From the abstract: “Seven 7-foot (2.1 m) diameter rotors produced 4500 watts in winds
of 27 mph (12 m/s), compared to 690 watts for one rotor. Spacing between rotors, and an offset
angle from the wind direction, provide fresh wind to each rotor, for 5 to 6 times the power at all
wind speeds.”
They work well and are efficient, but what about flying at several hundreds meters from the ground? By scaling in all dimensions? By implementing a belt? Within a network?
Videos of superturbine are great. The system seems stable and reliable. That is a really good point.
Problem I see with this design is the complexity of use as it involve many bolt fastening, adjusting and so on. If something like that could be deployed let’s say in 10 minutes, then it begin to be a lot more interesting.
Other point is stackability. How small can you pack that thing? How to transport it easily?
I think those questions are really important for small systems like superturbine, daisy, kiwee…
Thanks for the “They work well”… not yet … nowhere near… Working well is a long way off. I love testing and improving it. But there’s a really long road of game-changing performances ahead.
As for flying several hundred meters from the ground… The OTS shaft length is a fantastic indicator here. A closely repeated pattern on long lines in tension, connected and held apart by small rigid components - Has just been demonstrated at an AWESome scale with only a small lift kite controlled by 1 person. The rotor requires very little lift and that rotor is stackable. So more tension can be added thus more efficient torque transfer. The lines are not on a large diameter so there’s no really high speed drag. The rotor is already far higher than it needs to be, to be safe. (e.g. see how insanely close to the ground mine was. Yes I need to get sewing again.) OK the OTS was wobbly. And I personally don’t like sticks… as a very general rule.
As for making a Daisy ring to ring torque tube bigger. The results I’ve been eeeking out slowly say… For the same overall tension on top, more lines around a ring are more drag, but it’s also less ring compression.
Wider ring diameters may be more drag, but it’s also less ring compression.
All the lines go 1 way, so they can be faired to flow.
Diameters larger than spacings means the whole stack can be back-driven from completely squashed.
Hollow axis means it can be run around and also hoisted up and down a fixed line.
A really wide hollow axis, yes, needs a bigger ground station but starts being like carousel or The CSR (Centrifugally Stiffened Rotor-wing) as proposed by Mark Moore.
This doesn’t have to be a torque system alone… there can be props / blades on the driver wings.
yes they can fit inside lift networks or lited lattices.
Yes you could conceivably use a belt (if you like) (I don’t)
Above the shaft part if you keep the same architecture of lines running up under tension in rings… The Daisy type kite rotors not only fit into the general torque transmission pattern really well, they actively enable more scale because the driving kites expand the rings whilst lifting and pulling the line round.
Not sure yet if the wider rings means less ring compression effect works at long scales… It works on the short simulation lengths I’ve tried, where I have fixed end points.
All these calculations need to be independently verified of course… please
For starters I think I may have stopped some of the form finding too early with a kangaroo threshold value of 0.00000000001 Hoop rotation multi ring K2 loop DAM v2 8 lines wider 5,4lift.gh (3.5 MB)
Better yet …if you’ve got a decent computing rig… double thanks… This is blocking my processor now
A first goal would be producing as much as Sky Serpent ™, using the light kiwee rotors, then flying as height as kiwee. It would perhaps be possible to have a multirotor with the lifter kite, then a long rope-drive or belt relaying the torque, using a Daisy ring to built an adapted right angle gear or pulley without too much weight penalty.
Far more resource than 4 people and 1 weedy laptop is required to justify these implications…
Having said that I think my weedy laptop may have debunked my earlier claim a bit…
Video Description
By trying wider rings it looks like there is less compression on the rings for the same tension dynamic applied at the top as in the previous video. However this probably has a lot to do with how short the rig is and the fact the bottom ring attachment points are fixed in space. With a longer rig and a very long simulation, the results look more convincing.
Could really do with a bigger computer now. Getting very bogged down. Crunching this takes hours.
Pierre, what is the aim to do that? You can’t just do this without thinking to market, customers and so on.
I agree with rod, that would be a huge expense no one could afford.
Olivier,
Your AWES is a great product that can be attractive for some time as a novelty. After this time is it sure that numerous customers will want to expense 600-900 euros for a 100 W product, knowing a 100 W solar panel is about 170 euros or less and its weight is 2 kg?
So you have little time to lowing the sale price. If it is possible, for example with an automatised production, it is OK.
If not, perhaps some solutions can be studied: a larger product for the same price.
If it is not possible studying a condortium with a call to investors in order to produce a mix belt-Daisy or SuperTurbine ™, knowing Daisy and ST are efficient but don’t reach high altitude if the torque transfer system goes from the rotor to the ground, at least before possible significant improvements.
Ahah, your are totally right Pierre. The question might be is there a market for awes knowing that solar as cut done the prices so much, it almost kill any project before birth. We cannot obliterate the fact that this might happen to awes and that is what I try to alert on on my no market hypothesis post.
So yes, price as to be lower to reach large sales but we could also expect to live on niches. Well, Maybe niches are not enough, maybe we will burn our wings fastest than we might thought in our darkest dreams. Anyway, I can feel that all discussion start to focus on benchmarking, market, sales and so on. And that is great, AWES need to become more realistic to convince
Yes we need realistic systems to convince …
but we need big dreams to make AWES a strongly convincing reality.
So all the best bits of systems leaves us with …
a wide network of lifter kites on top of a layer of addressable service lines (maybe a lattice layer)
hoist lines arrayed below for harvest density (possibly x lattice linked at regular heights with deployment)
rotary fly gen sets hoist-able on an expandable circumfrence ring turbine leading edges CSR/Daisy/Makani/kiteKRAFT… for optimal efficiency
Single fixed power and tension line to ground for each lift node to ground node length (reduces drag) with possibility of multiple generators at multiple altitudes hoisted up … single lines x linked at layer heights as suggested between turbine heights
This is not however a torque transfer system as suggested by this thread.
It could use a small torque ring set for back driving
I think kitewinder stands on its own as a valid product.
Nobody is trying to claim kitewinder is cheaper than coal - er um I mean solar.
There is no small wind product that delivers cheap power. Never has been. Not yet. Power, yes, and plenty of it. This place comes close to maxing out the capacity of our breakers and grid-tie on a windy day. But it only serves me well since the previous owner and government paid for it. Otherwise you could pay your electric bill in perpetuity on the interest from the amount the wind energy system here cost, including concrete, tower, installation, long cable runs, inverter, etc., and still have the money left when you’re done. I could replace the turbine here with solar panels for the cost of a single major service (that requires a crane and crew) if it is ever required. There is usually no cheaper power than from the electric company. That’s what they do. Usually, you can’t beat their economy of scale.
Kitewinder serves well as an entertaining easy-to-operate working demo of an interesting concept, and may have actual use for providing small amounts of electricity in certain situations. Just the fact of a working AWE product available is ahead of 99% of the pack.
Everything starts with a dream, but endless dreaming about the mere concept of such arrays, envisioning hundreds, thousands, or even millions of elements, gets silly after a while, when the first task, if anyone were serious, would be to make a single element work. Then try getting two to work together, then combine just a few, etc.
The common crackpot mental disconnect is to use the difficulty of building millions of something as an unspoken excuse to never build a single working module, which would be the logical starting place, but like the con-man with his shell-game, or like a magician redirecting the audience’s attention to where the action is not, the con-man goes on talking about unlimited numbers of power modules, all the while congratulating himself as a great genius, hoping that the talk of millions of units will distract people from noticing he cannot create even a single such unit, let alone even just a few working together, no matter how much time he is given. Talk is cheap. The statistical chances of any supposed improved wind energy system proving superior to the state-of-the-art is abysmally low. far less than a fraction of one percent. You can safely take almost every one of them and throw it in the trash without losing anything but the tie and money already wasted on it. Wind energy is not a charity event where you get a medal just for showing up. It’s the Indy 500, and the average wheelbarrow is not even going to make it into the parking lot. You might get a medal for just smiling for the camera, but that’s the end of it, unless the typical crackpot can get that wheelbarrow to actually qualify. Then again it is a charity event to some extent, given the current climate, so investors are sometimes willing to be kidded along for a while, especially using OPM (other peoples’ money), and governments provide incentives whereby your slightly-more-expensive power can still be sold in many cases, but all such incentives are limited in both amount and duration. In general, you still have to be competitive to compete. Endless mere dreaming and posturing will most likely get you a place in the wind energy crackpot hall of fame.
I’m not one for endless dreaming, but I do like to remember the best bits when I wake up and get to it.
That was a short list of proven and simple bits to assemble… yes into a big scalable (by array) whole.
Talk is cheap. yes.
Time … time … to move on.
That’s why I started a simulation and went to the sewing machine after writing that… which by the way was a new concept description…
Keep progressing, is the message we’re all encouraging.
Solar looks to be cheaper than wind for homeowners. But it is the reverse as they scale.
Perhaps AWES could be still cheaper at very high scales. But the concern is making working small AWES then growing.
Without knowing anything about that product in particular, wind energy products from sources like that are notoriously poor quality, often not usable at all, often with fatal flaws right out of the box. If the do work at first, their ineffective or nonexistent overspeed protection will often result in destruction during the first very strong wind. Stores don’t carry them because they don’t like returns. Even if the product were perfect, the average customer will not understand how to use it or install it, and probably screw something up and require a lot of handholding which the store is not capable of providing because they don’t know anything either. Or they will destroy the packaging while opening the box, get everything out and after some time realize it is more complicated than they thought and find themselves returning a product that can then not be resold as new. A retailing nightmare. Most people do not understand wind energy. Most people do not live in a sufficient wind resource to use wind power at all, since population centers are usually located in comfortable areas. Most people do not have a large enough yard to make wind power an option. Most residential locations have too many obstructions such as buildings and trees. Towers require a fall zone equal to the tower height near property borders, often not available. Max height of any structure is usually restricted to 35 feet in populated areas, which is not high enough to get above turbulence and blockage from houses and trees. For the verge consumer, wind energy is simply not an option and unless a flying wind energy device could be flown from such impossible locations and guaranteed never to crash, airborne will not help solve that problem for “small” wind. Even solar is a challenge for small lots with buildings and trees blocking the sun. A partial shadow can render an entire panel ineffective. So solar for residential is not even better in many cases
Hi Doug, please can you provide some mean to reach hundreds meters altitude, using torque transfer (SuperTurbine ™, OTS, Daisy)? By scaling all dimensions or only the height? Thanks.
