Kitemill aquires KPS assets

Kitemill has acquired the intellectual property assets of Scottish KPS (Kite Power Systems)


And yep,
I was about to post


What KPS AWE technology is seen as valuable by KiteMill? “No secret sauce in AWE” seems to apply.

kPower would have gone for their kite quiver and groundgens, to re-rig in fig5 variants. Maybe W&I can take them for free as “storage”, to found a Lewis R&D farm.

@George Do you have any comments?

I think the KPS brand still has a lot of recognition.
Wondering how best to utilize / monetize this.

There’s this video with 1.3 M Views for example:

HI Luke, I am happy to hear this and as much as anything I am relieved that the KPS work has been preserved as there was talk at one point that everything would be deleted which would have been a terrible shame for AWES research efforts and the former staff of KPS. I really hope that Kitemill can find some useful ideas and tools within the KPS assets which can benefit their project directly. Before KPS was shut down we were working on the new minimum viable product, which was on a high level very similar to the Kitemill concept; this will hopefully allow some of the KPS assets to provide insights which can complement the Kitemill efforts. Maybe some of the KPS IP will eventually be part of a viable product but most importantly it was not lost, this I think would be important for any AWE company in a similar position and AWES research in general.


Unfortunately most of the KPS media, funding and recognition resulted from the soft kite period; a concept which was abandoned due to its lack of practicality, we got to a point when we had a 70 sq m soft kite to test but it was clear that it was going so difficult to operate and a serious safety risk to its operators. I think a lot of what KPS has done in the last 2 years has gone below the radar as the adjustment were made to try and focus on the new VTOL ridged wing concept with studies to support scalability and how to achieve a viable LCOE. It is real shame that we didn’t move away from the soft kite earlier and the more recent work could not have been taken through to demonstration.


KPS was wise to fear for operator safety, as their soft power kites grew larger. These are true monsters in strong wind.

What is the final disposition of KPS’s quiver of power kites? Of the 70m2 parafoil? kPower would be interested in bidding. Its a good wing to haul Inuit WindSleds closer to windward than the NPWs they currently have.

Unfortunately all the kites have already been sold in the initial assets sale around 30 of them, most of the KPS equipment was taken by a single buyer who is going to sell off or scrap everything. Most of the kites are garbage and are likely just being dumped, as for the 70m sq kite it is pristine.



Naturally AWE ventures in soft power kite R&D are interested in relevant KPS experience.

Our primary background is kite pro sport kite success, which has scaled directly to ship kites. Kite Pros customarily keep kites going for years in good condition, constantly switching out kites from a quiver to maximise power or avoid over-stressing, occasionally repairing tears, never packing away a wet kite, and so on.

Its presumed KPS kites became “garbage” due to the demands of automation, where human pilot skill and judgement and standard manual kite care cannot be provided. This “garbage” to us would offer valuable data on failure modes we may not have experience of (kPower has yet to wear out any kite in its large quiver, since 2007).

Any public insight into KPS’s specific engineering challenges with soft kites (and excessive tether wear) is very appreciated. A 70m2 parafoil is fairly unique, and should be flown in further AWE research. Was it a North Sails NZ parafoil, in the lineage of SkySails’ wings? Can it be acquired for testing?

Why do soft kite get damaged sometimes? good question, I guess if KPower has never worn out a kite in a cross wind, yo-yo, electrical energy generating system they should get more hours on the clock and more energy in the experiment. Reasons: Material fatigue, particle contamination, crash damage…

The 70 m sq is a custom KPS design and was fabricated in Sri Lanka, its very impressive. It might be possible to acquire it from the company that brought the KPS physical assets, I don’t know their details.


I well believe KPS wore out kites, as well as lines, flying in strong conditions under same-kite/all-conditions design assumption.

To make a kite last indefinitely requires a large quiver and frequent “sail changes”. Kiters and sailors who baby their sails get far longer service life. They cannot afford to destroy kites, so KPS data would be a great to share.

kPower has flown thousands of hours of babying its kites, of every kind. Yes, they fade and stain and require maintenance, even the washing and resizing practiced in the show-kite world.

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Thanks for this helpful information. A couple of questions please: is the lifetime of a tether comparable to that of soft kites by taking account of the wear in yo-yo use? And do you think if the lifetime of energy soft kites could be greatly improved by making them in much thicker and stronger fabrics?

We certainly got through more kites than tethers, but we were not prioritizing kite life in the experiments and the design. I think there is potential for manufacturing techniques on the horizon that could make a soft kite last longer involving advanced 3D bradding machine which can produce stronger seams and bridle attachment points, effectively making a kite that is not stitched and glued together sections of fabric but a more continuous structure; this hasn’t been tested to my knowledge.


I believe some high end sails are made this way, I remember dimly from a Kitesurfing documentary I saw a few years ago.

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XF film is used for tarps, and could not be a material for power kites due to the lack of dimensional stability. But this film is made in a continuous structure, unlike laminated fabrics whose layers tend to separate too early for an AWE use.

The ‘Lightweight Spar’ IP which Kitemill just purchased employs some of this technology although it is only partially soft kite type technology.

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The movie is called “Chapter One” and may be seen at

The quote “Makani’s wing will soon start producing green energy around the world” - I guess didn’t hit the future directly spot on in 2016…

Theres a Makani section at 51:24.

Alas, my memory serves me wrong. The weaved 3D sail was seen somewhere else. I believe I was looking at something like this:

I could recommend the movie otherwise

Reeling tether life factors and Soft Kite life factors differ. A KPS video disclosed a reeling line that had jumped the fairlead wheel, and was chafing on the sheave under load*. That was not a kite wearing factor.

On the other hand if flight automation failure caused the parafoils to often crash at full speed (“thump”), that is a kite life factor unrelated to tether wear.

Comparing special cases like this does not well predict whether tethers or kites are comparable in life-duty. The advantage will go either way according to specific design and conditions.

George, Who ended up with the Groundgen Winches? An interesting experiment with a double winch would be crosswind power kite arch stretched between anchor pulleys. The double winch could step tow the arch up into better wind from a stretched out surface alignment, paying out line as it climbs.

Once up, the alternating pumping mode would keep the kites working with very little phase loss. Are these a single motor-gen with double over-running clutching, or double motor gens? It hardly matters in early R&D but its a major production design choice, with the double clutching seemingly favored (to me).

(*) See KPS Video Linked at 4:30:

You should be careful using the term ‘reeling life factor’ or CBOS life factor to loosely as it has a very specific meaning in rope science which is the FOS x d:D ratio and is used as an input to fatigue calculations. I agree it has nothing to do with kite life, and I am unfamiliar with ‘kite life factors’, are there any mathematical definitions? or are these a more high level high descriptive term for failure modes?
By the way the video of the tether jumping off its sheave which you have posted several times, it is obviously a malfunction and very frustrating that the camera operator we hired decided that this was a good thing to have in a published video. But it was not a product just a test bed for kites and automation systems and not a test of tether protection technology (a winch which effectively protects a tether for a practical commercial service life would have to be different in many ways).
As for the winches the large winch, 500KW, is with the scrap merchants. The double winch mounted on the lorry I don’t know; it was in Germany for a while and it might have been sold to Kitemill. The device is not the same as in the old videos as one side has been replaced with a smaller winch now to allow testing at different scales. The transmissions of these two winches are independent there is one 100kg 15 m/s winch and a second 800 kg 8 m/s winch. The winch would be very useful to someone just getting started, so I hope it sees some new action if it hasn’t been scrapped in Germany already.

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