Hi Guys: Someone posted this on the AWEA Yahoo Small Wind for Home group. A flying wind turbine product for sale. They only claim 100 Watts, and they say they have 6 available, but allow 8 weeks for delivery? hmmm, well at least it's someone hanging out a shingle.
Doug S.
cut-and-paste of post below:

Doug:
I thought you would get a kick out of this. Is it violating any of your patents :)

www.pacificpowersails.com

The advantage of open-source developments is that many eyes spot
fundamental flaws early on - with software and hardware. Linux is
reputed to be more secure and reliable than Windows, which cost billions
to develop. This list is, as far as I can tell, the first and only
substantial effort to take AWE open-source, but it is still small. I am
trying to build up more conviction that we are at the beginning of
something great. Fortunately we do not have to make the software, or
anything else, perfect. We just have to make it good enough to get
used.

When the control software is demonstrably better than a well trained
human, permission for full automation should be forthcoming. I am not
saying we need to rush to get to that stage, but it has important cost
implications and the prospect of big profits tends to rule the
development of these things.

My experience (mainly in the fuel cell field) is that there is a
tendency to waste money making big demonstrators too soon. My plan is
therefore to get small kites systems working well and reliably before
spending the money to make them big. A huge amount of data can be
extracted from something the size of a small toy. It costs far less to
experiment on something that size and the viability of the software can
be demonstrated on a model of any size. Once the data is analysed and
understood scaling up is much easier. I learned the importance of this
approach from someone who studied Japanese businesses. He studied how
they developed so fast in the 60's and 70's and he found they spend far
more time planning projects than we do in the West. The planning makes
the start look slow but the progress near the end of the product launch
is far faster - and that is by far the most expensive bit.

Robert.

There is an amusing and informative commentary on the value of planning, teamwork, prototyping, etc. at 

Hi,

I completely agree with Robert.

As you might know, our group is currently developing an automated kite
control system.

I suggest to use multi agent control, based on the open robotic control
software framework (Orocos) as basic concept. This concept is well
explained in the following thesis:
http://essay.utwente.nl/58513/1/scriptie_I_Rezola.pdf
(page three and four).

If you think about implementing automated kite control systems, have a
look at this. It is well suited for development in small teams, where
each person implements a different part of the control system (e.g. kite
model, figure of eight controller, winch controller).

Regards:

Uwe Fechner
TU Delft

Attachments :

I think working systems can be run without any software at all. No wait, I KNOW from personal experience that working systems can be run with no software.
I'd save the software development to fine-tune systems once they've been up and running. There's nothing like inherent stability, in aircraft, or in wind energy. I'll take stable geometry over clever software for now, if possible.
No matter how many distractions one may think up, ya gotta fly that thing and get it working.
Doug S.

I'd sure go for a system that can fly without silicon.  I have not done any practical work (sorry ) but my preferred application is a water lifter, and handling the skip weight is just like having a constant tendency for the line reel to retract.  It seems to me that just that would save the kite  from most anomalies, and return it to the ground during lulls.  A low post and cradle should be able to receive it and provide some spring action.  For stability and easy launching, a train of kites sounds highly desirable, which does complicate things for launch and retrieval.  Either storage space can be provided for the whole train, flat, or or folded, or it can be wound onto a drum, or have winders on the extension lines to each tier, or some such solution.  Flying separate little spring-loaded reels would not cost much, and would let each tier launch at the same wind speed.  A long, tapered reel can compensate for spring wind-up.

Hi I just stumbled across the "Superbus", developed by Ockels, the Dutch astronaut who recieved a patent for my invention of a loop of kites pulling upward on endless clothesline loops, calling it "Laddermill", not knowing that I had already invented it as a teenager. Hey it's OK, how could he know? Personally, I never thought it worth patenting, since to me, the next step was a Superturbine(R).

Well, at least he's sticking with the theme of copying me in some way, using the name "Super" in "Superbus" - continued imitation is the sincerest form of continued flattery - reminiscent of the brand name "Superturbine(R)". Thanks Prof. Dr. Wubbo Johannes Ockels
No it's OK, I understand people named things "super" before I came along... And Dave S. named one contraption "ultra-something-or-other..." How 'bout "neato-turbine?" "groovy-wind"? I know, how 'bout "emperor's very good luck nice day fortunate dragon"?

The thing I don't understand is how someone could invent the laddermill without seeing that the next step to actually make it work well, going from a literalist and primitive, inefficient, stone-age drag-based machine using upwind/downwind motion, to a modern, spinning, crosswind, lift-based machine, like real turbines in the real world, is a Superturbine(R). Oh well I guess that's the nature of inventing: You have to see what others don't, and I guess it just comes easy. Other people have other skills that come easy to them, that are hard or impossible for me.

Nice idea for the bus - isn't it about time we started driving faster? Yes! Congratulations to Prof. Dr. Wubbo Johannes Ockels.

Doug Selsam

It is possible that each nation will have a first citizen being paid for giving someone else electricity made from a KES    Reports of such sales are invited to be recorded for posterity.    KES owner-operator, KES description, customer, date of energy sales, condition of the electricity sold, and amount of electricity are invited to be recorded.

Already many entities have made electricity from KESs/AWECS and used such electricty to do tasks within their own experimental environment.   What is being invited in this note regards selling energy to parties remote/distinct from the production entity.

For instance, say a kite-motor from Dave? generates electricity that is then conditioned and fed through a meter approved for net metering.  Would simply lowering one's own electrical bill be the subject of this call?  Such is interesting and indeed important and the report of such is invited for a second call for that sort; but the two branches of action will be keep separate in our news spots.

Type I: lowering one's own bill.   Working one's own devices.

Type II:  Selling energy to a third party.

Discussion is ever open.

Suppose someone buys a kite-motor or makes same; and then suppose one sets up a battery-charging lemonade stand at the resort beach boardwalk and charges some tourist's cellphone battery with a KES for $1.    The tourist gets bragging rights of having charge from the KES ...from the heavens.  The seller of the KES energy used in charging gets bragging rights for being an early performer in his or her territory as regards retailing kite-energy electricity "kitricity". 

Dave Santos early made electricity to power his cellphone to call Dave Culp; but as yet, I have no notes of DaveS selling kitricity to a third party.   Etc.   Do we have anything yet to record in the history books?  Will a customer of the Pacific Power-Sails sell kitricity to a campsite neighbor and record such for Upper Windpower?

Following development there will then be various records.

For example:

First in Germany to sell
one kW·h   _____________________ using _____________________ Etc.  to____, etc.
one MW·h  _____________________
one GW·h   _____________________

No rush.  Just setting up for the news.

Doug schrieb:
My own efforts in this direction (years ago):

1)
Flexifoils (two-line wing kites with single flexible spar) will stay in
the overhead "parking position" in a steady wind if the two lines go to
points on the ground which are about the span of the kite apart, at a
right angle to downwind. In this position the kite(s) can be reeled in
slowly without additional control.

If one line is quickly shortened and kept, the kite(s) will start to
spin in a circle, pulling hard and slowly losing altitude with each
revolution. After a few turns the lines become locked and the kites are
doomed. Working for Keith Stewart, we made a coaxial swivel, so the
kite(s) can spin without locking the lines and tried this out.

Now it only requires a slight asymetry to induce the spin to stay stable
and not lose altitude. This could be done with a spring in one line. I
only tried this once, but didn't get it right. I think with the right
spring, a stable spin could be achieved. In this position the kite(s)
could pull out on reels and produce power. However the spring would then
have to be on the mounting of one reel instead of in the line.

2)
Keith Stewart's inflatable kites are pretty stable without control. We
had a simple weight-shift system inside the kite which could put the
kite on one tack or the other, varying the line asimuth by about 90°
very stabily and a bit more less stabily. 90° swing is enough for
low-performance sailing, other purposes like bird-scaring or low-power
generation.

These things work in steady winds up to a certain level. Above this
level, with gusts, or worse with lulls, a human has to take over.

Theo Schmidt

Robert Copcutt schrieb:
Years ago I was thinking about what it takes to fly flexifoils. I think
the software is the least of the problems. The first problem I had when
working for Air Commodore Nance, who had bought the kite research vessel
"Assessor" from BP, was purely mechanical. The strong hydraulic winches
on board this craft were simply too slow to fly dynamic manoeuvres. I
tried stepping this up with pulleys, but it became very awkward. We only
managed to let out Flexifoil stacks statically but not fly dynamically.

The above could be solved, but the next problem is trickier: sensors.
The computer has to know where the kite is and what it is doing. For
fast kites this needs a combination of a visual or other semi-optical
system to track position and speed, and sensors on the lines to measure
angle and pull near the ground. Again, this can be solved, but is rather
involved.

The trickiest point of control, which may be unsolvable on land, is
during a lull. The lines must be pulled in and the kites induced to fly
circles or figures. As long as the lines are long, this works, but as
the lines shorten it becomes more and more difficult even for expert
humans and I expect even more difficult for automatic control systems.
Therefore each installation will require defined crash zones, perhaps
even ponds or nets or something in order to minimise damage. When the
system can demonstrate that it can land the kites in these zones in all
conditions, then permission for full automation may be forthcoming.

Cheers, Theo Schmidt

Primer on Airborne Wind Energy
Executive Paper Prepared for NASA by Douglas Spriggs Selsam December 2010

To NASA: Welcome to the world of Airborne Wind Energy (AWE).
Note: At the time of this writing NO useful AWE systems are commercially available.

Airborne Wind Energy is a subset of Wind Energy, a field with a 3000-year history.
Many false trails can be eliminated using the knowledge gained in these 3000 years.

A Short History of Wind Energy:

Step 1) 3000 years ago Iraq: Drag-based vertical-axis carousel, with wind blocking upwind cycle. The bullwheel, normally turned by draft animals, could be powered by just their skins, pushed by the wind on one side, if a wall was built to block the wind on the other side. (ground-based “kites” traveling downwind). Note: a hub rotating on an axle was used even then.

Step 2) 2000 years ago, in the Greek Islands, cross-wind sailing evolved into a cross-wind turbine design that placed several triangular sails at the tips of spars radiating from a central hub, mounted on a round building sited on a windy island. These represented the first “propellers”, sweeping more area than their sails by crosswind travel, never losing power or travel time to upwind movement. (ground-based “kites” traveling across the wind)

Step 3) 1000 years ago Europe developed long, slender blades with shaped airfoils, for high speed crosswind travel, reducing rotor solidity to a small fraction of the swept area, adding a gearbox. This is the same basic design used today, but modernized for electricity production.
(“kites” abandoned, replaced by “blades”, gearbox added)

The 1000-year Cycle in Wind Energy Technology:

~ Every 1000 years, wind turbines radically change. 1000 years is here again now. It is time. ~

False Trails in Wind Energy
False Trail #1: Drag-based machines: The earliest wind turbines used the simple “push” of the wind, with working surfaces traveling in a downwind direction. While easy to comprehend, drag-based devices are highly inefficient, and produce the LEAST amount of power for the material used.
Reasons for inefficiency of Drag-Based machines:
a) Reduced Relative Velocity (7/8 power reduction): Since the working surfaces travel WITH the wind, the relative velocity is reduced to about half, which reduces the force to ¼, and the power to 1/8, compared to a working surface that does not move downwind.
b) Upwind Travel Half Cycle (1/2 power reduction, minimum):
1. Reversal to return the working surfaces to an initial position wastes half of travel,
2. Forcing the working surfaces upwind against a 1.5 x wind velocity, uses power, rather than producing power.
c) 100% solidity: (5000% power reduction). Lack of travel across the wind gives up a possible 50x increase in swept area, over more working surface area, as modern rotors extract the Betz coefficient with a 2% rotor solidity.

Inefficiency of Drag-Based Turbines Versus Lift-Based Turbines:
Total efficiency of drag-based machines then, can be no more than 1/8 x ½ x 1/50 = 1/800th compared to a properly-designed wind turbine, based on working surface area, and 1/8 x ½ = 1/16th, based on swept area. These are best-case numbers. The reality is far worse.
AWE example of a drag-based machine: Magenn™
Key factors: efficiency of materials, efficiency of motion, efficiency of modality.

False trail #2: Reciprocating Cycles: The known history of wind energy begins with rotating vertical-axis carousels, and continues with all rotating designs, with no known examples of a successful reciprocating wind turbine product or design in 3000 years of wind energy.
Key factors: wear, spinning reserves.

False Trail #3: Cloth Kites: Referring to Steps 1 and 2 of the known history of wind energy, wind turbines indeed began with sails of stretched cloth or animal skins. As the art evolved, the supporting frames developed an airfoil profile and rotor solidity was reduced, causing blade speeds to increase to the point that finally the cloth covering was impregnated with resin, or was replaced by wood etc., becoming a solid blade. While cloth blades have been tried in the last 100 years, none has been successful, no turbine today uses cloth blades.
Key factors: wear, longevity, performance.


Distractions that Take one Away from Solving the Stated AWE Challenge:

Distraction #1 Redundant Spinning Reserves: “Wind Energy doesn’t matter anyway because it requires redundant spinning reserves using fossil fuels”:

Answer to restore focus to AWE: This is just an excuse to give up. You should stop now. If you believe this, then you should not be in charge of developing wind energy. A good AWE system should ideally emulate/provide “spinning reserves”, to the extent possible.

Distraction #2 Power Storage: “We must develop Storage of Power to address long-scale wind intermittency”:

Answer to restore focus to AWE: Energy Storage is a Distinct and Separate Challenge. If economical energy storage is developed, it can be immediately implemented for load leveling & peak shaving, by storage of nighttime generation for use during the day. This is a subject unto itself, equally valuable as energy itself, and should not be confused with wind energy, nor used as a distraction, since no economical storage solution has emerged and none is expected. A good storage solution could even tend to make wind energy less important, or even irrelevant, since off-peak electricity is almost free. So don’t use intermittency as an excuse or distraction.

Distraction #3: Excessive Size / Altitude in Early-Stage Development: Imagine the Wright Brothers hampered by the realization that airline transportation is best carried out at 30,000 feet altitude, thinking their first prototype had to be a fully-staffed, pressurized airliner with bathrooms, galley and crew. Obviously, aviation was best worked out at a small scale and relatively low altitudes for decades until the bugs were worked out. Wind energy also started with small units, powering rural America for decades, until the technology was sufficiently developed to build larger turbines. Since there is a proven useful wind resource at current turbine heights, and a proven demand for turbines at this scale, and since both turbines and flying models can be successfully built and flown within a large range of scales, it makes sense to develop the AWE technology at a smaller scale and a lower altitude, for now, than some final visions would suggest. If it’s going to work at all, it will probably work fine as a scale model.
And if you can’t get a scale model to work, why would anyone assume you could get a full-scale device to work? Key Point: Scale models speed development while lowering costs.

Distraction #4 Endless Discussion of Existing Rules and Laws: Again, imagine the Wright Brothers trying to work within then-existing railroad regulations. Without any working system that can deliver any level of usable power, at any scale, for any use, talk of existing laws is mostly just one more way of not getting anything done. Obviously, if AWE is developed, there will have to be rules in place to accommodate it. Without any idea of what form working AWE systems might take, it’s way too soon to make appropriate rules. While existing rules must be respected, to allow those existing rules to be an excuse to not fly something is inexcusable, since one may choose to test where there are no rules, or in locations so remote that bending the rules is not noticed nor protested. For NASA: Mark Moore (Dave North?) has noted that perhaps development outside the USA is advisable. This seems regrettable given a quasi-commitment to developing, or at least acknowledging the development of AWE, representing a US agency. Is a fixation on such rules just another way of acknowledging that our bureaucracy has become so unmanageable that it cannot accomplish any stated goal, since the various parts of the beast cannot ever be expected to work together, with one part always sabotaging the other parts? It would seem that our bureaucracy must decide if it is indeed committed to developing advanced clean energy solutions, and if so, it must stop standing in its own way, or there is no point in pretending to proceed forward with this effort.
Key Points: A workable system should be able to be demonstrated as a scale model, and have use as a small-scale product. Testing can be done at low altitudes or in remote locations, where there is nobody around to bother. Offshore is one option. Size and altitude are not acceptable excuses for nondevelopment of AWE.

Distraction #5 Finding Excuses in General: There have been reasonably efficient AWE systems demonstrated, that run in a steady-state manner, that can charge batteries, or be connected to the grid directly, or through an inverter. There is no reason that such systems cannot be built, run, and more fully developed, NOW. The only thing stopping us, is us!

The Technology: What Works? Where do Aviation and Wind Energy Intersect?
Answer: A wind turbine rotor is almost identical to an autogiro rotor

Introducing the WPU: Wind Processing Unit = a wind turbine rotor or autogiro rotor

Analysis by Venn Diagram: A Venn diagram showing an intersection of {the set of wind energy devices} and {the set of aviation devices} yields the intersection of the two sets: {the gyrocopter (or autogiro) rotor}.

An autogiro or gyrocopter rotor is THE SAME THING as a wind turbine rotor. They are so similar that one may be substituted for the other.
The autogiro or gyrocopter IS WHERE WIND ENERGY AND AVIATION INTERSECT.

This WORKING MEMBER (WPU) of an autogiro, that stays aloft carrying weight, when held against a relative wind, IS THE SAME EXACT WORKING MEMBER (WPU) of a wind turbine. The ONLY DIFFERENCE is the angle at which the rotor (WPU) is held.

The conventional wind turbine holds this WPU perpendicular to the wind.
The autogiro or gyrocopter holds its WPU at an angle to the wind.

Gyrocopters used as wind turbines: Shepard / SkyWindPower utilizes such gyrocopter rotors held at an angle to accomplish stationary tethered flight while simultaneously generating electricity. power captured by the rotor, in excess of that required to hold the machine aloft, is available for generating electricity.

The Selsam Superturbine® multi-rotor wind turbine, like a gyrocopter, and like Shepard / SkyWindPower, places its rotor(s) at an angle to the wind.

Reasons Superturbine® forms the proper basis for AWE:
Flyability: Ability To Fly: Superturbine® AWE Advantage #1: Superturbine® places its rotors at an angle to the wind, so they can fly (like a kite or gyrocopter) while producing power (like a Shepard / SkyWindPower wind turbine). Optimal angle alpha maximizes output while remaining aloft.

Reach: Ability to Reach from Ground to Sky: Superturbine® places multiple WPU’s (rotors) along the same driveshaft, yielding an elongated wind turbine. This elongation means that Superturbine® has the additional benefit that it can reach into the sky.

Light Weight Aloft: generator at base. Superturbine® is an elongate structure that transmits power to a generator. The generator can be the base station with no need to be airborne. The heaviest parts that generate electricity are anchored, nearest where the electricity is needed, with no need to be supported by aerodynamic forces.

Light Weight Aloft: cube/square law: (volume vs. surface area) Multiple small rotors weigh less than a single larger rotor of the same total swept area, by an order of magnitude. Superturbine® offers the lowest weight per unit swept area of any turbine type, especially important in AWE.

Blimps, Kites for Support: Superturbine® can utilize buoyant and aerodynamic lifting bodies, such as blimps, balloons, kites, etc., to extend its reach and remain airborne during calms.

Simplicity: Superturbine® can have as few as one (1) single moving part.

Passive operation: Superturbine® can operate without computer controls or algorithms

Unattended operation: Superturbine® does not require a human operator or pilot and can be left running without supervision.

Stage of development: Superturbine® is sufficiently developed that actual generating versions can be built and run now, with a high degree of confidence.

Authored by Douglas Spriggs Selsam
December 2010

OK Thanks Dave North for reading what I put together.
I never really finished it because I realized that filling in all the blanks would just be spilling my nascent I.P. ahead of the fact.

I've got some simple experiments to run here, a few simple configurations to test, and I have no allusions that anybody - any person, or any agency, is going to do anything to help build or test them. I mean, even if NASA came along announcing a funded effort toward AWE, I wouldn't expect any help. Which is OK since it's easier and faster to build a machine and try it, than to fill out the paperwork to get a grant to do the same thing. In one case you get it done, in the other, the idea dies of excessive paperwork and bureaucratic skepticism, with the would-be inventor exhausted and jaded from trying to drag people with steady, predictable jobs kicking and screaming into the land of building and running new and unknown technologies.

When I see the Pres. on TV talking about finding ideas like mine and developing them, I think: "Wow wouldn't that be nice, but a bureaucracy(s) as ponderous as we have today, has no way to "get there from here".

When you guys say you can't pick a winning horse (yet) but plan on winning the race, while admitting being a beginner, hey at least you admit being a beginner, but this is just the same old story of a new entrant pre-announcing their "win", in this case without even picking a horse! Usually the pre-announced winners at least have a favorite, yet lame, horse to ride.

So after spending that $100K, it would be nice if you guys could come up with something, but I am not expecting anything. Sounds bad I know. I guess the ball is in your court. Or more to the point, the ball is in everyone's court who purports to be a player, to prove they have something to contribute. Nobody can go on forever just coughing along on the fumes of a past reputation... can they?

Yup, plenty that can be done below 500 feet. In fact, staying below 500 feet might be the best thing that could happen to keep someone at a scale where things can be done quickly and cheaply, to arrive at a stable configuration that can be run in a set-it-and-forget-it mode.

Just think how much it would help to be able to say: Our system is working great at 500 feet - can we get permission to run at 600 feet?
Take baby steps. Don;t try to run up the whole stairway in one step or you'll fall on your face. We are "buying a stairway to heaven" here, and it's a stairway, not an elevator where you get in and are somehow magically at the top a minute later. This we have to build up a step at a time. Bottom-up rather than top-down development.

I'm waiting to hear what positive results you guys will have from spending that 100 G's.
After many years working toward advanced wind energy systems, my motto has become "The only thing slowing me down is the people who "are going to help"". Not the motto I was looking for. It just happens that way. I've become more aware of what to expect from any person or group, including NASA lately, reading how even during the space program, NASA did not design the hardware, but shopped for the technology from vendors. That's OK, we just have to understand what the roles are. What to expect and what NOT to expect. For exapmle, after spending many years interacting with NREL, getting to know their people, reading their stated goals, I had always assumed they built and tested new wind turbine configurations there, but as it turns out, they really don't even have a department for that. Despite what their website says. They don't actually do that. Why would they try new things? They already KNOW what works. So congratulations, they grandfather in the same old 1000-year-old design once again: single upwind rotor with gearbox, Europes main source if inductrial power for 1000 years.

I'm trying to play the role of inventor coming up with the solutions, building, running, and patenting them, but there doesn't seem to be anyone else filling in the blanks to play the other roles here - in every case the would-be helpers end up telling ME how to do what THEY said THEY were gonna do - another assignment for me is the best they can come up with. SO at that point, what help are they? I've already GOT nonstop assignments all-day, every day. What I need - what this effort needs, is others to participate and get this stuff up and running. At which point I know what the deal is: build it and run it and shut up cuz all the time talking with the would-be helpers is likely wasted time, taking away energy from fighting the actual battle, to instead just talk about it trying to convince newbies of the basics, etc. I've had years of that. It;s amazing I've been able to break away and make any progress whatsoever, and I can easily see why most people make no progress in AWE but remain in the all-talk mode forever - the system itself encourages that.

The main points I wanted to make are:
1) Most mistakes in wind energy have already been made many times. The pattern is predictable and repetitive: avoid repeating past mistakes made on the ground for 3000 years.
2) A gyrocopter rotor is identical to a wind turbine rotor, forming the natural juxtaposition of aviation and wind energy. The gyrocopter rotor flies and extracts energy from the windstream simultaneously. This rotor has been shown to be the best method of extracting power from the wind. So it can be used to construct working systems now. Is it the final answer? Hard to say but it is a reasonable place to start.

I'll be waiting to hear what you guys come up with. If the administration ever really gets serious about this stuff, you know where to find me and I can provide several next steps to have systems up and running quickly.
:)
Thanks
Doug Selsam
Selsam Innovations / USWINDLABS
14045 Mission St. Unit A
Oak Hills, CA 92344
Doug@Selsam.com
http://www.Selsam.com
http://www.USWINDLABS.com

Theo,

Your long history in this field is admirable and the experience you and
others on this list have gathered is never going to be dismissed by me.
However, there have been some recent developments that change the
picture quite dramatically.

Firstly only last month the disaster at Fukushima put the whole energy
industry in turmoil. It has created a window of opportunity that we need
to use as best we can. If we can unite globally and present an
optimistic, but realistic, message of optimism about AWE we might
finally overcome the resistance to funding our game changing technology.

The explosive growth of the internet and open-source contributions makes
a huge difference. Many on this list are resisting computerisation of
AWE, in some cases because the technology is not fully understood. It
needs to be borne in mind that in an open-source project of any
complexity no one person fully understands every element. Everyone
specialises in their own field and they leave the other bits to other
people. To me, the failure to develop a commercial AWE system without
automation is no surprise.

Open-source projects have already given us some important tools like the
OROCOS software Uwe talked about, the Arduino control circuits and so
on.

Sensors are developing rapidly because of micromachining and other
advances. Their cost and size is coming down fast and their speed and
accuracy is increasing. The paper Uwe linked to talks about predictive
control, signal filtering and other techniques that can overcome signal
delay problems. No one is saying it is simple or easy but if we break
the task into separate parts there are people who can develop each
little bit. It is a matter of generating a bit of public excitement
about AWE as an answer to our energy problems to attract the
contributors.

A properly automated flying wing will have no problem getting out of the
sky when the wind drops, the lightning approaches or an aircraft strays
into its patch. A wing with 4 rotors can be controlled well enough to
land in its docking station even in strong gusty winds. I am not
suggesting it will be easy to develop that ability, but many minds
working together can do it.

Robert.

Dave S.:
Yes the "blue tarp" mentality is exactly the type of thinking that I've been trying to explain all along, is where the newbies start in regular wind energy, without the experience to know that 10 years of blue tarps would be inefficient and require replacement 20-40 times in those 10 years.

At some point it is not worth repeating the truth over and over against a hail of newbie "what about a blue tarp?" protestations. We in wind energy have learned that we just have to move on. Unfortunately this has resulted in the bad apples ruining it for the rest of us true innovators, since the entrenched experts have heard about the advantages of "blue tarps" etc., for so many years now, that they are so jaded, that the mere idea of an "improved" wind turbine, whether ground-based or anything else, gets dismissed without examination at this point. It's so bad that even if an expert believes in a new design, he will not say so publicly for fear of being laughed out of the profession. At this point, practically no real expert will try anything new, which is sad indeed.

So the main point of this whole thing was to ask that important question when examining any aspect of your "new" and "improved" system, taking wind energy into the sky.

Those questions are:
1) Has this thing been tried yet at ground level, or on a regular tower?
2) If so, what were the results?
3) Knowing those results, should we try this in the air, or has it already been proven inadvisable?

MOST of the "new" ideas for AWE are long disproven, with no need to muddy the AWE waters with what is already known as complete nonsense.
Most of the "improvements" are long proven to ruin any turbine!

Cloth sails are one example. Shown many times to be unworkable despite many attempts by many many Professor Crackpots, believe me!!!
Is there any mistake more common to newbies than cloth sails? I don't think so! And they always think it;s their original idea! Cloth sails.... Let;s see.... ever tried??? Oh wait - YES!!! 3000 years ago! And they were dropped as turbines improved!
"Spiral airfoils" are another - disproven by DaVinci. Hello, forget being an expert in wind energy - do you have a high school education? Can you read a book? Can you even understand the pictures??? Geez!

But, there's no time to beat them to death one more time and no time to slow down for the people who insist that old ideas are new, or that proven bad ideas are somehow suddenly good ideas. You just can only entertain so much nonsense and get anything done.

Either you are an arrow headed toward a target, or you are splintered into complete ineffectiveness, by a hail of nonsense.

If you don't stand for something, you'll fall for anything. If you aren't up to speed on the state of the art in wind energy, without that basic background in the art, you're unlikely to improve the art. If you don't know what you're doing, you don't know what you're doing. Simple as that. If you refuse to listen to those who do, you'll just repeat the mistakes that others made long ago, many times, and you won't be the first - most of the mistakes people will make are very predictable. We've seen it all before for many years and now it's mostly the same old stuff, just with the word "airborne" added.

OK gotta go.
Stop by on your way back from Texas if you have time & gas!
:)
Doug S.

--- In AirborneWindEnergy@yahoogroups.com, "Doug" <doug@... Nice post. It's great to see some product out there. Regarding the cost, compare 100W *on a tower* to this system. Also, for remote operation analysis, you have to include the cost of the 5-mile extension cord. Or your PV module.

D.

--- In AirborneWindEnergy@yahoogroups.com, "Joe Faust" <joefaust333@... Thanks, Joe. It's nice to find a home regarding my current work. We just purchased an Ozone 4m inflatable, and expect to begin benchmarking next week. Know where I can find a remote anemometer (hot wire or turbine) that does data logging and weighs next to nothing?

David

Anything to get weight and drag off the airborne element would be beneficial. With a wire you have line management, fatigue, wear, and take-up issues. But it is simple enough that it seems worthy of a go.

Regarding conventional turbines and the large weight in the air, we can only surmise that it's cheaper, otherwise it would be done. The simplest approach would be a bevel gear and a couple of shafts to ground. But that is more parts and mechanical loss in the drive train.

David

Toward the search:

http://en.wikipedia.org/wiki/Anemometer

 

On Thu, 2011-04-14 at 21:39 -0700, dave santos wrote:
Ah, but open source can reassure you that there are answers. Firstly I
envisage 2 tethers on 2 reels so that the chances of the platform flying
free are minimized. Also, some of the intelligence can be on board so
that fault conditions can be handled locally. If one tether breaks the
remaining tether is reeled in. If some other fault occurs then both
tethers are reeled in as normal. The propellers are used in a passive
mode to slow and control the descent. When the platform is a second or 2
from the docking station a super capacitor on board powers the
propellers to slow and direct the descent for a safe landing.

If even these safety features fail then the platform will need some
repairs. Existing wind turbines need occasional repair yet remain viable
so I do not think these maintenance costs will be a major barrier.


Without straying too far off topic I think Fukushima is more serious
than Chernobyl. It also comes on top of rising concerns about oil
prices, slowing production and global warming.

I remember the days when you could buy electronic ignition systems to
retrofit in your car to replace the points. The manufacturers did not
trust electronics so they delayed fitting electronic features for a long
time. Now nearly all cars have what would once have been considered a
mini computer fitted as standard. Sure overconfidence must be stopped
but if a new technology allows AWE to progress from the status of an
irrelevant backwater to a mainstream industry then it needs to be
embraced.


Yes, I should have acknowledged these important pioneering efforts but
my focus was on kilowatt and megawatt scale systems.

My feeling is that each person needs to concentrate on what they know
and enjoy. I am an engineer and find legal matters tedious so my
inclination is to let others deal with certification. While it is an
issue I will just use the low altitudes currently available. As I said
before, it is important to make the development mistakes with small
cheap systems before scaling up. Going to high altitude is a scale-up
issue for the future. Once the low altitude systems are working well and
the need to go higher becomes urgent there are several options. The UK
is my 3rd country of residence so if the regulators here refuse to
cooperate I will move. There are island states extremely concerned about
sea level rise and I suspect a number of them would welcome large scale
AWE. As soon as people can see real examples of AWE generating megawatts
with capacity factors turbines can only dream of the rest of the world
will be forced to update their regulations.

Robert.

dave santos schrieb:
Anybody have his present addresses? I knew him quite well at the time but have
lost touch.

Cheers, Theo Schmidt

Dave S

It looks like a good start to me. One concern is the statement,
"develop avionics that ultimately conform to FAA/ICAO standards". These
standards may be unrealistically and unnecessarily severe. We need
special Tethered Aviation Concept of Operations (TACO) regulations. I
think it is reasonable that tethered craft look out for untethered craft
and make sure they get out of the way. Radar systems cost 1k to 10k so
it is not unreasonable for TACO above a certain altitude to have radar
and infra-red search systems. In return things like the severe
airworthiness and maintenance requirements that aircraft need to meet
will be relaxed.

Robert.

Robert Copcutt wrote:
As you say, Robert, we now have FOSS and also highly effective hardware,
even the beginnings of open source hardware. So, this isn't the problem.
The challenge is same it ever was: MECHANICS (in a very broad sense of
the word). Every small project I have ever worked on didn't have
qualified mechanical engineers or machinists even though most of the
work to be done was in this direction. It was more sexy to hire
electronic engineers (like me then) or computer programmers. Who then
spent most of their time fiddling with nuts and bolts. And even if they
were skilled (like I am moderately), unless you have a really well
equipped shop and lots of materials, you spend most of your time
ordering parts or shopping. The physical world makes for a lot more work
than cyberspace! And because people are naturally lazy, they will prefer
to spend hours programming to a fraction of this cutting, filing,
laminating or sewing.

....
Good point. I was thinking of a single or twin counterrotating rotor
job, or twin horizontal savonius rotor (plenty of such toys about, they
have s-shaped rotating wings), but the antics of the quad-rotor jobs is
astounding. You could have a quad for starting, steering, lulls and
landing, attached to a larger twin turbine for generation. Having
hover-power at any time solves the lull problem.

I think one of the first group of customers is going to be yacht-owners.
Either normal sailing yachts who simply want a generator out of the way
of their normal rigging, or solar-electric yachts for then when it is
windy with little sun. Yachts don't need a lot of power and their owners
are required to have lots of money! It would be a cinch to go dead
upwind with an electric boat and an air-borne generator.

Cheers, Theo Schmidt

--- In AirborneWindEnergy@yahoogroups.com, "Joe Faust" <joefaust333@... So many choices. Yes, we use both a hot-wire and a turbine based anemometer here at Accio, both from Omega. If I am going to launch something skyward, I need one that can run data down the tether, or one that records in-situ. Back to Google search.

--- In AirborneWindEnergy@yahoogroups.com, Robert Copcutt <r@... untethered craft
=========== ?

"they" for me was undefined as to the tethered craft or untetherd
craft.

There may develop an aviation environment that is more loaded with
tethered systems than with untethered systems. Aerial cableways.
Free-flight tethered AWECS. Aerial homesteading. Massive tethered kite
energy systems performing a myriad of tasks. Cost of avoidance of
collision for untethered craft might be miniscule compared to the cost
of avoidance performed by tethered systems. Efficient skies and waters
might respect the net costs as rules and decisions are made. There may
be tethered systems that take a year or more to deploy with design
intent never to be absolutely decomissioned, only maintained; such might
transport people and goods around the world by windpower; a single-place
ultralight could know where that tethered system is and avoid collision;
the tethered system would be seen by other aircraft and watercraft
through a variety of systems for redundancy. One does not move the
Empire State Building to get out of the way of any other user of the
airspace.

JoeF

On Fri, 2011-04-15 at 18:06 +0200, Theo Schmidt wrote:
If we put forward a coherent and exciting proposal we will get people
coming forward with all the skills we need. The boom of rapid
prototyping and 3D printing is something else that could help speed our
progress.

Is any of that code available to us to aid our progress? Open source is
about accepting help from anywhere.

I think it is safe to assume that mass in the air will always be more
expensive than mass on the ground. My inclination is therefore to
minimize airborne generation potential to nothing more than what is
required to keep the wing exactly where you want it at all times. The
rest of the generating power can come from the reel/winch. I notice
Makani do not seem to use a reel but I think that is a mistake because a
fixed length tether is limiting. A shock absorber is needed to stop the
wing bumping against its limits. It also limits altitude control. In low
winds you want to go high to catch the faster winds. In high winds you
want to stay low to protect the wing and tethers. Varying the reeling
out speed as wind speed changes also allows optimizing of power
generation. Reels also allow you to keep the tether off the ground/sea.
Since they offer so many advantages I think they are worth the expense.
They are used all the time in cranes, lifts and other places so the
technology know-how is there.

Yes, yacht owners should be valuable early adopters. It was quite a
revelation for me when I first realised that a flying wing could pull
faster than the wind. Once you are doing that you can pull in any
direction, as you say. Saul Griffith (CEO of Makani at the time) gave a
talk in Cambridge 2 years ago and he was dismissive of Skysails. He said
the ships had to slow down to get the full advantage of the tug from the
sail. He did not seem to appreciate that if they used a stiff wing the
Cl/Cd ratio would improve dramatically and that would allow them to tug
the ships at many times the wind speed in any direction. Cl/Cd for a
soft kite is apparently about 4 or 5 so tether tension starts dropping
before you get to wind velocity. A stiff wing can be 10 times better.


I foresee AWE generators having a selection of wings to suit wind speed.
For low winds you need large but light wings with strong tethers. They
will maybe be made using air inflated structural beams tensioning a
light fabric. For strong wind a much smaller wing that flies at much
higher speed is needed. Its surface therefore needs to be much stiffer
so it would be built more like an aircraft. The tethers will be lighter
but maybe longer to allow for the greater reel speed.

Robert.

Joe,

Good point but let's take the first steps first. The job of the aviation
authorities is to protect people and they do it very rigorously because
mishaps are extremely newsworthy and threaten the whole aviation
industry. Newcomers like AWE need to prove they have an important need
and cause no extra danger. Promising to make every effort get out of the
way will smooth the negotiating path. And why not? It is possible.
Tackling the issues of your more ambitious proposals need to come later.

Robert.

Bob,

Storing the low wind wings could be an issue which is why I suggested
using an air beam structure so that they can be collapsed when the winds
get too high for them, even when docked on the ground.

I am not sure it wise to try to keep anything constant because the power
of the wind can change many thousand fold in a few minutes. A wing
designed to generate in 3 m/s winds would break in 12 m/s winds (64
times more powerful) no matter how you try to protect it in flight.
Something designed for 20 m/s would drop out of the sky at 5 m/s. As
with wind turbines we will just have to forget about generating power at
low and high wind speeds, but the range over which we operate could be a
bit wider.

Robert.

Dave S

A combination of ground based radar, infra red cameras and microphones
would detect aircraft before any human, and pinpoint their position and
trajectory more accurately. One observation station could serve for many
AWE systems in a cluster or farm.

I agree GPS will have limited use. However, it is interesting to compare
that technology with what AWE needs to achieve. A GPS unit needs to scan
for suitable satellites and then measure incredibly accurately how long
the signals take to arrive from each. It then needs to do very complex
calculations to work out its position based on that of the satellites.
It then overlays that information onto a detailed map. To think that all
that functionality can be put into a tiny unit that costs a few hours
wages is to me a major reassurance that AWE can be automated.

Kite position can be determined with simpler sensors with faster
responses. For instance the sensors from a humble computer mouse could
determine exactly how far the tethers have been released. Other sensors
would measure the angle of the tether leaving the reel. More would
measure the tension in the tethers. That information together should
locate the kite better than GPS, and more quickly. GPS and video can be
used to confirm the primary measurements and detect faults.

Rather than letting kite elements fall to the ground where they are
likely to be damaged would it not be better to reel them into a
protective docking station.

Robert.

Dave S.:
Smart Kite? Smart Winch?
"Beware developing a "standard" for a dead-end platform"?

Since wind energy uses a rotor that's the same as a gyrocopter rotor, why would you be talking about kites? You warn against developing "dead-end platforms" - Why aren't you talking about gyrocopter rotors?
Do you not know that winches have not proven capable of steady-state reliable, economical electrical power generation? Is there an example of any successful wind energy system that uses a winch to extract the power? Do you truly believe this is likely, considering the wear on a winch, juxtaposed with the requirement for 20 years of low-maintenance operation?

Is not a cloth "kite", or anything made of cloth, already a long-proven dead-end platform with regard to wind energy? Is this not already well-known for about 100 years now? And before that for 1000 years even the cloth sails were just coverings for an airfoil-shaped wood framework. Tethered triangular cloth kites went out of style for wind energy 1000 years ago. Let's build on what's already known, not start from scratch as though we're just beginners. We don't have another 1000 years to repeat the same mistakes, do we? It's time for the next generation of turbines, that has to build on the last generation of turbines, not go back a few generations.
:)
Doug S.

On Fri, 2011-04-15 at 16:55 -0700, dave santos wrote:
Sorry for trying your patience but I am persisting because I think
general agreement on a plan to bring AWE to its full potential would be
very valuable. Please point me to it if I have missed it. What I feel we
need is an outline that newcomers can quickly read that explains clearly
where AWE is and how we plan to progress it. At the moment we seem to
have maybe 40 groups around the world all working in relative isolation.
That is fine to some extent but if there was a central plan it would
help the dispersed groups focus their attention. There is a huge fund of
experience on this list so I am trying to utilise it to firm up plans
for building a system in Cambridge. Your pessimism is understandable
because it is frustrating trying to develop a technology before its
time. I have been there and done that with fuel cells. However, I think
by embracing the power of open source we can overcome what were
previously show stopping problems.

Audio sensors will need the sort of sophisticated software employed by
voice recognition. A combination of clever sound matching algorithms,
libraries of sounds to compare with and so on. Again, a really big job
developing the software but once it is done it can be widely deployed
for little cost. Any video cameras will obviously also need intelligent
control. That is the field my one colleague is in. As you say, radar may
be sufficient at first but these other technologies need to be in the
plan to reassure those who could help but are having second thoughts.


I think as the kites get bigger and faster the chances of needing to
kill them need to decrease rapidly. If docking a wing safely is not
really easy there will be a temptation to leave the thing in the air too
long and cause an accident. Two independent winches as I am proposing
are less likely to both fail together.

I see the potential for AWE being bigger than GPS. Coping with things
like wind turbulence may have been a killer challenge for previous small
teams, but I foresee a new opportunity. Previously this cultural
reclusive thinking kept me from pushing my ideas harder and more
quickly. However, if we all keep our ideas to ourselves and only try to
raise funding for our own little groups we will all end up going in
circles. Therefore I have decided to gratefully grasp this opportunity
to start talking about some of my ideas and see if the experienced hands
can rubbish them. My plan is to make full use of the internet to
publicize the results of our theoretical and practical research.

Robert.