Thanks for the interesting post. Google is sponsoring something similar in the US: Makani Power is a company with kitesurfers doing some of the development work.
Makanipower.com

Glad to hear that KiteGen is alive and well!

Airborne wind power holds great promise and it is easy to get a glimpse of the source of the high EROEI that Ugo has talked about in this post and in previous ones.

I sometimes think of AWE and wind turbines as "hydro power for the atmosphere". Just like the sun's energy powers the hydrologic cycle, dumping rain over a river's basin which then powers a turbine as the water flows downhill, the sun's energy acting over vast areas alters the distribution of atmospheric pressure, creating gradient "slopes" along which huge air masses flow "downhill". The larger the areas affected, the steeper this gradient and the faster the air flow. So really a kite at altitude, where air speeds are higher, is a very efficient means for capturing solar energy that has affected vast areas of land and sea.

Please contact me if I can help in any way. Bravo.

Congratulations to Massimo Ippolito and his collaborators for having (nearly) achieved the impossible. Not only have they conceived a new and (probably) revolutionary way to harness wind energy, but they have also translated this general idea into an actual machine, with all details worked out, up to the last screw.
Obviously, the most crucial test is still to come: producing those MWs of electricity from a flying kite. But let's not forget that to arrive at the point where they are today, they had to overcome huge problems. Amongst which the engineering was probably not the worst: Italian bureaucracy, permits, financing, you name it.
I'd also like to add that not only the concept of AWE is innovative, but also the kind of project financing with the help of WOW, a company that allows anyone to be part of the effort. With the financial crisis around and banks ever more reluctant to finance projects like kitegen, this aspect of the whole project might be not the least important one.

Ralph

No, no no! This is not good at all! Italy is supposed to be the land of the "la dolce far niente"...
If this continues you will turn into an organazied nation of workaholics who will out compete the Germans in the area of renewables. Dio mio!

It will never work >;^)

http://www.infonegocio.com/xeron/bruno/italy.html

Hi, Ugo,

It's good to see this technology finally getting off the ground;I foresee a lot of bugs to be worked out, but the possibilities seem to be dazzling.

As I understand it, one of the very biggest problems with wind is that the good wind is so often a long way from the markets in need of the electricity.

It seems likely that there are many many places with good wind near cities in need of electricity where a kite gen farm could be built since the kites will fly several thousand feet up.

Convincing the public that a kite won't fall on thier house and little buffy is going to be quite a job.Solving this problem might be tougher than working out the technical bugs but there is a lot of sparsely populated suitable land that might simply be bought up or leased in some parts of the US;
I'm not so sure about Europe.

My guess is that if this technology becomes economically attractive most of the poorer densely countries will simply eat the risk and fly the kites over populated areas.

It is obvious that such machines will necessarily have to have a minimum spacing distance from machine to machine in order that they not interfere one with another in the event of storms or programming glitches or mechanical failures.

How many machines can be deployed per square kilometer or square mile according to current projections?

Personally I wouldn't be afraid to live and work on or near a kite gen farm as I realize safety measures will be designed in to get the kites down in a controlled fashion when there are problems.
It will take the public a while to become comfortable with this but nobody seems to be bothered about the possibility of a plane falling on thier house any more.

Most of the people who will get thier undies in a bunch over a kite gen farm will climb in a car and drive on a highway day after day with scarcely a thought given to the possibility that they will get run over by an eighteen wheeler or hit head on by a drunk.

Ugo,
There was some information available about the EROEI of different configurations of the KiteGen generators on this site
http://www.enel.it/rinnova/aree_tematiche/doc/Mario%20Milanese.pdf

but now there is nothing.
Do you have some information about the EROEI for different configurations ?

"In a couple of months, the system should be completely assembled; then it will be time to start flying tests."

It would have been better to wait until there were some actual flying test results before posting in TOD--there are zillions of things which sound good in theory, but don't actually work out in practice.

One thing, this sounds like it would be a threat to aviation if a plane flew into it--thus the aviation authorities might require a very extensive set of warning lights, etc--which could well make it cost prohibitive.

Why was I expecting this ?

Seriously though I'd be interested in the relative cost and maintenance of these versus turbines. What happens if they break loose and land on cars/cows etc ?

I have high hopes for KiteGen and wish Mr. Ippolito the best of luck. I'm not sure what sort of EROEI calcs have been put out there for KiteGen but I'd say 30:1 is reasonable. The most energy intensive parts of the whole design are:

1. The base (concrete and steel)
2. Neodymium magnets
3. Aluminum flywheel thingy

The base looks like it will last a very long time, maybe 50+ years, the neodymium magnets can be reused, and the aluminum can be recovered at only 5% of the energy used to extract it. Thus, KiteGen should have a fairly high residual value (in both energy and nominal terms) at the end of its life.

Actually in Berzano site (for the moment abandoned) no concrete was used to install and block the structure to the grond, even though the top of the hill was not so flat - on the contrary, as you can see in these photo.
http://www.flickr.com/photos/54499063@N04/5051288111/
http://www.flickr.com/photos/54499063@N04/5051288261/
http://www.flickr.com/photos/54499063@N04/5051907894/

While it will be interesting to see the results of this experiment, I doubt that the results will be the sort of large power output claimed by the promoters. For example, their graphic comparison between a horizontal axis machine and the kitegen and the description presented is incorrect. For a horizontal axis machine, the air flow thru the disc defined by the rotor diameter is fully utilized to power the turbine. It's not just the tips which produce the power. The blades have a twist, which when operated at the optimum speed, gives the proper angle of attack to the relative wind at each station along the blade to produce torque on the hub. With the Kitegen, only the area of the kite can produce a force and the swept area has little to do with the total power produced. Then too, the Betz Limit applies and the maximum power output can not reach 100% of that available in a cross sectional area of each kite exposed to the free stream wind.

I think that anyone with a novel idea should have the opportunity to test the concept. However, it's often simpler and less expensive to test an idea with a good model instead of building a full scale working system. Do you (or Kitegen) have a reference to some sort of numerical model of the device?

E. Swanson

Seems like one obvious limiting factor would be the area required for each one. Since the kite flys so high above, the risk of kites colliding and getting tangled means much more space is needed between them than conventional wind turbines. It's not like you'll see a whole hillside with these devices in close proximity to one another. But other than that it sounds like quite an interesting project. I particularly like what the cable is made of, 'high strength polyethylene' - gotta love it provided it has a long life.

Hello from California, where wind turbines have been generating power for the grid since 1981, and interest in wind-generated electricity has always been intense and active on many levels.
While KiteGen is an attractive and novel notion, I see the barriers to overcome are typical of any operation to harvest diffuse, non-fueled power. First, the quality of the electricity harvested (voltage, amperage) will vary, and will need considerable "conditioning", so it is imperative to give an annual KwHrs harvested, delivered in a grid-acceptable "condition", in order to understand the COE (cost of electricity) number, which is the first number that government agencies look at. As was pointed out in the "Dutch" study of small wind devices, power output is typically exaggerated. Second, the conversion directly of wind energy to electricity leads to problems of energy storage and electricity quality. All energy capture (in my opinion) from intermittent sources should be converted to water under pressure, where conventional hydrodynamic machinery can efficiently (and, more cheaply) create the right voltage, load, and instantaneous dispatch. Third, any "rare earth" factor in a system creates a cost factor that increases, rather than decreases, with scale. Fourth, all land-based systems (wind, solar) will invariably run into hostile populations, as the current installed wind turbines demonstrate. The future of non-fueled electricity generation lies offshore, over the horizon, where the operating scale becomes large enough and economical enough to meet COE requirements. Over-the-horizon offshore installations (OTHOI) are the future of this type of energy production, so the sooner the ancillary tools are created (autonomous, at-sea robots, offshore storage of power, transmission to shore of seawater under pressure, onshore conversion of power ("reverse river") the more readily schemes such as Kitegen are adopted.

I always thought we had enough energy. Why do we need more? How much will be enough?

"Indeed, virtually all popular discussion about the future of carbon-neutral energy is predicated upon the assumption of centralized generation by large-scale systems. For example, wind power is symbolized by images of massive farms, huge turbines dotting the coastline or prairie by both sides of the debate... The scale of the farms is not part of the debate. Geothermal, nuclear, hydropower, hydrogen and bioenergy, the main carbon-neutral systems supported by US Department of Energy grants, are all large-scale projects based upon a centralized generation paradigm, either because grants push research in that direction or because of the nature of the source, as in the case of geothermal...

Snip of KiteGen's thoughts along the lines of scale:

And due to the inner modularity of the technology, that foresees the multiplication of single steering units producing energy on a larger circular path, the scalability of the Kite Gen power plants comes without significant structural and cost constraints. In a way, the difficulty in growing the size of a plant can be compared to what it takes, having built an automobile, to build a long line of the same automobiles.

...In this sense, the energy systems touted as saviors of modern society, glorified and worshipped through ad campaigns full of calming, green vistas, have more in common with coal power plants of the past than any energy independence utopia of the future. They continue the tradition of monolithic energy systems, bringing with them the attendant social and political characteristics, the political economy of the energy of the past. Langdon Winner refers to the social and political dimensions associated with a given physical energy technology as an energy regime.

'To provide the variety of goods and services that sustain them, modern societies have created elaborate socio-technical systems that link production, distribution, and consumption in coherent patterns. Within such systems, the activities of work, management, finance, planning, marketing, and the like are coordinated in highly developed institutional arrangements. These institutions, together with the physical technologies they employ, can well be characterized, borrowing a term from political theory, as 'regimes' under which people who use energy are obliged to live. Such regimes of instrumentality have meaning for the way we live not unlike regimes in politics as such. It is possible to examine the full range of structural features contained in a particular socio-technical arrangement and to identify the qualities of its rules, roles, and relationships.' (Winner 1982: 271)
...
The energy regime of the past, and the one large-scale renewables stand to replicate, is characterized by 'extremely large, complex, centralized, and hierarchically managed' systems reliant on, and constantly reinforcing, a social contract that is predicated upon a highly developed technocrat class, the political will to support them and the positioning of 'energy users' as 'energy consumers,' purchasing from an amorphous energy system, 'black boxes - input/output devices whose internal structure is of no particular public concern.' (Winner 1982: 273;272).

Here emerges a crucial point of action for the radical, anti-authoritarian left. The development of new energy systems that mimic the energy regime of the past stand to repeat and strengthen the authoritarian, capitalist social forms of the past, quite literally cementing them in steel and iron, plastic and glass."
~ Rest of article: http://www.anarchist-studies.org/node/309

@Black_Dog
While it will be interesting to see the results of this experiment, I doubt that the results will be the sort of large power output claimed by the promoters. For example, their graphic comparison between a horizontal axis machine and the kitegen and the description presented is incorrect.

Actually that graphic, for the purpose of evaluating the energy output, is misleading. The kite will not span just that eight figure you see in that graphic. It will have instead a combined motion of a japanese fun and yoyo, and will span an area that can be about 500m x 500m. Then the power will be limited by the kite efficiency. I tried to explain this fact in two personal notes (unfortunately in Italian)

http://fuoripista.webs.com/PowerKite.pdf
http://fuoripista.webs.com/KitePowerFactor.pdf

Just a couple of questions.

Is this an attempt to keep industrial civilization going and, if not, what is the aim?

Has an environmental impact assessment been done?

How does the Kite get airborne in the first place?

I'm guessing the twin fans have something to do with it but they won't be able to blow the Kite and cabling to high enough altitude unless there is a steady regular breeze at low altitude at the time of launch.

Yes, there is undoubtedly a good consistent wind at elevated altitude but this will still be dependent upon 'regular' low altitude winds such as power wind turbines.

Nice idea in principle, hope it works but not convinced that it could be better than regular turbines until someone addresses the sticky issue of launch.

The first difficulty I think about would be launch and recovery of the kites. An unsuccessful launch or recovery might damage or destroy the kite and/or the tether, so this must be made into an infrequent event. Of course amateurs flying their own kites nearby could become entangled, perhaps as an act of sabatoge. But, I'm sure you've discussed these issues. Id just like to hear something about the solutions.

Ugo, thanks again for the report on kitegen, one of my favorites. And you are to be congratulated for emphasizing how much robots and computing power can change things. My favorite day dream there is the final realization by airlines that airline crews are far more likely to kill people with some sort of stupid reflex action in a tough situation than a calm, cool, smart robot would.

And I'll bet the robot would be cheaper to feed, and, with the right clothes, look equally cute to the ladies.

Similarly, in my own playground, solar thermal machines, I look forward to a mini power tower surrounded by very smart heliostats that have essentially perfect aim- at any of several towers as the sun moves around the earth.

-----It's amazing how many people (see comments on your kite above) think engineers are really, really stupid. Like, maybe, they think the sun moves around the earth.

Ugo,
This project deserves a high score for innovation!! I do, however, like many others in this thread, have some comments.

The Kitegen is a very innovative technology based on the idea of capturing the abundant energy of high altitude winds. It uses a kite that is launched from a ground based structure that contains all the machinery and control systems. The kite is expected to fly at altitudes up to 2000 meters and to provide energy by pulling on a set of cables that act on a power generator.

In Alfatroll AS (www.alfatroll.com) we make knowledge based systems for unmanned aircaft, all it takes with the autopilot and all - as well as its capability to avoid other traffic and following the ICAO Annex 2, "The rules of the air". The latter we call a "cognitive pilot", since it will react upon incidents that are popping up from "out of the blue", using a patented knowledge based system.

We are also active in http://www.uvs-international.org/, and participate in Unmanned related conferences and regulatory work in Europe (mostly). The European Commission driven effort to create a "Single European Sky" opens up for automatic air traffic control (ATC), but that is at least a decade or two away.

It is clear to me that such a system has a technical side (which you no doubt will solve), but also a regulatory side. The Eurocontrol (and the FAA) will regard these kites as "aircraft", and demand that they follow the rules of the air. If that is to be avoided, they will demand them to be operated in a separate, restricted airspace, open to nobody else. I have doubts that they will allow areas that cover varying altitudes from the ground and up to, say, 2000.

Key: Even any model plane operated professionally need to comply with these regulations in mind, according to the rules being drawn by the Eurocontrol. A kite attached to the ground resembles the balloons used during WWII to block incoming bombers (airspace wise, not the technology), and may pose significant problems for other air traffic, especially at 2000m - where the termals are strong.

Are you adressing this aspect at all? Maybe we, after Peak Oil, will have less traffic in the airspace, but until then I guess this must be addressed.

As for the technical side, after 45 years of flying gliders I am well familiar with the wind systems you are exploiting (even in Italy). Hang (ridge uplift driven) wind is one thing, while solar driven thermals are another. The latter only occur during certain hours during the day, and may vary in bursts and move around. We have discussed for decades how this energy can be captured, and maybe your solution is it. There also is an Australian solution, where they intend to create thermals in a ground based "funnel" - and capture energy there. Will look it up some time if it is of interest.

Maybe I am just adding vinegar in your soup, but dont let the critics stop the experimental effort. As you know, we need all the solutions for renewable energy we can get.

The promise of the kitegen is remarkable; preliminary calculations indicate an EROEI better than anything that can be obtained by traditional wind or solar technologies. However, one thing is paper, another is the reality of putting together a machine that had never been built before.

Making claims about EROEI before an operational system is built, it perhaps foolish.
The idea certainly has merit, but capacity factor is likely to be low.

The fundamentals suggest highly cyclic power, and widely varying loads.

Some real numbers are here:
http://www.kitegen.com/pdf/IEEE200611.pdf

Fig 8 looks good, and shows:

* Appx 23% of the time, negative power is needed, peaking at nearly 3x the average.
  A refined system would probably want to lower that peak.

* Average power is ~50% of the peak - so that will impact EROEI, 
  as 'double capacity' peaks will be the design parameter.

* Rope based energy transfer, is muck more complex than a simple Direct Drive 
  wind turbine

* A number of carefully phased kites, would be needed to smooth peaks, 
  and deliver a practical grid power source.
  ~25% positive time, suggests multiples of 4.

* It looks like some local storage would be mandated to handle the 
  rewind peaks - perhaps a flywheel would be sufficient ?

* even generation-path peaks are significant, and would need a lot 
  of spinning storage for local smoothing. A large number of kites, 
  with sub-second care in the pull phases, could lower demand on this 
  storage, but it would still need to be present for system ramp-up 
  and ramp-down.

Some of the notes suggest 12 kites on a 800m land base, which would need real care to prevent tangling the lines.
Blown kites will be a frequent issue, and it would be an operational cost.

Given good enough forecasting, such a site could work like any yacht (or kite surfer), with sets of sails, for wind speed ranges.
That would add a labour cost, but give a wide wind range tolerance.

All up, I'd call claims of an EROEI better than anything that can be obtained by traditional wind or solar technologies rather superficial and optimistic. - but I would encourage them to build a real system, and clock up the vital operating hours, to see the actual delivered up-times.

Some serious peak:average power issues exist here, along with some spectacular failure modes. They would make a great tourist attraction.

This really reads like something in the back of a magazine, right there with "flying cars" and "run your car on water"

I'm really sort of disappointed in the clowns casting doubt on this device. I think the Kitegen idea is a fantastic idea. It didn't take me long to come up with theoretical solutions to what are turning out to be common questions in this thread:

1. How does the Kite get launched?

My wife said it might be a little helium balloon that gets popped when the kite's high enough - and that's coming from someone who's never written an e-mail in her life - but that's exactly one way to do it - use a weather balloon type device. I'm sure the actual method will be more sophisticated, but why not let it be a weather balloon, except that #2 becomes an issue during launch ...

2. How do the Kites avoid entanglement?

I don't see how it could be difficult. Anyone who's flown a two-handled kite can understand that the kite is absolutely controllable. Left, right, up, down, whirl, twirl, higher, lower, etc. The Kitegen I imagine is a far heavier kite that will not swerve suddenly so much so that a machine controlling the ropes will be unable to adjust. Similar to ABS, the system is able to modulate the brakes far faster and purposefully than a human driver. Rather than thinking in terms of tens of seconds, the computers are making adjustments in thousandths of one second. I can't imagine outside of total computer failure that entanglement will be an issue.

I hope the Kitegen is a tremendous success, and it sounds like it will be.

Bravo!

The construction of a full-size prototype is great news! I wish it every success.

Most of the negative comments above appear to be due to a lack of knowledge about KiteGen. There is quite a lot of detailed information available and it is clear from reading it that the people involved with KiteGen are clever and know what they are doing. KiteGen is a simple concept but one that needs a great deal of human intelligence and applied mathematics to maximise the amount of power produced.

I think the best piece of literature about KiteGen so far is the PhD dissertation by Lorenzo Fagiano. You can find it at http://www.windoperationsworldwide.eu/en/faq/
Part I (chapters 1-7) is essential reading in my opinion.

What is interesting is that the paper suggests that a KG-carousel (with kite-steering units running on a circular railway track) might not produce as much power as a KG-yoyo configuration. This is different from earlier literature.

The paper also states that a wind farm with KG-yoyo units spaced every 250m on a square grid could produce six to ten times the power of conventional wind turbines in the same area.

@Tony Brewer

What is interesting is that the paper suggests that a KG-carousel (with kite-steering units running on a circular railway track) might not produce as much power as a KG-yoyo configuration. This is different from earlier literature.

That is a paper of high technical level, and it is difficult to approach. However, in a personal note, I tried to simplify the terms to compare the carousel and the stem, and it results that the carousel is much more convenient in term of mass per unit power.

http://fuoripista.webs.com/CaroselloYoyo.pdf

Fascinating post, Ugo. I feel now more optimistic about the future of our civilisation than I have for a long time - though that's not saying much.

Two questions:

What is the nameplate power output of the prototype? I have seen the figures 100 kW and 3 MW in the Kitegen publicity, but it's not clear what these refer to.

A more general question about high altitude wind, which has been raised in response to an earlier post of yours, but not, as far as I can tell, been answered: how great a problem is the intermittency of generation? I would imagine it's a lot less than ground based devices, and the prospect of a much wider geographical spread of generators (i.e. in regions unsuitable for "traditional" wind turbines) should mitigate the problem further, but some sort of back-up will still be needed: any idea how much?

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