Fort pointed out that Makani has adopted an asymmetric bridle for its looping kiteplane, once again adopting AWES art kPower has pioneered for years, for all its looping foils.

The problem for Makani is that off-angle kiteplane orientation causes an imbalance by weighing or dragging more on one side than the other. In hover-mode this imbalance must be compensated for by differential motor control. Obviously the M600 is compensating in the videos, but can these non-linear forces saturate control easily? When reeling out and in, does the kiteplane tend to crab sideways problematically? Does this factor slow reeling velocity? The answer may be yes, especially in complex marginal states. Perhaps the M600 needs more bridle asymmetry to "help turn", as Fort put it, but cannot tolerate optimal loop asymmetry in other flight modes. A servo-bridle akin to AWES control pods may be needed, but adds more mass and complexity.

In general, fast kiteplanes suffer from tether-shock if they snub up. Asymmetric tether shock could spin the kiteplane. Peak tether force control, by paying line out fast, and shock absorbers are needed, and some teams are adding these features. So many troublesome modes to worry about...

Attachments :

Evoking the paradox of modernist EU's nihilistic search for self-meaning, here we see luminous tethers in the Dutch night associated with TUDelft's 100kW AWES groundgen, in show-biz mode. There is no 100kW actually produced by the HQ sled kites, much less in proportion to unreeling as suggested, but artists are allowed their fantasy. TUDelft did similarly illusory techno fantasy with Saraceno as with Roosguarde.

Once again, kPower flew an innovative kite concept first in the AWE community, if not so stylishly (more like animals). A luminous tether was featured at Ambient Camping at Port Aransas last Spring (as rigged by Ray Luna). Our version used electro luminescent line, while the Dutch seem to have used fiber-optic.

Its obvious that luminous tethers are very visible and would enhance airspace safety at night. The odd fact is that daytime is the harder tether visual challenge, but possible with colored streamers (and/or strobes), as kPower has tested (markers every 50ft under strictest FAA FAR spec).

https://www.youtube.com/watch?v=9B-RHdS7eO0

Sadly, the AWEC2017 recording failed, so we await back-up sources. This could be quite revealing analysis, on merits; or junk.

This much is known, that Fort brought Techo-Economic (energy) Analysis with him from NREL, and its only as good as its premises (GIGO principle). For Makani, the tempting bias is a priori presumption of it's architectural down-select as superior, and thus only explore variant designs in that extreme design space. Another cause for bias is to underestimate the difficulty of factors like offshore operations, scaling-laws, and many more problems, while overestimating the effect of mitigations, net power output, etc.

What's actually needed is a sound techno-economical analysis of all AWES architectures, to predict winners by true fundamentals. Makani's most-complex architecture may pale in diligent broader study, against cheaper lower-complexity groundgen gliders, groundgen ship kite derivatives, and so on.

----------------
A Techno-Economic Analysis of Energy Kite
Tucker, Nicholas (Makani / X)
Quick, Megan (Makani / X)
Date
2017-10-05
To reference this document use:
uuid:86224277-9cda-417a-aba2-97c9c57dee0e
Part of collection
Conference proceedings

https://repository.tudelft.nl/islandora/object/uuid%3A86224277-9cda-417a-aba2-97c9c57dee0e?collection=research

Too late for the XPrize contest, but it may be that simply lifting water and transporting it to where its needed is the bigger opportunity with kites, rather than harvesting clouds, which depends on both wind and suitable clouds.

Slowly transporting large airborne masses of water in wind-speed range may be reasonable working velocity. Yes, human transport at 0.8 Mach is economically favored these days, but the average canal still flows far slower than a kite might. Kites can also lift tubes as pipelines. These make sense for opportunistic sessions with interchangeable sources and sinks.

Many details of kite-based water transport have been explored here over the years, mostly in regard to wildfire and drought relief, and are in the Open-AWE_IP-Cloud



--------------------------------------------

Ever since AWEC-branded conferences displaced pioneering grass-roots AWE players after HAWPcon09, Chico, CA, and shifted to Northern EU insider control, US conferences have lapsed. Dr Harrop saw the glaring gap and tried to gin-up November's IDTechX conference in Santa Clara, CA, as an AWE featuring event. There was scant US interest in participating, so Harrop seemingly had to go it alone, but its to his credit that he's trying-

https://www.idtechex.com/usa2017/show/en/speakers/10633/airborne-wind-energy-wind-power-where-previously-impossible

It may well be some key new actor attended, that a seed was planted, even if the AWE conference track did not take fire.

Given Harrop's late entry into the AWE field, misleading conference politics, and the hype-distorted public record, he is naturally seeing AWE as "mainly a European thing". In fact US AWE R&D is comparable or greater in scale, counting Makani's giant budget and staffing, and all the small "hidden" US players unable to afford attendance at yearly EU events. Similar confusion exists in Harrop claiming a trend from soft to rigid wings in AWE, based primarily on the AWEC conference club. In fact, both soft and rigid wing efforts are growing fast, while severe scaling laws, safety-critical failure modes, and LCOE challenges await the final contest for large-scale design success. Only soft ship kites have ever delivered MW scale power, in years of successful sea-trials no less, while Makani is not saying how little net power its M600 is actually putting out.

---- from the IDTechX report outline -----

4.6.Airborne Wind Energy options: trend cloth kite
source page- https://www.idtechex.com/research/reports/off-grid-electric-vehicle-charging-zero-emission-2018-2038-000569.asp

Lorenzo Fagiano admirably presented stark calculations predicting unit-kites must be rather large to optimally harvest winds at the "high" altitudes AWE is being allotted by airspace authorities (~500m). Ultimately how large, one cannot yet say, since square-cube scaling limits are not yet part of the numeric modeling. Even so, soft kites are already revealed favored by the paradox that their lower-L/D working-velocities suffer proportionally less tether-drag than high L/D. Square-cube model extension can only widen the soft kite's theoretic efficiency advantage, best summarized by power-to-mass figures, if not Loyd's Limit.

While these conclusions are long known on the AWES Forum by purely heuristic arguments, Lorenzo now adds mathematical agreement from within academia. In past years I went as far as to define an AWE dimensionless number of the ratio of kite area to allowable altitude*, dubbed the "Faust Number" in Joe's honor (for all his enormous contribution to AWE studies).

The fateful aspect is that so many AWE venture down-selects are afoul of the accumulating predictions, and likely doomed thereby. Lorenzo also touched on prototype work and catapult launch details.

http://www.awec2017.com/presentations/keynote-lorenzo-fagiano

------
* Based on a common proportion derived from power kites, lets here specifically define 10 units area to 30 units high as having a Faust Number of 1. Thus a 10m2 kite at 30m high, and a 2000m2 kite at 600m high, are both FN 1 valued. Most AWES have FNs <1, and an optimal FN may be around 2, based on short-line power kite rigs.

AWE has many possibilities for modulating power output, to match wind conditions to load demand. No other wind tech has such inherent flexibility, but classical sailing in 2D comes closest to power kites in 3D. We need great flexibility to master the most extreme wind and load dynamics. Note that only open-AWE kitefarm theory, as elaborated on the AWES Forum over the years, integrates all these operational modes, including mixed-architectures, according to TRL progression, ongoing fly-off testing, seasonal, site-specific, and real-time weather conformance, etc.

Quick list of top airborne power modulation methods-

- Vary number of unit-kites.

- Vary size of unit-kite (quiver principle).

- Vary altitude.

- Vary sweep pattern.

- Vary AoA of wings.

- Vary location in kite window.

- Give way downwind or haul upwind.


Thanks for any additional means identified.

Hi DaveS,
Good starting list. But what is "TRL progression"? Never heard of it.
Some additions to the list seem possible based on different kinds of kite
movements. Your side-to-side oscillating kite attached to the tether of a
pilot kite creates a movement that controls the power, and it could be
controlled to some extent by the tension in the tether created by the pilot
kite. So in some cases, tether tension can be used to control the power
output, and other variables could be varied to vary the tether tension. In
other words, tether tension could be regarded as a secondary modulator in
that case.
Another modulating movement is that a Bird Windmill blade flying in vertical
circles parallel with the wind while supported by a pilot kite. The tension
in the tether created by the relative pulling forces of the pilot kite and
the Bird blade would determine the size of the Bird blade orbit and the
power. A smaller, higher rpm orbit would usually produce more power. The
tension in the tether is again a secondary modulator. The AoA of the pilot
kite would be a primary modulator. If the size of the kite were variable,
then that could be used aa a primary modulator.
The tip speed ratio (TSR) of a kite would have a strong influence on the
pulling force that the kite produced.
The diameter of a suspended wind turbine would influence the power, along
with many other aspects of the wind turbine, and in principle, each of those
could be varied to modulate the power..
The aerodynamic profile of a kite would strongly influence the power by
influencing the L/D ratio.
Some of these are design details that modulate power primarily for extended
periods, and others can be used to modulate power quickly, but there isn't a
clear distinction between the two. Most anything that can be varied might be
used to modulate the power.
Each type of kite would employ a different combination of power modulation
methods, and not include some of them. Some might be unique to a particular
kind of kite.
It seems that some variables are primary and others are secondary when it
comes to modulating power.
So I'm not sure that a list of the ways to modulate the power can be
compiled such that it is exhaustive or based on clear distinctions between
the methods. Do you believe that it can be? If you could compile such a
list, how might it be useful? The subject seems worth thinking about, so
thanks for bringing it up.
PeterS

TRL progression is simply the development of a technology over time from prototypes to mature commodity (TRL 1-9). With kites, sweep is the equivalent of TSR. The list of basic power modulation methods need not be proven complete.


-----------------------------e---------------

Hi Dave,
"With kites, sweep is the equivalent of TSR." Never heard that before, and
it doesn't make sense. Please show me your reference.
PeterS

Sweep is a term of art in kite power. Its fundamentally the same relation as TSR, as the ratio of true to apparent wind. Note sweep also applies to geometric area, but TSR is purely an apparent wind term.

Let us define Sweep Number as the integer-equivalent of TSR, but for a kite motion that need not trace orbits. We may be the original documented reference, but the apparent wind theoretic basis is almost 200 yrs old.



--------------------------------------------

DaveS,
As I suspected. Nonsense.
PeterS

Its not that complicated. After all, many AWE teams equate their kites with "the tip of a turbine blade". TSR and sweep velocity really are comparable. Kiter's "sweep" is meaningful usage, not "nonsense" in in the technical kite community.
--------------------------------------------

DaveS,
Now you have changed the term from "sweep" to "sweep velocity". Show me your
reference for "sweep = TSR". "Sweep velocity" does not equal "TSR". You are
talking nonsense.
You somehow believe that if something can be related to something else in
some way, then those two things are identical. Nonsense.
Sweep velocity is a component of the formula for calculating the TSR, It is
not the TSR. Show me your reference.
Kite velocity (sweep velocity) divided by the true wind velocity equals the
TSR of the kite.
PeterS

Dimensionless sweep velocity is integer equivalent to TSR as defined here.
Its the same ratio of true to apparent wind.

Sorry if this seems nonsensical.

--------------------------------------------

Yes Joe, we are defining a dimensionless number equivalent to TSR for sweep as used by kiters, who can say "fast" or "slow" sweep meaningfully. There is a canonical implication of motion to sweep, as a verb.

Pierre notes elevation a power modulation basis, which is similarly implict (but as a subset of kite-window kite location effects).

--------------------------------------------

Dave,
"Dimensionless sweep velocity is integer equivalent to TSR as defined here.
Its the same ratio of true to apparent wind."

More nonsense. Show me your math and define your terms. And justify your
violation of the principle of parsimony.
Furthermore, anything can be true if one adds "as defined here":
Up is down and down is up, as defined here. (Definition: The Earth is in
space, and in space there is no difference between up and down.)
I am standing on the moon, as defined here. (Definition: The moon was and so
still is part of the Earth.)
PeterS

Peter,

Next time you wish to change the discussion topic, please form a new topic. If the following explanations to relating TSR to "Sweep Number" do not explain enough, go ahead and form the new topic.

The math of ratios has been presented, such that the ratio of true wind and apparent wind velocity at a turbine blade tip is the TSR and we are similarly defining a power kites sweep in multiples of true wind. If you need a numerical example, a blade tip moving 80mph in a 20 mph wind is TSR-4 (80/20=4) and a kite sweeping 80mph in a 20 mph wind is SN-4 (80/20=4). The two 4s are "integer-equivalence". We are defining SN as "sweep number", as our term of art in kites, which do not have to sweep circles, but can sweep all kinds of paths in the kite window.

Here is a recent typical AWE reference for you to note how kite sweep and TSR are implicitly related.

http://iopscience.iop.org/article/10.1088/1742-6596/854/1/012019/pdf

Here's RolandS in 2012 using "sweeping back and forth" (eights) like we all talk-

http://www.windsystemsmag.com/article/detail/392/kiting-for-wind-power

Don't give up too quickly if at first power kite expertise seems like nonsense. Its very intuitive in practice, compared to reading about it,

daveS
 









Dave,

"Dimensionless sweep velocity is integer equivalent to
TSR as defined here.

Its the same ratio of true to apparent wind."



More nonsense. Show me your math and define your terms. And
justify your

violation of the principle of parsimony.

Furthermore, anything can be true if one adds "as
defined here":

Up is down and down is up, as defined here. (Definition: The
Earth is in

space, and in space there is no difference between up and
down.)

I am standing on the moon, as defined here. (Definition: The
moon was and so

still is part of the Earth.)

PeterS













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Peter,

Next time you wish to change the discussion topic, please form a new topic. If the following explanations to relating TSR to "Sweep Number" do not explain enough, go ahead and form the new topic.

The math of ratios has been presented, such that the ratio of true wind and apparent wind velocity at a turbine blade tip is the TSR and we are similarly defining a power kites sweep in multiples of true wind. If you need a numerical example, a blade tip moving 80mph in a 20 mph wind is TSR-4 (80/20=4) and a kite sweeping 80mph in a 20 mph wind is SN-4 (80/20=4). The two 4s are "integer-equivalence". We are defining SN as "sweep number", as our term of art in kites, which do not have to sweep circles, but can sweep all kinds of paths in the kite window.

Here is a recent typical AWE reference for you to note how kite sweep and TSR are implicitly related.

http://iopscience.iop.org/article/10.1088/1742-6596/854/1/012019/pdf

Here's RolandS in 2012 using "sweeping back and forth" (eights) like we all talk-

http://www.windsystemsmag.com/article/detail/392/kiting-for-wind-power

Don't give up too quickly if at first power kite expertise seems like nonsense. Its very intuitive in practice, compared to reading about it,

daveS
 









Dave,

"Dimensionless sweep velocity is integer equivalent to
TSR as defined here.

Its the same ratio of true to apparent wind."



More nonsense. Show me your math and define your terms. And
justify your

violation of the principle of parsimony.

Furthermore, anything can be true if one adds "as
defined here":

Up is down and down is up, as defined here. (Definition: The
Earth is in

space, and in space there is no difference between up and
down.)

I am standing on the moon, as defined here. (Definition: The
moon was and so

still is part of the Earth.)

PeterS













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A few pages in a popular book we had not noticed before: Wubbo makes a nice appearance advocating a 50MW AWES, and other old names figure-

https://www.goodreads.com/book/show/2904804-earth

DaveS,
Now you have changed your terminology "sweep" again to "sweep number" as if
that is what you said all along. That is dishonest slipping and sliding to
avoid acknowledging your original mistake. Show me your reference for "sweep
number = TSR".
You are violating the principle of parsimony by introducing ambiguous and/or
unnecessary terms.
"Sweep" refers to the cross wind movement of the kite, in whatever
direction, for whatever distance, and at whatever speed. It must be further
modified in order to have a numerical value or ratio. It does not equal the
TSR, as you claimed.
PeterS

Peter,

"Sweep" as I've used it here really is the ratio of kite apparent wind velocity to true wind velocity. There is no change except defining and refining terminology specifically to try to help you understand the meaning better, and yes, we habitually create new terms of art in AWE here on the forum. Perhaps even "AWE" itself was coined here first, not just lesser specialized jargon like sweep number, to help you and others know just what is meant.

Lets agree the word "sweep", as kiters commonly talk, is rather vague for engineering discussion purposes, so we have helpfully defined sweep number more narrowly to be a kite engineering counterpart of wind-turbine TSR. That's not such a bad thing. Lets say as well that swept geometric area is the other meaning of "sweep", which is not the TSR-associated meaning.

Again, please carefully take desired side topics to their own threads, and sorry that the well-intentioned kite sweep explanations did not make sense. Always hoping the best for you,

daveS




--------------------------------------------

Rod comments two months ago on greentechmedia.com-

"Alphabet X considered my Daisy AWES recently but "do not see an immediate path for collaboration""

He goes on-

"I've said it for a while now...
Kite Networks are going to kick the arse straight out of this un-scalable flygen design."

It does seem X's AWES architecture is destined to be eclipsed by large kite networks, on fundamental principles. Fort recently also declined kPower's offer to convert the M600 to a pilot-kite-supported AWES, to improve safety, output, and LCOE. As currently configured, the likely lifetime of an M600 is a few days or weeks at best, with very serious crash consequences. At least our emails no longer go unanswered, so we are on record as the creators/developers of specific AWE IP open to the average open-source experimenter, but not to X, as a major stealth player who sees no path for collaborations with our low-complexity AWE community.

see comments-

https://www.greentechmedia.com/articles/read/alphabet-remains-committed-to-makani-wind#gs.zv_c3=M

Mechanical metamaterials commonly embody auxetic dynamics, which can also be identified in airborne kite network metamaterials. The alternative term to Auxetic is Negative Poisson Ratio. A starting model for auxetic kitematter is Wubbo's SpiderMill multiplied as trains cross-linked side-to-side in a regular 2D lattice. Its encouraging when a possible new solution in one discipline maps to a known solution in another.

In basic kite net variations, open spaces might trace out Auxetic Hexagons, which are pinched shapes like an hourglass, or Auxetic Parallelograms, like cells of a Miura tessellation. These variable geometries replicated in wind-excited rag and string will remain auxetic. There is a quirk to account for. Often a novel study model presents its auxetic cancelation state first, for example seeing a regular rectangle state instead of an auxetic hexagon. A better view is both states alternating with each other in unbounded succession, symmetrical in time.

https://en.wikipedia.org/wiki/Auxetics

https://en.wikipedia.org/wiki/Miura_fold

Hi Pierre,

While there is no comprehensive systematic study yet of kite lifecycles, there is vast expert experience to draw on (like Peter Lynn), and kite durability is amazing and just gets better. How long does a strong pair of pants last? Fabric is tough stuff.

In practical experience its hard to wear out either a power kite or pilot kite, to generate actual lifecycle data, because its so easy to repair a kite or buy a newer kite. Both kinds of kites are flown from quivers by pros, with new and old, and high and low wind kites to choose from. Its the same general kite-pro culture, with the same general practices. Best practice is important, like not to abuse a kite by flying it too much wind, de-rating its max wind capability as it ages. Kites also vary in build-quality and materials, and therefore lifecycles do vary, pilot and power kites alike, but better kites are harder flown, so its a complex picture. On the theoretic side, both pilot and power kites are subject to the same fundamental engineering, given equivalent materials and build-quality. Ideal design and operations keeps materials at their design-working-load for maximum life.

Conclusion: Its not rigorously studied if either pilot or power kites are inherently longer lived, but they are comparably durable in expert practice.

daveS

Typical kites have a single bridle network to conform the kite shape to a single general flight mode. Limited steering and trim inputs are done by varying line lengths. Emerging new AWES networked kite topologies introduced here are multiple bridle networks on one wing to support new pumping flight modes. We have considered a few early designs in this space without distinguishing the multi-bridle aspect.

Take drogues as a starting example. Imagine a standard drogue canopy double bridled (from both sides). It can then operate in reversible directions according to which side's bridle set is tensioned. The spare bridle would stream loosely. A new drogue pumping cycle works in energetic reversing flows, like tidal flow. Next imagine an SS wing with multiple bridles. Several basic variations are possible for shunting and tacking between states by varied bridle sets. A major capability of multi-bridles is to constrain a wing to a desired state-space, reducing undesired states.

These new kite architectures are inspired by the need to pump our AWES deterministically (stably). Many possible useful flight modes based multiple bridles await discovery. A close dynamic similarity case is heddle mechanisms in weaving looms that alternate bridle-like patterns. Sailors also often rig double lines, using one set or the other on a given tack.

Open-AWE_IP-Cloud

Thanks for your indications DaveS.

 

From Peter Lynn's article about durability (14 months) http://www.peterlynnhimself.com/newsletter/Jan_Nl_10.html there is an interesting analysis of tear resistance, strechiness, shape change, pilot and traction kites:

 

"After 14 months up a tree, the Skysilk was still harder to tear than some low quality 42gm fabrics are when new off the roll- and a new Skysilk sample was about twice as tear resistant as the treed stuff. Partly this is because tear resistance is generally the flip side of stretchiness- and it's by being quite stretchy that Skysilk gets it's exceptional tear resistance, but it's still impressive.

Unfortunately, traction kites and sports kites do not perform well when built from stretchy materials. This is because, as for yacht sails, any wind or pressure induced shape change will generally make aerodynamic performance worse. Stretchiness isn't a problem for theme type single line kites though- or for relatively low L/D kites like Pilots."

 

I underlined the important indications. Resuming a pilot kite could have a better lifetime and tear resistance thanks to the stretchiness of its fabric.

If this point is confirmed pilot kites could be more largely investigated as a main axis of AWE search.

 

PierreB

 

 

 

Its unscientific to prematurely conclude (rather than hypothesize) stretchier cloth alone means pilot kites inherently last longer than power kites, rather than just being one factor of many. In actual kite design practice, working power kites are often made of thicker ( therefore LESS stretchy but LONGER lasting) fabric than pilot kites, even if the polymer is otherwise identical.* My thickest and thinnest fabric kites are both OLs by KiteShip, and the lifetime would vary accordingly, if I could wear out either. The "stretchier" OL has been repaired once, after a thrashing thick low-stretch flip-wing under it tore it.

I propose that operational practices will often prove to be the most important determinant of kite life, power or pilot kite. Peter Lynn and I would both agree that testing has not yet proven the answer either way. Peter would agree that mistreating a kite is the fastest way to kill any kite, and taking care of a kite is the longest way to wear it out. One can design a kite-care protocol accordingly, with far more effect on lifecycle than the many details of how kitemakers choose fabric, like thicker cloth for durability, even if stretch is inherently lowered thereby.

Testing is once again the best practice, to settle any doubts, just ask Peter Lynn.

-------
* Racing kites, like racing sails, are often made to last only a few races, being built as light as possible. Stretching out of shape due to strained thin material is the common condition to retire the sail. Cruising sails are built with heavier cloth to last several years of use.

Single-Skin soft kites have advanced greatly in recent years. They still vary greatly in design, but a common feature is a tailored cupped Leading Edge to form a better airfoil. Here are some thoughts on the cupped-dege subject-

- Its been mysterious why cupped leading edges are so "solid" when the maximum pressure is on the outside surface at the stagnation point, and therefore seemingly should collapse the LE. The answer is that the transverse tension in the cloth helps hold the design shape without air pressure; one can maintain the cupped shape in a vacuum or against adverse pressure. This invisible transverse tension exists in all spanloaded anhedral kite wings.

- The edge-cupping effect is well-known in sails as a "cupped leech" state where over-tension of a leech-line (TE) is at fault. Too-loose a leech-line causes a flapping leech with less power. Sail LEs are variably-cupped by Cunningham Tension. Clearly the cupped SS kite LE or TE is a controllable effect, by incorporating a leech-line style adjustment input. This has great promise for gybing SS wings able to reverse leading and trailing orientation.

- SS iso-kite surfaces in networks can employ the cupped-LE to adapt to wind from any direction. Without needing rotation like ordinary kites, the iso kite surface merely tilts away from the wind direction to create the desired AoA, and the resultant LE can be cupped by either active or passive response. The optimal reverse state of relaxed cupping for an SS kite TE follows the sailing norm; to relax tension just enough for smooth flow without flapping.

- The cupped LE mechanism helps SS iso-kite networks be a viable alternative to rotating non-iso unit-kite AWES architectures.

Open-AWE_IP-Cloud

Kite energy is phonon-based physics on the same broad spectrum of mechanical energy as sound and heat, with the same fundamental properties across many magnitudes of scale. There is a lot for periodic networked kite developers to learn from phonon engineering research into metamaterials and phononic crystals (like just how those related paradigms differ and overlap). Our experimentally driven kite work has put us at the theoretic engineering phonon physics frontier. We are even uniquely extending the scope of general phononic science by several added scale orders-of-magnitude, into the megascale engineering realm of GW networked kite AWES.

Here is a particularly good overview of recent progress in phononics. As usual, seek to map general phonon concepts and varied outside examples to our emerging networked kite concepts, which requires a considerably advanced understanding of both kites and physics. Note in particular how the fundamental concept of temperature in this overview scales-up from microscopic to macroscopic, and how our pioneering exploration of Debye Temperature of kite materials, Planck's Constant reworked for kite scale, and other such notions the kite has taught us, is in key ways actually ahead of other phonon physics communities lacking specific kite insights-

http://ecourse.uoi.gr/pluginfile.php/75309/mod_resource/content/1/Sound_and_heat_revolutions_in_phononics.pdf

Latest KPS Scotland Herald coverage reminds us that oil-patch tech giant, Shlumberger, is a backer. They are real tigers in complex data acquisition in a tough outdoor heavy industry, while so many other investors are rather shut-into factory automation. Shlum's geologic prowess is also an AWE edge, since anchoring properly at lowest cost is a large part of future AWE. Below is a link to Shlum's smooth claim to be an environmental steward, as if decades of supporting cheap fossil fuel by superior prospecting was unambiguously moral.

Nevertheless, entry into AWE represents a long term possibility of the fossil fuel world living up to ecological aspirations. The entire fossil-fuel world is feeling the hurt of early loss of energy market share to renewables, and the scramble is on to secure a piece of the new energy world. In AWE we now count a half dozen of the biggest petro-players testing the breeze. kPower's "coal-to-kite" hybrid plant conversions is the most radical fusion of fossil and wind energy.

The KPS article is the usual handful of crumbs of new information. What is not yet clear is whether KPS can transition to an M&A phase and become a conglomerate of world AWE R&D, or will just be another one-shot down-select that bet wrong. Shlum's Houston HQ is likely to be more attuned to US AWE starts than KPS itself, and its on kPower (Austin)'s todo-list to pitch R&D consolidation.

In KPS's case, the selection of the power-parafoil represents a trend away from Makani and Ampyx's complex kiteplanes by the "top" contenders (while affiliated EU programs tinker with quadcopter-dependent AWES, prompting Dr. Harrop to call "drones" as the current AWE architectural trend). KPS faces its biggest hurdle to prove its twin-kite architecture is optimal, despite the manifest risk of interference, and so many alternative topologies. If not, KPS must pivot or die.
---------------

http://www.slb.com/about.aspx

http://www.heraldscotland.com/business_hq/15711989.How_a_Glasgow_firm_is_using_kites_to_help_meet_electricity_needs_in_the_developing_world/

Fortunately engineering materials do not stretch too much when kept within design working load. Kite sports are very dynamic, but stretched kites are not a problem. No doubt some stretch occurs, but like racing sails, stretch would only be a concern in close competition. Where is a tested kite that failed by stretching? Pumping loads can also be smoothed by elastic elements, if needed.
--------------------------------------------

Notes-

If it is desired by an engineer that a pilot and power kite last just as long, simply test to adjust designs or flight operations to match up lifecycles.

A quiver of kites is the most realistic and professional kite case. Add extra power or pilot kites to a quiver to maintain equivalent lifecycle between the two quiver subsets.

Matched kite lifecycles are an easy engineering requirement to attain, given so many low-complexity adjustments. Matched lifecycles may be a nonessential desirement, just as a car is expected to outlast its tires, and tires are maintained and rotated, as a set, to equalize life.

Many complicating factors make definite kite-life conclusions tricky, like sand v grass surface (grass better), UV exposure (cloudy northern locations better), etc. Abusing kites is common in racing or rising wind conditions. Turbulent winds are a common site-specific problem.

Wind velocity varies enough in kiting that a high wind pilot-kite (like a Gomberg Falcon w/ tail) can be designed for a wind greater than a low wind power-kite (like a Flysurfer). What counts is specific design velocity, sweep (relative wind) or not (absolute wind).

Conclusion- Kite lifecycles are broadly under the effective control of the engineers and PICs, and also reflect budget assumptions (more money = better build and materials = longer life)..

JohnO,

Great to hear from you. You have been missed! Hoping all is well in your life.

Yes, kPower's low-complexity "Cinderella strategy" (aka "born in a manger") is naturally slow to attract major financial support, but aims to finish big. Working the KPS-Shlumberger/Houston angle may be a path forward, since KPS by itself is not motivated to do M&A with peers, but is beholden to its backers. We do not forget Wubbo lived in Houston, to train as an astronaut, effectively becoming a Texan (and citizen of the world).

There are two kPower biz news items to report-

- kPower has been invited to present AWE to the UTexas Business School in early 2018, which could lead to a real business team (not just kite experts). kPower is also being actively shopped around Austin's formidable tech start-up venture culture. We were considered the best pitch ever made to Austin's House of Genius, two years ago, but contented ourselves with the high praise as we continued just testing, testing, testing.

- Roy Mueller (Jalbert's Aerology Labs) recently reached out to kPower to propose a merger. Roy may even move to Texas, since Boca Raton, Florida, is no longer the best place to develop kite tech as when Jalbert was alive. Roy brings first-class kite design and build to kPower, the very great spirit of Jalbert himself.

As kPower finally gains serious investment traction, you will be one of the first hired in an AWE business executive capacity. Let us endure to that happy juncture.

Cheers,

daveS


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