[HN Gopher] Kite Turbines
___________________________________________________________________
Kite Turbines
Author : Kaibeezy
Score : 240 points
Date : 2021-11-09 07:57 UTC (1 days ago)
(HTM) web link (windswept-and-interesting.co.uk)
(TXT) w3m dump (windswept-and-interesting.co.uk)
| Kaibeezy wrote:
| Morphologically interesting here is these are HAWT at the top and
| VAWT at the bottom.
|
| A kite isn't the only way to do this, could alt be; some kind of
| semirigid textile mushroom; suspended between buildings or across
| a chasm; integrated into a built structure; an inflatable; an
| aerostat; and so forth.
| tonylemesmer wrote:
| What happens when the wind drops?
| wmertens wrote:
| Then the kites have to be rolled back home until the wind is
| good again.
| ncmncm wrote:
| Fly them over failed nuke plant reservations. Those have no-fly
| zones marked on all the maps, so you can go up where the wind is
| really blowing without creating a navigation hazard.
| riffraff wrote:
| no need for no-fly zones
|
| > Kite turbines can fly under 30m above ground - making them
| the only CAA ANO CAP393 compliant airborne wind energy system.
| UncleOxidant wrote:
| Sure, but the higher up you can go the more wind there
| generally is. It's one of the big potential advantages of
| kite windpower over fixed blade systems.
| vanderZwan wrote:
| That is pretty great! But GP is right in the sense that to
| really extract a lot of energy you want to go higher into the
| air too, so why not make use of those no-fly zones for
| scaling this up?
| sirt_2513 wrote:
| you can also make kites for under water usage, make use of the
| tide movements which never stops.
| wmertens wrote:
| It's back-and-forth though so you are constantly changing
| direction and losing power.
| Grustaf wrote:
| The wind also changes direction sometimes, that's not
| necessarily an issue. Several companies are doing this, like:
| https://minesto.com/
| kitd wrote:
| _constantly_
|
| Well, once every 6-ish hours. But even then, you put the
| turbine on an axle to turn it into the flow. Windmills have
| been doing this for centuries.
| wmertens wrote:
| ah yes, I was thinking of wave energy sorry.
|
| Actually, yes, that would indeed be a good use of the
| concept - anchor the generator to a submerged bouey (so as
| to not disturb shipping) and it will always be pointing in
| the right direction and generating. Nice!
| gorgoiler wrote:
| My brother has one of those Cannondales with a single sided front
| fork. He's also got a dynamo hub in his front wheel.
|
| With some sturdy ground stakes to pin his upside-down bike the
| ground, this could make a neat source of power when your off-
| bike, in the field. What's the smallest possible clone of this
| that you could bike-camp with, I wonder?
| adrianN wrote:
| Hub dynamos produce a couple of watts tops. You're probably
| much better off buying a small solar cell.
| adrianN wrote:
| This is interesting for replacing small wind turbines, which
| often break before they recovered their embodied energy[1], but I
| have a hard time seeing this technology replace large scale
| commercial wind turbines. Kite based wind power has been talked
| about for years, but somehow it fails to materialize. I assume
| cost and safety concerns play a role.
|
| [1]http://theoildrum.com/node/6954
| UncleOxidant wrote:
| The autonomous control of the kite is one of the big issues. It
| was basically not possible when the idea was first presented in
| the 80s - there weren't computers small enough with enough
| computing power needed for the task. Also there were materials
| problems. Now we've made a lot of progress on both fronts, but
| still, the control software is a huge issue. We were planning
| on using reinforcement learning to learn a controller for our
| kite (when I was in the biz), but getting enough data to learn
| on was an issue - the kite design was an iterative process -
| the kite design would change and that meant we needed to
| recollect data to enable us to model the new kite changes,
| wash, rinse, repeat.
| sandworm101 wrote:
| Launch costs. Kites work well enough when the wind is blowing
| but a lull, or even a quick change in direction, can see them
| crash to the ground. Then someone has to launch them again. I
| cannot see them ever being practical outside of those very rare
| places where the wind literally never stops.
| Grustaf wrote:
| Kites like Makani's are autonomous, and that's really one of
| the harder aspects to get to work.
| wmertens wrote:
| Makani's kite is steered. This one just needs to stay
| aloft. Launching it is just a matter of a wind-up spool on
| a windvane-like small rotating platform (no more than a few
| m high)
| Grustaf wrote:
| I know how it works, what are you arguing for or against?
| mainpeanut wrote:
| You wrote
|
| > Kites like Makani's are autonomous
|
| They wrote
|
| > Makani's kite is steered. This one just needs to stay
| aloft
|
| The implication is that you are suggesting that
| autonomous steering is neat and the other person is
| suggesting that not needing steering is neater.
|
| Also, Makani was steered into the ground literally and
| figuratively. It's been cancelled. It will never do what
| it said it could do because its creators won't keep doing
| it. It's over.
| Grustaf wrote:
| No, I just meant what I wrote.
|
| I'm simply agreeing with the guy that said that launching
| is expensive. It's indeed the hardest part for any kite
| energy system, I know this from experience, I spent
| several years in this industry.
|
| If you could live with having to launch and land the
| system manually, that would change the equation
| completely.
| mainpeanut wrote:
| > Kites like Makani's are autonomous
|
| The are also cancelled, gone, don't exist, will never
| happen
| AceJohnny2 wrote:
| Makani (of Google X) tried this at a large scale. It didn't work
| out for them, but they open-sourced all their stuff:
|
| https://x.company/projects/makani/
| moffkalast wrote:
| Well that's just utterly overcomplicated and overengineered. No
| way they could produce that at scale for dirt cheap for
| underdeveloped remote areas, which is what this sort of thing
| would be the best application for.
|
| Compared to this project that's essentially a few rings and a
| bike transmission.
| msadowski wrote:
| I really enjoyed the documentary about their work:
| https://m.youtube.com/watch?v=qd_hEja6bzE
| Cyber3x wrote:
| This is one of the best videos on Youtube. I really liked how
| they documented their progress. If only the video lasted
| longer.
| mainpeanut wrote:
| Well funded grad students trying to scale-down an airplane
| into a kite
| UncleOxidant wrote:
| More like they scaled up a kite into a largish 4 rotor
| airplane.
| UncleOxidant wrote:
| Very good documentary on the project. It's amazing what you
| can do with basically an unlimited budget. I worked at a
| much, much smaller kite power startup that folded soon after
| Google stopped funding Makani (investors lost interest
| because they figured if Google wasn't funding in this space
| it must not be viable). Anyway, looking at that documentary
| it seemed clear that Google must've poured hundreds of
| millions of dollars into that company over it's lifetime. So
| many engineers and so many resources. I was kind of envious,
| but then again the ready funding might have been part of
| Makani's downfall, you're forced to make different design
| decisions when money isn't so plentiful.
| msadowski wrote:
| I think they were considered a moonshot project? That's
| probably one way you can justify a massive funding.
| wmertens wrote:
| Very different concept though - using a steered kite vs what is
| basically a self-erecting small wind turbine.
|
| Way less logic and parts needed vs Makani
| AceJohnny2 wrote:
| It seems to me Makani's problem is they wanted larger scale
| power generation, and of course can't rely on constant wind,
| so needed a way to settle and recover. Of course that's not a
| problem for smaller-scale builds like the OP.
| LVB wrote:
| This feature film about Makani (another kite project) was
| extremely well done: https://www.youtube.com/watch?v=qd_hEja6bzE
| riffraff wrote:
| notice this is a vastly different project though: it's not a
| high-flying kite with complex steering logic; it's a small wind
| wheel that transmits torque to the ground. If this things
| crashes to the ground there is basically no expensive damage.
| kkjjkgjjgg wrote:
| Wouldn't the potential for damage at least correlate to some
| extent with the potential for energy that can be harvested?
|
| Even hobbyist kites can become quite scary when the wind gets
| stronger. I don't want to be hit on the head by a kite
| turbine in strong winds.
| wmertens wrote:
| this looks to be made from only soft parts though. Worst
| case you get snipped by a tensed string (could still do
| damage)
| kkjjkgjjgg wrote:
| The soft parts on hobby kites get quite hard when they
| are strained by the wind, though. As I said - it should
| depend on the energy they can harvest - the same energy
| can also force them into the ground, or onto your head.
| riffraff wrote:
| I was referring to the cost of the equipment getting
| destroyed by crashing: makani's (and others) kites are
| pretty expensive and crashing one is a Big Deal, it does
| not seem the same in this design.
|
| Potential for damage and energy are probably correlated, in
| the sense that this design seems to attempt to harvest low-
| altitude winds (30m), while makani and others wanted to get
| the high-altitude stronger and more constant ones.
|
| This design does not have an heavy high flying turbine, it
| has a small lightweight one, and they plan to have multiple
| tethering ropes so I think the risk you face is in fact in
| the same ballpark as a hobbyist kite.
|
| IANA wind-electricity-physics person tho, so take
| everything I say with a large grain of salt.
| goodpoint wrote:
| Almost too well done. It feels like advertising...
| mainpeanut wrote:
| Or a resume. The project was cancelled
| whoomp12342 wrote:
| seriously this is cool. Can you imagine having a few of these on
| the roof of your house in conjunction with solar panels?
| kens wrote:
| The privacy popup at the bottom of this page makes entertaining
| reading...
| Tade0 wrote:
| Personally I can't get over the overuse of ellipsis.
| robin_reala wrote:
| Regarding their use of YouTube, the best way of working around
| that problem (at least without using a privacy-preserving
| provider) is to embed from youtube-nocookie.com instead of
| youtube.com.
|
| https://support.google.com/youtube/answer/171780 (and look at
| the "Turn on privacy-enhanced mode" section)
| spowerei wrote:
| I don't understand why Makani got so much attention in this
| thread.
|
| Flying things need to be lightweight.
|
| Electrical generators are heavy.
|
| Makani: Ok I will build a flying generator ... :thinking:
|
| Related Keywords:
|
| - Airborne wind energy (AWE) (the name of the field)
|
| - Fly-gen (mechanical to electrical conversion happens in the
| sky)
|
| - Ground-gen (mechanical to electrical conversion happens on the
| ground)
|
| Other resources worth of attention:
|
| - On the edge, possibly near to commercialization:
| https://www.ampyxpower.com, ...
|
| - Commercial solutions: https://thekitepower.com/, ...
|
| - Project similar to the one linked (rigid wing):
| https://www.someawe.org, it also have a nice conceptual map style
| overview of the field https://www.someawe.org/awe-map-the-
| someaweorg-airborne-wind...
|
| - Forum with knowledgeable people on AWE:
| https://forum.awesystems.info/
| UncleOxidant wrote:
| Makani had huge amounts of capital from Google to work with. As
| you point out there are other much smaller players in the field
| who keep the generator on the ground and generate power from
| the upward pull of the tether. I worked at one of these
| startups. But after Google canceled Makani it became very
| difficult to find funding because angel investors figured that
| if Google got out of the game it must not be viable. And so we
| folded.
|
| > - On the edge, possibly near to commercialization:
| https://www.ampyxpower.com
|
| A CGI video does not convince me that they're near to
| commercialization.
| spowerei wrote:
| You are right, I used the wrong wording:
|
| "possibly near to commercialization"->"they have something
| flying"
|
| Many others should be mentioned, i.e.
| https://www.kitemill.com/
| tromp wrote:
| The ampyxpower website claims they translate tether tension
| into rotational energy to drive the generator, but how does
| that work?
| uranium wrote:
| Making flying things lightweight is a means to an end, not the
| goal or a hard requirement. Makani experimented with a wide
| variety of solutions before settling on their final model. The
| initial work on soft kites had serious durability issues, IIRC.
| What they ended up with looks a lot like a very lightweight
| airplane, for good reason.
|
| [Former Makani software engineer, here. I wasn't involved in
| the early stuff, or the design trades, but I heard a lot about
| it.]
| spowerei wrote:
| I'm realizing my phrasing was too critical. I think it's a
| very good thing that Makani explored that "design path" and
| shared the knowledge acquired with that level of details. I
| would also say that rigid wing has more potential for AWE,
| but I am pessimist toward 'fly-gen'/'energy-kite' solutions,
| because when dealing with a gas as bearing medium reducing
| weight seems a reasonable and trending rule of thumb. It's
| difficult/too-vague to compare designs with substantially
| different ramifications, some of which are still
| hypothetical, but it's maybe worth if it leads to a better
| understanding or general awareness.
|
| I am curious, do you know why Makani went 100% 'fly-gen'?
| From by biased point of view I would say that it was easier
| to bootstrap (more control agency, easier take off and
| landing) but harder to scale.
|
| I tried to skim through the 1k+ pages 3 part report available
| from Makani (https://x.company/projects/makani/), but it
| doesn't seem to speak much about the considerations which
| when into that early design choice. Do you know more?
|
| Is it possible to summarize them or it's an organic set of
| reasons which cannot be untangled nor simplified like often
| happen when dealing with complex systems?
|
| [Mechanical Engineer here]
| cdeonier wrote:
| What's the reason for the emphasis on weight? From reading the
| technical reports (from Makani), there were larger issues with
| the design unrelated to the weight.
|
| As an example, Makani's Y-bridle design to attach the tether to
| the kite introduce stability issues during hover, and limited
| their control when the kite was aloft making circles, which in
| turn limited their power generation.
| UncleOxidant wrote:
| > What's the reason for the emphasis on weight? .... As an
| example, Makani's Y-bridle design to attach the tether to the
| kite introduce stability issues
|
| It's quite possible that if their kiteplane was much lighter
| that these tether issues would have been much less of a
| problem. Remember that the Makani tether also had to include
| some copper cable for power transmission to the ground. That
| makes the tether itself heavy as well.
| code123456789 wrote:
| Looks very interesting. Didn't find a word about birds' safety on
| your landing page. This is even less visible to birds than
| traditional turbines, if I am not mistaken.
| awestroke wrote:
| 2.4 billion birds are killed by cats every year. 600 million by
| flying into glass panes. 200k by flying into wind turbines.
| (these are US statistics, so not global numbers)
|
| The bird death argument is completely meaningless in several
| aspects. I'd rather make cats illegal than put any kind of
| breaks on wind power expansion.
| kkjjkgjjgg wrote:
| I don't trust those numbers.
| gambiting wrote:
| Ok, then either post better ones or say why you don't like
| them, or what is the reason for distrust. Just saying "I
| don't trust these numbers" adds absolutely nothing to the
| discussion. Imagine if I said "I trust these numbers" - is
| that helpful?
| kkjjkgjjgg wrote:
| The billion birds things seems to go back to one single
| "study", and there already seem to be doubts about it htt
| ps://www.npr.org/sections/13.7/2013/02/03/170851048/do-
| we... (although I think npr is a weird source, I don't
| know).
|
| In any case, those are probably just napkin calculations.
| And I bet I can find a wild variety of estimates for
| birds killed by wind turbines, too - depending on whether
| the person doing the estimating wants turbines to succeed
| or not.
|
| It seems likely they don't kill the same birds as wind
| turbines, either. And not in the same locations.
|
| All in all the comparison might just make not much sense
| to begin with.
|
| How many birds are being killed and eaten by humans, for
| example? Probably several billions more, but they are not
| the same birds that are being killed by turbines.
| gambiting wrote:
| Well, that's a much better reply, thank you. And yes, I
| agree - the numbers aren't directly comparable, but thank
| you for making it much clearer why.
| adrianN wrote:
| Your statistics are of course true, but cats and wind
| turbines kill different species of birds. It does make sense
| not to put wind turbines where endangered birds are nesting.
| eecc wrote:
| Just paint a blade black. The dazzle effect will keep birds
| away. https://www.bbc.com/news/science-
| environment-53909825.amp
| wmertens wrote:
| There's a whole bunch of thread with wings attached in a fairly
| small radius. I would think birds can see this way better.
| russellbeattie wrote:
| Ever since I saw Big Hero 6, I've wondered about the practicality
| of something like this. Blimps with generators seems like
| something to explore!
|
| https://media.wired.co.uk/photos/606da5dc581351b2c44d7d4c/ma...
| Grustaf wrote:
| Flying conventional wind turbines aren't that good, they suffer
| from most of the downsides of both normal wind turbines and
| kite turbines.
|
| The idea with kite energy (in serious projects) is to eliminate
| the need for a tower and the inner parts of the blades.
|
| The kites can be seen as the tip of the blades, which is where
| almost all the energy is generated.
|
| Kite energy can dispense with the tower because they are
| tethered with a largely horizontal cable, so there is no lever
| involved and the foundation can be much smaller. You could sort
| of do that with the flying turbines, but that wouldn't really
| work in a city environment.
| blackoil wrote:
| This looks interesting for off grid areas. Even a small prototype
| can run water pumps etc. They look like should be easy to
| transport and install.
| lorey wrote:
| There's also Kitekraft from YC:
|
| - https://medium.com/kitekraft/kitekraft-takes-off-with-y-comb...
|
| - https://www.kitekraft.de/
| K0balt wrote:
| This is cool, but I'm not seeing how this could be useful in
| unattended application. It will need relaunching on a regular
| basis, and will wear a lot. Even string wears Internally just
| flying in the wind.
|
| My guess is that except in some specific applications like winter
| use in polar regions, solar power will end up producing more
| energy for the same investment over time.
|
| Cheap solar is hard to beat, and the new printable panels promise
| to make it even harder.
|
| Solar is just a lot of energy compared it to kinetic sources.
| It's counterintuitive.
|
| A typical single solar cell from a panel (5 watts) does the work
| of lifting a 5kg weight 300m high every hour. It's kinda mind
| blowing.
| heavenlyblue wrote:
| I don't understand the maths behind your last paragraph, can
| you clear it up please?
| EForEndeavour wrote:
| Raising a mass of m = 5 kg by a height of h = 300 m under
| gravitational acceleration g = 9.8 m/s^2 represents an
| increase in gravitational potential energy of E = mgh = 14700
| joules.
|
| Power is the movement of energy over time, measurable in
| joules per second, or watts. Moving 14700 joules in 1 hour =
| 3600 seconds represents 14700 J / 3600 s = 4 watts of power.
| pjs_ wrote:
| If your body was perfectly efficient at converting calories
| into gravitational potential energy, the calories in a
| single can of coke would be enough to carry you 1km into
| space
| mwint wrote:
| Is there a rule of thumb for the true efficiency of that
| calculation? I.e if I drink one can of coke, how far can
| I climb a ladder on the energy I metabolized from it?
| aidenn0 wrote:
| > My guess is that except in some specific applications like
| winter use in polar regions, solar power will end up producing
| more energy for the same investment over time.
|
| Or energy generation at night and in cloudy areas.
| Nasrudith wrote:
| Automated relaunching could handle the unattended part. As for
| applications perhaps it could work as a compliment to solar
| panels for deployable night time power generation? Given
| general trends of economies of scale, huge tower wind turbines
| perform better on a permanent basis but kites would be far more
| dispatchable and transportable in a casual way. Might be
| roughly similar in niche to a gasoline or diesel generator
| aside from the obvious limitations exchange (not burning fuel
| for power vs being usable indoors or underground with proper
| ventilation, smaller footprint).
| politician wrote:
| You could probably launch these over the top of an existing
| solar farm. It doesn't look like they will cast much shadow.
| ishtanbul wrote:
| I work in the wind industry. Dont see any chance of this becoming
| commercially accepted
| rhn_mk1 wrote:
| That's a lazy comment. Please explain when you have something
| substantial to say, instead of just baiting.
| jcun4128 wrote:
| yeah arm chair comment, too many parts (strings), Makani
| couldn't do it
| lanamo wrote:
| a bird killer.
| wmertens wrote:
| Makani needed expensive equipment and locations, and worked
| very differently.
| jcun4128 wrote:
| I wonder if you were to design a conventional turbine that
| was made out of a telescoping rod. The blades were CF with
| fabric like an old wind mill, and then
| gearbox/motor/charging circuit... say it was only 10 ft
| tall, compare it to this (power).
|
| 1.5KW is nice but guaranteed 30mph constant wind?
| AlexAndScripts wrote:
| Why, out of curiosity?
| Uberphallus wrote:
| Not parent, but aside from the novelty factor:
|
| For small scale energy production small VAWTs [0] are
| relatively cheap, they offer more W/m2, and they are much
| more easily serviceable and installable.
|
| For large scale production it's orders of magnitude less
| efficient, plus having multiple kites on the same plane
| brings in the wake effect [1] in full force. That's why
| regular turbines are generally laid in lines rather than wide
| surfaces, or with significant separation between them.
|
| [0] https://en.wikipedia.org/wiki/Vertical-axis_wind_turbine
|
| [1] https://www.wind-energy-the-facts.org/wake-effect.html
| fragmede wrote:
| Okay, but why is everything wind-related so impossibly
| _big_? What 's the physics behind needing blades so big
| that they can't fit into a cargo container? Instead of
| several very large turbines, why not 1000 or 10,000 of
| them?
| gtpedrosa wrote:
| I think the Makani documentary does a good job explaining
| the problem in less than 2 min [1].
|
| [1] https://youtu.be/qd_hEja6bzE?t=392
|
| Regarding the size x quantity, I believe the reason lies
| in where the best wind is, which is usually high above
| the ground. The roughness of the terrain and obstacles
| generate shear and turbulence, which translates into more
| stress for the components. The higher wind has a more
| uniform distribution across the rotor and is higher in
| magnitude than in lower heights. So for small wind
| turbines to have access to the best wind, you would have
| to build expensive structures to reach there, making it
| infeasible. Hence kite approaches like the one posted and
| Makani (with different principles).
| wmertens wrote:
| Power goes up exponentially with size. To get good RoI,
| you need to go huge.
| divbzero wrote:
| Power is roughly proportional to the wind turbine's cross
| sectional area. So power scales by the square of blade
| length but isn't quite exponential.
| Tuna-Fish wrote:
| It's more than square, because bigger also means taller
| which means more wind.
| Grustaf wrote:
| Yes, it's not exponential at all. Larger blades also need
| to be thicker, and the tower stronger etc. But still,
| it's economies of scale like everywhere else.
| flavius29663 wrote:
| It's more than squared, it's cubed. If you consider
| height advantages, it's going to produce 22 times more
| energy for each doubling of the blade length.
| http://large.stanford.edu/courses/2011/ph240/parise1/
| Tuna-Fish wrote:
| And not only is there more output, it's more valuable per
| unit.
|
| Higher winds are much more stable. Both in having less
| completely still days, and having the median be much
| closer to the maximum. A wind turbine that is built big
| enough starts having a large part of it outbut be
| effectively baseload instead of intermittent, and as more
| renewables are built out, baseload capacity is
| increasingly more valuable than intermittent.
| pjc50 wrote:
| Not only does the area argument apply (see Betz limit),
| but also you get higher wind speeds at higher altitudes.
| amelius wrote:
| Bird catchers.
| andy_ppp wrote:
| I was actually thinking about an alternative energy source from
| the sea... it would float on the surface and be like a set of
| interlinked chains in a fabric with dynamos in them that the
| simple harmonic motion of the ripples of water constantly could
| be used to create electricity.
|
| Let's suppose out at sea each peak to trough is 60cm and the
| movement up and down causes the internal dynamo to be driven by
| 30cm for each one - you probably need two lines into each one,
| positive and negative serially and you could get a pretty good
| average amount of electricity probably.
|
| No idea if it would work or the output would be too uneven but
| there is a lot of sea and it seems a bit easier to build and
| repair than something that sits statically in the water.
| leoedin wrote:
| A lot of work has gone into wave power, but broadly it's not
| got anywhere - there's a lot of complexity in building machines
| which are robust enough to deal with all sea states and the
| hostile marine environment, and the amount of energy which can
| be extracted hasn't made any of the trials so far particularly
| cost effective.
| whoomp12342 wrote:
| I too have thought about this but more like an ocean/tide use
| case. basically a bobber/sinker with a generator
| Chris2048 wrote:
| Guessing it would need some weight to allow it to sink a
| little, but also be buoyant. Maybe aerated concrete (or even
| normal concrete) is the answer?:
| https://www.seasteading.org/wp-content/uploads/2015/12/The-C...
| guerrilla wrote:
| This is already in production in Portugal.
| SuchAnonMuchWow wrote:
| see https://en.wikipedia.org/wiki/Wave_power which include a
| description of the device you mention, among other ideas to
| extract the power from sea waves.
| the100rabh wrote:
| Being from India where during kite festival hundreds of birds die
| due to colliding with threads that kites are flying from. I am a
| little concerned with this solution. But I guess that can be
| added to the design somehow.
|
| Also it just generates 1.5KW which I think its pretty low. Maybe
| I did not understand this completely.
| steve_gh wrote:
| This looks really interesting. Not a replacement for large scale
| (e.g. offshore) wind, but a complement.
|
| I work in infrastructure management. This might be a good
| solution for site power roadside or trackside.
| kitd wrote:
| Agreed. Large-scale might be a stretch, but the low cost and
| weight, open source design, and the ease of transport would
| make this ideal for temporary installations, eg what you
| mention, emergencies or even in the developing world.
| marmakoide wrote:
| A portable kite turbine, tested on the field and that is a
| finished product, not a prototype. 24V DC, 100 watts guaranteed
| with 25 km/h winds, a very conservative estimate
|
| https://kitewinder.fr/
| Kaibeezy wrote:
| Nice! Basic description: Parasail kite with a small bladed
| turbine hanging off it. 100 Watts, 4.5 kg, no tools to
| assemble. EUR900 is not cheap, but the price should come down
| eventually.
| marmakoide wrote:
| I seat the office next to the team of people who designed it
| and who are currently producing it. Cost is mostly because of
| the current low production volume : they can't buy full
| containers of screws, bearings, motors, they can;t order
| thousands of injection molded parts.
|
| They assemble it themselves. They make the control board
| mostly themselves, apart from the PCB which is made in China.
| They also produce the plastic (molded resin I think) and
| metal parts (we have a big CNC mill) themselves, so they can
| handle low production volumes without a big upfront
| investment.
|
| They recently tested it on the Brittany coast under heavy
| winds, it did fine. It was tested a lot on Aquitaine coast.
| Kaibeezy wrote:
| That all sounds so familiar. I was involved with design and
| low-volume production of a complex optical assembly long
| before AliExpress. We tried using surplus lenses and
| prisms, which were practically free compared to new or
| custom stuff, but the inability to standardize was
| ultimately more costly in terms of re-engineering,
| searching for parts, etc. Balancing all that out was an
| ongoing challenge. I remember finding a factory in India
| that could make us prisms at a very reasonable price and it
| was a huge relief. They came in individual handmade
| pasteboard (cheap frangible cardboard with surface layers
| of very thin paper) boxes with hand-lettered labels glued
| on. Old school.
|
| I think these will be very appealing for campers, off-grid,
| emergency and other backup situations when they can hit a
| somewhat lower price. I understand solar panel costs are
| dropping, but it isn't always sunny everywhere!
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