But we’re not trying to solve plastic recycling here. I think more concrete questions, that will yield more concrete answers, are: you’re using a lot of this UHMWPE rope, how can you use less of it (see Kitewinder’s and Ampyx’s testing for example), are there alternatives, and what can you do with it when it becomes unusable?
All this indicates that the flexible synthetic fabric wings, after short-term use, above all in crosswind operation, will go to the incinerator, as for UHMWPE rope but after a longer use.
It is therefore a burning problem (if I may say so) for the ecological aspect of the whole, and which must be considered.
Keep in mind that an AWES is not kitesurfing, as it involves a continuous use.
So a rigid wing, preferentially in recyclable material like aluminum, can be a solution for this issue.
Of course, all this only matters if one persists in aiming for commercialization.
This analysis of yours is too perfunctory to be of any use.
That is all your problem. Almost all the experts are on ResearchGate, which does not mean that all members of ResearchGate are necessarily experts.
On the other hand, we can be sure that those who are refused by ResearchGate are not and never will be experts, especially those who don’t care about their advice.
Did you consider SciHub? I am not really against pirating papers. Getting access to papers is like CD records in the nineties, SciHub is the Napster of academic publications
Me? Yes, I use SciHub, and LibGen, and… I’m very happy for their existence. I wouldn’t be able to do what I’m doing without them.
I think the lesson here is real concerns for a clean planet are often outweighed by the clean & green fluff-hype, designed to overcome logic in well-meaning people through emotional appeal disguised as facts. It does indeed pay be somewhat skeptical of such claims and to do a little independent research, ask what may sometimes be uncomfortable questions, and possibly pull back the cover on feel-good fantasy, to get a glimpse of reality. It has often been observed that when “all” of the “experts” “agree” on some topic, that in itself can often be a negative indicator, preceding an unexpected paradigm shift.
This is like theater of the absurd. Cart ahead of the horse. As I’ve often said, AWE is like the proverbial 3 blind men trying to describe an elephant - except for one pesky detail - in this case there is no elephant (viable AWE system). Well over a decade of this endless busy-body activity “what if this?” and “what if that?”. The biggest psychological factor I see is people with too much time on their hands suffering from global warming derangement syndrome. Step one would be powering a single home, not these endless promises to power hundreds or thousands of homes “next year”. To me, it is a great comedy. Oh well you’ve gotta get SOMETHING out of it - at least we can maybe appreciate the humor.
The other consistently frustrating thing about most every article TRYING to discuss AWE is the “authors” know even less about AWE than the supposed practitioners. Half the articles I read still mention long-abandoned projects like Altaeros and Makani as though they are still in play! It’s all just one big echo chamber of ignorance! Less than worthless.
This reminjds me of when, as a lad, I asked my mom why they called it “drag racing”. Her reply: “Maybe because they have to drag their feet to stop?” I believe the real answer is they were racing on “the local drag” meaning a strip of street people “drag” up and down “trolling” for some fun on a Saturday night. I think the last person to use foot-dragging to stop was Fred Flintstone.
As I have pointed out more than once, the terms “lift mode” and “drag mode” have been in use for decades (or more) in wind energy. Kite-reeling would normally fall under the Savonius concept, except for using lift to artificially increase the area from which to extract “drag”. The tether is “dragged” from the drum. How do you know? Because it is dragged out at less than the speed of the wind itself (?)
The notion that newbies to wind energy decided in their innocent naivety to name the Makani concept using two levels of “lift” to generate electricity as a “drag machine” (because it “drags” its propellers through the air) is, I would say, about as astute and accurate as my young mom’s musings about “drag racing” being so-called because the driver drags his (or her) feet to stop - just not accurate.
Really, to my way of thinking, and I’m not saying it is correct, just my impression, all these “scientific” “papers” are meaningless until someone can demonstrate an economical energy solution. Right now in my neighborhood, people are swapping out rebuilt Bergey turbines for failed machines. Bergey turbines have enjoyed the reputation as “the best” or “most reliable” turbine in “small-wind” as long as I can remember. (Yet I can show you many pictures of missing blades, destroyed turbines, etc.)
They have been the choice for “scientists” for any project such as one that proved hydrogen as energy storage returns something like 3% of the energy put in, you know, learning about reality. One fatal flaw of the Bergey line has always been the furling cable breaks within the first few years of operation, so you can’t furl it in case you need to shut it down, or in preparation for an oncoming severe storm. Seems to happen to every single one of them. In all the years of NREL, Bergey, and a lot of installers helping to refine the Bergey design, no “engineer” or “scientist” had ever solved the furling cable failure issue. It was only recently that someone noticed the problem was the turbine trying to “push” the flexible cable into its “jacket” or conduit. As the old saying goes, “You can’t push a rope”. The cable would fold instead of going into its jacket every time the turbine furled on its own, and the constant bending of the steel strands would reliably cause the cable to fail, even if nobody ever used it. Well after 40 years of this scrutiny by the world’s leading “scientists”, the manufacturer, and everyone else, someone finally figured out you could add a spring or a weight, to keep tension on the cable from the ground, supposedly solving the problem. Looking back, this seems so obvious in retrospect, yet for years even the manufacturer’s tech support would tell you “Ahh, don’t worry about the furling cable - you don’t need it - they always break anyway - we just added it because at one point some municipality wouldn’t allow an installation unless it had a way to shut down the turbine” - that sort of thing.
So in all those years of scrutiny of the Bergey machines, nobody had stumbled across something that basic. And Bergey is about the only survivor in the small-wind “industry” since solar got so cheap. That is the reality of wind energy at least at a small scale, and I doubt if any scientific paper was involved in finding or even recognizing such a simple solution to what should have been an easily-identified cause of cable failure. There is an old saying in wind energy about the modern wind energy industry having been kick-started by a proverbial “farmer with a welder”. Seems to still be in play. In my experience, the role of “science” in wind energy seems to be more about analyzing and fine-tuning things made to work by practitioners in the field, rather than contributing actual solutions in terms of basic configurations. If AWE is still at the point of trying to figure out the difference between lift mode and drag mode, I don’t even know what to say.
Roddy I would not worry about what anyone “says”. Talk is cheap. If something works, it works. If not, then not. No idle bystander’s opinion will change that, no matter what their supposed credentials… Don’t let it worry you. It is not a true factor, and does not matter in the least.
This is true, but AWES were studied as aerial devices before being considered wind turbines. What do the means envisaged for kite-reeling and those implemented for the wind turbine have in common?
A kite-reeling system and a Savonius turbine have this in common:
A swept area that is “dragged” downwind. then must return upwind, using power to return upwind.
The downwind travel during the power stroke tends to reduce the power output by reducing the relative windspeed.
But the Savonius turbine has the advantage of steady, continuous output rather than intermittent, pulsating output.
When you see any new wind energy scheme, notice the tendency to think “this time it’s different!” The proponents of any new scheme tend to believe that none of the lessons learned in the last couple thousand years of wind energy apply to them.
For instance they tend to think that showing people a photo of 50 people, all drawing a hefty salary, should convince the public that they have a serious effort. And the general public may indeed be convinced by the group-selfie, but people who know wind energy know that there is only a single surviving manufacturer in “small wind”, and that survivor only survived by heavy government subsidies, heavy government regulation now at all levels that effectively outlaw all the competing companies, and a very lean workforce of just a very few people. Rather than trying to see how MANY mouths they can feed, they would be hard-pressed to hire even a single extra person, maintaining a skeleton crew, with no extra money to hire a single “extra” person. An average household uses maybe 1000 dollars of electricity per year, or maybe 2000 for heavy users of electricity. Any system that costs more than that could only be rationalized by artificial financial support, and would therefore not constitute an actual energy solution. There is no room for 50 people whose combined “talents” produce nothing useful for any purpose. No small wind company who expects to survive would be issuing press-releases about “renting office space”. Such a situation of needing to support that many “office workers” would in itself spell doom for any such startup company. Any small company that expects to grow needs to have a natural built-in potential profitability or at least a clear path to profitability. If they can’t power a single home with AWE, why would anyone believe they are about to power hundreds, thousands, or millions of homes? Well as I’ve observed over the years, the reason they would believe it is because their main source of information is the hype issued by the companies, presenting (so far anyway) a one-sided, unrealistic story. The “Dr. Pater Harrops” of the world (and it goes downhill from there), simply have no experience in wind energy to understand the repetitive and typical nature of the claims they are seeing, let alone recognizing claims even more absurd than any previous example. But, just as a thousand wannabes chasing the Savonius concept based on the attractiveness of its simplicity do not ruin the case for legitimate wind energy technology, the many failures of wannabe AWE practitioners in no way negates the viability of AWE as a concept.
OK now realizing that nuclear fusion is just a fancy way of boiling water, there are several fusion energy companies emerging, funded by the usual billionaires. One is called “Helion”. If fusion gets traction, AWE and many other clean energy efforts might be doomed. But don’t worry too much about Helion. How can we tell? They have a group selfie! You’ve seen the rest of that movie!
OK this is in “News Coverage” because even though it is positioned as “news”, actual news is about things that really happen:
Note how this “story” checks all the boxes: “fight climate change” “hydrogen”,“zero emissions” “a quarter the cost”, “increased payload” - well if it were powered by AWE, it might be zero emissions. Anyway, maybe they should add “3-D printing”, “provides broadband”, ya know…
Now, I’ve always been a huge fan of huge blimps - or just blimps and airships in general, and this article sounds very exciting!
Except for one thing: I’ve been reading similar articles for over 50 years, and never seen one come true. There is an announcement like this every 3 or 4 years it seems. They’ve all sounded “very exciting” with no apparent reason why they won’t actually happen, but they never do. In our somewhat similar field, we are used to this. It’s always the same thing: big press-release, followed by… NOTHING.
I’d like to think this one will be different, but the pattern is 100%, and undeniable…
Oh well, it’s fun to dream. I hope this one comes true. (But I won’t hold my breath!)
Update: I checked out their website:
They do in fact check more trendy boxes:
- Providing wi-fi to Africa and underdeveloped regions
- delivering hydrogen fuel as cargo
- disaster relief - how could I have left out “disaster relief”?!?!
Seems like every press-release breakthrough has such obligatory “attributes”.
“Just in case” it is not useful for its intended purpose, they have a “plan B” (providing wi-fi - think “Altaeros” - after all that AWE hype, they now have one blimp, powered by an extension cord from the ground (diesel?), and purport to be the answer for bringing wi-fi to undeveloped regions…)
And “just in case” Plan B doesn’t work out, they can deliver hydrogen as cargo…
And “just in case” that falls flat on its face, they will be available for “disaster relief”! Did they miss anything? What about a group selfie? I haven’t checked.
Perhaps an AWE possibility with a design something like LTA Windpower? On the website the announced air speed is 280 km/h (78 m/s) , so likely leading to a high glide ratio, hence perhaps the possibility of a high angle of elevation, and a constant positioning in altitude to avoid takeoffs and landings, except in the event of a big storm.
That said the fastest speed for an airship is only 115 km/h (32 m/s), so far below 280 km/h.
Basically airship could be the simplest solution, above all if the risk of hydrogen use is strongly mitigated: a lighter than air with also aerodynamic lift (wings) carrying one or more conventional wind turbine(s) …
A “designer” solves wind energy… again…
Article includes a quote from Mike Barnard.
Know-nothings, “improving” an art about which they have not the slightest clue.
Some things never change.
Another M. Barnard’s article: Dodgy wind? Why “innovative” turbines are often anything but
The designer led to Robert Murray smith designing a whole bunch of experimental designs. The original didn’t work but his bodging effort are plain to see. Plenty of room for design exploration. He even made a wind wall with pc fans which I find to be awesome. There an obvious threshold to meet but with a little effort anything’s possible. Much like baking cakes or a good roast.
HYPE CYCLES & tech: Saw this opinion on hype cycles:
while reading this article by a helicopter developer about EVTOL “flying car” type vehicles.
The example they use is the Joby flying car effort. Joby was an early AWE player, but quickly gave up on that idea.
(No axe to grind here, just thought the articles were relevant and interesting for AWE.)