26 ms·

Vertical turbines are more efficient in large-scale wind farms: study

266 points by kieranmaine 5y ago

darig 5y ago
A pilot or bird can see the blades on a horizontal turbine, as they are perpendicular to the flight path.
mikro2nd 5y ago
VAWTs suffer from 2 serious drawbacks: 1) they're crap at starting up - i.e. going from stationary to moving - and usually need some supplementary help to do so, and 2) they're noisy - as in noisy as hell! I wouldn't want one within 500m of my house. I recall seeing report of a similar result many years ago (at least 10, perhaps much more) where VAWTs deployed in complementary pairs were shown to be more efficient, so this looks like a repeat /rediscovery of the same result.
- blakesterz 5y ago
  That's interesting. Hydro is crap at startup too (they need black start units, at least the big ones do) [What I wrote here about black start was pretty much wrong, not sure what I was thinking] so maybe that's not too big of a problem, but that sound thing seems bad, even if the units are out on the water. Those things are loud, I had no idea! "The noise emission from the wind turbine was measured, at wind speed 8 m/s, 10 m above ground, to 96.2 dBA" https://www.mdpi.com/1996-1073/9/1/19/htm https://www.mdpi.com/1996-1073/9/1/19/htm [Edited to add: What I wrote about hydro black start units was really wrong, I wasn't thinking when I wrote that, it needs far more detailed explanation like the comment below.]
  - probablypower 5y ago
    > * Hydro is crap at startup too (they need black start units, at least the big ones do) * This is a misunderstanding. All generators require an excitation current to start up. Most generators get this excitation from the grid. For large, important generators they also have black start, so that they can provide excitation on-site. This means they don't need to bootstrap themselves from a grid. Hydro tends to have black start not because 'they need it' but because it is critically important from a grid security perspective. During a blackout, you want your high inertia, flexible machines online first - these are hydros for systems that have them. If you don't have blackstart on these machines, you need them on some other machine online first to energize the grid. You wouldn't put blackstart units on wind turbines, simply because they are worthless if there isn't already an energised grid to support into (they aren't grid forming). So you can always assume grid-based excitation current for wind generators. I think OP was talking about the cut-in speed (at what wind speed can the turbine start producing power). For HAWTs this is at wind speeds of around 5 m/s. For VAWTs, I don't know, but I assume it is a little higher based on the OP's comment, and that they may even need some mechanical assistance to get them spinning in the first place.
    - blakesterz 5y ago
      Nuts, you're totally right. I really know better, not sure how I got that so wrong.
  - JohnJamesRambo 5y ago
    Are you sure about that, because I was just reading the Black Start Wikipedia yesterday and it listed Hydro as one of the best at requiring little start up power. Hydro is often the Black Start source for other power plants.
    - blakesterz 5y ago
      I am sure I was wrong :-)
  - antiterra 5y ago
    The paper you linked suggests that horizontal turbines are even louder: “The noise emission at 6 m/s 10 m above ground was measured to 94.1 dBA, this while while operating at optimum tip speed. Available noise surveys performed on similar sized operating at optimum tip speed. Available noise surveys performed on similar sized HAWTs [27–30] HAWTs [27–30] has established noise emissions of 95.1–100.2 dBA and 97.3–102.4 dBA for 6 m/s and has established noise emissions of 95.1–100.2 dBA and 97.3–102.4 dBA for 6 m/s and 8 m/s respectively”
- Valgrim 5y ago
  What's the source of the noise? The turbine itself? the air flow around the blades?
  - FriedrichN 5y ago
    And would it still be an issue if they're in the sea?
    - giantg2 5y ago
      I would guess that would increase the infrastructure/cost for transmission if you have to put them further out to sea.
      - FriedrichN 5y ago
        Where I live the turbines are already quite far out, I don't think I'd be able to hear them if they were of the vertical kind.
        giantg2 5y ago
        95db over water could be heard from a couple miles away, especially if the atmospheric conditions are right. I don't know how far out the current ones are since we don't have any around here. This brings up another interesting point. If there are concerns around ship engines and submarine sonar or ELF for marine life, I wonder if any testing has been done concerning that with the turbines.
      - JulianMorrison 5y ago
        In the UK wind farms are usually put in the sea.
    - jelder 5y ago
      Noise pollution is pretty harmful to sea life, especially cetaceans. https://oceanservice.noaa.gov/facts/ocean-noise.html https://oceanservice.noaa.gov/facts/ocean-noise.html
- rswskg 5y ago
  All large wind turbines are loud. Like, unbearably loud.
  - harg 5y ago
    I don't believe this is true. There's an installation of 9 1MW turbines (perhaps quite small in comparison to the largest ones around today) near where I live that I frequently cycle past (within ~50m). Even in strong winds they are barely audible.
    - baud147258 5y ago
      how audible wind turbine also depends on which direction the wind is blowing
- deleted 5y ago
  [deleted]
- jillesvangurp 5y ago
  I think there may have been turbines with those two problems but that does not mean that all turbines are like that. Merely that there were some issues to sort out back in the day when you read about someone allegedly having these issues. Basically, noise would indicate either some problem with loose parts, a lot of friction, turbulence or something else that is clearly being inefficient. Obviously to compete with state of the art horizontal turbines, you'd use highly durable materials with awesomely low friction and generally be shooting for very high levels of efficiency. Some other things I've seen suggests that small vertical turbines are suitable for deployment in urban environments where they work with low/variable wind speeds at completely acceptable noise levels. You could put these on your roof even. I left a link elsewhere in this thread if you are interested. Basically the article is about a group of scientists that ran the numbers and came up with different conclusions than you. 15% more efficient is quite a lot.
vanviegen 5y ago
The article seems to be talking about the efficient use space (sea area). However, speaking as a layman, these vertical turbines appear to be structurally more complex and to consist of more material, so I would expect them to be more expensive per MWh. Would they be more efficient than traditional horizontal wind parks when looking at total cost of ownership?
- Pxtl 5y ago
  On the other other hand they seem mechanically simpler because the entire turbine doesn't have to be mounted to pivot depending on the direction of the wind, and the column that holds up the turbine and blades is much shorter.
  - JulianMorrison 5y ago
    Also the generator can be at ground level, rather than having to perch at the top.
    - tobtoh 5y ago
      Don't quote me on this, but I recall reading that there is a layer of air at ground level that is very turbulent/choppy due to it's interaction with the ground which makes it terrible for wind power generation.
      - lippel82 5y ago
        Only the generator is at the bottom, the power still comes from the upper part of the structure and is transferred mechanically, I would assume.
      - Pxtl 5y ago
        What the parent-post means is that the machinery of the generator is positioned at the bottom below the blades instead at the top of a tall column behind the blades. Presumably this creates some savings in terms of construction and maintenance.
fnord77 5y ago
since the article doesn't say or show what a verticle axis turbine is: https://www.researchgate.net/publication/333316757/figure/fig1/AS:761705160261639@1558616070610/Different-kinds-of-vertical-axis-wind-turbines-VAWT-a-Savonius-b-Darrieus-with.jpg https://www.researchgate.net/publication/333316757/figure/fi...
- _Microft 5y ago
  Wikipedia is also helpful: https://en.wikipedia.org/wiki/Vertical-axis_wind_turbine https://en.wikipedia.org/wiki/Vertical-axis_wind_turbine https://en.wikipedia.org/wiki/Wind_turbine#Horizontal_axis https://en.wikipedia.org/wiki/Wind_turbine#Horizontal_axis
probablypower 5y ago
>“Modern wind farms are one of the most efficient ways to generate green energy. However, they have one major flaw: as the wind approaches the front row of turbines, turbulence will be generated downstream. The turbulence is detrimental to the performance of the subsequent rows.” Yes, this is called a 'wind shadow' and it relates to the slower, turbulent, dirty air coming out of the back of a wind turbine being less energy rich for the turbines behind it. Wind farms are designed to minimize wind shadow impacts based on prevailing wind directions. > “[VAWTs] can be designed to be much closer together, increasing their efficiency and ultimately lowering the prices of electricity. In the long run, VAWTs can help accelerate the green transition of our energy systems, so that more clean and sustainable energy comes from renewable sources.” This sounds like it will make the wind shadow effects worse. > The research found that VAWTs increase each other’s performance when arranged in grid formations This seems like straight bullshit, and is really unclear. The argument seems to be that VAWTs are somehow positively impacted by wind shadows? The air coming out the backside of a turbine (VAWT or HAWT) is less energy dense and more turbulent, so the results seem fundamentally flawed. The best design is one that minimizes the amount of 'wind shadow' being swept by turbines. I am entirely unconvinced.
- amelius 5y ago
  Perhaps the new design somehow reduces the shadow effect by extracting wind energy from higher layers of air?
- _Microft 5y ago
  If you want to have a look at the study, it is linked from the article.
- metalliqaz 5y ago
  I'm not an expert, but I thought one of the main advantages of vertical turbines was better usage of rapidly changing wind
- mumblemumble 5y ago
  The paper's here, if you want to see how they came to the result. The PDF is paywalled, but you can view it in their online reader for free. https://www.sciencedirect.com/science/article/pii/S096014812100344X https://www.sciencedirect.com/science/article/pii/S096014812... Properly understanding it is well beyond me, but it looks like it's about carefully arranging the turbines with respect to each other's wakes. While this is based on modeling and not empirical experimentation, it doesn't look like they just pulled the idea out of a hat. Getting the 15% improvement seems to require that the pattern is optimally oriented with respect to the wind direction, so I'm guessing real world benefit wouldn't be anywhere near that great.
singularity2001 5y ago
wind sails (kites) are the future
- Faaak 5y ago
  absolutely not. I'm sorry makani went under (there's an excellent documentary about them on YT), but when you compare their extreme complexity for a "simple" 600kW unit to newer wind turbines that are now reaching 10MW, you'll see why
  - usrusr 5y ago
    Skysails Power is shipping.
    - Faaak 5y ago
      Per their datasheet, the SKS PN-14 produces 80-200 kW. Now compare this to a modern Vestas V164 8000kW turbine. The latter seems way simpler engineering-wise to me
      - usrusr 5y ago
        You are comparing a 20 tonnes system to a 1300 tonnes system
        cr1895 5y ago
        But then having a nominal capacity of 8000kW from the 20mt system, you’d need maybe 1200 tonnes of the 20mt systems. I’m not sure how that’s better or simpler. Sounds vastly more complex and expensive.
Kaibeezy 5y ago
I keep wanting to read that title as: Vertical turbines far more efficient than large-scale wind farms But then you read up and it's really: Vertical turbines far more efficient when in large-scale wind farms than they are individually Whether they can ever be made to be efficient enough to make sense seems to be the question.
- blok 5y ago
  > Vertical turbines far more efficient when in large-scale wind farms than they are individually The article is saying that in large-scale wind farms, vertical turbines are more efficient than horizontal axis wind turbines (the "traditional form factor"). With horizontal axis turbines in large wind farms, there is always a loss of efficiency through the "wake effect" where some of the turbines are downwind from the others. But the study seems to have found that this can actually increase the efficiency of vertical turbines. Which is very unexpected.
  - Kaibeezy 5y ago
    > The article is saying that in large-scale wind farms, vertical turbines are more efficient than horizontal axis wind turbines Is it? So much for my reading comprehension score today. ETA: I read the underlying paper this time (https://www.sciencedirect.com/science/article/pii/S096014812100344X https://www.sciencedirect.com/science/article/pii/S096014812...) and I'm fairly certain what it's actually saying is: Vertical turbines far more efficient when in large-scale wind farms than they are individually, and furthermore their increase in efficiency can be greater than the increase in efficiency readily attainable by HAWTs because VAWTs can be placed close together and gain downstream efficiency, whereas HAWTs can't be placed so close together and even when relatively far apart lose downstream efficiency due to turbulence, but YMMV depending on local conditions and other factors, for example: the steadiness of the wind, because VAWTs often need a boost to start from a stop. Which is probably not the title they wanted to use, eh? Imma hop in my boxy but safe Volvo and go watch "Crazy People" again now.
    - ndonnellan 5y ago
mabbo 5y ago
Land use efficiency is not the same as economical efficiency. Arguing that we should build vertical turbines because they are more land-use-efficient is silly, because land is cheap where we build wind farms. The only efficiency that matters is power generated per dollar invested. And if these vertical turbines were more efficient that way, then we would already be using them widely.
- worldsayshi 5y ago
  Maybe the reason they are cheaper is simply because they have a head start on building the supply chain and manufacturing process?
- Flashtoo 5y ago
  Not every part of the world has large amounts of cheap land available for wind farms. Land use efficiency is important there.
  - hajile 5y ago
    It's my understanding that vertical turbines need far less height to be effective. If you can get away with moderate towers on various existing structures, then the amount of available land increases dramatically.
mumblemumble 5y ago
Initial hot take: I'm not sure they're measuring efficiency in a way that's really meaningful to me? There are so many ways you could measure it. You could measure it as the % of wind energy passing through the turbine's plane that is taken out of the air, or the the efficiency of using that energy to get the rotor turning, or the efficiency of converting the rotor's kinetic energy to electrical energy. (edit: Or I could, y'know, do the sensible thing and check the article. They're measuring power output for a given wind speed and direction. Which I think means, in effect, all of that end-to-end.) But I'm not sure any of those are, in and of themselves, what really matters at scale. The more interesting questions, I'm guessing, are things like, "How much energy can we get out of a plot of land of a given size?", or, "How much energy can we generate for a given cost to install and maintain?" Both of which, I would assume, are more difficult to directly extrapolate from thermodynamic efficiency in wind turbines than they are for something like photovoltaics, because of the "moving parts" factor.
- 7952 5y ago
  I think this is efficiency in terms of much energy you can extract for a given area of sea or land. Wake effects mean that wind turbines cannot be placed in a particular zone downwind of another turbine. If wake effects are lower then you could potentially get a higher density of turbines in a given area. This is something that is already considered in terms of turbine height and placement. Sometimes they are placed at closer intervals along the perimeter of the zone and then lower densities within. Of course lots of factors are considered with the final "efficiency" being about getting the highest return for an investment.
  - brianwawok 5y ago
    If land is your dominating cost factor, its how many kw per acre can you generate. So dense circular turbines seem good. If the cost to produce the turbines is the dominating cost factor, and traditional turbines are "cheaper" to build, it could be a win in some cases to use more land with normal wind turbines. The more you spread them, the less problem you have with wake on downstream turbines. Or it could vary based on land value of where you are installing a given plant.
antattack 5y ago
If you look at the actual study[1] it's not just vertical turbines but also their formation [2]that (could) increase efficacy of large-scale wind farms. [1] https://www.sciencedirect.com/science/article/pii/S096014812100344X?via%3Dihub https://www.sciencedirect.com/science/article/pii/S096014812... [2] https://ars.els-cdn.com/content/image/1-s2.0-S096014812100344X-ga1_lrg.jpg https://ars.els-cdn.com/content/image/1-s2.0-S09601481210034...
- scythe 5y ago
  >For the configurations analysed, pairs of VAWTs exhibited a 15% increase in power output compared to operating in isolation, when the second rotor was spaced three turbine diameters downstream and at an angle of 60° to the wind direction. This seems like a major limitation of the finding. The wind direction is variable. If your clever idea only works when the wind is blowing exactly west, it's not so clever.
  - dylan604 5y ago
    But in areas where the wind farms are built, isn't one of the deciding factors that the wind primarialy blows in one direction? Similar to airports and how they decide which way to build their runways. LAX doesn't even have North/South runways because of this.
    - bluGill 5y ago
      Wind is rarely exactly in one direction. A constant west wind isn't always directly 270 degrees, there is a large plus/minus factor in that.
  - mhandley 5y ago
    From figure 6 in the paper, it looks like you get the win for anything from 30 degrees angle upwards. But with 0 degrees angle, the turbines seem to interfere, and you get something like 50% loss. So with a westerly prevailing wind (from 270 degrees), you'd likely put the turbines in rows at 210 or 330 degrees. If you used 210 degrees, and the wind comes from 210 degrees, you lose. Almost all the rest of the time you win. With some simple analysis of historic wind directions, you ought to be able to choose the angle to maximize net output by putting the inefficient angle in a direction that is relatively uncommon.
nabla9 5y ago
Unfortunately they don't have video of the fluid flow simulation. The effect must come from vortex interaction or syncronization and it would be interesting to see. If there is some form of strong coupling it may increase efficiency but induce vibrations.
Gravityloss 5y ago
You could have horizontal axis turbines with half of them rotating clockwise and half anticlockwise, though it seems the effect is minor, less than 2%: "counter-rotating configurations were more efficient in power generation than the control case in which all turbines have one clockwise rotor; the alternate-row case was found to produce 1.4% more power " https://www.sciencedirect.com/science/article/abs/pii/S2213138816301072 https://www.sciencedirect.com/science/article/abs/pii/S22131... Overall there's probably a lot of ways left to optimize on wind farm level. For example the yaw angles https://www.sciencedirect.com/science/article/abs/pii/S0306261920310230 https://www.sciencedirect.com/science/article/abs/pii/S03062...
- selimthegrim 5y ago
  And just when I was imagining twiddling my thumbs in opposite directions...
deleted 5y ago
[deleted]
exhilaration 5y ago
Wikipedia has pictures if like myself you have no idea what a vertical wind turbine looks like: https://en.m.wikipedia.org/wiki/Vertical_axis_wind_turbine https://en.m.wikipedia.org/wiki/Vertical_axis_wind_turbine
- mod 5y ago
  So does the article.
  - exhilaration 5y ago
    You mean that header image? It's super small on my phone.
k1rcher 5y ago
So this reflects economy of scale (more turbines per area) rather than higher output/turbine, right?
SavantIdiot 5y ago
That is surprising. They have an inferior efficiency already due to the Betz limit (it is proportional to surface area facing the wind) and will always be about 60% max for a HAWT and worse for VAWT. However, the dynamics of turbulance have been one of the hardest things to model in large wind farms. The article is a bit light on details, but the last time I went to the Sandia Labs wind turbine conference in Albuquerque, VAWTS were nowhere to be seen (2015) and the biggest modeling challenge was large farm interferrence. Very interesting. Betz Limit: https://en.wikipedia.org/wiki/Betz%27s_law https://en.wikipedia.org/wiki/Betz%27s_law
- nullifidian 5y ago
  https://youtu.be/EM-gCvhQhPU?t=508 https://youtu.be/EM-gCvhQhPU?t=508 This lady says Betz limit doesn't apply to VAWT.
  - SavantIdiot 5y ago
    Huh, did not know. Thanks for the link. Kind of disappointing, I was hoping for an explanation, not a claim.
    - palae 5y ago
      This paper has some insight: https://iopscience.iop.org/article/10.1088/1742-6596/753/2/022056/pdf https://iopscience.iop.org/article/10.1088/1742-6596/753/2/0...
      - SavantIdiot 5y ago
        I suppose I could have Googled instead of complaining, so thanks for doing the work for me! :) [I like how the first citation is from a 1920's paper (by Betz).]
efnx 5y ago
I’ve been wondering why we don’t have these on top of our street lights. I imagine a street light with a Darrieus vawt on the pole under the light and a small solar panel on top.
- tachyonbeam 5y ago
  Noise, maintenance, added cost and complexity. Then you also have the issue that you need an inverter and some kind of scheme to communicate with the mini wind turbines so they don't drive the voltage too high or some other kind of scheme for regulating that.
- foolfoolz 5y ago
  because a whole city with turbines on each street light might produce the same amount of power as 1 large scale wind farm at a fraction of the maintenance cost
  - lofi_lory 5y ago
    The new Siemens offshore turbines put out up to 16MW. This has blown me away. Tho, they are scary machines and I get uncomfortable looking at them (like single balcony on a huge wall kind of uncomfortable). Aesthetically the vertical ones are much, much better IMO. Especially if they can be placed in an symmetrical pattern, not this super optimized complex mess traditional ones show.
  - patrickk 5y ago
    https://www.youtube.com/watch?v=gcSnwW5v3f8 https://www.youtube.com/watch?v=gcSnwW5v3f8 There is a roadside vertical turbine concept which seems promising. It uses lampposts as a mounting point, reducing materials needed, reusing existing cables in the lamp, and scavenges energy from trucks thundering by. And since it's in a developed area, you don't affect existing views.
kuprel 5y ago
The vertical axis turbine seems like it would scale in size better since the blades are spinning perpendicular to gravity
- jhayward 5y ago
  They are subject to much higher dynamic forces, rapidly cycling between windward and lee side. Vertical turbines have worse wear characteristics, and it only gets worse as they get bigger and need more massive airfoils.
jeffreyrogers 5y ago
Has any research been done on the effects of wind farms on local wind/weather patterns? It seems like taking energy out of the wind in a relatively concentrated area would have downstream effects. (I'm not anti-wind energy, I'm just curious).
- lofi_lory 5y ago
  I think offshore wind farms have been proposed to protect the US from hurricanes. So apparently they substantially decrease wind energy.
  - deleted 5y ago
    [deleted]
  - cr1895 5y ago
    > offshore wind farms have been proposed to protect the US from hurricanes No, certainly not seriously.
    - lofi_lory 5y ago
      https://news.stanford.edu/news/2014/february/hurricane-winds-turbine-022614.html https://news.stanford.edu/news/2014/february/hurricane-winds...
      - cr1895 5y ago
        An estimate of 78,000 turbines is truly a thought experiment, not a realistic solution. There does not exist manufacturing capacity or installation capacity to achieve this (not even remotely close). The offshore wind pipeline, globally, is orders of magnitude fewer WTGs, and procurement & installation pressure is already expected to be very tight in the coming decade. This is made more difficult in the US due to the complexities of offshore wind installation imposed by the Jones Act. It’s a neat concept. But it will never be realized.
- baq 5y ago
  i'm not aware of any comparisons but imagine a sparse forest.
lacker 5y ago
I hope these researchers don't stop with just writing papers, and actually see if they can convert their theory into practice. If it's true that there's a far more efficient way to run wind farms, it seems like it could be a huge profit opportunity.
wingineer 5y ago
Wind turbine design engineer here: There are several significant barriers to adoption that VAWTs face. 1. The wind resource is more powerful and more consistent higher off the ground. The hub heights of industry standard horizontal-axis wind turbines are reaching 135+ meters for the new generation of large offshore machines. These vertical axis machines are much lower to the ground. 2. Contrary to the claims of the authors in the Renewable Energy Paper (they say "The potential applications for VAWTs are endless, because the turbines are cheaper and easier to manufacture and maintain. "), vertical axis turbines have consistently had fatigue issues. There is an interesting history of the test-campaigns of vertical-axis machines at Sandia National Laboratories [1] that discusses this. In the 70s and 80s vertical machines were much more common than they are today. 3. It is a huge risk for an industry that is shipping proven technology to switch to a new paradigm that will require much more research and testing to work at scale. It's certainly possible and I find the possibility fascinating as a curious engineer. I would love to have a secure position developing VAWT tech or working on airborne wind machines (check out ground-based generator concepts to get an idea of where I think that will progress, not ill-conceived onboard generator kites like Makani). The problem of wake blockage in large wind farms (and from adjacent farms to each other) is definitely significant though. The current "top" strategy is wake steering, where turbines at the front use their yaw drive to capture less power and allow for more power to reach the turbines in the rows following. [1]. The bleeding edge of this may be vertical wake steering, which can entrain high-energy wind from above the farm into the plant to capture more power [3]. [1] https://energy.sandia.gov/wp-content/gallery/uploads/SAND2012-0304.pdf https://energy.sandia.gov/wp-content/gallery/uploads/SAND201... [2] https://www.nrel.gov/docs/fy17osti/68396.pdf https://www.nrel.gov/docs/fy17osti/68396.pdf [3] https://ieeexplore.ieee.org/document/7963037 https://ieeexplore.ieee.org/document/7963037
- breischl 5y ago
  Tangentially, I ran into the bladeless vortex concept recently (https://vortexbladeless.com/ https://vortexbladeless.com/), do you have a take on that? It seems like all your concerns/critiques from above would apply equally, but then I don't have any real expertise in the area.
  - 5y ago
buovjaga 5y ago
John Dabiri (referenced and thanked in the study) and his team have been researching this topic for a long time: https://dabirilab.com/ https://dabirilab.com/
jillesvangurp 5y ago
The "Just have think" youtube channel did an episode on VAWTs just last week: https://www.youtube.com/watch?v=gcSnwW5v3f8 https://www.youtube.com/watch?v=gcSnwW5v3f8 Vawts are mechnically quite simple and compact. You can put them just about anywhere. And they can operate even at low wind speeds, regardless of where the wind comes from. There's a company experimenting with these along highways to get energy from vehicles driving by. The idea here is to simply wrap them around existing street lights. Not a lot of energy per turbine obviously but it adds up if you do it along a few miles of highway. And they are cheap, small, lightweight, and easy to install.
- A_No_Name_Mouse 5y ago
  Nice video. > There's a company experimenting with these along highways to get energy from vehicles driving by. Those turbines will be slowing down the windflow, causing extra resistance for the traffic. The video doesn't mention that. Does anyone know if that effect is significant enough to reduce or even reverse the overall benefits (especially given the large % of ICE vehicles)?
sfblah 5y ago
Serious question. I live in a hilly area where there's a lot of wind much of the time. Is there some kind of residential analog to rooftop solar I could install? Or is the infrastructure just too expensive and complicated for a hobbyist?
- duffyjp 5y ago
  You can buy something in the 1-3 KW range at Home Depot. I've seen one in person at an off-grid house and the owner couldn't understand why people even used solar. This was 15+ years ago though, so solar was MUCH more expensive than today while a turbine I'd imagine was about the same?
  - sfblah 5y ago
    I assume it'd be super expensive to grid tie it though, right? Sorry. I'm a total noob at this stuff.
  - newyankee 5y ago
    I suspect the intermittency of wind is higher and requires a decent amount of energy storage to smoothen the output. As energy storage gets cheaper, probably off grid installations can complement their solar installations with wind as well, depending on the location.
- cr1895 5y ago
  Residential wind power? Wind energy is something that greatly benefits from scale: it’s why the current and next generation of turbines have rotor diameters exceeding hundreds of meters. You’d probably be much better served by using solar panels.
  - sfblah 5y ago
    Sure. I just meant for fun or for a project. The biggest cost is probably grid tying, right?
gmokki 5y ago
This company has been slowly developing vertical wind trubines: https://windside.com/ https://windside.com/ They are not (yet) for mega installations, but since they are almost silent and maintenance free they can be used both in urban areas and in sahara/antarctis where things just have to work.
sn_master 5y ago
Do they have one shape or multiple? I tried searching for a photo of one but getting a mix of results.
sova 5y ago
The ancient windmills of Nashtifan continue to be vertical to this very day. https://www.youtube.com/watch/3qqifEdqf5g https://www.youtube.com/watch/3qqifEdqf5g

266 points by kieranmaine 5y ago

A pilot or bird can see the blades on a horizontal turbine, as they are perpendicular to the flight path.

VAWTs suffer from 2 serious drawbacks: 1) they're crap at starting up - i.e. going from stationary to moving - and usually need some supplementary help to do so, and 2) they're noisy - as in noisy as hell! I wouldn't want one within 500m of my house. I recall seeing report of a similar result many years ago (at least 10, perhaps much more) where VAWTs deployed in complementary pairs were shown to be more efficient, so this looks like a repeat /rediscovery of the same result.

blakesterz 5y ago
That's interesting. Hydro is crap at startup too (they need black start units, at least the big ones do) [What I wrote here about black start was pretty much wrong, not sure what I was thinking] so maybe that's not too big of a problem, but that sound thing seems bad, even if the units are out on the water. Those things are loud, I had no idea! "The noise emission from the wind turbine was measured, at wind speed 8 m/s, 10 m above ground, to 96.2 dBA" https://www.mdpi.com/1996-1073/9/1/19/htm https://www.mdpi.com/1996-1073/9/1/19/htm [Edited to add: What I wrote about hydro black start units was really wrong, I wasn't thinking when I wrote that, it needs far more detailed explanation like the comment below.]
- probablypower 5y ago
  > * Hydro is crap at startup too (they need black start units, at least the big ones do) * This is a misunderstanding. All generators require an excitation current to start up. Most generators get this excitation from the grid. For large, important generators they also have black start, so that they can provide excitation on-site. This means they don't need to bootstrap themselves from a grid. Hydro tends to have black start not because 'they need it' but because it is critically important from a grid security perspective. During a blackout, you want your high inertia, flexible machines online first - these are hydros for systems that have them. If you don't have blackstart on these machines, you need them on some other machine online first to energize the grid. You wouldn't put blackstart units on wind turbines, simply because they are worthless if there isn't already an energised grid to support into (they aren't grid forming). So you can always assume grid-based excitation current for wind generators. I think OP was talking about the cut-in speed (at what wind speed can the turbine start producing power). For HAWTs this is at wind speeds of around 5 m/s. For VAWTs, I don't know, but I assume it is a little higher based on the OP's comment, and that they may even need some mechanical assistance to get them spinning in the first place.
  - blakesterz 5y ago
    Nuts, you're totally right. I really know better, not sure how I got that so wrong.
- JohnJamesRambo 5y ago
  Are you sure about that, because I was just reading the Black Start Wikipedia yesterday and it listed Hydro as one of the best at requiring little start up power. Hydro is often the Black Start source for other power plants.
  - blakesterz 5y ago
    I am sure I was wrong :-)
- antiterra 5y ago
  The paper you linked suggests that horizontal turbines are even louder: “The noise emission at 6 m/s 10 m above ground was measured to 94.1 dBA, this while while operating at optimum tip speed. Available noise surveys performed on similar sized operating at optimum tip speed. Available noise surveys performed on similar sized HAWTs [27–30] HAWTs [27–30] has established noise emissions of 95.1–100.2 dBA and 97.3–102.4 dBA for 6 m/s and has established noise emissions of 95.1–100.2 dBA and 97.3–102.4 dBA for 6 m/s and 8 m/s respectively”
Valgrim 5y ago
What's the source of the noise? The turbine itself? the air flow around the blades?
- FriedrichN 5y ago
  And would it still be an issue if they're in the sea?
  - giantg2 5y ago
    I would guess that would increase the infrastructure/cost for transmission if you have to put them further out to sea.
    - FriedrichN 5y ago
      Where I live the turbines are already quite far out, I don't think I'd be able to hear them if they were of the vertical kind.
      - giantg2 5y ago
        95db over water could be heard from a couple miles away, especially if the atmospheric conditions are right. I don't know how far out the current ones are since we don't have any around here. This brings up another interesting point. If there are concerns around ship engines and submarine sonar or ELF for marine life, I wonder if any testing has been done concerning that with the turbines.
    - JulianMorrison 5y ago
      In the UK wind farms are usually put in the sea.
  - jelder 5y ago
    Noise pollution is pretty harmful to sea life, especially cetaceans. https://oceanservice.noaa.gov/facts/ocean-noise.html https://oceanservice.noaa.gov/facts/ocean-noise.html
rswskg 5y ago
All large wind turbines are loud. Like, unbearably loud.
- harg 5y ago
  I don't believe this is true. There's an installation of 9 1MW turbines (perhaps quite small in comparison to the largest ones around today) near where I live that I frequently cycle past (within ~50m). Even in strong winds they are barely audible.
  - baud147258 5y ago
    how audible wind turbine also depends on which direction the wind is blowing
deleted 5y ago
[deleted]
jillesvangurp 5y ago
I think there may have been turbines with those two problems but that does not mean that all turbines are like that. Merely that there were some issues to sort out back in the day when you read about someone allegedly having these issues. Basically, noise would indicate either some problem with loose parts, a lot of friction, turbulence or something else that is clearly being inefficient. Obviously to compete with state of the art horizontal turbines, you'd use highly durable materials with awesomely low friction and generally be shooting for very high levels of efficiency. Some other things I've seen suggests that small vertical turbines are suitable for deployment in urban environments where they work with low/variable wind speeds at completely acceptable noise levels. You could put these on your roof even. I left a link elsewhere in this thread if you are interested. Basically the article is about a group of scientists that ran the numbers and came up with different conclusions than you. 15% more efficient is quite a lot.

vanviegen 5y ago

The article seems to be talking about the efficient use space (sea area). However, speaking as a layman, these vertical turbines appear to be structurally more complex and to consist of more material, so I would expect them to be more expensive per MWh. Would they be more efficient than traditional horizontal wind parks when looking at total cost of ownership?

Pxtl 5y ago
On the other other hand they seem mechanically simpler because the entire turbine doesn't have to be mounted to pivot depending on the direction of the wind, and the column that holds up the turbine and blades is much shorter.
- JulianMorrison 5y ago
  Also the generator can be at ground level, rather than having to perch at the top.
  - tobtoh 5y ago
    Don't quote me on this, but I recall reading that there is a layer of air at ground level that is very turbulent/choppy due to it's interaction with the ground which makes it terrible for wind power generation.
    - lippel82 5y ago
      Only the generator is at the bottom, the power still comes from the upper part of the structure and is transferred mechanically, I would assume.
    - Pxtl 5y ago
      What the parent-post means is that the machinery of the generator is positioned at the bottom below the blades instead at the top of a tall column behind the blades. Presumably this creates some savings in terms of construction and maintenance.

fnord77 5y ago

since the article doesn't say or show what a verticle axis turbine is: https://www.researchgate.net/publication/333316757/figure/fig1/AS:761705160261639@1558616070610/Different-kinds-of-vertical-axis-wind-turbines-VAWT-a-Savonius-b-Darrieus-with.jpg https://www.researchgate.net/publication/333316757/figure/fi...

_Microft 5y ago
Wikipedia is also helpful: https://en.wikipedia.org/wiki/Vertical-axis_wind_turbine https://en.wikipedia.org/wiki/Vertical-axis_wind_turbine https://en.wikipedia.org/wiki/Wind_turbine#Horizontal_axis https://en.wikipedia.org/wiki/Wind_turbine#Horizontal_axis

probablypower 5y ago

>“Modern wind farms are one of the most efficient ways to generate green energy. However, they have one major flaw: as the wind approaches the front row of turbines, turbulence will be generated downstream. The turbulence is detrimental to the performance of the subsequent rows.” Yes, this is called a 'wind shadow' and it relates to the slower, turbulent, dirty air coming out of the back of a wind turbine being less energy rich for the turbines behind it. Wind farms are designed to minimize wind shadow impacts based on prevailing wind directions. > “[VAWTs] can be designed to be much closer together, increasing their efficiency and ultimately lowering the prices of electricity. In the long run, VAWTs can help accelerate the green transition of our energy systems, so that more clean and sustainable energy comes from renewable sources.” This sounds like it will make the wind shadow effects worse. > The research found that VAWTs increase each other’s performance when arranged in grid formations This seems like straight bullshit, and is really unclear. The argument seems to be that VAWTs are somehow positively impacted by wind shadows? The air coming out the backside of a turbine (VAWT or HAWT) is less energy dense and more turbulent, so the results seem fundamentally flawed. The best design is one that minimizes the amount of 'wind shadow' being swept by turbines. I am entirely unconvinced.

amelius 5y ago
Perhaps the new design somehow reduces the shadow effect by extracting wind energy from higher layers of air?
_Microft 5y ago
If you want to have a look at the study, it is linked from the article.
metalliqaz 5y ago
I'm not an expert, but I thought one of the main advantages of vertical turbines was better usage of rapidly changing wind
mumblemumble 5y ago
The paper's here, if you want to see how they came to the result. The PDF is paywalled, but you can view it in their online reader for free. https://www.sciencedirect.com/science/article/pii/S096014812100344X https://www.sciencedirect.com/science/article/pii/S096014812... Properly understanding it is well beyond me, but it looks like it's about carefully arranging the turbines with respect to each other's wakes. While this is based on modeling and not empirical experimentation, it doesn't look like they just pulled the idea out of a hat. Getting the 15% improvement seems to require that the pattern is optimally oriented with respect to the wind direction, so I'm guessing real world benefit wouldn't be anywhere near that great.

singularity2001 5y ago

wind sails (kites) are the future

Faaak 5y ago
absolutely not. I'm sorry makani went under (there's an excellent documentary about them on YT), but when you compare their extreme complexity for a "simple" 600kW unit to newer wind turbines that are now reaching 10MW, you'll see why
- usrusr 5y ago
  Skysails Power is shipping.
  - Faaak 5y ago
    Per their datasheet, the SKS PN-14 produces 80-200 kW. Now compare this to a modern Vestas V164 8000kW turbine. The latter seems way simpler engineering-wise to me
    - usrusr 5y ago
      You are comparing a 20 tonnes system to a 1300 tonnes system
      - cr1895 5y ago
        But then having a nominal capacity of 8000kW from the 20mt system, you’d need maybe 1200 tonnes of the 20mt systems. I’m not sure how that’s better or simpler. Sounds vastly more complex and expensive.

Kaibeezy 5y ago

I keep wanting to read that title as: Vertical turbines far more efficient than large-scale wind farms But then you read up and it's really: Vertical turbines far more efficient when in large-scale wind farms than they are individually Whether they can ever be made to be efficient enough to make sense seems to be the question.

blok 5y ago
> Vertical turbines far more efficient when in large-scale wind farms than they are individually The article is saying that in large-scale wind farms, vertical turbines are more efficient than horizontal axis wind turbines (the "traditional form factor"). With horizontal axis turbines in large wind farms, there is always a loss of efficiency through the "wake effect" where some of the turbines are downwind from the others. But the study seems to have found that this can actually increase the efficiency of vertical turbines. Which is very unexpected.
- Kaibeezy 5y ago
  > The article is saying that in large-scale wind farms, vertical turbines are more efficient than horizontal axis wind turbines Is it? So much for my reading comprehension score today. ETA: I read the underlying paper this time (https://www.sciencedirect.com/science/article/pii/S096014812100344X https://www.sciencedirect.com/science/article/pii/S096014812...) and I'm fairly certain what it's actually saying is: Vertical turbines far more efficient when in large-scale wind farms than they are individually, and furthermore their increase in efficiency can be greater than the increase in efficiency readily attainable by HAWTs because VAWTs can be placed close together and gain downstream efficiency, whereas HAWTs can't be placed so close together and even when relatively far apart lose downstream efficiency due to turbulence, but YMMV depending on local conditions and other factors, for example: the steadiness of the wind, because VAWTs often need a boost to start from a stop. Which is probably not the title they wanted to use, eh? Imma hop in my boxy but safe Volvo and go watch "Crazy People" again now.
  - ndonnellan 5y ago

mabbo 5y ago

Land use efficiency is not the same as economical efficiency. Arguing that we should build vertical turbines because they are more land-use-efficient is silly, because land is cheap where we build wind farms. The only efficiency that matters is power generated per dollar invested. And if these vertical turbines were more efficient that way, then we would already be using them widely.

worldsayshi 5y ago
Maybe the reason they are cheaper is simply because they have a head start on building the supply chain and manufacturing process?
Flashtoo 5y ago
Not every part of the world has large amounts of cheap land available for wind farms. Land use efficiency is important there.
- hajile 5y ago
  It's my understanding that vertical turbines need far less height to be effective. If you can get away with moderate towers on various existing structures, then the amount of available land increases dramatically.

mumblemumble 5y ago

Initial hot take: I'm not sure they're measuring efficiency in a way that's really meaningful to me? There are so many ways you could measure it. You could measure it as the % of wind energy passing through the turbine's plane that is taken out of the air, or the the efficiency of using that energy to get the rotor turning, or the efficiency of converting the rotor's kinetic energy to electrical energy. (edit: Or I could, y'know, do the sensible thing and check the article. They're measuring power output for a given wind speed and direction. Which I think means, in effect, all of that end-to-end.) But I'm not sure any of those are, in and of themselves, what really matters at scale. The more interesting questions, I'm guessing, are things like, "How much energy can we get out of a plot of land of a given size?", or, "How much energy can we generate for a given cost to install and maintain?" Both of which, I would assume, are more difficult to directly extrapolate from thermodynamic efficiency in wind turbines than they are for something like photovoltaics, because of the "moving parts" factor.

7952 5y ago
I think this is efficiency in terms of much energy you can extract for a given area of sea or land. Wake effects mean that wind turbines cannot be placed in a particular zone downwind of another turbine. If wake effects are lower then you could potentially get a higher density of turbines in a given area. This is something that is already considered in terms of turbine height and placement. Sometimes they are placed at closer intervals along the perimeter of the zone and then lower densities within. Of course lots of factors are considered with the final "efficiency" being about getting the highest return for an investment.
- brianwawok 5y ago
  If land is your dominating cost factor, its how many kw per acre can you generate. So dense circular turbines seem good. If the cost to produce the turbines is the dominating cost factor, and traditional turbines are "cheaper" to build, it could be a win in some cases to use more land with normal wind turbines. The more you spread them, the less problem you have with wake on downstream turbines. Or it could vary based on land value of where you are installing a given plant.

antattack 5y ago

If you look at the actual study[1] it's not just vertical turbines but also their formation [2]that (could) increase efficacy of large-scale wind farms. [1] https://www.sciencedirect.com/science/article/pii/S096014812100344X?via%3Dihub https://www.sciencedirect.com/science/article/pii/S096014812... [2] https://ars.els-cdn.com/content/image/1-s2.0-S096014812100344X-ga1_lrg.jpg https://ars.els-cdn.com/content/image/1-s2.0-S09601481210034...

scythe 5y ago
>For the configurations analysed, pairs of VAWTs exhibited a 15% increase in power output compared to operating in isolation, when the second rotor was spaced three turbine diameters downstream and at an angle of 60° to the wind direction. This seems like a major limitation of the finding. The wind direction is variable. If your clever idea only works when the wind is blowing exactly west, it's not so clever.
- dylan604 5y ago
  But in areas where the wind farms are built, isn't one of the deciding factors that the wind primarialy blows in one direction? Similar to airports and how they decide which way to build their runways. LAX doesn't even have North/South runways because of this.
  - bluGill 5y ago
    Wind is rarely exactly in one direction. A constant west wind isn't always directly 270 degrees, there is a large plus/minus factor in that.
- mhandley 5y ago
  From figure 6 in the paper, it looks like you get the win for anything from 30 degrees angle upwards. But with 0 degrees angle, the turbines seem to interfere, and you get something like 50% loss. So with a westerly prevailing wind (from 270 degrees), you'd likely put the turbines in rows at 210 or 330 degrees. If you used 210 degrees, and the wind comes from 210 degrees, you lose. Almost all the rest of the time you win. With some simple analysis of historic wind directions, you ought to be able to choose the angle to maximize net output by putting the inefficient angle in a direction that is relatively uncommon.

nabla9 5y ago

Unfortunately they don't have video of the fluid flow simulation. The effect must come from vortex interaction or syncronization and it would be interesting to see. If there is some form of strong coupling it may increase efficiency but induce vibrations.

Gravityloss 5y ago

You could have horizontal axis turbines with half of them rotating clockwise and half anticlockwise, though it seems the effect is minor, less than 2%: "counter-rotating configurations were more efficient in power generation than the control case in which all turbines have one clockwise rotor; the alternate-row case was found to produce 1.4% more power " https://www.sciencedirect.com/science/article/abs/pii/S2213138816301072 https://www.sciencedirect.com/science/article/abs/pii/S22131... Overall there's probably a lot of ways left to optimize on wind farm level. For example the yaw angles https://www.sciencedirect.com/science/article/abs/pii/S0306261920310230 https://www.sciencedirect.com/science/article/abs/pii/S03062...

selimthegrim 5y ago
And just when I was imagining twiddling my thumbs in opposite directions...

deleted 5y ago

[deleted]

exhilaration 5y ago

Wikipedia has pictures if like myself you have no idea what a vertical wind turbine looks like: https://en.m.wikipedia.org/wiki/Vertical_axis_wind_turbine https://en.m.wikipedia.org/wiki/Vertical_axis_wind_turbine

mod 5y ago
So does the article.
- exhilaration 5y ago
  You mean that header image? It's super small on my phone.

k1rcher 5y ago

So this reflects economy of scale (more turbines per area) rather than higher output/turbine, right?

SavantIdiot 5y ago

That is surprising. They have an inferior efficiency already due to the Betz limit (it is proportional to surface area facing the wind) and will always be about 60% max for a HAWT and worse for VAWT. However, the dynamics of turbulance have been one of the hardest things to model in large wind farms. The article is a bit light on details, but the last time I went to the Sandia Labs wind turbine conference in Albuquerque, VAWTS were nowhere to be seen (2015) and the biggest modeling challenge was large farm interferrence. Very interesting. Betz Limit: https://en.wikipedia.org/wiki/Betz%27s_law https://en.wikipedia.org/wiki/Betz%27s_law

nullifidian 5y ago
https://youtu.be/EM-gCvhQhPU?t=508 https://youtu.be/EM-gCvhQhPU?t=508 This lady says Betz limit doesn't apply to VAWT.
- SavantIdiot 5y ago
  Huh, did not know. Thanks for the link. Kind of disappointing, I was hoping for an explanation, not a claim.
  - palae 5y ago
    This paper has some insight: https://iopscience.iop.org/article/10.1088/1742-6596/753/2/022056/pdf https://iopscience.iop.org/article/10.1088/1742-6596/753/2/0...
    - SavantIdiot 5y ago
      I suppose I could have Googled instead of complaining, so thanks for doing the work for me! :) [I like how the first citation is from a 1920's paper (by Betz).]

efnx 5y ago

I’ve been wondering why we don’t have these on top of our street lights. I imagine a street light with a Darrieus vawt on the pole under the light and a small solar panel on top.

tachyonbeam 5y ago
Noise, maintenance, added cost and complexity. Then you also have the issue that you need an inverter and some kind of scheme to communicate with the mini wind turbines so they don't drive the voltage too high or some other kind of scheme for regulating that.
foolfoolz 5y ago
because a whole city with turbines on each street light might produce the same amount of power as 1 large scale wind farm at a fraction of the maintenance cost
- lofi_lory 5y ago
  The new Siemens offshore turbines put out up to 16MW. This has blown me away. Tho, they are scary machines and I get uncomfortable looking at them (like single balcony on a huge wall kind of uncomfortable). Aesthetically the vertical ones are much, much better IMO. Especially if they can be placed in an symmetrical pattern, not this super optimized complex mess traditional ones show.
- patrickk 5y ago
  https://www.youtube.com/watch?v=gcSnwW5v3f8 https://www.youtube.com/watch?v=gcSnwW5v3f8 There is a roadside vertical turbine concept which seems promising. It uses lampposts as a mounting point, reducing materials needed, reusing existing cables in the lamp, and scavenges energy from trucks thundering by. And since it's in a developed area, you don't affect existing views.

kuprel 5y ago

The vertical axis turbine seems like it would scale in size better since the blades are spinning perpendicular to gravity

jhayward 5y ago
They are subject to much higher dynamic forces, rapidly cycling between windward and lee side. Vertical turbines have worse wear characteristics, and it only gets worse as they get bigger and need more massive airfoils.

jeffreyrogers 5y ago

Has any research been done on the effects of wind farms on local wind/weather patterns? It seems like taking energy out of the wind in a relatively concentrated area would have downstream effects. (I'm not anti-wind energy, I'm just curious).

lofi_lory 5y ago
I think offshore wind farms have been proposed to protect the US from hurricanes. So apparently they substantially decrease wind energy.
- deleted 5y ago
  [deleted]
- cr1895 5y ago
  > offshore wind farms have been proposed to protect the US from hurricanes No, certainly not seriously.
  - lofi_lory 5y ago
    https://news.stanford.edu/news/2014/february/hurricane-winds-turbine-022614.html https://news.stanford.edu/news/2014/february/hurricane-winds...
    - cr1895 5y ago
      An estimate of 78,000 turbines is truly a thought experiment, not a realistic solution. There does not exist manufacturing capacity or installation capacity to achieve this (not even remotely close). The offshore wind pipeline, globally, is orders of magnitude fewer WTGs, and procurement & installation pressure is already expected to be very tight in the coming decade. This is made more difficult in the US due to the complexities of offshore wind installation imposed by the Jones Act. It’s a neat concept. But it will never be realized.
baq 5y ago
i'm not aware of any comparisons but imagine a sparse forest.

lacker 5y ago

I hope these researchers don't stop with just writing papers, and actually see if they can convert their theory into practice. If it's true that there's a far more efficient way to run wind farms, it seems like it could be a huge profit opportunity.

wingineer 5y ago

Wind turbine design engineer here: There are several significant barriers to adoption that VAWTs face. 1. The wind resource is more powerful and more consistent higher off the ground. The hub heights of industry standard horizontal-axis wind turbines are reaching 135+ meters for the new generation of large offshore machines. These vertical axis machines are much lower to the ground. 2. Contrary to the claims of the authors in the Renewable Energy Paper (they say "The potential applications for VAWTs are endless, because the turbines are cheaper and easier to manufacture and maintain. "), vertical axis turbines have consistently had fatigue issues. There is an interesting history of the test-campaigns of vertical-axis machines at Sandia National Laboratories [1] that discusses this. In the 70s and 80s vertical machines were much more common than they are today. 3. It is a huge risk for an industry that is shipping proven technology to switch to a new paradigm that will require much more research and testing to work at scale. It's certainly possible and I find the possibility fascinating as a curious engineer. I would love to have a secure position developing VAWT tech or working on airborne wind machines (check out ground-based generator concepts to get an idea of where I think that will progress, not ill-conceived onboard generator kites like Makani). The problem of wake blockage in large wind farms (and from adjacent farms to each other) is definitely significant though. The current "top" strategy is wake steering, where turbines at the front use their yaw drive to capture less power and allow for more power to reach the turbines in the rows following. [1]. The bleeding edge of this may be vertical wake steering, which can entrain high-energy wind from above the farm into the plant to capture more power [3]. [1] https://energy.sandia.gov/wp-content/gallery/uploads/SAND2012-0304.pdf https://energy.sandia.gov/wp-content/gallery/uploads/SAND201... [2] https://www.nrel.gov/docs/fy17osti/68396.pdf https://www.nrel.gov/docs/fy17osti/68396.pdf [3] https://ieeexplore.ieee.org/document/7963037 https://ieeexplore.ieee.org/document/7963037

breischl 5y ago
Tangentially, I ran into the bladeless vortex concept recently (https://vortexbladeless.com/ https://vortexbladeless.com/), do you have a take on that? It seems like all your concerns/critiques from above would apply equally, but then I don't have any real expertise in the area.
- 5y ago

buovjaga 5y ago

John Dabiri (referenced and thanked in the study) and his team have been researching this topic for a long time: https://dabirilab.com/ https://dabirilab.com/

jillesvangurp 5y ago

The "Just have think" youtube channel did an episode on VAWTs just last week: https://www.youtube.com/watch?v=gcSnwW5v3f8 https://www.youtube.com/watch?v=gcSnwW5v3f8 Vawts are mechnically quite simple and compact. You can put them just about anywhere. And they can operate even at low wind speeds, regardless of where the wind comes from. There's a company experimenting with these along highways to get energy from vehicles driving by. The idea here is to simply wrap them around existing street lights. Not a lot of energy per turbine obviously but it adds up if you do it along a few miles of highway. And they are cheap, small, lightweight, and easy to install.

A_No_Name_Mouse 5y ago
Nice video. > There's a company experimenting with these along highways to get energy from vehicles driving by. Those turbines will be slowing down the windflow, causing extra resistance for the traffic. The video doesn't mention that. Does anyone know if that effect is significant enough to reduce or even reverse the overall benefits (especially given the large % of ICE vehicles)?

sfblah 5y ago

Serious question. I live in a hilly area where there's a lot of wind much of the time. Is there some kind of residential analog to rooftop solar I could install? Or is the infrastructure just too expensive and complicated for a hobbyist?

duffyjp 5y ago
You can buy something in the 1-3 KW range at Home Depot. I've seen one in person at an off-grid house and the owner couldn't understand why people even used solar. This was 15+ years ago though, so solar was MUCH more expensive than today while a turbine I'd imagine was about the same?
- sfblah 5y ago
  I assume it'd be super expensive to grid tie it though, right? Sorry. I'm a total noob at this stuff.
- newyankee 5y ago
  I suspect the intermittency of wind is higher and requires a decent amount of energy storage to smoothen the output. As energy storage gets cheaper, probably off grid installations can complement their solar installations with wind as well, depending on the location.
cr1895 5y ago
Residential wind power? Wind energy is something that greatly benefits from scale: it’s why the current and next generation of turbines have rotor diameters exceeding hundreds of meters. You’d probably be much better served by using solar panels.
- sfblah 5y ago
  Sure. I just meant for fun or for a project. The biggest cost is probably grid tying, right?

gmokki 5y ago

This company has been slowly developing vertical wind trubines: https://windside.com/ https://windside.com/ They are not (yet) for mega installations, but since they are almost silent and maintenance free they can be used both in urban areas and in sahara/antarctis where things just have to work.

sn_master 5y ago

Do they have one shape or multiple? I tried searching for a photo of one but getting a mix of results.

sova 5y ago

The ancient windmills of Nashtifan continue to be vertical to this very day. https://www.youtube.com/watch/3qqifEdqf5g https://www.youtube.com/watch/3qqifEdqf5g