complex topic. While a flat rigid disc set crosswind can be argued to be a "pure drag" case, a soft drogue requires true lift around its margin to inflate crosswind. In the most extreme real-world case, a soft drogue can be a ring-wing of high AR.

                That's why it was seen proper to disambiguate this vague statement, ""A simple drogue develops almost pure drag force...", which is not very factual for soft-drogues. Modern analysis of Drag will continue as an increasingly complex topic, and we will need to keep track of the ambiguities.