Wind turbine design engineer here:<p>There are several significant barriers to adoption that VAWTs face.<p>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.<p>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.<p>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).<p>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].<p>[1] <a href="https://energy.sandia.gov/wp-content/gallery/uploads/SAND2012-0304.pdf" rel="nofollow">https://energy.sandia.gov/wp-content/gallery/uploads/SAND201...</a>
[2] <a href="https://www.nrel.gov/docs/fy17osti/68396.pdf" rel="nofollow">https://www.nrel.gov/docs/fy17osti/68396.pdf</a>
[3] <a href="https://ieeexplore.ieee.org/document/7963037" rel="nofollow">https://ieeexplore.ieee.org/document/7963037</a>
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.<p>Betz Limit: <a href="https://en.wikipedia.org/wiki/Betz%27s_law" rel="nofollow">https://en.wikipedia.org/wiki/Betz%27s_law</a>
I keep wanting to read that title as: <i>Vertical turbines far more efficient</i> than <i>large-scale wind farms</i><p>But then you read up and it's really: <i>Vertical turbines far more efficient</i> when in <i>large-scale wind farms</i> than they are individually<p>Whether they can ever be made to be efficient enough to make sense seems to be the question.
Initial hot take: I'm not sure they're measuring efficiency in a way that's really meaningful to me?<p>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.<p>(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.)<p>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.
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.<p>Would they be more efficient than traditional horizontal wind parks when looking at total cost of ownership?
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.<p>(I'm not anti-wind energy, I'm just curious).
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 <i>noisy</i> - as in noisy as hell! I wouldn't want one within 500m of my house.<p>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.
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.<p>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.
since the article doesn't say or show what a verticle axis turbine is:<p><a href="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" rel="nofollow">https://www.researchgate.net/publication/333316757/figure/fi...</a>
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%:<p>"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 "<p><a href="https://www.sciencedirect.com/science/article/abs/pii/S2213138816301072" rel="nofollow">https://www.sciencedirect.com/science/article/abs/pii/S22131...</a><p>Overall there's probably a lot of ways left to optimize on wind farm level. For example the yaw angles <a href="https://www.sciencedirect.com/science/article/abs/pii/S0306261920310230" rel="nofollow">https://www.sciencedirect.com/science/article/abs/pii/S03062...</a>
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?
John Dabiri (referenced and thanked in the study) and his team have been researching this topic for a long time: <a href="https://dabirilab.com/" rel="nofollow">https://dabirilab.com/</a>
><i>“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.”</i><p>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.<p>> <i>“[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.”</i><p>This sounds like it will make the wind shadow effects worse.<p>> <i>The research found that VAWTs increase each other’s performance when arranged in grid formations</i><p>This seems like straight bullshit, and is really unclear. The argument seems to be that VAWTs are somehow positively impacted by wind shadows?<p>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.<p>I am entirely unconvinced.
This company has been slowly developing vertical wind trubines:
<a href="https://windside.com/" rel="nofollow">https://windside.com/</a><p>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.
The "Just have think" youtube channel did an episode on VAWTs just last week: <a href="https://www.youtube.com/watch?v=gcSnwW5v3f8" rel="nofollow">https://www.youtube.com/watch?v=gcSnwW5v3f8</a><p>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.<p>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.
The ancient windmills of Nashtifan continue to be vertical to this very day. <a href="https://www.youtube.com/watch/3qqifEdqf5g" rel="nofollow">https://www.youtube.com/watch/3qqifEdqf5g</a>
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.<p>[1] <a href="https://www.sciencedirect.com/science/article/pii/S096014812100344X?via%3Dihub" rel="nofollow">https://www.sciencedirect.com/science/article/pii/S096014812...</a>
[2] <a href="https://ars.els-cdn.com/content/image/1-s2.0-S096014812100344X-ga1_lrg.jpg" rel="nofollow">https://ars.els-cdn.com/content/image/1-s2.0-S09601481210034...</a>
Wikipedia has pictures if like myself you have no idea what a vertical wind turbine looks like: <a href="https://en.m.wikipedia.org/wiki/Vertical_axis_wind_turbine" rel="nofollow">https://en.m.wikipedia.org/wiki/Vertical_axis_wind_turbine</a>
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.
Unfortunately they don't have video of the fluid flow simulation.<p>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.
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.