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Hi all, Some more news.
We have already 60 complete mechanical kiwee set ready of kiwee one . Made some small improvements again on the way like loosing one bearing in each mad pulley ( direct french translation 
)
Still struggling with electronics. Our electronician is under the wave ( again direct translation, I like that sorry ) and still did not manage to deliver V2 version of kiwee. To accelerate dev, I debug the card by myself last month. Issues with buck DC/DC tuning, power mosfet that has been enhanced and many more that I already forget. Card will be rerouted and then itâs ready to go.
Software has improve a lot to makes kiwee as foul proof as possible. Some examples : output power are checked before being switched on . Hot generator plug / unplugged is ok too. We have a test routine to check that setup is ok before reeling out. Otherwise you will just end up with an enormous knot. Well that is hundreds of small details.
Dominique ( my associate ) went to Niger with 3 âafrican kiweeâ last week to pump water from well. He came back yesterday, donât know yet how it goes . He was with a french embassador and a dozen armed guys for protection knowing the political context in Niger at the moment. âAfrican Kiweeâ is a light version of kiwee with no electronic control, only a DC/DC converter.
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Thanks, dave. I Had some news by email from dominique today. He told me he did mean power output around 80W throughout the trip. Unfortunately it seems kiwee worked really well but the pump we bring failed⊠Damn it. Hardware is hard
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Kitewinder Kiwee featured in âFaut pas rĂȘverâ Faut pas rĂȘver - Les aventuriers du vent en streaming - Replay France 3 | France tv at 1h34â
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Congrats on a PR boost on French TV! Unfortunately it is not available to see from my location.
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On the video above, at 2:43, it is stated that 120 Kiwee ââunits were distributed worldwide. This video was made approximately three years ago, when Kitewinder was transitioning to another product. Therefore, itâs reasonable to assume that this represents the total number of Kiwee ââunits sold.
And I am not aware of a single peer-reviewed scientific publication (or even any) devoted to this rope-drive AWE technology, including measurements, simulations, scalability, except sometimes a mention of its existence.
Conversely:
I have one. But I tested it only once⊠The lines are quite long and It was not easy to find a place. The kite sold with it was quite unstable (more than an equivalent lifter I had).
The wind was a bit weak, so I donât even know or remember if I produced energy.
Using it without the manual was quite difficult, and I was losing sheets of the paper manual in the wind. Maybe someone has a copy somewhere ?
I later damaged one of the propeller as it was stored in my garage (it is kind of empty/foamy, not strong as foils I am more familiar with).
A few month ago, I was asked to get rid of the battery for safety reasons (I have removed it but not brought it to disposal yet). No alternative was proposed at this stage.
However, I wore the T-shirt quite a lot !
If somebody wants to make some tests, let me know !
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Perhaps this can help?
I just tried to log in to the site above about a KiweeOne manual. I have a problem with this site: I donât recommend logging in. So I join an old PDF of the same Kiwee manual.
Notice-Utilisation-KiweeOne-V2-Français.pdf (3.2 MB)
Also, if the battery is unusable, would it be possible to run the device directly with the generator (without the battery) at least to see if anything works, although thatâs not recommended and maybe not possible?
Concerning the blades, they might not be the same on all Kiwees: it would be interesting to know.
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The best reference that I found is an article by ALEXANDER BOLONKIN in 2002, where he states that the energy transfer from a high-speed cable drive is more efficient than the energy transfer from an electric cable in the units of energy per kilogram weight. He discusses various cable materials and suggest cable speeds of 300 m/s. Below is an excerpt from Bolonkinâs article for a 20 MW system.
âOne of the main innovations of the given invention is the cable transfer (transmission) of energy from the wind rotor located at high altitude to the electric generator located on ground. In proposed Installation it is used a new cable transmission made from artificial fibers. This transmission has less a weigh in thousands times then copper electric wires of equal power. The wire having diameter more 5 mm passes 1-2 ampere/sq.mm. If the electric generator produces 20 MW with voltage 1000 Volts, the wire cross-section area must be 20,000 mm2, (wire diameter is160 mm). The cross-section area of the cable transmission of equal power is only 37 mm2 (cable diameter 6.8 mm for cable speed 300 m/s and admissible stress 200 kg/mm2, see Project 1). The specific weight of copper is 8930 kg/m3, the specific weight of artificial fibers is 1800 kg/m3. If the cable length for6
altitude 10 km is 25 km the double copper wire weighs 8930 tons (!!), the fiber transmission cable weighs only 3.33 tons. It means the offered cable transferor energy of equal length is easier in 2682 times, then copper wire. The copper wires is very expensive, the artificial fiber is cheap.â
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Thanks for this quote (excerpt page 5 on the second link). The references for this publication are below.
Utilization of Wind Energy at High Altitude | International Energy Conversion Engineering Conference (IECEC)
PDF available on:
(PDF) Utilization of Wind Energy at High Altitude
This study covers several implementation methods, including the one shown in figure 1, which would be closer to Kiwee.
Kiwee introduced new elements (right-angle idler pulley) that made the device work. None of these elements have been fully studied, and we still donât know what the real scalability limits are.
The simplest thing would be to build a bigger Kiwee, then an even bigger one, and see.