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Re: Marginal Returns When Conventional Turbines Fly

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  • dougselsam
    Well Dave here s how it is: Guess what your engineering challenge is in turbine design? Guess what the main challenge is? It is overspeed protection. Whatever
    Message 1 of 11 , Jan 8, 2010
      Well Dave here's how it is:
      Guess what your engineering challenge is in turbine design?
      Guess what the main challenge is?
      It is overspeed protection.
      Whatever kite, rotor, or whatever you put in the air, whether from a tower, or self-suspended, will have to deal with high winds and gusts at some point. That is when you will have to face the cubic power curve because once mother nature gets ahold of your machine that can take the lighter winds and efficiently turn them into electricity, you have a monster on your hands in higher winds.

      I have a whole big pile of burnt-out stators here from trying to get turbines fine-tuned to give up power production at the top end of the power curve in response to that cubic power curve. It is not the would-be designer in his fantasy world of his armchair and computer, or perhaps crayons and paper, who gets to decide arbitrarily if his machine has to deal with the cubic power law. It is the fact you have to deal with. It is reality. It is 1/2 MV^2 X the windspeed one again, since the volumetric flowrate of these 1/2MV^2 particles increases linearly with windspeed.
      There are 2 places where all the hypotheteization in the world will do you no good:
      1) Making power - you can't fake it, and even if you nail it, you're only half-way there
      2) Overspeed protection: without it all you have is a turbine that is ruined every time it encounters a very strong wind, (which seem to arise in direct proportion to how well you DON'T have your overspeed protection worked out.)

      Why does Superturbine(R) exist?
      And yes you are right there are scaling limits to propellers, since their weight grows as a cubic function (L x W x H) of diameter whereas swept area grows as a square function (pi r^2). This means that a rotor gets less power per unit mass in direct proportion to its size. Additionally, smaller rotors spin faster, eliminating the need for gearing. You may read all about it in my patents.

      These are the reasons for Superturbine(R). I would have to say you aren't even paying attention to what my patents say, nor paying attention to any of all that I have worked out.

      So in your fantasy world you have my propellers too big and crashing and hopefully nopody gets killed - wow how about if that is your big kite instead? Where do you get that? I am the one advocating many comparatively tiny propellers, whereas you are silly enough to be talking about Manhattan being the place to fly your giant kite machines.

      With regard to your statement that the real wind turbine world could learn a lot about membrane technology from the kite folks: I guess you have really not digested what I have explained: The wind turbine world STARTED OUT using EXCLUSIVELY MEMBRANES (cloth sails), and that ibncludes the first propellers as still seen in the Greek islands. It took 1000 years to slowly make the blades narrower and narrower as airfoils improved and speeds increased. Soon they were adding resin to the cloth for strength, and the blades got so efficient that they took up only a small amount of the area of the circle, and were basically not much wider than the origibal spar for the slow, comparatively inefficient sails.

      Sure we have a couple of stubborn examples of real wind turbine people who continue to advocate sails for blades. The main question is why would you add all that extra area just to cut performance?
      The last shakeout for the clothe sail kitelike blades was in the 1960's and '70's. It was slowly recognized that the cloth tatters in wind and sun and that regular blades actually use less material than just the spar for a sail that will have too much thrust-loading in strong winds. Wind turbine design is all about removing, not adding material. You are just slinging bits and pieces of the fact that you aren't even paying attention. If you have something to tell the big wind people about your sails that require a spar stronger than their blades, why not contact G.E. or Vestas? After all, they could certainly benefit from such superior knowledge as you opbviously have. I mean you sound like you REALLY know what you're talking about. There are many windfarms going in all over the world that could certainly benefit from your advanced knowledge and save a lot of money using sails instead of blades!
      Realistically I think you owe it to mankind to immediately get ahold of the big wind people and set them straight.
      But you are instead "too busy for that" right?
      Or maybe, as long as you stay in the fantasy world that:
      1) you have to deploy high in the air, but can't get a permit;
      2) Manhattan would be a good place to deploy (sure nobody worried about danger from the sky there)...
      Things like that make it so you will always have an excuse to never have a working model, therefore you are relegated to perpetually trying to show by blogging that every known fact in wind energy is somehow wrong simply on the basis that you have not gotten even far enough along to have faced any of these physical realities.

      The exact reason I am citing examples of the groundhugger scam turbines that don't work is so people can see that the fantasy know-it-all denial-of-reality turbines always start out with drag-based reciprocating-cycle turbines that try and fill too much working area with sheet metal or cloth sails, bring progress backward 3000 years while they tout in their ignorance the next big step in wind energy. We are asked to ignore the primitive, naive, and innocent nature of the designs on the basis of some special feature, whether it be magnetic bearings or whether it be that the machine can somehow support itself without a tower.
      That is all
      Class dismissed
      D.S.


      --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
      >
      > Doug,
      >  
      > "I think you should read my post a little more closely", as you wrote to another.
      >  
      > No expert on this list doubts the cubic power by wind speed law. What is questioned is the ROI of chasing that power into high Re for an aviation system, which involves many killer trade-offs including capital cost, induced drag, & safety. So any designer who presumes, as a useful but crude working assumption, extracting power at the square of windspeed, is a smart cookie. My previous post is as clear, but i don't mind repeating until you get the point.
      >  
      > What predicts the severe scaling limitation of your favored idea of flying solid high L/D turbines is the same cubic volume law, but in this case its smart to see how we will not be able to use conventional turbine construction to scale much beyond about a mw rating before the energy required just to maintain flight has eaten up power out, especially as wind dies. When such a device predictably crashes early in its hoped life cycle there is not much value left in the wreckage. Hopefully no one died.
      >  
      > One avenue is wide open- to scale membrane based solutions, which have a fantastic quasi two dimensional tensile structure advantage, even if L/D suffers. Battened membranes are hot, but don't rule out parachute like devices prematurely, they scale amazingly well.
      >  
      > Get these points right & you can teach the grounded turbine folks something new from AWE culture.
      >  
      >  
      >  
      >  
      >  
      >  
      >
    • Robert Stuart
      ... From: dougselsam Date: Friday, January 8, 2010 9:01 am Subject: [AWECS] Re: Marginal Returns When Conventional Turbines Fly ... Trees
      Message 2 of 11 , Jan 8, 2010
        ----- Original Message -----
        From: dougselsam <doug@...>
        Date: Friday, January 8, 2010 9:01 am
        Subject: [AWECS] Re: Marginal Returns When Conventional Turbines Fly

        >
        > Well Dave here's how it is:
        > Guess what your engineering challenge is in turbine design?
        > Guess what the main challenge is?
        > It is overspeed protection.

        Trees manage to reduce their drag somewhat in high winds, primarily by letting leaves roll up into cones and move closer to each other. We might also look at using flexible structures. I've found that controlled buckling, as demonstrated by extending a common tape measure, can provide normal rigidity for normal loads, along with extreme flexibility and controlled recovery to avoid damage from overloads. This capacity can be added just as a function of the shape of the spars, with no extra parts to build.

        If one does not wish to let the main structure bend in a wholesale manner, smaller elements can still be set to trip spoilers, air-brakes, or other devices, or to change pitch angles, etc. Helicopter rotor hubs are adopting flexible elements instead of hinges, with excellent results, so the parts count can still be held down.

        Bob Stuart
      • dave santos
        Doug,   Over speed protection as a major issue with hot wings has been well covered on this list.   A fat docile slow-speed foil with relaxed L/D, as
        Message 3 of 11 , Jan 8, 2010
          Doug,
           
          Over speed protection as a major issue with hot wings has been well covered on this list.
           
          A fat docile slow-speed foil with relaxed L/D, as developed by NASA, is a good choice for speed-limiting prototypes. George Parks taught me this back in the 80s & i've used them extensively, including my first working AWE generator turbine in 2007 & the 2008 water pumping AWE turbine. Just like the crudely carved turbines OtherPower has taught, drag limiting of these wings is helpful to avoid overspeed.
           
          For kites elastic aft bridling limits surge usefully (just as a sailor dumps air from a sail in a gust) & a dipping boom at the ground absorbs surge, as does elastic line like nylon. I say weight is a far bigger issue in AWE, but here we disagree.
           
          The weirdest thing is your insistent claim that no one has working AWE prototypes. KiteLab has around half a dozen different successful power-out devices flown in public & there have been years of AWE demos all over the world. Just because they don't fly "daily", don't deny them.
           
          Someday, like regular aviation, AWE will perfected enough to fly over, say, NY, as locating generation near the demand is great. Note my futuristic dream tri-tether scheme is properly membrane driven.
           
          Try & beat the existing Gigafly parafoil with your imaginary AWE turbines of solid construction. A parafoil can be stacked to multiply power greatly. Do you really think "sky serpents" will ever compete to high altitude with all those heavy draggy hubs & a monster torsion tube? Even Makani knows you got to eliminate that mass.
           
          dave
           

           

        • dave santos
          Robert,   You are quite right that many known techniques will effectively deal with overspeed/surge.   The tree example you gave is a wonder of such ideas
          Message 4 of 11 , Jan 8, 2010
            Robert,
             
            You are quite right that many known techniques will effectively deal with overspeed/surge.
             
            The tree example you gave is a wonder of such ideas such as the leaf furling & clumping. I have been stymied by TJ's challenge to get tree windpower out effectively as the whole branch system is a bunch of self canceling mass dampers such that the trunk barely oscillates in strong wind, compared to a free wing.
             
            Conclusion: While there are many essential qualities (like safety) an AWE system must have, & surge management is one, the biggest engineering challenge is WEIGHT TO POWER-OUT. Conventional high L/D turbines grow far too heavy with scale by cubic mass law.
             
            daveS
             


            --- On Fri, 1/8/10, Robert Stuart <bobstuart@...> wrote:

            From: Robert Stuart <bobstuart@...>
            Subject: Re: [AWECS] Re: Marginal Returns When Conventional Turbines Fly
            To: AirborneWindEnergy@yahoogroups.com
            Date: Friday, January 8, 2010, 11:28 AM

             


            ----- Original Message -----
            From: dougselsam <doug@selsam. com>
            Date: Friday, January 8, 2010 9:01 am
            Subject: [AWECS] Re: Marginal Returns When Conventional Turbines Fly

            >
            > Well Dave here's how it is:
            > Guess what your engineering challenge is in turbine design?
            > Guess what the main challenge is?
            > It is overspeed protection.

            Trees manage to reduce their drag somewhat in high winds, primarily by letting leaves roll up into cones and move closer to each other. We might also look at using flexible structures. I've found that controlled buckling, as demonstrated by extending a common tape measure, can provide normal rigidity for normal loads, along with extreme flexibility and controlled recovery to avoid damage from overloads. This capacity can be added just as a function of the shape of the spars, with no extra parts to build.

            If one does not wish to let the main structure bend in a wholesale manner, smaller elements can still be set to trip spoilers, air-brakes, or other devices, or to change pitch angles, etc. Helicopter rotor hubs are adopting flexible elements instead of hinges, with excellent results, so the parts count can still be held down.

            Bob Stuart


          • dougselsam
            OK I am gonna ask this one more time: It is one thing to tell me that McConney etc. HAVE working prototypes now, that operate NOW and have power output data
            Message 5 of 11 , Jan 11, 2010
              OK I am gonna ask this one more time:
              It is one thing to tell me that McConney etc. HAVE working prototypes now, that operate NOW and have power output data NOW.
              That is nice to hear.
              Very tantalizing.
              But could you please provide a link to some way to believe this?
              I mean, is there something we can click on to verify this fact? A power output scatter plot? A movie that shows a voltage and amp meter? A statement of power out by a team member? I want to believe you and see no reason why this could not be true, but I have seen no evidence in the form that we in (ahem) wind energy are used to see.
              So just to avoid confusion:
              I am not asking for mere statements of brand names
              I am not asking for nebulous or nonspecific statements
              I am asking for evidence
              I am asking for data
              I am asking for ONE link that shows anyone making usable power of any type with an airborne system.
              Thank you :)
              Doug Selsam

              --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
              >
              > Doug,

              > The weirdest thing is your insistent claim that no one has working AWE prototypes. KiteLab has around half a dozen different successful power-out devices flown in public & there have been years of AWE demos all over the world. Just because they don't fly "daily", don't deny them.
            • dougselsam
              Well true to form Dave Santos cannot resist arguing with any significant statement I make: I warn that the biggest engineering challenge in wind energy is not
              Message 6 of 11 , Jan 11, 2010
                Well true to form Dave Santos cannot resist arguing with any significant statement I make:
                I warn that the biggest engineering challenge in wind energy is not making power, it is protecting your turbine from overspeed once you have energy capture mastered.
                Dave S. counters that the biggest challenge is making power, in coming up with a machine lightweight enough to do the job.
                OK then Dave S., let me re-iterate:
                AFTER you have gotten a machine light weight enough that can also make the power you want THEN your challenge will be what happens to this lightweight and highly-efficient machine when the windspeed doubles.
                THEN you will have to deal with the cubic power curve.
                You stated in another recent post, in your repetitive denial of every salient fact I bring up, that you are better off ignoring the cubic power curve that the industry hinges upon.
                Wanna know where that comes from?
                That is typical newbie talk.
                You THINK you can ignore the cubic power curve since, when not making any power anyway, facts are just fantasy.
                You THINK you can ignore the proven main challenge of wind energy, overspeed protection, because you haven't gotten that far yet.
                Note that rather than coming up with a reason why what I said is not accurate, you simply declare that what I said is not true, substituting your own declaration. I don't think that is a sensible debating style.
                Please explain WHY you will not face the challenge of overspeed protection once you have a light enough machine to fly and make power?
                Without an explanation that is believeable, you are not countering my point. And my point was simply to warn what has already been learned in the real world of wind energy. Why would you want to deny that? Why would you not say "WOw maybe he is trying to let me know what my next step will be ahead of time?"
                You are once again exhibiting complete denial of virtually ALL the known facts of wind energy. The rules of thumb upon which the industry has grown for 3000 years.
                Let's just get it down as recorded:
                You are in denial that:
                1) the power in wind is a cubic curve with relation to speed
                2) that overspeed protection is the biggest engineering challenge in wind energy...
                Meanwhile you might note that in the field of wind turbines as they exist, the way turbines are categorized is by their method of overspeed protection. Other than that they are all similar.
                They sink or swim by what they do when the first storm hits.
                Companies survive or go bankrupt based not on power production, but on reliability and ability to service the warranty on the turbines.
                Look up Kenetech for a famous example: Once the leading wind turbine manufacturer in the U.S., Kenetech went bankrupt when it turned out that they were testing their turbines in the Altamont Pass, and the lighty-built turbines worked fine in the Altamont Pass, but Tehachapi and other locations turned out to be slightly more punishing and then machines had a high failure rate and so the company went bankrupt trying to service the warrranties. See, what will happen when you get your kites in the air with all the computer-controlled spools with cables reeling in and out at 60 mph, is 2 things:
                1) potential customers will want to see a ROI;
                2) you will have to indemnify the turbines with a warranty;
                3) you will have to have yor turbines certified by an independent wind energy certifying authority before you can get large projects indemnified;
                Good luck with denying overspeed protection as the major engineering challenge.
                It is you who will have to answer when your machines break. Easy to ignore when it is all talk, right? Well when the phone rings and it is another failed turbine you will be singing a different tune, I promise. It is only after your lightweight turbines are failing regularly that you can see that you need to address the biggest challenge in wind energy. Oh wait I get it - if you insist on being thousands of years behind the curve it won't matter? Nope, it has always been the issue: Turbines in Europe, using oiled wooden bearings and brakes, were famous for bursting into flames if the rotor got out of control. Ah but who cares, right? That doesn't impact your ability to blog nonsense all day.
                Of course Kenetech was a bit further along than waving a blade around in a crowded room and producing drawings of hypothetical turbines. But when it came down to whether they had a truly viable technology, it was overspeed protection that was their true challenge, one they did not meet, and so the company failed. This is true of all wind turbines. The "making power" part is routine and mostly a textbook exercise - a book which has not been read by most would-be innovators.
                Ok gotta run - heck I have a turbine in a crate that needs to be shipped! I hope its overspeed protection turns out to be adequate for the long haul - what a cliff-hanger! Oh well it is a subtle art and one in which a difference of a degree or two can mean the difference between a machine that survives forever and one that burns out or rips apart!
                Doug S.

                --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
                >
                > Robert,
                >  
                > You are quite right that many known techniques will effectively deal with overspeed/surge.
                >  
                > The tree example you gave is a wonder of such ideas such as the leaf furling & clumping. I have been stymied by TJ's challenge to get tree windpower out effectively as the whole branch system is a bunch of self canceling mass dampers such that the trunk barely oscillates in strong wind, compared to a free wing.
                >  
                > Conclusion: While there are many essential qualities (like safety) an AWE system must have, & surge management is one, the biggest engineering challenge is WEIGHT TO POWER-OUT. Conventional high L/D turbines grow far too heavy with scale by cubic mass law.
                >  
                > daveS
                >  
                >
                >
                > --- On Fri, 1/8/10, Robert Stuart <bobstuart@...> wrote:
                >
                >
                > From: Robert Stuart <bobstuart@...>
                > Subject: Re: [AWECS] Re: Marginal Returns When Conventional Turbines Fly
                > To: AirborneWindEnergy@yahoogroups.com
                > Date: Friday, January 8, 2010, 11:28 AM
                >
                >
                >  
                >
                >
                >
                >
                >
                > ----- Original Message -----
                > From: dougselsam <doug@selsam. com>
                > Date: Friday, January 8, 2010 9:01 am
                > Subject: [AWECS] Re: Marginal Returns When Conventional Turbines Fly
                >
                > >
                > > Well Dave here's how it is:
                > > Guess what your engineering challenge is in turbine design?
                > > Guess what the main challenge is?
                > > It is overspeed protection.
                >
                > Trees manage to reduce their drag somewhat in high winds, primarily by letting leaves roll up into cones and move closer to each other. We might also look at using flexible structures. I've found that controlled buckling, as demonstrated by extending a common tape measure, can provide normal rigidity for normal loads, along with extreme flexibility and controlled recovery to avoid damage from overloads. This capacity can be added just as a function of the shape of the spars, with no extra parts to build.
                >
                > If one does not wish to let the main structure bend in a wholesale manner, smaller elements can still be set to trip spoilers, air-brakes, or other devices, or to change pitch angles, etc. Helicopter rotor hubs are adopting flexible elements instead of hinges, with excellent results, so the parts count can still be held down.
                >
                > Bob Stuart
                >
              • Dave Culp
                What you ask isn t likely, Doug. Half a dozen privately/angel funded startups have in fact produced--and exhaustively measured--power as you specify ( I am on
                Message 7 of 11 , Jan 11, 2010
                  What you ask isn't likely, Doug. Half a dozen privately/angel funded startups have in fact produced--and exhaustively measured--power as you specify ( I am on the advisory board for several; have worked as a salaried employee for another--you witnessed presentations from at least 3 fully-funded corporate entities in Chico). However, they aren't likely to publish their data any time soon; perceiving the market space as potentially crowded, and IP as potentially valuable (well duh. As I recall the patent office still has its doors open, and even the likes of GM, GE and Boeing have been protecting their intellectual property these past couple of centuries. Greedy bastards--so buy stock). Early commercial tower-based turbine biz was the same way if you'll recall.

                  The major question isn't whether it's possible to produce power in this way--or even whether the investment community will get involved--the answers are yes (on the order of $50 million has been raised from private investors, worldwide). The real questions are whether such systems can produce power cheaply enough to overcome their inevitable teething problems. The answer is probably yes, but surely not definitely. There remain huge unknowns; mostly political. From a worldwide perspective, small and micro AWE such as is routinely discussed here aren't necessary to drive this beast; there are major players already in the space (Boeing, Google, TU Delft; both the Netherlands and Italian governments, to name a few), there will be many more as the recession eases and petroleum prices continue to increase.

                  Bottom line, there is room for all to play; kites aren't going to take market share away from tower-based turbines this year or next--but very likely will, one day. The question is when.

                  Dave

                  PS: you may know this and be just tongue in cheek, but Makani isn't spelled McConney. They are from California, not Ireland.


                  On Mon, Jan 11, 2010 at 8:16 AM, dougselsam <doug@...> wrote:
                   

                  OK I am gonna ask this one more time:
                  It is one thing to tell me that McConney etc. HAVE working prototypes now, that operate NOW and have power output data NOW.
                  That is nice to hear.
                  Very tantalizing.
                  But could you please provide a link to some way to believe this?
                  I mean, is there something we can click on to verify this fact? A power output scatter plot? A movie that shows a voltage and amp meter? A statement of power out by a team member? I want to believe you and see no reason why this could not be true, but I have seen no evidence in the form that we in (ahem) wind energy are used to see.
                  So just to avoid confusion:
                  I am not asking for mere statements of brand names
                  I am not asking for nebulous or nonspecific statements
                  I am asking for evidence
                  I am asking for data
                  I am asking for ONE link that shows anyone making usable power of any type with an airborne system.
                  Thank you :)
                  Doug Selsam



                  --- In AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...> wrote:
                  >
                  > Doug,

                  > The weirdest thing is your insistent claim that no one has working AWE prototypes. KiteLab has around half a dozen different successful power-out devices flown in public & there have been years of AWE demos all over the world. Just because they don't fly "daily", don't deny them.


                • spacecannon@san.rr.com
                  All, the reason that Makani doesn t have more data available is because it doesn t work effectively enough to be feasible, too many bugs. Anybody with any
                  Message 8 of 11 , Jan 11, 2010
                    All, the reason that Makani doesn't have more data available is because it doesn't work effectively enough to be feasible, too many bugs. Anybody with any mechanical background can look at that and say...(well my wife says I need to hold my tounge more), anyway the word contraption comes to mind.

                    Spacecannon


                    ---- Dave Culp <dave@...> wrote:
                    > What you ask isn't likely, Doug. Half a dozen privately/angel funded
                    > startups have in fact produced--and exhaustively measured--power as you
                    > specify ( I am on the advisory board for several; have worked as a salaried
                    > employee for another--you witnessed presentations from at least 3
                    > fully-funded corporate entities in Chico). However, they aren't likely to
                    > publish their data any time soon; perceiving the market space as potentially
                    > crowded, and IP as potentially valuable (well duh. As I recall the patent
                    > office still has its doors open, and even the likes of GM, GE and Boeing
                    > have been protecting their intellectual property these past couple of
                    > centuries. Greedy bastards--so buy stock). Early commercial tower-based
                    > turbine biz was the same way if you'll recall.
                    >
                    > The major question isn't whether it's possible to produce power in this
                    > way--or even whether the investment community will get involved--the answers
                    > are yes (on the order of $50 million has been raised from private investors,
                    > worldwide). The real questions are whether such systems can produce power
                    > cheaply enough to overcome their inevitable teething problems. The answer is
                    > probably yes, but surely not definitely. There remain huge unknowns; mostly
                    > political. From a worldwide perspective, small and micro AWE such as is
                    > routinely discussed here aren't necessary to drive this beast; there are
                    > major players already in the space (Boeing, Google, TU Delft; both the
                    > Netherlands and Italian governments, to name a few), there will be many more
                    > as the recession eases and petroleum prices continue to increase.
                    >
                    > Bottom line, there is room for all to play; kites aren't going to take
                    > market share away from tower-based turbines this year or next--but very
                    > likely will, one day. The question is when.
                    >
                    > Dave
                    >
                    > PS: you may know this and be just tongue in cheek, but Makani isn't spelled
                    > McConney. They are from California, not Ireland.
                    >
                    >
                    > On Mon, Jan 11, 2010 at 8:16 AM, dougselsam <doug@...> wrote:
                    >
                    > >
                    > >
                    > > OK I am gonna ask this one more time:
                    > > It is one thing to tell me that McConney etc. HAVE working prototypes now,
                    > > that operate NOW and have power output data NOW.
                    > > That is nice to hear.
                    > > Very tantalizing.
                    > > But could you please provide a link to some way to believe this?
                    > > I mean, is there something we can click on to verify this fact? A power
                    > > output scatter plot? A movie that shows a voltage and amp meter? A statement
                    > > of power out by a team member? I want to believe you and see no reason why
                    > > this could not be true, but I have seen no evidence in the form that we in
                    > > (ahem) wind energy are used to see.
                    > > So just to avoid confusion:
                    > > I am not asking for mere statements of brand names
                    > > I am not asking for nebulous or nonspecific statements
                    > > I am asking for evidence
                    > > I am asking for data
                    > > I am asking for ONE link that shows anyone making usable power of any type
                    > > with an airborne system.
                    > > Thank you :)
                    > > Doug Selsam
                    > >
                    > >
                    > > --- In AirborneWindEnergy@yahoogroups.com<AirborneWindEnergy%40yahoogroups.com>,
                    > > dave santos <santos137@...> wrote:
                    > > >
                    > > > Doug,
                    > >
                    > > > The weirdest thing is your insistent claim that no one has working
                    > > AWE prototypes. KiteLab has around half a dozen different successful
                    > > power-out devices flown in public & there have been years of AWE demos all
                    > > over the world. Just because they don't fly "daily", don't deny them.
                    > >
                    > >
                    > >
                  • dave santos
                    Doug,   Your accusations of rampant technical ignorance on this list seem mostly based on flawed reading. Please try & catch up on old posts you have yet
                    Message 9 of 11 , Jan 11, 2010
                      Doug,
                       
                      Your accusations of rampant technical ignorance on this list seem mostly based on flawed reading. Please try & catch up on old posts you have yet to read & patiently reread the posts that so provoked your anguished complaints. For example, handling surge is well covered. I'll repeat old explanations with you off-list to spare others tedium.
                       
                      Convince yourself that AWE is real by making your own, its not that hard. Don't expect folks to adequately meet your peculiar demands anymore than NREL did. Please keep future posts concise, if possible. Lets concentrate on adding critical new knowledge to the AWE adventure.
                       
                      Thanks in advance,
                       
                      DaveS
                       
                      PS Your own writings well cover the cubic-mass limitation of conventional turbines on towers. The logic applies even more to flying turbines & the "super turbine" is not exempt. In fact, dependence on torque tubes is a severe cubic scaling wall & cableways are the standard solution. That your multi rotor only develops a fraction of what the same rotors are capable of, if mounted square to the wind without masking, suggests the super turbine has an uphill battle supplanting existing turbines. But don't give up trying for better solutions to tap upper winds on a far larger scale.
                       
                      Correction- A spar stayed off terrain is not Tensarity (no air), but a battened sail is.
                       



                      --- On Mon, 1/11/10, dougselsam <doug@...> wrote:

                      From: dougselsam <doug@...>
                      Subject: [AWECS] Re: Surge Management & Marginal Returns When Conventional Turbines Fly
                      To: AirborneWindEnergy@yahoogroups.com
                      Date: Monday, January 11, 2010, 11:07 AM

                       
                      Well true to form Dave Santos cannot resist arguing with any significant statement I make:
                      I warn that the biggest engineering challenge in wind energy is not making power, it is protecting your turbine from overspeed once you have energy capture mastered.
                      Dave S. counters that the biggest challenge is making power, in coming up with a machine lightweight enough to do the job.
                      OK then Dave S., let me re-iterate:
                      AFTER you have gotten a machine light weight enough that can also make the power you want THEN your challenge will be what happens to this lightweight and highly-efficient machine when the windspeed doubles.
                      THEN you will have to deal with the cubic power curve.
                      You stated in another recent post, in your repetitive denial of every salient fact I bring up, that you are better off ignoring the cubic power curve that the industry hinges upon.
                      Wanna know where that comes from?
                      That is typical newbie talk.
                      You THINK you can ignore the cubic power curve since, when not making any power anyway, facts are just fantasy.
                      You THINK you can ignore the proven main challenge of wind energy, overspeed protection, because you haven't gotten that far yet.
                      Note that rather than coming up with a reason why what I said is not accurate, you simply declare that what I said is not true, substituting your own declaration. I don't think that is a sensible debating style.
                      Please explain WHY you will not face the challenge of overspeed protection once you have a light enough machine to fly and make power?
                      Without an explanation that is believeable, you are not countering my point. And my point was simply to warn what has already been learned in the real world of wind energy. Why would you want to deny that? Why would you not say "WOw maybe he is trying to let me know what my next step will be ahead of time?"
                      You are once again exhibiting complete denial of virtually ALL the known facts of wind energy. The rules of thumb upon which the industry has grown for 3000 years.
                      Let's just get it down as recorded:
                      You are in denial that:
                      1) the power in wind is a cubic curve with relation to speed
                      2) that overspeed protection is the biggest engineering challenge in wind energy...
                      Meanwhile you might note that in the field of wind turbines as they exist, the way turbines are categorized is by their method of overspeed protection. Other than that they are all similar.
                      They sink or swim by what they do when the first storm hits.
                      Companies survive or go bankrupt based not on power production, but on reliability and ability to service the warranty on the turbines.
                      Look up Kenetech for a famous example: Once the leading wind turbine manufacturer in the U.S., Kenetech went bankrupt when it turned out that they were testing their turbines in the Altamont Pass, and the lighty-built turbines worked fine in the Altamont Pass, but Tehachapi and other locations turned out to be slightly more punishing and then machines had a high failure rate and so the company went bankrupt trying to service the warrranties. See, what will happen when you get your kites in the air with all the computer-controlled spools with cables reeling in and out at 60 mph, is 2 things:
                      1) potential customers will want to see a ROI;
                      2) you will have to indemnify the turbines with a warranty;
                      3) you will have to have yor turbines certified by an independent wind energy certifying authority before you can get large projects indemnified;
                      Good luck with denying overspeed protection as the major engineering challenge.
                      It is you who will have to answer when your machines break.. Easy to ignore when it is all talk, right? Well when the phone rings and it is another failed turbine you will be singing a different tune, I promise. It is only after your lightweight turbines are failing regularly that you can see that you need to address the biggest challenge in wind energy. Oh wait I get it - if you insist on being thousands of years behind the curve it won't matter? Nope, it has always been the issue: Turbines in Europe, using oiled wooden bearings and brakes, were famous for bursting into flames if the rotor got out of control. Ah but who cares, right? That doesn't impact your ability to blog nonsense all day.
                      Of course Kenetech was a bit further along than waving a blade around in a crowded room and producing drawings of hypothetical turbines. But when it came down to whether they had a truly viable technology, it was overspeed protection that was their true challenge, one they did not meet, and so the company failed. This is true of all wind turbines. The "making power" part is routine and mostly a textbook exercise - a book which has not been read by most would-be innovators.
                      Ok gotta run - heck I have a turbine in a crate that needs to be shipped! I hope its overspeed protection turns out to be adequate for the long haul - what a cliff-hanger! Oh well it is a subtle art and one in which a difference of a degree or two can mean the difference between a machine that survives forever and one that burns out or rips apart!
                      Doug S.

                      --- In AirborneWindEnergy@ yahoogroups. com, dave santos <santos137@. ..> wrote:
                      >
                      > Robert,
                      >  
                      > You are quite right that many known techniques will effectively deal with overspeed/surge.
                      >  
                      > The tree example you gave is a wonder of such ideas such as the leaf furling & clumping. I have been stymied by TJ's challenge to get tree windpower out effectively as the whole branch system is a bunch of self canceling mass dampers such that the trunk barely oscillates in strong wind, compared to a free wing.
                      >  
                      > Conclusion: While there are many essential qualities (like safety) an AWE system must have, & surge management is one, the biggest engineering challenge is WEIGHT TO POWER-OUT. Conventional high L/D turbines grow far too heavy with scale by cubic mass law.
                      >  
                      > daveS
                      >  
                      >
                      >
                      > --- On Fri, 1/8/10, Robert Stuart <bobstuart@. ..> wrote:
                      >
                      >
                      > From: Robert Stuart <bobstuart@. ..>
                      > Subject: Re: [AWECS] Re: Marginal Returns When Conventional Turbines Fly
                      > To: AirborneWindEnergy@ yahoogroups. com
                      > Date: Friday, January 8, 2010, 11:28 AM
                      >
                      >
                      >  
                      >
                      >
                      >
                      >
                      >
                      > ----- Original Message -----
                      > From: dougselsam <doug@selsam. com>
                      > Date: Friday, January 8, 2010 9:01 am
                      > Subject: [AWECS] Re: Marginal Returns When Conventional Turbines Fly
                      >
                      > >
                      > > Well Dave here's how it is:
                      > > Guess what your engineering challenge is in turbine design?
                      > > Guess what the main challenge is?
                      > > It is overspeed protection.
                      >
                      > Trees manage to reduce their drag somewhat in high winds, primarily by letting leaves roll up into cones and move closer to each other. We might also look at using flexible structures. I've found that controlled buckling, as demonstrated by extending a common tape measure, can provide normal rigidity for normal loads, along with extreme flexibility and controlled recovery to avoid damage from overloads. This capacity can be added just as a function of the shape of the spars, with no extra parts to build.
                      >
                      > If one does not wish to let the main structure bend in a wholesale manner, smaller elements can still be set to trip spoilers, air-brakes, or other devices, or to change pitch angles, etc. Helicopter rotor hubs are adopting flexible elements instead of hinges, with excellent results, so the parts count can still be held down.
                      >
                      > Bob Stuart
                      >


                    • dougselsam
                      Hi Dave Culp: Thanks for replying. What you say is all well and good but unfortunately it only qualifies as anecdotal. We veterans know that the reason for
                      Message 10 of 11 , Jan 12, 2010
                        Hi Dave Culp: Thanks for replying. What you say is all well and good but unfortunately it only qualifies as anecdotal. We veterans know that the reason for not showing power output is normally embarrassment at the low numbers. No numbers across an entire "industry" means an industry with no numbers good enough to show. I maintain there is still no evidence that anyone is making any significant power in this field. It is one thing to talk of an "industry", to drop impressive names of big corporations. Such hype and namedropping is specifically what I said I was not looking for. What does it take to show power being generated? About $100 worth of instrumentation.

                        Please see this Youtube video of a Superturbine(R) with output measured and the meter shown on camera:
                        http://www.youtube.com/watch?v=AA6YVWYyRvc

                        Sure if the turbine made no power we could wait and make excuses forever: "We need more funding, we need a $5 million wind tunnel, we couldn't get a permit..." but when you actually HAVE something to show, you can't resist showing it, and you will find a way.

                        >>>on the order of $50 million has been raised from private investors
                        (I need an office! We need to hire some people! We gotta have someone work on the website! We need to hire a full-time blogger!)
                        ***That is enough to go to Harbor Freight and buy an amp meter
                        ***See what I mean about hype? Change the subject? Impress me with dollar signs?

                        ***Here's a wind energy company that blew through $25 million with a "superior technology" yielding no result. Article by Paul Gipe, world's leading wind energy author.
                        http://www.wind-works.org/articles/vort_closure_hend.html

                        I am just trying to make sure we keep our feet on the ground here. The real wind energy world has shown that there is no substitute for data and performance and that it is easy to throw away large sums of money to yield nothing substantial. We have heard all the same hype from day 1 from a hundred scammers and it carries no meaning except that you feel sorry for the hypsters. Someday you will thank me or agree.

                        Google has contacted me about funding my company. Last I left off I was talking to a guy named Dr. Jeffrey Greenblatt at Google, and they were trying to decide whether to give us a grant or invest in our company. Then they seemed to lose interest. BP has also contacted me. Beyond petroleum? They also seem to suffer from attention deficit disorder - although I am hard-pressed to find anyone who doesn't claim to suffer from that these days in this world full of ready-made excuses. Time will tell whether any of these folks are serious. Meanwhile we can't let the big talkers slow us down. We have laid the groundwork for this future industry and will continue our development of useful products and expand our patent portfolio around the world. I've recently been invited to a conference on how to change the world with such luminaries as Jeff Bezos and Bill Gates. Hopefully some of these deep-pockets entities will soon move beyond the all-talk format with regards to participating in Superturbine(R) technology which shows the potential to solve some of the main problems currently facing the world.

                        Thanks :)
                        Doug Selsam
                        USWINDLABS.com
                        ~brawk!~


                        --- In AirborneWindEnergy@yahoogroups.com, Dave Culp <dave@...> wrote:
                        > What you ask isn't likely, Doug. Half a dozen privately/angel funded
                        > startups have in fact produced--and exhaustively measured--power as you specify ( I am on the advisory board for several; have worked as a salaried
                        > employee for another--you witnessed presentations from at least 3
                        > fully-funded corporate entities in Chico). However, they aren't likely to
                        > publish their data any time soon; perceiving the market space as potentially
                        > crowded, and IP as potentially valuable (well duh. As I recall the patent
                        > office still has its doors open, and even the likes of GM, GE and Boeing
                        > have been protecting their intellectual property these past couple of
                        > centuries. Greedy bastards--so buy stock). Early commercial tower-based
                        > turbine biz was the same way if you'll recall.
                        >
                        > The major question isn't whether it's possible to produce power in this
                        > way--or even whether the investment community will get involved--the answers
                        > are yes (on the order of $50 million has been raised from private investors,
                        > worldwide). The real questions are whether such systems can produce power
                        > cheaply enough to overcome their inevitable teething problems. The answer is
                        > probably yes, but surely not definitely. There remain huge unknowns; mostly
                        > political. From a worldwide perspective, small and micro AWE such as is
                        > routinely discussed here aren't necessary to drive this beast; there are
                        > major players already in the space (Boeing, Google, TU Delft; both the
                        > Netherlands and Italian governments, to name a few), there will be many more
                        > as the recession eases and petroleum prices continue to increase.
                        >
                        > Bottom line, there is room for all to play; kites aren't going to take
                        > market share away from tower-based turbines this year or next--but very
                        > likely will, one day. The question is when.
                        >
                        > Dave
                        >
                        > PS: you may know this and be just tongue in cheek, but Makani isn't spelled
                        > McConney. They are from California, not Ireland.
                        >
                        >
                        > On Mon, Jan 11, 2010 at 8:16 AM, dougselsam <doug@...> wrote:
                        >
                        > >
                        > >
                        > > OK I am gonna ask this one more time:
                        > > It is one thing to tell me that McConney etc. HAVE working prototypes now,
                        > > that operate NOW and have power output data NOW.
                        > > That is nice to hear.
                        > > Very tantalizing.
                        > > But could you please provide a link to some way to believe this?
                        > > I mean, is there something we can click on to verify this fact? A power
                        > > output scatter plot? A movie that shows a voltage and amp meter? A statement
                        > > of power out by a team member? I want to believe you and see no reason why
                        > > this could not be true, but I have seen no evidence in the form that we in
                        > > (ahem) wind energy are used to see.
                        > > So just to avoid confusion:
                        > > I am not asking for mere statements of brand names
                        > > I am not asking for nebulous or nonspecific statements
                        > > I am asking for evidence
                        > > I am asking for data
                        > > I am asking for ONE link that shows anyone making usable power of any type
                        > > with an airborne system.
                        > > Thank you :)
                        > > Doug Selsam
                        > >
                        > >
                        > > --- In AirborneWindEnergy@yahoogroups.com<AirborneWindEnergy%40yahoogroups.com>,
                        > > dave santos <santos137@> wrote:
                        > > >
                        > > > Doug,
                        > >
                        > > > The weirdest thing is your insistent claim that no one has working
                        > > AWE prototypes. KiteLab has around half a dozen different successful
                        > > power-out devices flown in public & there have been years of AWE demos all
                        > > over the world. Just because they don't fly "daily", don't deny them.
                        > >
                        > >
                        > >
                        >
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