Messages in AirborneWindEnergy group.                           AWES10348to10400 Page 104 of 440.
Group: AirborneWindEnergy Message: 10348 From: joe_f_90032 Date: 10/17/2013
Subject: Dr. Roland Schemehl

Group: AirborneWindEnergy Message: 10350 From: joe_f_90032 Date: 10/17/2013
Subject: Benjamin Franklin ... and his gold

Group: AirborneWindEnergy Message: 10351 From: joe_f_90032 Date: 10/17/2013
Subject: Re: Dr. Roland Schemehl

Group: AirborneWindEnergy Message: 10352 From: joe_f_90032 Date: 10/17/2013
Subject: Re: Dr. Roland Schemehl

Group: AirborneWindEnergy Message: 10353 From: edoishi Date: 10/17/2013
Subject: Pumping Air with Power Kite

Group: AirborneWindEnergy Message: 10354 From: edoishi Date: 10/17/2013
Subject: Re: KiteSat: "hello world"

Group: AirborneWindEnergy Message: 10355 From: edoishi Date: 10/17/2013
Subject: Re: KiteSat: "hello world"

Group: AirborneWindEnergy Message: 10356 From: Pierre BENHAIEM Date: 10/17/2013
Subject: Re: Pumping Air with Power Kite

Group: AirborneWindEnergy Message: 10357 From: edoishi Date: 10/18/2013
Subject: Re: KiteSat: "hello world"

Group: AirborneWindEnergy Message: 10359 From: joe_f_90032 Date: 10/18/2013
Subject: Re: Pumping Air with Power Kite

Group: AirborneWindEnergy Message: 10360 From: joe_f_90032 Date: 10/18/2013
Subject: Re: Toy LED Kite AWES by Ben Chapman

Group: AirborneWindEnergy Message: 10361 From: dave santos Date: 10/19/2013
Subject: Circular Cableway with Anchor Bypass

Group: AirborneWindEnergy Message: 10362 From: dave santos Date: 10/19/2013
Subject: Peter Lynn announces new utility-kite designs at super-low prices

Group: AirborneWindEnergy Message: 10363 From: Rod Read Date: 10/20/2013
Subject: Re: Peter Lynn announces new utility-kite designs at super-low price

Group: AirborneWindEnergy Message: 10364 From: Rod Read Date: 10/20/2013
Subject: good and bad bets

Group: AirborneWindEnergy Message: 10365 From: joe_f_90032 Date: 10/20/2013
Subject: Omnidea's second focus: Airborne Platform

Group: AirborneWindEnergy Message: 10366 From: joe_f_90032 Date: 10/20/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10367 From: joe_f_90032 Date: 10/20/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10368 From: dave santos Date: 10/20/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10369 From: joe_f_90032 Date: 10/20/2013
Subject: Roland Schmehl

Group: AirborneWindEnergy Message: 10370 From: joe_f_90032 Date: 10/20/2013
Subject: Re: Roland Schmehl

Group: AirborneWindEnergy Message: 10371 From: mikebarnardca Date: 10/21/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10372 From: Bob Stuart Date: 10/21/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10373 From: Pierre Benhaiem Date: 10/21/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10374 From: Mike Barnard Date: 10/21/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10375 From: dave santos Date: 10/21/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10377 From: joe_f_90032 Date: 10/21/2013
Subject: Nominations WGA for 2013 ?

Group: AirborneWindEnergy Message: 10378 From: Mike Barnard Date: 10/21/2013
Subject: Re: good and bad bets

Group: AirborneWindEnergy Message: 10379 From: joe_f_90032 Date: 10/21/2013
Subject: Group moderation

Group: AirborneWindEnergy Message: 10380 From: Mike Barnard Date: 10/22/2013
Subject: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10381 From: Mike Barnard Date: 10/22/2013
Subject: Parafoils and Rain

Group: AirborneWindEnergy Message: 10382 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Parafoils and Rain

Group: AirborneWindEnergy Message: 10383 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10384 From: Mike Barnard Date: 10/22/2013
Subject: Re: Parafoils and Rain

Group: AirborneWindEnergy Message: 10385 From: Pierre BENHAIEM Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10386 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10387 From: Mike Barnard Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10388 From: dave santos Date: 10/22/2013
Subject: Re: Parafoils and Rain

Group: AirborneWindEnergy Message: 10389 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Parafoils and Rain

Group: AirborneWindEnergy Message: 10390 From: joe_f_90032 Date: 10/22/2013
Subject: Wing-surface messaging

Group: AirborneWindEnergy Message: 10391 From: Mike Barnard Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10392 From: Pierre BENHAIEM Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Group: AirborneWindEnergy Message: 10393 From: dave santos Date: 10/22/2013
Subject: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES

Group: AirborneWindEnergy Message: 10394 From: joe_f_90032 Date: 10/23/2013
Subject: Towing manuals

Group: AirborneWindEnergy Message: 10395 From: joe_f_90032 Date: 10/24/2013
Subject: Flexrotor UAV wows ...

Group: AirborneWindEnergy Message: 10396 From: Mike Barnard Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES

Group: AirborneWindEnergy Message: 10397 From: Pierre BENHAIEM Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES

Group: AirborneWindEnergy Message: 10398 From: dave santos Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES

Group: AirborneWindEnergy Message: 10399 From: joe_f_90032 Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale

Group: AirborneWindEnergy Message: 10400 From: Pierre BENHAIEM Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES



Group: AirborneWindEnergy Message: 10348 From: joe_f_90032 Date: 10/17/2013
Subject: Dr. Roland Schemehl

Dr. Roland Schemehl has been strongly communicating AWE movement to the world.


 Dr. Roland Schmehl is an associate professor at the Institute for Applied Sustainable Science Engineering and Technology (ASSET) at Delft University of Technology, The Netherlands. For more information, call +31 15 278 5318, email r.schmehl@tudelft.nl mailto:r.schmehl@tudelft.nl?subject=Referred%20by%20Wind%20Systems%20Mag or visit www.kitepower.eu http://www.kitepower.eu/.


See: 

http://www.energykitesystems.net/TUDelft/index.html

and suggestion for improving the page are welcome.  Updates from each AWE worker at TU Delft would be welcome and absorbed.   


A generalized link on Roland:   [2710 hits]
http://tinyurl.com/RolandSchmehlKITES


Roland, update?   

Thanks for the ambassador work you have been doing above the leadership in basic studies. 


Lift, 

JoeF
Group: AirborneWindEnergy Message: 10350 From: joe_f_90032 Date: 10/17/2013
Subject: Benjamin Franklin ... and his gold
Benjamin Franklin

has been installed in the combination award
World Hang Gliding Association. 

Benjamin Franklin's story of his youth of tethering a wing to his body (second wing) for transporting himself in a dynamic free-moving kite system has resulted in forming him as a kind of grandfather to hanging by tether from stiffened flexible wings for the purpose of free-moving in fluids.   He would later suggest pulling ships by kites.  Though his lightning experiments might be receiving more press and art image, his seeding hang gliding and traction by kite are recognized. Two or more wings coupled by tether was somehow embedded in Ben's psyche; and he did something about such kite.
FRANKLIN TOWED BY HIS KITE
The True Benjamin Franklin, by Sydney George Fisher  See book.
Congratulations to Ben!  Welcome to the world of AWE; 
thanks for your early insights.

Group: AirborneWindEnergy Message: 10351 From: joe_f_90032 Date: 10/17/2013
Subject: Re: Dr. Roland Schemehl
Clip from page:  ORIGINAL PAGE

Example there is open for discussion: 
=======================================
NOTICE: this is a dated clip. Please go to TU Delft for current courses and schedules. 
The following clip is for study by the AWES tech community
=======================================
AE4W20
Wind Power
ECTS: 3

Responsible Instructor
NameE-mail
Prof.dr. G.J.W. van Bussel   G.J.W.vanBussel@tudelft.nl
Dr.ing. R. Schmehl   R.Schmehl@tudelft.nl
Contact Hours / Week x/x/x/x
2/2/0/0
Education Period
1
2
Start Education
1
Exam Period
2
3
Course Language
English
Course Contents
Lectures 1, 2: Basics of systems for energy exchange with fluid flow.
A comparative introduction of flow-based power generation methods
• Gas and steam turbine: thermodynamic cycle, staging, ducts, bypass 
• Propeller and helicopter rotors
• Horizontal and crosswind (“vertical axis”) wind turbine rotors:
- open "atmosphere" cycle, single rotor, …
• Kite power systems: harvesting wind at higher altitudes, tethered airfoil, …
Advantages and disadvantages of these techniques are discussed, also the chronology of their development (in relationship to each other).

Lecture 3,4: Atmospheric flows and wind conditions
• Atmospheric boundary layer, turbulence generation
• Characteristics of wind at low and high altitude, stability, persistence
• Available wind resources, suitable deployment locations

Lecture 5, 6: Fundamentals of aerodynamic power extraction from fluid flows.
• 2-dimensional energy extraction principles
• Trefftz plane considerations
• Roles of shed and trailing vorticity in energy extraction
• 3-dimensional extraction principles
• Extraction of energy from steady and unsteady flows
• Effect of airfoil flexibility

Lecture 7, 8: Design of airfoils for power extraction
• (Thick) airfoils for wind turbine rotors
• Flexible (inflatable) membrane airfoils for kites
- ram-air foils
- leading edge inflatable foils
• Stall phenomena in wind turbine rotor blade and kite operation 

Lecture 9, 10: Power extraction with wind turbines
• Wind turbine concepts: horizontal & vertical axis WT, ducted WT
• Wind turbine design theory (Lanchester, Betz, Glauert)
• Aerodynamic losses, induction optimisation, wake rotation 
• Control, constraints stall & off-design operation

Lecture 11, 12: Power extraction with kites
• Kite power theory: cross wind versus altitude operation
• Conversion maps, cross wind factor versus roll out factor
• Power cycle (trajectory) optimization
• Automatic operation, autopilot for tethered airfoils
Study Goals
Convey how aerodynamics is used for power generation. Connect fundamental subjects of aerodynamics to applications different from aircraft.
Education Method
Lectures and exercises
Literature and Study Materials
Course lectures. The students can download the course lectures, background material and assignments from the accompanying blackboard site. Blackboard will also be used extensively for submitting exercises and response to students.

Recommended literature:
The recommended literature for each chapter will be indicated in the course lectures.
Assessment
Written examination
Group: AirborneWindEnergy Message: 10352 From: joe_f_90032 Date: 10/17/2013
Subject: Re: Dr. Roland Schemehl

Special link over TU Delft yet within TU Delft:


 http://tinyurl.com/TUDelftKITES

and 

special link for related images: 

http://tinyurl.com/TUDelftIMAGESkites
Group: AirborneWindEnergy Message: 10353 From: edoishi Date: 10/17/2013
Subject: Pumping Air with Power Kite
Continuous experiments are being conducted at the Texas AWE Encampment, far faster than being uploaded to the forum...

Here is a crude video of the kPTO being used with a stock parafoil to compress air into a tank:
Group: AirborneWindEnergy Message: 10354 From: edoishi Date: 10/17/2013
Subject: Re: KiteSat: "hello world"

Latest video of KiteSat under development by kPower and New Tech Kites.

First flown on July 22 2013 at the TX AWE Encampment to send "hello world" to the forum.

First public debut at AWEC2013 in Berlin at the Templehof Airport (note Uwe Ahrens smiling at it and EnerKite's wing flying in the background).

KiteSat is currently in WOW-Paolo's hands, touring Italy...


Video also features Jumbo Kite Sat - a larger (4M diameter rotor) flying under kPower's original 6M delta. 


 
Group: AirborneWindEnergy Message: 10355 From: edoishi Date: 10/17/2013
Subject: Re: KiteSat: "hello world"
Group: AirborneWindEnergy Message: 10356 From: Pierre BENHAIEM Date: 10/17/2013
Subject: Re: Pumping Air with Power Kite

An hydraulic accumulator can also be used as device for temporary storage,like a flywheel.

 

PierreB
Group: AirborneWindEnergy Message: 10357 From: edoishi Date: 10/18/2013
Subject: Re: KiteSat: "hello world"

whoops again, that video is no longer working ?? Try this:  http://www.youtube.com/watch?v=dyyfWbCvZFc 
Group: AirborneWindEnergy Message: 10359 From: joe_f_90032 Date: 10/18/2013
Subject: Re: Pumping Air with Power Kite
Group: AirborneWindEnergy Message: 10360 From: joe_f_90032 Date: 10/18/2013
Subject: Re: Toy LED Kite AWES by Ben Chapman

Any AWES company might thrive with Ben on your team!  Just say'n.

JoeF
Group: AirborneWindEnergy Message: 10361 From: dave santos Date: 10/19/2013
Subject: Circular Cableway with Anchor Bypass
 
Modern horizontal safety-line study case for kite-arch turreting capability as depicted by Rod; the COTS hardware is suitable for scale experiments, and can be imitated at far larger scales; note bypass curves-
Group: AirborneWindEnergy Message: 10362 From: dave santos Date: 10/19/2013
Subject: Peter Lynn announces new utility-kite designs at super-low prices

We have enjoyed watching Peter Sr. lately converge his engineering mastery onto two strategic kite types, the pilot-lifter, and the traction-kite, now to be offered by China's largest kite manufactuer, Kaixuan. A 22m2 pilot parafoil will go for 280 USD and a "revolutionary" 4m2 single-skin power-kite for 90 USD. This is breakthrough kite R&D; advanced ultrasimple ultralight design at half the price of competing wings.

KiteLab methods long shared on the forum often combine these kite types into AWES platforms, and potentially into large dense arrays, so Peter's latest announcement is especially welcome progress-
Group: AirborneWindEnergy Message: 10363 From: Rod Read Date: 10/20/2013
Subject: Re: Peter Lynn announces new utility-kite designs at super-low price
It looks a bit like a shrimp / lobster tail

Shrimp and lobster get surprising speeds for their look.
All that tail muscle, connects a long in-line paddle.

I'm planning a design soon that has a sort of shrimp tail look too.
A shortening series of furling loadpaths. Based on swimming pool lane ropes with their floating pulley parts. Unwinding to reveal a set of net mesh panels and tethering to the next loadpath.
After launch I imagine Dutch rolling the leading edge could apply cyclic loading on the back lines
Group: AirborneWindEnergy Message: 10364 From: Rod Read Date: 10/20/2013
Subject: good and bad bets
Group: AirborneWindEnergy Message: 10365 From: joe_f_90032 Date: 10/20/2013
Subject: Omnidea's second focus: Airborne Platform
 WO2012125052  Airborne platform 

The team seems to have two large branches of interest. One is the "Atmospheric Resources Explorer" while the other is a "Magnus Effect" involved "Airborne platform."

Our incomplete page: 
Group: AirborneWindEnergy Message: 10366 From: joe_f_90032 Date: 10/20/2013
Subject: Re: good and bad bets

Its companion article:
 INVEST CAREFULLY; WIND ENERGY ‘INNOVATIONS’ ARE RARELY KOSHER
2013/05/08 · by Mike Barnard 
Group: AirborneWindEnergy Message: 10367 From: joe_f_90032 Date: 10/20/2013
Subject: Re: good and bad bets

He had an earlier article in March of 2013 

ARE AIRBORNE WIND TURBINES A PLAUSIBLE SOURCE OF CHEAP CLEAN ENERGY? 


2013/03/07 · by Mike Barnard

Group: AirborneWindEnergy Message: 10368 From: dave santos Date: 10/20/2013
Subject: Re: good and bad bets
Barnard's virtues are that he eagerly learns as he goes, and is not afraid of debate. He is the new Gipe, but this time AWE is on the radar. Give him allowance for being new to AWE study, a very complex subject, so many of his intuitive misgivings are well resolved engineering issues, and he does not even yet know many of the strongest arguments for AWE.

Barnard's most detailed AWE opinion piece-

http://barnardonwind.com/2013/03/07/are-airborne-wind-turbines-a-plausible-source-of-cheap-clean-energy/


On Sunday, October 20, 2013 7:50 AM, "joefaust333@gmail.com" <joefaust333@gmail.com
Group: AirborneWindEnergy Message: 10369 From: joe_f_90032 Date: 10/20/2013
Subject: Roland Schmehl
Correct spelling:   Roland Schmehl 

http://www.energykitesystems.net/RolandSchmehl/RolandSchmehl.jpg

For the 
full image set, click HERE
Group: AirborneWindEnergy Message: 10370 From: joe_f_90032 Date: 10/20/2013
Subject: Re: Roland Schmehl
Interesting page and interview set: 
https://1890.allianz.de/ausgaben/2-2013/im-sturm-erobert/index.html
Roland Schmehl is one of the several persons there. 
Group: AirborneWindEnergy Message: 10371 From: mikebarnardca Date: 10/21/2013
Subject: Re: good and bad bets
Hi . . .

I see some of my articles on wind energy are popping up in this discussion group, so I thought I'd chime in.

I certainly have outstanding questions regarding AWE:
1. What aviation legal framework do they operate under in different countries, and have those legal frameworks accepted these technologies as allowable?
2. Which technologies have actually solved the land-and-relaunch problem in an automated, zero-runway model with high reliability?
3. Only one technology that I've found appears to not require onboard electronics on the wings themselves, as it uses dual-winches for control so all of the power needed is on the ground. Everything else except Makani requires batteries it would appear (Makani generates power on the wing itself rather than via regenerative braking on the winch, which introduces problems of other kinds). What is the service time of the batteries for working fairly significant mechanical loads? What is the maintenance period?

A couple of other articles I've written on the subject are here.  



Cheers,

Mike 
Group: AirborneWindEnergy Message: 10372 From: Bob Stuart Date: 10/21/2013
Subject: Re: good and bad bets
Welcome, Mike,

On Q3: Capacitors would be the storage medium of choice here, as the cycles of operation are very short.  They have no particular fatigue limit, and are getting better all the time.  Recently, someone made news by using cheap caps to replace his car battery, something I would not have tried with a carburetor in winter.

The niche that I think most receptive to kite power is the enhancement of old, silted-in hydro power installations.  The electrical infrastructure is in place, and the locations are often remote enough for low liability.  Drought is affecting some locations. Wind being more frequent than rain or melting, it can store a lot of power in even a shallow lake, or keep a dam full for maximum output.  The output can cover premium-price peak demand load, offsetting other renewables.  A kite's flight could be a good match to haul skips of water up an inclined railway.  If the wind picked up during a haul, it would just go a bit faster, and if it declined, a bit of water might be spilled.  The weight of the skip cart returns the kite to the starting position for each cycle. When the wind dies, the railway helps with the kite-train storage, with the cable reeled onto the cart, and one pilot kite left on a pole.  

You might want to think of another class - medium altitude wind power.  High enough to rival the tallest tower, but low enough to be controlled by two lines from the ground, and not affect most flight operations.  Mastery in that region seems like a sensible step to the higher altitudes and more investment, even if the higher kites need another technology.

Best,
Bob Stuart

On 21-Oct-13, at 12:38 AM, <mbarnardca@gmail.com
Group: AirborneWindEnergy Message: 10373 From: Pierre Benhaiem Date: 10/21/2013
Subject: Re: good and bad bets

Mike,
 
Welcome to this forum about AWE.
 
1. No complete answer now.A farm of AWES needs a huge  no-fly zone (see your articles themselves,but also Land and space used - EnergyKiteSystems ) regarding both aviation (space used) and safety zone (land used) without inhabitants.The main reason (as you know) is the length of tethers in all wind directions.So keeping an advantage over conventional wind turbines requires a maximization of the space.Implementation offshore are expected but in this case the differences of wind power are not so high according to the altitude far of the coast.
 
2. Makani with take-off helicopter-mode.But reliability on long time of operations is difficult with such a mode.
 
3. For technologies using a ground generator,small turbines aloft feeding the low needed energy for control systems could be a solution.
 
PierreB
 
http://wheelwind.com (towards a mix).
 
Group: AirborneWindEnergy Message: 10374 From: Mike Barnard Date: 10/21/2013
Subject: Re: good and bad bets
Thanks Bob.

Regarding the on-wing battery, I'm less interested in the storage technology than in how electricity gets into it. This seems to be a fairly large disconnect that I haven't seen addressed outside of a couple of solutions.

Most of the technologies I've assessed have battery-powered control systems on the wing or bridle which run micro-winches for kite control, or move ailerons. Most of the systems project up to 95% flying time / capacity factors over a year as well. The tethers are load-bearing, and electrifying them isn't an option that seems viable in most instances -- issues of weight, strength, diameter on winch drums, insulation, rain -- although Makani's/ Altaeros and Magenn solutions require that. One option, the TwingTec, would have required an onboard air pump and sensors to maintain overpressure in the tensioning air beam.

The prototypes and demonstrations have typically run a few hours at most, well within the lifespans of lightweight batteries for the load required. I'm curious for the large number of single-tether wing and kite systems how recharging of the battery is proposed to be done and what the implications for maintenance and LCA are. What are the implications for capacity factor?

Which technologies have solved for this concern beyond conceptually?

Cheers,
Mike
On 2013-10-21, at 3:52 PM, Bob Stuart wrote:
Group: AirborneWindEnergy Message: 10375 From: dave santos Date: 10/21/2013
Subject: Re: good and bad bets

Welcome to the AWES Forum Mike.

Questions regarding aviation regulations and AWE are addressed here- 



Concerns about aerospace complexity have been taken up by the open-source Low-Complexity AWE school ("rag and string only"). Many designs now exist that do not require any electrical systems aloft (except for FAA mandated nav lights for night operations).

Unlike conventional wind, practical AWE often depends on oscillating power outputs, so the concern for in-system storage to smooth power out is an inherent design issue, rather than a wind-fraud "red flag". Its the same with any piston engine which relies on small flywheel masses, or any electrical circuit relying on capacitance, for smooth output.

Your valid misc. concerns about issues like runaway, scope, and so on, have all been carefully studied, with compelling solutions found for virtually any objection. Lets fully cover all such questions in future posts.

The biggest challenge to the conventional wind paradigm is understanding how the latest gigawatt-scale unit Low-Complexity AWE appears feasible, based on a far superior resource (~1000x), with no insuperable engineering or economic barriers. We look forward to your specific challenges to the disruptive new AWE paradigm, as a reality check,

daveS
Group: AirborneWindEnergy Message: 10377 From: joe_f_90032 Date: 10/21/2013
Subject: Nominations WGA for 2013 ?
1,  [[Apologies for the span ad post; the wrong icon was clicked. We click off about 20 span messages a day.]]


2. Nominations are open for 2013   Please send nominations to Wayne German or post them hereon or direct me. Thanks.

Filler from 1909: 
An Old Bicycle Brought Into Service In The Los Angeles Tournament.
Group: AirborneWindEnergy Message: 10378 From: Mike Barnard Date: 10/21/2013
Subject: Re: good and bad bets
Glad to be here Dave. I expect to learn a lot. I am, as you point out skeptical about claims of replacing HAWTS with AWES but I know a lot of bright, talented and highly credentialed people are working in this space. 

I'll dig through the links and pointers you provided over the next few days to see where state of the art is so that I can ask more informed questions. 

Cheers,
Mike

----------------------------- ipad -----------------------
The future is already here. It's just not very evenly distributed. - William Gibson
Group: AirborneWindEnergy Message: 10379 From: joe_f_90032 Date: 10/21/2013
Subject: Group moderation
Please, if you find your post not posting within 3 minutes, 

give me a private email and I will see if your posts 
are being moderated. We want regulars to be "unmoderated"
... 
thanks
JoeF
Group: AirborneWindEnergy Message: 10380 From: Mike Barnard Date: 10/22/2013
Subject: Comments/Questions on FAA TACO
Hi Dave et al . . .

I just read through the excellent v1 FAA TACO that Dave seems to own (congrats on that, Dave).  Great stuff and I'm unsurprised as a current paraglider pilot and former airforce brat that the issues are complex and just starting to be addressed. http://www.energykitesystems.net/CoopIP/TACOentry6Feb2012.html

a. My first comment I think is echoed directly in the document and by many here: anyone intending to build a company in the AWES space would be advised to read this document as a draft requirements statement so that they know what they are getting into and can scale their needed investment properly. As a technical architect (one of my hat's), the non-functional requirements and constraints are either well elaborated or at least listed. Tremendous resource. This is less of a concern for academic concerns aimed at solving a particular technical problem of course.

b.  If I understand it correctly, the US FAA has agreed that individual test AWES systems can fly with a limited ceiling of 500' and 1000' diameter from fixed and known locations during daylight hours only for testing / prototyping purposes. Can someone confirm that they have agreed to this, or is this merely the request and there are other restrictions in place?

c.  Some of you may know that I spend a lot of time on the social license aspect of HAWTs; it's a primary goal of mine. As such, when I read the following, I literally did laugh out loud.  I urge you not to consider this aspect to be simple in any way, or that spreading a bit of money to a subset of stakeholders to be adequate to overcome it.
"Barriers to broad AWE societal stakeholder acceptance, like NIMBY 
(not-in-my-back-yard) forces, will melt before a rich new tax base that more 
than offsets any negatives."
d.  A key question that became obvious as I read through the TACO is that it is a rag-and-string TACO. This is very reasonable, and it does touch on non-rag-and-string concerns, but only glancingly.  Is there something similar for the Makani's and Ampyx' of the world?
I'll ask a separate question that occurred related to rag-and-string technology based on reading through this.
Cheers,
Mike
Group: AirborneWindEnergy Message: 10381 From: Mike Barnard Date: 10/22/2013
Subject: Parafoils and Rain
Hi all . . .

Based on reviewing the Weather Hazards section of Dave's draft TACO (http://www.energykitesystems.net/CoopIP/TACOentry6Feb2012.html), I noticed that I don't see rain listed.

As a paraglider, I know one thing about rain: when flying it enters through the leading edge cell openings and accumulates in the trailing edge, causing wing stalls which leads to paraglider pilots falling out of the sky. Paragliders avoid rain like the plague as a result.

Outside of exactly one ultralight single skin paraglider that's been demonstrated but is not being sold, all parafoils use air flowing into the cells combined with low porosity skins to maintain airfoil profiles.  

I haven't seen any mention of this attribute of parafoils in the literature I've read to date. What's the AWES common technical response to this if there is one?

Cheers,
Mike
Group: AirborneWindEnergy Message: 10382 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Parafoils and Rain

Nice question, Mike. Thanks. 


rain and kite systems
Group: AirborneWindEnergy Message: 10383 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

Mike and all, the following incident in a kited paraglider might have indicated a neglect to have local air traffic control informed of a "tether-in-the sky". There were not the line-visibility markers. Tow-launch operations by hang gliders and paragliders seem to neglect making the long tow lines visible; and the amount of coordination with local control towers is something to be explored.        Video: 36 seconds: 


Paragliding incident - airplane almost crash to my towing line
Group: AirborneWindEnergy Message: 10384 From: Mike Barnard Date: 10/22/2013
Subject: Re: Parafoils and Rain
Has a kite designer modeled the performance degradation tradeoffs of intentionally increasing porosity via drain holes yet or is it to be done? Has SkySails already dealt with this due to their extensive ocean experience?

Inflation, launch, velocity, handling and lift will all be affected by this after all. 

Cheers,
Mike

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The future is already here. It's just not very evenly distributed. - William Gibson
Group: AirborneWindEnergy Message: 10385 From: Pierre BENHAIEM Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

For an utility-scale AWES the permanent no-fly zone should concern the whole system,tether and wing, according to all wind directions.It is like a huge  building which radius is the length of the tether.

 

PierreB
Group: AirborneWindEnergy Message: 10386 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO
 
Group: AirborneWindEnergy Message: 10387 From: Mike Barnard Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO
Yikes. 

I did tow paragliding in Ontario and there was a permanent NOTAM in place for the site. Apparently some pilots don't read them according to the instructor there and planes did intrude in the airspace. I'm glad this never happened when I was hooked in. 

That said, I watched a WWII replica warplane buzz by at eye level 500' away in British Columbia a year ago at 2500' altitude, and three attack helicopters fly by 400m away and 200m down in Bali two weeks ago prior to the APEC conference. We have specific guidelines for making ourselves visible in the air when powered aircraft approach, dominantly turning so that our canopies are more square to the plane. 

A tether line will always be thin. Any thought to adjusting angle of kites to intruding aircraft by the ground crew for higher visibility?

Mike

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The future is already here. It's just not very evenly distributed. - William Gibson
Group: AirborneWindEnergy Message: 10388 From: dave santos Date: 10/22/2013
Subject: Re: Parafoils and Rain
Many sport and hobby soft kites already have simple sand/water drains in the trailing-edge. Another helpful feature is a reduced frontal intake area (often with flap valves). A good example of all these features in a popular trainer kite is the HQ Hydra line. Parafoils, with so many cells, and the presumption of fair-weather use, have not required this capability. This point is a TACO omission, so it will be added in future versions. The obvious conclusion is that such drains be a design-default in safety-critical parafoil AWES, and perhaps be mandated in FARs.

An intuitive parafoil drain design is to vent across all cells at the TE, as well as provide multiple small drains from wingtip to wingtip. Even hollow rigid wings need careful rain and condensation drain design, but single-skin concepts like Mothratech avoid the whole issue. Its well known that modern kites fly with only slightly reduced performance in rain (KiteLab Ilwaco flies single-skin experiments in rain routinely and Enerkite has reported parafoil AWES rain operation). 

Lets not forget rain collection as a niche in our giant-kite design toolkit, with elaborate networks of gutters, drains, hoses, and tanks possible. Many hot deserts have considerable rainfall aloft that normally evaporates well above the surface, but in reach of kites. We also recall the ancient Polynesian kite magic of flying sponges into clouds to harvest fresh water.


Thanks, Mike, for your appreciation of TACO, and especially for finding gaps and flaws to remedy.
 






On Tuesday, October 22, 2013 8:40 AM, Mike Barnard <mbarnardca@gmail.com
Group: AirborneWindEnergy Message: 10389 From: joe_f_90032 Date: 10/22/2013
Subject: Re: Parafoils and Rain

Stephan Brabeck, as technical director (CTO) of SkySails GmbH, has been invited to address the question of kite-design relative to rain, moisture, dew, or sea-spray. He has about 14 years experience in related matters.


Group: AirborneWindEnergy Message: 10390 From: joe_f_90032 Date: 10/22/2013
Subject: Wing-surface messaging
The world of kite-system-wing-surface messaging has ancient roots, yet the unfolding future invites fantastic operations.   The ancient: kite covers showing symbols and scenes giving meaning to pilots and spectators.  Advertising messaging forms a rich part of kiting history; fly colors, words, pictures, fine-art, flags, etc.  


The contemporary scene has illuminated night display.   Then consider the Goodyear blimp all sided with motion messages.

Flexible LCD screens will permit a new era of sky messaging. The very sails of kite systems may become active for getting messages out to the world. Advertising, entertainment. area illumination, messaged shading, education, politics, disaster communications, etc.   And some of this will be a means for secondary income in working energy AWES in niche markets. 

Teasers: 
Group: AirborneWindEnergy Message: 10391 From: Mike Barnard Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO
On this point, my stunt and power kiting experience and physics tell me that most designs -- the defunct Magenn being a possible exception -- require a three or four to one tether length to altitude ratio in order that the tether can be an effective vector of force and the flying kite can be at the strongest angle of attack to the wind. 

Three questions:  

A. I'm sure modeling has been done on compromises of steeper angles for higher winds with lower extraction.  Are there specific papers or reports on this aspect I can read?

B. Much of the documentation including Pierre's suggests the tether length as both the altitude and radius limit, however straight up hasn't been an option that I've seen in designs to date. With high altitude winds being the target, and at minimum greater than current HAWT heights to achieve differentiation of potential output, 1000' altitude ceiling would appear to require more like a radius of up to 4000'. What papers and reports on this aspect have been done?

3. Which devices / designs are the best at harnessing power at a steeper angle? Magenn has been mentioned, but which other technologies should I look at?

Cheers,
Mike

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The future is already here. It's just not very evenly distributed. - William Gibson
Group: AirborneWindEnergy Message: 10392 From: Pierre BENHAIEM Date: 10/22/2013
Subject: Re: Comments/Questions on FAA TACO

The paradox is more the kite is high tapping strong winds,less the kite is efficient if it is too near of the zenith.Documents are available on http://www.kitepower.eu/publications.html.

 

Note to Mike:you show some doubts about the real capacity of AWE as utility-scale I share also:too much land and space used due to the tether;non enough reliability when numerous take-off and recovering are needed; add the low efficiency regarding Betz'limit;the wear of flying components with chemical agents and UV. Other point:utility AWES should be implemented farshore (and also in deserts) ;nor the differences between the power of high and low altitude winds are not so important far on the coasts.

 

The diameter of offshore turbines increases towards...high altitude winds.

www.swayturbine.no/ shows an interesting design where the generator is 25 m diameter,lighter due to both flexibility and higher tip speed.

 

I have some mix designs (FR2975445 A1 with good search report (no X,no Y,only A) on http://wheelwind.com/ ,Airborne Seaborne Wind Energy System with two options:light rim-drive and of type dynamo of bicycle.Now I prefer the first.Cascad of lines allow to hold the turbine.

 

So the better for Airborne Wind Energy seems to be a component allowing a far lighter construction for offshore turbines.

 

PierreB,

 

http://wheelwind.com






 
Group: AirborneWindEnergy Message: 10393 From: dave santos Date: 10/22/2013
Subject: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES
Tether-Angle is another poorly understood AWE issue, with many confused mistaken notions in print. One fact stands out, from kite sports, that nominal power is harvested somewhere around 45 degrees elevation. The kiter flexibly adjusts elevation angle to match a given kite to windspeed and load. This reflects real operational factors like wind-gradient (velocity increase with height). The simplistic theoretic advantage of flying low (and dangerous) in the kite window, in the absence of a wind gradient, is as misleading as the theoretic advantage of somehow making high power near zenith*. The picture is complicated by kites that sweep-cycle high and low, and kites so big in proportions that they cover a large angle of the window.

The dire problem of over-long tethers causing airspace and land-footprint sprawl is only inherent to fixed single-anchor unit cells, and most AWES developers are stuck in this rut. The problem disappears in more advanced thinking; for example, crosswind arches of pure wing, shifting anchors to upwind locations in the cell, and dense arrays (crosslinked aloft) where the tether angle penalty is paid only once by the upwind lines, and all downwind array units share the single offset. This is how gigawatt unit-scale becomes practical.

Variations on these simple solutions allow highly-perfected AWES will be able to overfly dense populations, just as normal aircraft do, subject to standard aviation safety and reliability metrics (~2030).


* Excess helium lift to secure a high elevation angle is especially misguided, as an aerostat is driven down by wind, compared to kites, with far greater costs.
 
Group: AirborneWindEnergy Message: 10394 From: joe_f_90032 Date: 10/23/2013
Subject: Towing manuals
Group: AirborneWindEnergy Message: 10395 From: joe_f_90032 Date: 10/24/2013
Subject: Flexrotor UAV wows ...
Group: AirborneWindEnergy Message: 10396 From: Mike Barnard Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES
Hi Dave et al . . .

In the interests of learning more and trying to understand Dave's suggestion below, I've been trying to dig into arch kite generation approaches.

So far I've found some pretty arch kites at kite festivals, a few 3d computer models without any working details, rotating ribbon kites and no documentation on how arch kites are expected to generate power.

- I understand fully how SkySails and similar pumping kites generate power via regenerative braking at the winch.
- I understand how Makani and similar concepts fly small wind turbines at high speeds through the air to generate electricity on the kite.
- I understand how Altaeros takes a ducted wind turbine embedded in a blimp to high altitudes to maximize wind speed over a small wind turbine.
- I understand the purely mechanical concepts of having kites tow stuff uphill to create potential kinetic energy to generate power.
- I understand how the Magenn aerial Savonius design generated power by have the blimp spin on an axis with electric motors.

I don't understand how kites that sit in one place at moderate altitudes are going to generate power, especially in context of only rags and string aloft. Is it just lots of kites, hence lots of lift so a large mass rising slowly then controlled to fall slowly, pulling cable out through regenerative winches but with tons of torque geared up massively for electrical generation?

I certainly see Dave's points regarding multiple tethering points having reliability and safety advantages. I'm less sold on the tether angle argument, in part because the linkage to power generation is not obvious.

Please help, perhaps by pointing to technical papers or articles I've been unable to find on the Yahoo group or using Google. Right now it looks as if it has similar problems to Savonius devices in concept: lots of torque, no fast movement, hence more useful for things other than generating electricity like pumping water. A working prototype, or published and peer-reviewed paper on the mechanics of the solution would be very advantageous.

Thanks,
Mike
Group: AirborneWindEnergy Message: 10397 From: Pierre BENHAIEM Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES

"I don't understand how kites that sit in one place at moderate altitudes are going to generate power, especially in context of only rags and string aloft. Is it just lots of kites, hence lots of lift so a large mass rising slowly then controlled to fall slowly, pulling cable out through regenerative winches but with tons of torque geared up massively for electrical generation?"

I either.See old posts about arches.Note that an arch has two anchors,so it is limited to dominant winds,excepted in case of implementation of a device such a circular track. A possibility:as static traction kite to carry turbines aloft.Another possibility is described in videos from Roddy:the arch is on a circular track allowind both adaptation to wind directions and making some power by being piloted from anchors,the generator being at ground. Other indication by DaveS on numerous posts:oscillating according to Bose-Einstein theories:I do not know anything about them but I think DaveS will be happy to explain the modus operanti.

 

PierreB
Group: AirborneWindEnergy Message: 10398 From: dave santos Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES
Pierre,

Megascale crosswind arches are designed as the primary scaling solution to create cheap bulk-lift in the smallest land-airspace. In principle, any kind of WECS can be raised on close-spaced halyards under an arch (cascade-launch). Rod's many versions of megascale arches cover many of the choices- HAWT flygens, looping foils, wingmills, and so on. The choice of WECS remains open, subject to years of compenent testing. Even a balloon can lift a WECS; giant arches just allow larger cheaper AWE, by lifting more.

We also know several powerful inherent arch-oscillation modes (jellyfishing, Dutch-roll shimmy, phugoid). These exact modes are also seen in TUDelft kite-force numeric simulations and wind-tunnel testing of arched parafoils ("staked out" like an arch, without tethers). There is no scaling barrier seen to these phenomena operating at km scale, and the calculated power is monstrous. Mothra1, at 300m2, flew exactly as intended (under easy launch and land control), and could set the AWE peak power record by simply hoisting conventional small HAWTs.

Rather than mock EBS as applicable to large kite lattice dynamics, you should try to make a small scale model of the offshore concept you are lately promoting. You are seeking to attract investors on the basis of naive engineering speculation, without bothering with even the smallest working prototype. This is a "Red Flag" by Mike's criteria.

On the other hand, Mike will continue to uncover the vast body of foundational discussion and experiments showing just how open-source megarches can make mega-power, if simply by hosting dense WECS arrays cheaper and better than LTA,

daveS


 







On Friday, October 25, 2013 3:02 AM, Pierre BENHAIEM <pierre.benhaiem@orange.fr
Group: AirborneWindEnergy Message: 10399 From: joe_f_90032 Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale
EBS ??? Consider if BES was intended: Bose-Einstein Statistics (BES)
Group: AirborneWindEnergy Message: 10400 From: Pierre BENHAIEM Date: 10/25/2013
Subject: Re: Summary of Tether-Angle "Non-Issue" for Utility-Scale AWES

DaveS,

 

"We also know several powerful inherent arch-oscillation modes...".Not me.Please can you explain oscillation modes,or refer to documents?Are oscillations downwind (power?)/upwind (losses?) or crosswind?How the power is produced?

 

PierreB