I do know why I was directed here. I play Space Engineers, a sci-fi, engineering survival game, and you start your base by using wind turbines, solar panels or both. And the turbines can be placed both horizontally or vertically. Normally, it's easier to get "optimal" results by placing them vertically. Also, wind turbines work always, as opposed to solar panels that stop working at night, forcing to add batteries to your base if you want to have power at night. With turbines the batteries are optional until you have the resources to make them. Also, for the sci-fi part, the turbines work even in the void, supposedly by having a (tiny) temperature diferential between one part of the turbine versus the other making them rotate.
Because the oligarchs want you to believe that the world can run on these "free" solar sources. Engineers who do actual analysis without bias are not going to agree with this. That is why such projects are heavily subsidized by ignorant tax money. With that said, Rosie gives fantastic summaries of technical topics for the layman. You really get the gist of the topics she covers. No stupidification for the masses here.
Same. All i can think of is, that I'm subscribed to Dave on the EEVBlog. EEV is stand for "electrical engineering Video". This sharing the engineering part RUclips may have decided to recommend me the video. And i liked it.
Nice to see someone who is enthusiastic about developing an alternative energy source, while being honest and realistic about what it can and cannot do. Ideologues help no one. Keep up the good work!
I am thinking about a vertical axis wind turbine that looks like a tree, I call it : e-tree, the bottom is brown like a trunk, the blades are green like leaves, on the trunk of the e-tree, there are features of : mobile network, light and power outlet, to charge a car for example
I’m particular to VAWT designs because I live in a region where space is at a premium, so the overall horizontal size being smaller is a big plus for me
Interesting video. I have solar and wanted to also install a wind turbine, but for a residential area, it seemed impractical. I watched this video because a "Just Have a Think" directed me here. I look forward to more of your videos. Understanding the engineering challenges standing in the way of making alternative sources of energy work is fascinating. :-)
In urban areas the wind is block and broken up by so many structures that there's not much efficiency. For instance I can step outside my house and it feels calm. Then I take my boat to a lake near by and I realize how much wind there actually is. Big lake, not small lake, like around 30,000 sq. acres so once you're away from the shoreline you're unprotected. You'd have to make a tall tower, but then you probably run into regulations about how high you can make a structure.
It 'might' be practical for a residential area. When you get solar installed on a roof, a technician surveys the site to estimate potential solar energy based on various factors, like your latitude, or the shading from trees. If you get a vertical turbine, you should expect someone to do a similar estimate. Keep in mind, typical commercial solar cells are only efficient to around 20% brand new, so when anyone claims VAWTs aren't efficient enough for an urban setting, remind them that all that really matters are long term gains or savings, which would be estimated by an actual technician or VAWT dealer.
@@satadenai9182 You're contradicting yourself in your comparison to solar panels. You switch from efficiency in conversion of energy when talking about solar, to price efficiency when talking about wind, specifically VAWT. That doesn't work. There are different types of efficiency. I see people throw out that 20% thing as if it's bad, but it it really? As you said there's cost efficiency, and for cost efficiency solar panels, where they get the light they need, are WAY MORE cost efficient than the power grid. The only thing that comes close is wind turbines, those big ones. Cost efficiency is measured by how much production you get out of the thing over time. In different locations with current pricing for panels and electricity, in the US depending where you live as the cost of electricity varies from location to location, they can pay themselves off in 6 - 12 years now. That's how much the prices have gone down, and how much value that 20% returns. So ROI is outstanding considering panels can last about 30 years the way they are made now. But I'll stick with the point on urban and residential areas because it's going to be a rare location where wind isn't broken up. Maybe if you're one of the top few homes on a hill that puts you higher than most the other homes, maybe. And, a person coming out to a home can't make a judgement about the yearly trends of wind in your particular area. That person could only make a judgement about a particular day. That data is captured by NOAA with its main forecasting system, but it's for winds aloft, not ground level. There are ground stations that capture data but those are pretty limited. It's a lot different for solar where really a person is checking obstruction, the angle of your roof, etc... The amount of light in a general region is known data. And as is pointed out in this video, there are no VAWT units which are as efficient as HAWT. I watched a video after this one about VAWT and the outputs aren't as good as HAWT units. One company has a home unit that gives about 1600W output, but that's MAX. I think the range was something like 160W - 1600W. I also watched a video for the top 5 units at the end of 2020. None were VAWT. I can't say if that was a bias on the part of the person making a video, but I assume he knew what he was doing. In general you need a larger VAWT to give enough power to make it worth having some unit being a bit of an eyesore, and even then in a residential area you'd have to assume that most days you'd only be getting 1/4 - 1/2 its capacity due to lighter winds, and in which case the output is so little that to me I couldn't justify it in any way. Then the downside. They break. Parts wear out. Yes with a VAWT the parts are generally at the base, but with a home unit that doesn't matter so much. Even with HAWT you're not mounting the unit 40 ft up in the air unless you have a 2 story home and a place to mount it. So I wouldn't compare home wind units to solar panels. If you want a wind unit then you get one and hope it all works out for you. Solar on the other hand is typically warrantied for 20 years, the panels take a lot of abuse, even hail, and if you live in a sunny location for most the year, you're getting the MAX rated output for most the day, and not 25 - 40% of that value
@@thesoundsmith I have a pretty small yard and I seriously doubt that I could get the building permit. I think that wind and solar are the perfect combination, but it's much harder to get wind projects approved because they make noise. : -)
Came from “Just have a think”. Subscribed. Liked. Comparisons made on the basis of aerodynamic efficiency really provide little useful information. It seems to me that everybody focuses on Betz efficiency, when the efficiencies that really matter are lifetime cost efficiency and lifetime carbon efficiency. By these I mean (Energy output/lifetime cost) and (Energy output/carbon input). The first is a straightforward economic appraisal, bangs for bucks sort of thing and the second enables comparisons to be made in environmental terms. I’d love to hear your thoughts on these issues.
Well said. I'd add installation costs and the amount of concrete needed to secure the base of a HAWT to the ground to that. A cubic yard of concrete gives off 400 pounds of CO2!! A VAWT has most of it's weight at the bottom and can be secured by guidelines if needed. Also, perhaps one version might be better for snowier climates as well?
@@Hypercube9 Yes, the Darrieus (edit, Savonius) type is aerodynamically very inefficient, being drag rather than lift, but can operate over a much greater range of wind speeds and withstand extremes such as mountain tops, Antarctica etc. VAWT ability to operate regardless of horizontal wind shear is a definite advantage in a built environment.
@@q.e.d.9112 I think Savonius is the drag one. But idk why people are trying to find the absolute best / most efficient thing. What suits one person's needs might not be appropriate for a different location or climate or budget. It's not like anyone on YT is planning on building their own wind farm! LOL Most people just want to lower their electric bills or power their rural cabin.
A couple of points missed by Rosie: VAWTs have actually operated with greater efficiency than VAWTs. In the 1980s (when I was working in Altamont Pass, California) the Flowind 250 kW VAWTs achieved the greatest specific output (units of kWh/sq.m) of the turbines in the Pass - and it wasn't because of better wind speed. It was normalised for wind speed and attributed to the "troposkein" (skipping rope) shape of the blades which formed a closed shape on the central tower. This eliminates the tip vortex which is a significant source of drag on turbines with open ends (as on all HAWTs and constant radius VAWTs). The troposkein blades were favoured in the 1980s for large VAWTs because in theory they eliminate bending in the blades, though only from centrifugal loading. Which brings us to the second point: the biggest drawback of VAWTs is that the aerodynamic bending loads on their blades fully reverse every revolution (think of the upwind blade being blown towards the tower, whereas the downwind blade is being blown away from the tower). Given fatigue's well-known role as a major design driver, this is a big drawback. Also their slower tipspeed (about half that of HAWTs), which gives them the low noise advantage, doubles the torque on the shaft, driving up the cost of the gearbox.
Very good explanation Rosie - I am the co-founder of Southwest Windpower - The company is gone but we studied countless designs over the years. We produced over 170,000 wind turbines like the AIR and Skystream - There are so many challenges with the vertical axis even if someone figured out the aerodynamics - Blade fatigue was always a big issue. Lower bearing issues when they did not use upper guy-wires. Even on a roof, you still get noise. - Last is finance. They are so unconventional that all financial institutions will not touch them.
I ride bike too, though only for about 30 years 😊 And you're right that traffic gives a boost to cyclists. Did you see this video, this company want to harness traffic turbulence to make wind power: ruclips.net/video/gcSnwW5v3f8/видео.html
It was very interesting that Rosie mentioned that VAWTs are better in turbulent airflow conditions than HAWTs. There was a recent study [at the University of Warwick, I think] that performed thousands of hours of simulations and they demonstrated that VAWTs work much better than HAWTs in denser arrays, so the generating capacity per square kilometre of wind farm foot print can (potentially) be much higher. I think VAWTs are likely to become more common in the future due to this, especially in places that are tight for land area (like the UK)
Efficiency is a essential but there is also a lot of other advantages using a vawt noise, aesthetics, wild life hits and prevailing weather conditions that they can handle with no down time and having the bulk of your major components at ground level and i would think much cheaper to produce. Ive pondered this for years because of all the little exhaust whirlygigs on sheds and factories the spin silently for years. Its almost like someone built a hawt and all the research went into them. Food for thought
I've just discovered your channel and I really like the fact that you're giving real world context for the information, real experts from the field delivering information directly to the public is important and I'm grateful to you. Your chart has a comparison for efficiency in terms of power generation per unit of cross-section area, completely valid statistic with which to compare them, but it's also possible (though I haven't tried to find out) that the vertical axis turbine either lets you capture more cross-sectional area per unit of land taken up or more cross-sectional area per dollar you spend building it. One thing that immediately jumps to mind is that horizontal turbines have a circular cross section, the wind going through the corners of the square they take up is uncaptured. If you have an HA turbine that gets 50% efficiency and a VA turbine that only gets 40%, but the VA design lets you capture more of the available cross-sectional area for the same dollar value the VA might still win. On top of that you have some other considerations like the fact that the swept volume of a vertical design is always the same, whereas a horizontal one that's steerable needs to have an enormous sphere of space available where the blades could be even if they're not there most of the time. Again that's not a consideration for utilities who are trying to secure big open areas of land or ocean for their wind farms, but they might be very important considerations for a landowner trying to put up as much turbine in a constrained space as they can. Thanks for the great videos again, I'm going to go finish going through your back catalog.
Thanks for your comments, and you make some great points. You mention that efficiency isn't everything, that cost and other factors are relevant. Stay tuned on the channel for some videos on the concept of LCOE (levelised cost of energy) and related concepts, to hear more about how energy professionals deal with the issues you have observed.
Really useful video. Has anyone heard of a reasonably priced vertical turbine that produces around 5-6kw. I have a small farm, we’re up on the hills & it’s constantly windy. Even on nice summer days there’s still a breeze. I have a large shed in the yard which would be suitable for mounting a turbine on. I think this is a more practical solution than an equivalent horizontal axis turbine on a mast out in a field somewhere.
I am in the same position - plus I have been refused planning for a 6Kw HAWT on a 9.5 m. pole because people are tweeting about noise (I live almost half a mile from my nearest neighbours, so that is rubbish) and "what about the poor birds"... My father previously had a small HAWT turbine mounted on the end of the house, but we had to take it down as it was causing structural problems.
VAWT were used during the 2012 London Olympics. Though it's now 10 year old tech you may want to check it out. I have been a fan since then and like you say, more research is needed into VAWT's. The potential for use in urban areas is enormous.
There is a company that want to and is in the final stages of going to implementation of vawt installed on the middle part of highways to collect the wind energy produced by cars. The amount of energy isn't high, but it is more than enough to power lighting for the highway and more. If this is implemented and other micro energy producers are implemented, then we will reduce our overall need for electricity from the bigger scale energy sources.
Just Have A Think sent me and I am so glad he did! This is the only video I ever needed to get a solid introduction to VAWTs. Very well explained and answered all my initial questions. You have a new subscriber in me!
Strong content! As a patent attorney (and engineer (electrical)), I see one or two 'new' wind-power designs each year. IMO, the intuition and science are not always on the same page (explained below). These 'inventions' typically address one of the following issues: 1. Turbine Blade Efficiency: This means forming the blades to create a stronger force at the blades. There seems to be some tradeoff between lift and 'wind capture' - think "airfoil vs. sail boat sail". IMO, there's room for an optimal blend of these two, but I've not seen it nor have I seen it approached scientifically. 2. Wind "Amplifying" This is the idea that a higher wind speed can be created from a lower-speed wind. These usually take the form of a funnel or a deflector of some sort. Here, the laws and mathematics of fluid dynamics are the obstacle; so, doing so in a small space looks really difficult. Having felt the winds on the downtown streets of Dallas, this 'feels' plausible, but perhaps only in a tall device (defeating one of the attractions of the VAWT -- a low ground profile). 3. Electrical Turbine (generator) Start Speed Here's one area that I think is primed for improvement. Today's VAWT generators just don't turn in winds under 4.5m/s (or similar miles/hour); those that do have 'top out' electrical production that limits their uses to little more than LED lightbulbs. What is needed are VAWT generators that can, with minimal mechanical loss, gear-up and down based on the wind speed. On that note, existing gear boxes are associated with high-power-loss, heat, and maintenance. Lesser issues are noise, appearance, and local power-storage (although power-storage is THE industry issue in small-scale renewables). A desired feature in some environments is the ability to raise and lower a VAWT. Because "you" are reading this that means you're interested; so, if you have a solution, please link to it here by responding to this comment, and if you (yes, you) want to make a break-through in this space, solve any or all of issues 1 through 3, above.
Hi all the problems of the Savonius turbine can be solved everything from vibrations impulse stresses and low speed by dividing your stresses to diffirent positions. I did build a prototype . It excellerate very fast and there is no visible vibrations in the structure. I need funding to build a strong reliable model for testing and evaluating by univercities and research institutions
One way to possibly increase the efficiency of VAWT systems could be by changing the surface structure of the blades to be more like a golf ball which uses the aerodynamics to increase some lift, reduce drag and effectively increase distance but that last factor doesn't much matter as much as the first two. Presumably, this could add to efficiency on the leading and trailing winds when applied relationally to the blade shape dynamics.
I recall seeing a video of a guy who 3d printed a golf ball textured computer fan and found that it was much worse than a regular fan blade. The dimples have the specific purpose on a golf ball of generating turbulence to increase the amount of air flowing close to the skin around the ball which reduces the drag from the vacuum behind the ball. As well as help the backspin of the ball create lift. But in a wing, turbulence reduces lift by making the air break away from the surface. If you want to look up texture additions to help wings, look up whale fin bumps.
Thanks, I'm glad it was helpful for you 😊 Let me know when you make some progress on your portable wind turbine, I would love to see it! And tell me if there are any other topics you are having trouble finding information on, maybe I can help out.
Pretty good description on the various turbines, and good info all around, I also came here from Just have a Think. Though the way you praise the horizontal axis makes it feel like the vertical ones would be used in the same space in the same spacing between them, but they wouldn't be. Since the ground footprint for a VAWT could potentially be the same as a HAWT, but the aerial footprint is much smaller because you don't need to worry about a huge rotation axis that's taken up only 30% of the time, so you can fit a lot more of the vertical turbines in a space than horizontal. So instead of worrying about turbines hitting eachother, you'd have to worry about too tight a spacing taking up the wind energy inefficiently. More turbines in less space means higher energy output, regardless if the efficiency is lower than that of the other type of turbine. Something else to consider is not everybody has the space for a horizontal turbine, so even if it is much less efficient, it's still getting more energy out of it than otherwise possible. The more people adopt the technology, the faster it's efficiency will improve. A different tool for a different use. Pretty good content otherwise.
Yes - we might put up a simple , vertical axis turbine on our narrowboat - to get some energy to top up the batteries without having the bother of horizontal-axis head-choppers. (Dot)
Greetings from across the Atlantic, Dr. Barnes, As an engineer (discipline: electrical/electronics + systems) and inventor, dabbling now and then in renewable energy technologies particularly around the ocean, I happened upon your RUclips channel, thoroughly enjoying your video tutorials on wind turbines, and the sense of engineering balance of trade-offs. That appreciation and gratitude doubles for also presenting the Laws of Thermodynamics well in recognizing “green energy” scams. I shall especially recommend your channel to technical students and more vitally their undertrained teachers. At your request, I suggest these topics for future videos: 1 - Turbine Gearing. Electromechanical energy from turbines often exhibits regulated output as alternating current at a specific frequency - usually 50 Hz or 60 Hz, but shipboard this can be 400 Hz. Since wind and hydropower turbine-driven generators do not cycle so uniformly, doubtless there are some wondering how wind and hydropower turbines mechanically regulate their electrical output. I presume a continuously variable transmission or similar gearbox transmission gets implemented, or perhaps something more solid state electronic in a rectifier and DC regulator feeding a large AC inverter circuit. Mechanical friction a regular contributor to turbine inefficiency, this should include some methods used to reduce friction in wind turbine gearing. Of course, that could develop into a mini series of its own. 2 - Energy Density; Power Availability. Like the Betz Limit for wind turbines or Bekenstein Limit for information holding capacity per the physics involved, the death knell for many proposed green energy technologies often proves the engineering economics of energy density. A close cousin of this with renewable energy sources (all forms) is power availability and reliability versus weather day or night, to wit: A wind turbine yields zero power when the wind is calm; photovoltaic panels only produce power when sunlight shines (starlight or moonlight at night, not enough to be useful - and so on. In terms of energy desnity, the more plentiful source of hydrogen is petrochemical hydrocarbons, not electrolyzed water - one reason why the petroleum industry does not fear hydrogen-powered stuff. Thank you! Blessings, DSE
Isn't there also the issue that with vertical axis turbines, the shaft has to take up bending forces? This causes more friction in the best case but can lead to lower lifespans in the worst.
Bending forces, yes. Friction, no. The bending forces can wreck bearings, which is why it is nice that the main bearing for VAWT are at the bottom, easily accessible for replacement.
Friction from bending can also be reduced if the bearing isn't fixed horizontal but can move the same way a constant velocity joint dose ( The CV joint at the end of car drive wheels)
Thanks for the vid Rosie. Having worked in the small wind industry, selling over 2,000 small wind turbines, installing and servicing some 200 of them and living on a small wind turbine in my backyard the past 13 years, I'm very familiar with both HAWT and VAWT turbines. Some 10 years ago, an independent engineering firm did studies on various VAWT and HAWT turbines, at the same location, on the same tower heights and found HAWT's produce: 4-8x more energy than VAWT's, of comparable turbine ratings. Their study found that VAWT's were generating enough power to offer a: 80-160-yr. ROI while the average HAWT turbine offered: 20-25-yr. ROI. Most everyone loves the look and idea of VAWT's but they're simply yard art, they produce virtually no energy which is why the large, commercial wind turbines, never use them. In most cases, 1x 350W solar panel will far out-produce any VAWT, at a small fraction of the price.
Wow, that is really interesting! Do you have details of that study? I would love to check it out. I am hoping to do something similar on here, but I need to save up for all the turbines first! Maybe you can help me by telling me the most popular brands or turbine types you installed, so I can do those ones first. I think in addition to making nice "yard art" they are also really fun educational engineering projects. So as long as we are not pretending they are a real part of our climate change efforts then I like them simply for being fun and educational and looking cool 😀
@@EngineeringwithRosie I think the question you posed as to whether VAWTs are not efficient enough yet for commercial use is due to a lack of development or an inherent inefficiency is a great question. It's not that they produce no energy; while it is certainly true that there is published data that shows certain VAWT installations did not performed well, these tend to be in poor wind sites where a HAWT would do no better. There is other data from large VAWTs in good wind sites that have produced a lot of energy quite reliably.
One recomendation to your VT - place you VT into the tube to protect the VT against strong wind. You can than pull the tube down to “open” the VT. In case of emergency you put the tube up and your VT is save. Because the blades of VT you can not adjust according to wind
One “efficiency” you didn’t mention. A v.a.w.t. can be much shorter, which costs less money, therefore giving you more bang for the buck. They can also produce power at lower wind speeds.
Yes, there is the efficiency of the unit, but what about: The amount of materials needed? The longevity of the unit as a whole? The ease/safety of maintenance? Recyclability of the spent materials at End of Life? Thanks Rosie.
Wow, great question and I made this new video just for you on how those factors can all be combined to compare the overall cost of different generation types! (jk, I started making it months ago, but the timing of your question is impeccable) ruclips.net/video/6_BGHy4sfMs/видео.html
Although efficiency is a key parameter, I believe more important is energy/dollar. If the efficiency is 30% lower, but the cost is 50% lower, it may still be viable solution. Also, one should also add cost of "noise" and damage to the environment, e.g. killing birds
You also have the ongoing costs and replacement costs, in other words, total cost of ownership. If a VAWT is cheaper to build, cheaper to maintain and lasts as long or longer, then that would also change things. But I agree you need to actual, real examples operating to confirm the design.
@@maxmustermann9587 Yep. It tends to be human nature to assume your old assumptions are still valid. Not arguing for right or wrong of it, just that once industry is rolling down the hill it's unlikely anyone will ask are they rolling down the right hill.
There is something so much more beautiful about the shapes designers come up with for VAWTs and hopefully they do continue to develop and we get that big leap forward! Looking forward to the next video! Did you come across any biomimetic turbines in your research. I remember seeing some in very early stages based on hummingbird wings, trees and insect clap-and-fling. It feels a bit like wind turbine alchemy trying to overcome the betz limit but they're still interesting ideas! It's great to see how your channel is growing and I hope you're enjoying making these videos as much as we enjoy watching them! Cheers to you Rosie!
I agree that there are some really beautiful VAWT designs out there, especially some of the Savonius ones. I think they are probably nice as public art projects, but we shouldn't pretend they are reducing emissions in any meaningful way when they put them on skyscrapers or median strips. Biomimetics is an interesting topic, I want to do a video on that. I have heard people say that there are wind turbines based on hummingbird wings, or tubercles on whale fins. But I have to say I have never seen any major manufacturer interested in that. So I want to look into it more and make a video about it. Owl wings were the legitimate inspiration for the vortex generators that they put on blade tips to reduce noise, so I was thinking a visit to an owl sanctuary could be in order! Thanks so much for your nice words about my channel, the support means a lot. I am enjoying the community that is growing around the channel and hope to do more community building stuff this year, with a newsletter and Patreon community. I am looking forward to a bit more growth so I can bring in some pro help to reduce my workload a bit, it is more work than I can sustain to do weekly videos on my own.
This is very informative Rosie! Thanks for explaining this. I'm working on a diy savonius rotor right now. It spins and I'm excited to make power with it soon. I'm trying first with a stepper motor, which has permanent magnets and does make AC voltage which is good for low-loss transmission to the batteries, for DC rectification. My comment was really gonna be about the question of efficiency. If there is some power to be had at my site, shouldn't I get what I can to top up my batteries. A simple, quiet VAWT is better than not having one at all. And homemade means it won't cost too much $. I look forward to the next video on design of VAWTs. DIY engineering is fun!
Sounds great! If you are enjoying making it then it is worth it! Share some photos/videos on my facebook or instagram pages when you're finished, I'd love to see it!
Nice introduction to VAWTs. In the 1980's to 1990's loads of work was done on VAWTs. There was a company in the UK called VAWT lead by Dr Ian Mays which eventually became the extremely successful Renewable Energy Systems. They built several large scale prototypes which were thoroughly tested in the field including in Carmarthen Bay and the Isles of Scilly. The big issue that resulted in stopping research was fatigue. It appears that VAWTs have a much worse fatigue environment than HAWTs. The British Library probably holds copies of the research reports.
The lifetime maintenance cost remains to be evaluated, the temperature drop in Texas earlier this year caused a loss of electrical power that Horizontal axis(conventional wind turbines) froze and failed to deliver power does address other considerations. The simplicity of VAWT is compelling. The longevity of simpler engineering designs has been proven over time..
Texas didn’t invest in the anti-frost technologies that already exist. Presumably because its not cost effective if it doesn’t happen often but with climate changes they are likely to become more common.
@@alisonshellum9870 The last time that I looked, the Sun does not shine at night. The wind stops and starts presumably due to climate change. I think most people do not want higher energy costs, who does. I just received notification that our local power company will be raising rates due to the proposed tax hike on businesses. So much for people making less than $400,000 per year not getting a tax hike.
@@MrRickyw01 Thats down to your local politics and failure to tax fossil energy giants to cover future green investments. Other countries have been investing in renewables effectively for many years. Battery storage exists to help store solar energy in the daytime for use at night time and EVs with vehicle to grid will enhance this. Most younger people accept that we all have to pay for the mistakes of the older generations.
@@alisonshellum9870 You missed my point. The local power company is owned by the citizens of my city. Your right that it is an energy giant. However their only source of income is from the people using their electricity. When the taxes go up they have no alternative but to pass on the taxes and the cost of natural gas. They stopped burning coal many years ago. Germany did follow your thought. They currently employ an ex-German Prime minister to be nice to Putin, since Germany has become beholden to Russia for Energy.
Although efficiencies are important, when comparing the two types, it is surely profitability that is a more important factor viz initial cost + running and replacement costs per KW/hour of electricity produced under similar conditions. I believe VAWTs will always be less efficient at extracting energy from the wing but they do often work at lower wind speeds.
thanks for the video rosie! very educating! water engineer here, learning a lot from you! all these years after my fluid mechanics course, still learning things!
I'm a power engineer. I work primarily with energy generation and exchange. I am genuinely curious here- doesn't the HAWT put an extreme amount of pressure and wear on the bearing holding the turbine shaft? Like, those turbine blades look to way several tons, and there is no counter weight on the other side of the bearing. Would this not seize bearings a lot? I deal with bearings all the time and don't see how this would work for more than say, a decade before the bearing fails. Please let me know, anyone, if it's more resilient than I'm thinking.
Ultimate efficiency is a very important thing to understand - especially for large scale utility projects. But for most practical, smaller-scale installations, the more relevant factors include: initial investment & maintenance costs, noise levels, proximity to the use-case and to a way to store the energy produced. You may be able to get far better wind 50 meters up offshore; but that doesn't matter if you're trying to go off-grid on your own property, or hoping to increase your factory's power-failure resistance.
Great job! Curious to see what the efficiencies are when you factor in cost, not just to build, but operational lifetime as well. Also, presumably that efficiency loss can be made up by being able to place more in a given area?
Efficiency is simply the total amount of energy available, divided by the amount captured. Cost doesn't factor. There is a concept LCOE - Levelised Cost of Energy that takes into account all the equipment and maintenance costs, divided by the amount of energy produced in its lifetime. Investors use that value rather than efficiency to compare options. And now we are going beyond LCOE to include value - how much can you sell the electricity for. I have a video coming up on that next week, so check back then! But I need to note that so far, VAWTs all have higher LCOE than HAWT. Doesn't mean they always will, but it is not as easy to make a cheap and reliable VAWT as many people assume.
@@EngineeringwithRosie Can you do a short analysis on small VAHTs - like what someone would build as a camping generator? (using a battery pack) It has been a long time since I studied these, but I recall that VAHTs require external torque to start them up aerodynamically which would make such a machine overly complex. If not, then one could use pieces like wind surfing masts and sail cloth blades for a very light weight package.
@@kenhnsy a battened sail cloth savonius design would be very interesting. Although for backpacking I would be tempted to use electrolysis to store HHO in a bag for use later instead of a battery since the gas would be lighter than air even, whereas meaningful battery storage is heavy. But if you just mean for charging emergency devices and such I could see a small vaht generator design being plausible. Just wondering if it outweighs the benefit of a folding solar panel in terms of reliability.
That was very interesting. There seems to be in the countries I know about quite a lot of popular resistance to onshore wind, and often one of the arguments is noise. Perhaps vertical wind turbines could be a solution here, sacrificing some efficiency for public acceptance. You could also put them in towns and cities, producing locally produced power, even when the sun is not shining.
I would be curious to know your thoughts on the newer sail or kite wind power generation. That technology seems even more scalable/cost-effective than current generations of large utility turbines.
more scalable - in what way? And how would they be more cost-efficient? They require a lot more active control, require more airspace, have to be spaced further apart as the kites can freely move and could otherwise collide, and do not produce nice consistent power. And due to the nature of all the moving parts they also require more maintenance. They do have the benefit of having a small footprint on the ground and producing a lot more power. So while they can be really good for certain applications, they are not even close to being viable for the bulk baseload of power - which is the biggest problem we have with renewable so far. Using them on a ship to decrease fuel-usage is a completely separate area but one were they can deliver their full potential, easily doubling their efficiency compared to when producing electricity.
Recently had Electric solar installed with my water solar. I never really wanted a turbine but you might have sold me! The VAWT's aren't so ugly and quiet! And having a possible night time trickle charge would be nice. Thanks!
The best application i've seen for VAWT has been roadside energy capture along highways. I read of a pilot where recaptured energy is fed to electrified roadbeds with electric vehicles using EM regenerative charging from the roadbed while in motion.
Hi Larry, great comment! Maintenance is not included in efficiency calculations which is purely the amount of energy extracted compared to the maximum. But there is a measure, LCOE (levelised cost of energy) which does include these very important considerations. I plan to make a video on that topic soon, it is much more widely relevant than efficiency on its own as you are clearly aware.
True energy efficiency of the design would be: (Total energy required to manufacture/build/maintain/remediate structure @EOL)/Total energy generated over life of the structure The differences in the design's nominal efficiency of energy extraction from the wind merely determine the area efficiency of the design, ie how much land you have to spread them over to meet your energy output target. Obviously the area efficiency is important, and will also feed into the total cost of the wind farm build, so may well override the energy efficiency due to initial investment requirements; it would be interesting to see how all the figures compare.
@@thecraggrat Great point! That is measured by Energy Return on Investment, EROI. en.wikipedia.org/wiki/Energy_return_on_investment Want to see a video on that?
Hello Rosie, Thank you for your video. There is only one fundamental fact that you need to make clear on the difference between Vawts and Hawts, On the Horizontal axis wind turbine, All 3 blades (3 is the accepted best number) deliver an equal output into the wind in the instance. The prop can be balanced for high speed output., The numbers alone tell you that the Hawts are the clear winner. On the Hawts , only one blade works at a time and its output is further resisted by the returning blades. You can draw it as many ways as you like but the returning blades do cause a drag. So you need a Vawt with a blade area 3 times the size of tbe corresponding Hawt, It is very simple.
There are a few more benefits for VAWT's as well. With lower speeds and more compact area's there would be less effect on birds and bats then HAWT's. Mainly I am looking at a compliment to my solar panels and batteries here in Canada and so I want a turbine I can build that is quiet and does not need such a large tower. VAWT's seem to be the better choice for this. Also I think they look so intriguing too. My plan is to convert an old honey extractor to a VAWT
Hi Tom, HAWTs are known to be destructive to airborne wildlife like bats and birds, as you said. Is there any evidence that VAWTs are safer for wildlife? If so, I'm sold!
Lovely videos. Thanx for making them. I would love to se a video on what type of turbine horizontal / vertical that would make the most sense for private use. I feel there the constraints might for different result as size and ease of use might become more of a factor. =) Keep up making more great videos. =)
I think VAWTs mounted horizontally at the top corners of tall, oceanfront buildings is one great application for them as the wind direction is generally constant and the horizontal mounting takes advantage of the vortices.
HAWT's: The variation in rotational speed along the blade's long axis, as well as the ljmiting factor if tip speed, is also a problem in Helicopter and Propellor driven aircraft blades as well. For example, if you get the tip speed going too high, the tip can cause small repetitive micro-burst shockwaves as they break the sound barrier. The air around them expands to the point it is no longer touching the blade, and then snaps back around it, rapidly, and it does this so violently that it causes cavitation localized on the blade tip. The blade, when it is in a point of no air (air voided from its surface by the sudden shockwave, basically) the TIP no longer has any air resistance and wants to spin faster than the rest of the blade, causing the blade to flex wildly in the forward direction of rotation. Then when the air smashes back together around the blade tip, it actually causes MORE air resistance at the tip than before the shockwave pushed away all the air, and thus slows the blade tip even further than it was before the air left the surface of the blade. This causes the blade to flick back away from the direction of travel (deflect/bend) even further than normal. This then happens... HUNDREDS of times a second, and you get blades flexing, bending, warping, wobbling, snapping, and shattering all over the place, and VERY rapidly turning into VERY fast moving shrapnel. This is why long rotor blades for aircraft often have specialized tips and shape geometry, to break up the aerodynamics a bit or to cause the air to delay leaving the airfoil for juuust a fraction of a second longer than without the different geometry. This also helps to quiet the blade, allow the blades to spin faster, and provide MORE lift due to being able to spin faster and move more air overall. The same is true, relatively, for wind turbines. Your industry resolved part of this problem by chqnging blade geometry, but it also sort of solved itself, in that the wind turbines are not powered, but providing "power". Fascinating. :-)
With the vawt being maintenance cost effective as well as space efficient wouldn't the loss of generation efficiency be overcome by just adding more vawt turbines and still come out more cost efficient maintenance wise?
They would parasite from each other. Decreasing overall efficiency. That's why wind turbines are spaced away from each other. With some very specialised exceptions like roof line vertical ones rotated to be horizontal. But then they become directional. So if your roof isn't angled just right they no reason to use them
SeaTwirl is a Swedish company that makes revolutionary floating vertical axis wind turbines (VAWT), custom made for the conditions at sea. Very interesting.
Thanks for a great video! I've always thought that turbine designs have more difference in efficiency. This opened my eyes. Simpler, more robust and easier to maintain, why would I choose the other alternative over 10-20% efficiency add?
Levelized Cost of Electricity. If 10% increase in efficiency costs you another $5000 upfront, but you make an additional $10,000 over the life of the system it's worth it. As a developer of Vertical Axis Turbines for hydro, the broad statements like "simpler" are misleading. Our systems are mechanical pretty basic, however the forces are way different than industry standard and the power electronics handle it differently. You trade simplicity one place to another.
@@Rokmonkey32 Thanks for your reply. I'm thinking about building my own system mostly out of junk lying around, something like oil drum savoniuses put up on old flag poles These things are just simpler to build and repair. Numbers you threw are out of my league and goal. I'm not about making or even using money. I'm trying to create atleast a little of power with something made out of repurposed stuff. Even 20Wh average is better than nothing when I did it myself out of almost nothing.
Echoing what Nate said. Cost efficiency should be the main thing you consider. In which case it's how much you pay vs. the total output of the unit over its lifetime. This in turn would be compared against what grid electricity costs, and with that total output, did you save money or make money. I'm not big on wind for households unless solar isn't an option. They don't generate nearly the kind of power a modern household uses. You really need to be in a place where it's windy most of the year, AT your home. Plus, those smaller units for homes break, probably more frequently than the large wind turbines uses for powering the grid. Plus, you need a few to give power output you need for the home. So urban areas and residential areas are not very good places for these. Wind near ground level gets broken up, deflected, etc... and you would need the unit to be up above rooftops, probably by at least 20ft. for them to be effective. But even at that height wind is still being broken up by wind that comes up off a home by deflection. Anyone who lives in a residential area and then takes a boat to a nearby lake, large lake, can tell you the difference is pretty large. So in this case, a wind unit is these environments is probably giving you 25 - 40% of it's rating, and on rare days you get 100%. I'm pretty much in the path of the Texas wind corridor and it can be calm where I live at ground level, but go to the lake near by and there's white caps on the water, and I'm feeling the wind hit me pretty hard. Now, the tops of the trees are catching the wind near the home, but at ground level there's very little. So if you can, solar if a better option for a home in those areas. If you have a good place for the panels they'll give you 100% of their rating much more often than a wind turbine will. So if you plan on buying a wind turbine for the home, do research, but there is no good wind data for where you live in particular, and the only way to get that info is for you to measure wind in about the same spot you would put the turbine, over an entire year. If on the other hand you live in a windy rural location and you feel wind regularly at ground level, then much better odds they're worth the investment. But, I'd still rather have solar if the location is good for that. Single panel production, where a panel is about 1.5 x 1m, they give about 400W, some better, some worse. I also think the cost/watt (cont.) is lower for solar panels. In specific if I had a ranch style house where one side is south facing if I lived in the N. Hemisphere, those roofs EASILY have the space for enough panels to give you more energy than your house can consume. A central AC unit for instance uses somewhere between 3000 - 5000W, once again some being out of this range. An electric clothes dryer uses 2000 - 5000W. A modern gaming PC can have a graphics card that uses 200 - 300W and the CPU that drives the PC can use 60 - 200W. Then what if you use power tools, etc.... I wouldn't install panels to power both central air and a clothes dryer at the same time, unless you also have input from the power grid, but I would at least get up to about 9000W with panels, if I want to almost completely power my home or be off grid, and then not run central air when running a clothes dryer.
@@johndoh5182 Thanks for your time, there was lot of good info and great too. Electricity price has more than doubled in the last two years so going off grid is my goal. I live in north-east part of Finland where there is not so much sunshine but I still have some panels waiting to be installed. Six 250W panels, looking to double that when another bargain comes up. Just got used 4kW inverter that takes almost everything you feed her, solar or wind. 10kWh gel batteries also waiting to be in action. I live on Russian border in an old house build after war and to nearest city is about 30 miles. Heat comes from burning wood and 90% of the electricity is needed to heat the water. 1600W water heater, of course it's only on use some of the time, our hot water tank is pretty well insulated. No need for air conditioning, our summer is rarely that hot and when it is, it does not last too long. Water comes from our own well using automatic electric pump, 700w, I think. House is build on a hill on beach of a lake that is on the south side. Usually the strongest winds come from the south. Our house is surrounded by small fields with couple of taller trees giving shade. Fields are mostly not in use and offer lots of space to put up some wind generator poles/towers. +20ft is not a problem. Low average wind speed (7-9mph) is also not a problem when dealing with generators optimized for lower wind speed conditions. They generate less but they generate anyway. I got a hold of 22kW AC electric motor. Sucker weights 440 pounds. Collecting strong magnets to convert it into permanent magnet generator. Time shows if the winds will rotate it or will it be something else. You talked about modern house power needs. My house is far from modern with pretty low need of electricity. Cooking using burned wood is an option I often use. Couple of winters ago I realized I had not been using an electric stove for four months; did almost all my cooking in our big brick oven. My gaming laptop draws some power but nothing spectacular. No dryers for clothes here, we have ropes outside for that. Mostly we dry our clothes inside, moistens the air a bit. Fridge and deep freezer consume very little power and most of the year the freezer runs on fumes because it's on the cold storage room enjoying outside temps. The only reason I would think of a solar system closer 10kW is an electric car. The prices here makes an electric vehicle a distant dream. Not that it works properly in our winter time when it's -30°F in recent technology. The great thing about the place where I live; when it does not shine, it blows (pun intended). Solar, wind and gas generator in the heart of the winter is the plan. Been thinking about wood gas generator. The wood is plentiful and growing tree sucks much more carbon than it produces when burned. Been gathering supplies and knowledge to start living my dream of being mostly self sufficient. Been growing some of my own food and spices, eating fish from the lake and meat from the forest. Hard times are coming. I hope it's not too soon, I do enjoy the easier life.
I think putting these around lamp posts on the sides of motorways is interesting... closest to fast Lane and the air being pushed by cars would provide wind.
I think you bought up most relevant points. Vertical axis turbines are usually plugged by snake oil salesmen and have no use at all in utility generation. Distributed generation is about as much use as a chocolate fireguard. You're far better off, as an individual, taking shares in a proper turbine than installing a miniature one in your garden. Don't forget that large vertical axis wind turbines have been trialled, and actually an issue not many people think of is bearing wear and gyroscopic effects. The out if balance loads on the main bearing are high, to say the least. Generally these turbines are not self starting but that's not a problem for modern electronics and could even be an advantage for storm conditions. "Sea twirl" is a business that seems to exist primarily to harvest money from gullable investors in return for computer graphics and promises if solutions to problems that don't exist. There will be others on the same bandwagon
The logistics of such a thing would be a nightmare. The material, the design, the construction would all be tremendously expensive and difficult to manage. In fact, a lot of theoretical and doable constructions of literally any mechanic is superior to the commercial variants in efficiency but their cost offer diminished returns so they are not viable.
As a retired engineer, how about a combination of the two HWAT and VWAT? 💡 If you were to put a wind channeling and speed increasing by reducing the input/output diameter (funnel shape) that fed a HWAT on a vertical axis, you could get the best of both worlds. The wind capture funnel(s) would be required to be in a circular shape with a smooth curve that would not remove most of the wind force. but divert it upwards. The vertical axis mounted blades would then be able to have access to the speed increased air. The air flow would obviously be through the top with a screen across it to prevent animals from getting into the blades. Another way to think about this might be a water turbine. Basically the same principle with multiple sources of water. This would increase the efficiency by increasing the wind speed being applied to the blades and also making it omnidirectional. The best of both worlds.
I think your video quality would increase a lot if you put up some towels or other sound absorbing material behind the camera :) The shadows from your hands could also be removed with better lighting for a more proffesional look :) There’s a lot of videos on how to light up a scene, so it might be worth taking a look there :)
Where I live used to be characterised by its windmills, but ironically wind speeds are not consistent enough for utility turbine deployment today. My house often has an onshore breeze and high wind in the winter, so a practical quiet way to harvest wind energy combined with solar and ideally energy storage would be interesting.
Hey Rosie, how about side by side tests for various wind turbines, see how they perform against each other at the same site. I mean like a competition. Much work I suppose... could be a fun project..
I would like to do it, and have been thinking a lot about it, but the cost is a bit prohibitive right now. I don't think it will work well if I get them given to me by manufacturers, because then there is pressure to say nice things about the product I got for free. Maybe I can set up a Patreon or some other crowd funding and have people donate and vote on which models they'd like to see tested first.
One of the big killers of VAWT is the simple fact that the force acting on the blade (lift design) is only there during aprox ½ of each rotation. During the retreating and advancing portion of the rotation the lift is nullified. One way to possibly over come this is to use some type of variable pitch system.. maybe… look up voith drive (water tractor propeller system) it uses a constantly changing pitch system to maximize thrust in that case but something similar could be adapted to a VAWT
Hi Rosie! I'm an engineer like you! I appreciated a lot your video, I subscribed and posted a link to this video on a sailing Facebook channel. Cheers.
The rotor configuration is important to the self-starting characteristics of the rotor. The graceful curved blades on some Darrius-type VAWTs are not there to look nice, they actually improve the ability of the rotor to self-start because there is always some part of the rotor that is at the optimal angle of lift to start the rotor turning, and as that part of the rotor turns away from that angle, another part of the rotor is turning into that optimum angle. Self-starting behaviour is a particular difficulty with VAWTs, but it can be overcome with careful design.
Drag type VAWTs are self-starting. People have sometimes combines drag type and lift type to make the combination self-starting. It would be best to have a freewheel between them as the lift type will need to spin much faster to be efficient, I think.
I feel a mix of the two, where applicable, is best. Solar cost per watt is going down but efficiency is still not what it could be. HAVT will be best option for the vast array of wind conditions not suitable for HAVT. Medians on freeways. Urban industrial rooftops or plant towers. Commercial buildings. Also the lack of transmission loss. Being closer to existing infrastructure is a huge factor beyond simple efficiency. Great video.
Just off the top of my head, if for vertical turbines that each blade could rotate, you would design it so a blade catches the downwind, but when it is moving back around to being upwind, if I'm getting this right, that the blade has rotated to where it's not catching the wind, just like wind moving over a wing, you would have more efficiency. However you'd add complexity and cost, and the blades couldn't be too fancy like some of them are. The turbine would have to sense the direction of the wind which is easy enough, and then that would determine the way the blades orient. Maybe this already happens without a blade rotating.
@@EngineeringwithRosie Lower to the ground will definitely help, but the rotor diameter tends to be lower, so the force at the tips is lower. VAWT tip speeds never reach the supersonic!
Interesting discussion of the pros and cons of the different types. It is good to hear from an engineers perspective why the 3 blade turbine is now the standard and most common form. I think a good topic for a future video would be about the impact scale has on the wind power produced by turbines, I would be interested to know if due to their small scale, whether domestic turbines can ever be effective and about the trends towards larger turbines, particularly offshore.
Really enjoyed the video. As an amateur engineer I have a plan in my head for a vertical axis turbine that gets round the problem of the blades rotating into wind and robbing efficiency. My idea involves a drum with blades that fold flush to the drum but come out for half a revolution to catch the wind. The timing of the blade actuation would be cam based. The positioning of the cam would be provided by a wind vane that always faced the wind thus ensuring the blades were always open at the right time. How that would work in reality I'd love to know. Keep up the good work.
I think that's a really fair assessment of the VAWT vs HAWT. In adding complexity to increase efficiency, potentially a variable pitch design similar to what cyclotech is developing for VTOL aircraft could capture more energy with a smaller cross sectional area.
There are now a number of papers that have shown that a set of counter rotating VAWTs can be packed much more densely than HAWTS, and so achieve better land use efficiency. They are counter rotating to make better use of turbulence cause by upstream turbines, thus boosting the energy efficiency of the grid as a whole, even though each individual turbine still has lower efficiency than a HAWT.
@@SMD1999 ha ha, Google speaks Chinese! I can say two things in Mandarin "I don't understand what you're saying" and "I am stuffed full." I can't write them though
I'd like to see more comparisons along this line: amount of wind generation per physical area. Does placing more of the simpler, lower-cost VAWTs in the same physical area as a single higher-efficiency, more complex HAWT have a balancing point? And if so, what is that balancing point?
Thanks mate,, a windy day here on tge deck stuck in italy,, thought with the current govt 110% payback for energy efficient home improvements,, its a wind wind, bahaha
Scott McKie -- Hi Rosie -- very well done video. One topic that you might also think about adding in your section about vertical shaft turbines and their blades is the following, and it comes from being an aircraft pilot. The topic is named the "AOA" or "angle of attack" of the blade - as it interacts with the wind - which, because of the vertical axis -- is coming from only one direction at a time. The maximum efficiency point of each blade / wing - is when the blade is just a little behind 90 degrees, i.e., "leading edge up", i.e., almost "in-line" with the direction of the wind. This position produces the maximum amount of "lift" - which is transferred to the vertical. Also -- you did not explain the "percentage" of interaction with each blade - with the wind between the vertical and horizontal axis turbines. A horizontal turbine -- has it's blades turned "into the wind" for 100% interaction, i.e., continuously produced lift - while the standard vertical axis turbine only has 100% efficiency as described above. FYI -- the only vertical axis wind turbine that can come close to a horizontal shaft axis wind turbine - would be a design where each vertical blade would be gear driven off of the Ground connected stationary vertical shaft of the turbine itself. This way each vertical turbine blade would always be "turned into the wind" - for maximum efficiency on the windward side to the turbine -- but why do it.
@8:40 I'm not a great mech designer, but it seems simple enough to design a pivot on the VAWP blades so they lock with the wind direction (i.e. max push force obtained from wind) and pivot to show minimum resistance on the "into the wind" return path.
I wondered about that before, but I was thinking of a blade that isnt solid, but has a bar at each side connected by something like a bungee cord, inbetween the bars would be strong flexible material, so the push of the wind would also expand the blade whilst driving it, and when that wind energy is used it springs back to the closed position on its way back. i think if it worked at all it would have to only be small scale
One efficiency only available to Vertical Axis Wind Turbines is in the use of magnets. You put polar opposite magnets in the base and the turbine, and can get close to a frictionless bearing. I've seen these for marine applications, where noise, vibration and maintenance are the key issues, Horizontal Axis Turbines are generally prohibitive to sleep on a sailboat and are almost always missed in favour of solar, but getting the real estate for the amount of solar on a small boat is a pain, especially with sails up. I'm hoping VAWT keeps developing well.
One point about savonious illustration was there is a design popular in the 1970 made from 55 gallon barrels usually three stacked high. The barrels were cut in half and instead of meeting edge to edge as shown here overlapped the axis so wind on the catching side was turned 180 degrees and pushed on the up wind side. The three barrels faced 120 degrees a part to even out the torque with three maximum points per revolution. Guess you could use more but point is the changing wind direction is more dynamic like a Pelton wheel compared to a water wheel with flat floates or paddles. It brings up a question how much more efficient would curved buckets on a wheel be than flat ones?
for a home use , lower cost output unit , i would go vertical unit , 30% is better than 40% in the total cost of running an mainting the unit . i can understand why commercial units are hwt's , cause they dont want the cost of reinventing the wheel . great vid .thanks
I have a four part engineering puzzle you may find of interest. First I watched part two to this vid first so I'ma reference it. I wrote about the use of a shield/scoop around the blades. It fixes many issues of Vawt's. Second: you've heard of a blade less fan. Basically a wing shaped like a ring. Known to increase air flow over that provided by the internal fan by 15 X and more. A Dyson Fan. Third: when I was in school, I learned about jet engine design from an 16mm military training film. We join the narrator at a fondue party or some whatever. A man sits across the room next to a shade lamp smoking a cigarette. The narrator points out how the smoke flows between the man and the lamp because smoke rises. The man turns on the lamp. When the lamp heats up the smoke is pulled to the inside of the shade then up. Yea we were taught with cigarettes. I assume you know why the smoke did as it did. Fourth: I had a small blade less fan. One small flood later I had a toy to play with. I took the ring wing thing and made 4' legs for a 4' diameter ring. Painted it flat black and put it in the sun. It did generate air flow. Cutting slots near the bottom to provide air flow to the core it became a fan with no moving parts, If you placed a 6' diameter Vawt over it and kinda down and around the top edge it powered a bike tire dynamo enough to light the bulb. Kinda. The blade pattern I used was like a conch shell. Fat end down. In my opinion this is the path grasshopper. If you do poke around at it I would be interested to know how it goes.
I think the biggest benefit of a VAWT is that they can be placed a lot closer to each other, and in places that wouldn't make sense for HAWT. Like all along the sides of a motorway, which would have the benefits of capturing not only the wind, but vehicle air turbulence, and there is a lot of free real estate that could be capitalized just for that. Even a drop of 10% efficiency would be outweighed by the sheer number of turbines that can be installed
I have a design of a vertical wind turbine that works on compression and it has zero drag so a very small turbine can produce a lot of power. Vertical wind mills work on suction and you can only get a limited amount of suction. The vertical turbine under compression is far more efficient than a horizontal wind mill turned by suction. The pressure drop behind the blade on a horizontal is what can cause the blade to turn but once it is at zero pressure you can not get any more power from the blade. If you put a vertical turbine under pressure you can keep building the pressure thereby getting more power. This is how a car motor works. The piston is put under pressure and you get a lot of power from a small package. My friend has a v8 motor that can create 700 HP and small enough to fit in a F-150 ford from 1999. You increase the pressure on the piston to do this. You can never get that kind of power from suction (vacuum) . The air flow over an air plane wing creates a pressure drop and the wing is lifted into the space where the pressure drop happens. A pressure drop on one side of a surface can never be as great as a high pressure compressed air flow on the other side of the surface. I know a guy who said his wind turbine had a 3 to 1 compression ratio. I looked at it and It had many problems but was still better than any horizontal wind mill. My design has a 4 to 1 compression ratio and does not have any of the problems that his does ( he has to rotate the building into the wind with his and that is a big problem). He refused to believe that it is possible to get a 4 to 1 compression ratio, but my math can prove that mine will do that. Small package but will put out a lot of power. I know that some of you will want the plans but at this time it is classified.
I'm not sure if you are aware of Vertogen, but they are working on an self-governing variable pitch VAWT mechanism that might improve the efficiency of VAWTs significantly. It might be fair to say that "automatic variable pitch" is the holy grail of VAWT technology as it promises improved efficiency, improved self-starting and another layer of safety against overspeed. Only time will tell if the benefits outweigh the downsides produced by the complexity.
I've never watched anything about turbines before and I have no idea why The Algorithm suddenly decided to show me this, but I really enjoyed it.
I do know why I was directed here.
I play Space Engineers, a sci-fi, engineering survival game, and you start your base by using wind turbines, solar panels or both. And the turbines can be placed both horizontally or vertically. Normally, it's easier to get "optimal" results by placing them vertically. Also, wind turbines work always, as opposed to solar panels that stop working at night, forcing to add batteries to your base if you want to have power at night. With turbines the batteries are optional until you have the resources to make them.
Also, for the sci-fi part, the turbines work even in the void, supposedly by having a (tiny) temperature diferential between one part of the turbine versus the other making them rotate.
Because the oligarchs want you to believe that the world can run on these "free" solar sources. Engineers who do actual analysis without bias are not going to agree with this. That is why such projects are heavily subsidized by ignorant tax money.
With that said, Rosie gives fantastic summaries of technical topics for the layman. You really get the gist of the topics she covers. No stupidification for the masses here.
Who's that Al Gorithm person anyway???
agreed
Same. All i can think of is, that I'm subscribed to Dave on the EEVBlog.
EEV is stand for "electrical engineering Video". This sharing the engineering part RUclips may have decided to recommend me the video. And i liked it.
Nice to see someone who is enthusiastic about developing an alternative energy source, while being honest and realistic about what it can and cannot do. Ideologues help no one. Keep up the good work!
very enthusiastic indeed !
I am thinking about a vertical axis wind turbine that looks like a tree, I call it : e-tree,
the bottom is brown like a trunk, the blades are green like leaves,
on the trunk of the e-tree, there are features of : mobile network, light and power outlet, to charge a car for example
I’m particular to VAWT designs because I live in a region where space is at a premium, so the overall horizontal size being smaller is a big plus for me
What about the wind speed
@@ashiks.a.4560 wind speed is free, space, however, isn't.
@@ashiks.a.4560 And the type of wind.
Interesting video. I have solar and wanted to also install a wind turbine, but for a residential area, it seemed impractical. I watched this video because a "Just Have a Think" directed me here. I look forward to more of your videos. Understanding the engineering challenges standing in the way of making alternative sources of energy work is fascinating. :-)
In urban areas the wind is block and broken up by so many structures that there's not much efficiency.
For instance I can step outside my house and it feels calm. Then I take my boat to a lake near by and I realize how much wind there actually is. Big lake, not small lake, like around 30,000 sq. acres so once you're away from the shoreline you're unprotected.
You'd have to make a tall tower, but then you probably run into regulations about how high you can make a structure.
It 'might' be practical for a residential area. When you get solar installed on a roof, a technician surveys the site to estimate potential solar energy based on various factors, like your latitude, or the shading from trees. If you get a vertical turbine, you should expect someone to do a similar estimate. Keep in mind, typical commercial solar cells are only efficient to around 20% brand new, so when anyone claims VAWTs aren't efficient enough for an urban setting, remind them that all that really matters are long term gains or savings, which would be estimated by an actual technician or VAWT dealer.
@@satadenai9182 You're contradicting yourself in your comparison to solar panels. You switch from efficiency in conversion of energy when talking about solar, to price efficiency when talking about wind, specifically VAWT. That doesn't work.
There are different types of efficiency. I see people throw out that 20% thing as if it's bad, but it it really? As you said there's cost efficiency, and for cost efficiency solar panels, where they get the light they need, are WAY MORE cost efficient than the power grid. The only thing that comes close is wind turbines, those big ones. Cost efficiency is measured by how much production you get out of the thing over time. In different locations with current pricing for panels and electricity, in the US depending where you live as the cost of electricity varies from location to location, they can pay themselves off in 6 - 12 years now. That's how much the prices have gone down, and how much value that 20% returns. So ROI is outstanding considering panels can last about 30 years the way they are made now.
But I'll stick with the point on urban and residential areas because it's going to be a rare location where wind isn't broken up. Maybe if you're one of the top few homes on a hill that puts you higher than most the other homes, maybe.
And, a person coming out to a home can't make a judgement about the yearly trends of wind in your particular area. That person could only make a judgement about a particular day. That data is captured by NOAA with its main forecasting system, but it's for winds aloft, not ground level. There are ground stations that capture data but those are pretty limited.
It's a lot different for solar where really a person is checking obstruction, the angle of your roof, etc... The amount of light in a general region is known data.
And as is pointed out in this video, there are no VAWT units which are as efficient as HAWT. I watched a video after this one about VAWT and the outputs aren't as good as HAWT units. One company has a home unit that gives about 1600W output, but that's MAX. I think the range was something like 160W - 1600W. I also watched a video for the top 5 units at the end of 2020. None were VAWT. I can't say if that was a bias on the part of the person making a video, but I assume he knew what he was doing.
In general you need a larger VAWT to give enough power to make it worth having some unit being a bit of an eyesore, and even then in a residential area you'd have to assume that most days you'd only be getting 1/4 - 1/2 its capacity due to lighter winds, and in which case the output is so little that to me I couldn't justify it in any way.
Then the downside. They break. Parts wear out. Yes with a VAWT the parts are generally at the base, but with a home unit that doesn't matter so much. Even with HAWT you're not mounting the unit 40 ft up in the air unless you have a 2 story home and a place to mount it.
So I wouldn't compare home wind units to solar panels. If you want a wind unit then you get one and hope it all works out for you. Solar on the other hand is typically warrantied for 20 years, the panels take a lot of abuse, even hail, and if you live in a sunny location for most the year, you're getting the MAX rated output for most the day, and not 25 - 40% of that value
Why impractical? Think of them like TV antennae. Where they can work, there is almost no downside.
@@thesoundsmith I have a pretty small yard and I seriously doubt that I could get the building permit. I think that wind and solar are the perfect combination, but it's much harder to get wind projects approved because they make noise. : -)
Came from “Just have a think”. Subscribed. Liked.
Comparisons made on the basis of aerodynamic efficiency really provide little useful information. It seems to me that everybody focuses on Betz efficiency, when the efficiencies that really matter are lifetime cost efficiency and lifetime carbon efficiency.
By these I mean (Energy output/lifetime cost) and (Energy output/carbon input). The first is a straightforward economic appraisal, bangs for bucks sort of thing and the second enables comparisons to be made in environmental terms.
I’d love to hear your thoughts on these issues.
Same! Such algorithm.
This is brilliant! Take less space. Installed on a homes roof. Can be close to the ground ...or not. Quieter. More efficient.
Well said. I'd add installation costs and the amount of concrete needed to secure the base of a HAWT to the ground to that. A cubic yard of concrete gives off 400 pounds of CO2!! A VAWT has most of it's weight at the bottom and can be secured by guidelines if needed. Also, perhaps one version might be better for snowier climates as well?
@@Hypercube9
Yes, the Darrieus (edit, Savonius) type is aerodynamically very inefficient, being drag rather than lift, but can operate over a much greater range of wind speeds and withstand extremes such as mountain tops, Antarctica etc.
VAWT ability to operate regardless of horizontal wind shear is a definite advantage in a built environment.
@@q.e.d.9112 I think Savonius is the drag one. But idk why people are trying to find the absolute best / most efficient thing. What suits one person's needs might not be appropriate for a different location or climate or budget. It's not like anyone on YT is planning on building their own wind farm! LOL Most people just want to lower their electric bills or power their rural cabin.
A couple of points missed by Rosie: VAWTs have actually operated with greater efficiency than VAWTs. In the 1980s (when I was working in Altamont Pass, California) the Flowind 250 kW VAWTs achieved the greatest specific output (units of kWh/sq.m) of the turbines in the Pass - and it wasn't because of better wind speed. It was normalised for wind speed and attributed to the "troposkein" (skipping rope) shape of the blades which formed a closed shape on the central tower. This eliminates the tip vortex which is a significant source of drag on turbines with open ends (as on all HAWTs and constant radius VAWTs). The troposkein blades were favoured in the 1980s for large VAWTs because in theory they eliminate bending in the blades, though only from centrifugal loading. Which brings us to the second point: the biggest drawback of VAWTs is that the aerodynamic bending loads on their blades fully reverse every revolution (think of the upwind blade being blown towards the tower, whereas the downwind blade is being blown away from the tower). Given fatigue's well-known role as a major design driver, this is a big drawback. Also their slower tipspeed (about half that of HAWTs), which gives them the low noise advantage, doubles the torque on the shaft, driving up the cost of the gearbox.
Very good explanation Rosie - I am the co-founder of Southwest Windpower - The company is gone but we studied countless designs over the years. We produced over 170,000 wind turbines like the AIR and Skystream - There are so many challenges with the vertical axis even if someone figured out the aerodynamics - Blade fatigue was always a big issue. Lower bearing issues when they did not use upper guy-wires. Even on a roof, you still get noise. - Last is finance. They are so unconventional that all financial institutions will not touch them.
Those are great insights!
Yaaay I've wondered what the differences are for years. Such an awesome video to explain it briefly.
I have been riding touring bicycles for half a century. The assistance I get from fast heavy traffic is very noticeable. Thank You for this video.
I ride bike too, though only for about 30 years 😊 And you're right that traffic gives a boost to cyclists. Did you see this video, this company want to harness traffic turbulence to make wind power:
ruclips.net/video/gcSnwW5v3f8/видео.html
Ha, that's how I found your channel!
@@EngineeringwithRosie So you are promoting that sort of scam? Disgusting!
It was very interesting that Rosie mentioned that VAWTs are better in turbulent airflow conditions than HAWTs. There was a recent study [at the University of Warwick, I think] that performed thousands of hours of simulations and they demonstrated that VAWTs work much better than HAWTs in denser arrays, so the generating capacity per square kilometre of wind farm foot print can (potentially) be much higher. I think VAWTs are likely to become more common in the future due to this, especially in places that are tight for land area (like the UK)
Efficiency is a essential but there is also a lot of other advantages using a vawt noise, aesthetics, wild life hits and prevailing weather conditions that they can handle with no down time and having the bulk of your major components at ground level and i would think much cheaper to produce. Ive pondered this for years because of all the little exhaust whirlygigs on sheds and factories the spin silently for years. Its almost like someone built a hawt and all the research went into them. Food for thought
I've just discovered your channel and I really like the fact that you're giving real world context for the information, real experts from the field delivering information directly to the public is important and I'm grateful to you.
Your chart has a comparison for efficiency in terms of power generation per unit of cross-section area, completely valid statistic with which to compare them, but it's also possible (though I haven't tried to find out) that the vertical axis turbine either lets you capture more cross-sectional area per unit of land taken up or more cross-sectional area per dollar you spend building it. One thing that immediately jumps to mind is that horizontal turbines have a circular cross section, the wind going through the corners of the square they take up is uncaptured.
If you have an HA turbine that gets 50% efficiency and a VA turbine that only gets 40%, but the VA design lets you capture more of the available cross-sectional area for the same dollar value the VA might still win. On top of that you have some other considerations like the fact that the swept volume of a vertical design is always the same, whereas a horizontal one that's steerable needs to have an enormous sphere of space available where the blades could be even if they're not there most of the time.
Again that's not a consideration for utilities who are trying to secure big open areas of land or ocean for their wind farms, but they might be very important considerations for a landowner trying to put up as much turbine in a constrained space as they can.
Thanks for the great videos again, I'm going to go finish going through your back catalog.
Thanks for your comments, and you make some great points. You mention that efficiency isn't everything, that cost and other factors are relevant. Stay tuned on the channel for some videos on the concept of LCOE (levelised cost of energy) and related concepts, to hear more about how energy professionals deal with the issues you have observed.
Really useful video.
Has anyone heard of a reasonably priced vertical turbine that produces around 5-6kw.
I have a small farm, we’re up on the hills & it’s constantly windy. Even on nice summer days there’s still a breeze.
I have a large shed in the yard which would be suitable for mounting a turbine on.
I think this is a more practical solution than an equivalent horizontal axis turbine on a mast out in a field somewhere.
I am in the same position - plus I have been refused planning for a 6Kw HAWT on a 9.5 m. pole because people are tweeting about noise (I live almost half a mile from my nearest neighbours, so that is rubbish) and "what about the poor birds"... My father previously had a small HAWT turbine mounted on the end of the house, but we had to take it down as it was causing structural problems.
VAWT were used during the 2012 London Olympics. Though it's now 10 year old tech you may want to check it out. I have been a fan since then and like you say, more research is needed into VAWT's. The potential for use in urban areas is enormous.
There is a company that want to and is in the final stages of going to implementation of vawt installed on the middle part of highways to collect the wind energy produced by cars. The amount of energy isn't high, but it is more than enough to power lighting for the highway and more.
If this is implemented and other micro energy producers are implemented, then we will reduce our overall need for electricity from the bigger scale energy sources.
Oh God, more things for drivers to become impaled, twisted and variously impacted upon.
@@OkenWS Nope. Guardrails will be placed in between. This isn't in the US. It is in Britain.
Imagine thinking the US would install small scale wind turbines to help ease power grid demands. That's not maximum profit.
Just Have A Think sent me and I am so glad he did! This is the only video I ever needed to get a solid introduction to VAWTs. Very well explained and answered all my initial questions. You have a new subscriber in me!
Strong content!
As a patent attorney (and engineer (electrical)), I see one or two 'new' wind-power designs each year.
IMO, the intuition and science are not always on the same page (explained below).
These 'inventions' typically address one of the following issues:
1. Turbine Blade Efficiency:
This means forming the blades to create a stronger force at the blades.
There seems to be some tradeoff between lift and 'wind capture' - think "airfoil vs. sail boat sail".
IMO, there's room for an optimal blend of these two, but I've not seen it nor have I seen it approached scientifically.
2. Wind "Amplifying"
This is the idea that a higher wind speed can be created from a lower-speed wind.
These usually take the form of a funnel or a deflector of some sort.
Here, the laws and mathematics of fluid dynamics are the obstacle; so, doing so in a small space looks really difficult.
Having felt the winds on the downtown streets of Dallas, this 'feels' plausible, but perhaps only in a tall device (defeating one of the attractions of the VAWT -- a low ground profile).
3. Electrical Turbine (generator) Start Speed
Here's one area that I think is primed for improvement.
Today's VAWT generators just don't turn in winds under 4.5m/s (or similar miles/hour); those that do have 'top out' electrical production that limits their uses to little more than LED lightbulbs.
What is needed are VAWT generators that can, with minimal mechanical loss, gear-up and down based on the wind speed.
On that note, existing gear boxes are associated with high-power-loss, heat, and maintenance.
Lesser issues are noise, appearance, and local power-storage (although power-storage is THE industry issue in small-scale renewables).
A desired feature in some environments is the ability to raise and lower a VAWT.
Because "you" are reading this that means you're interested; so, if you have a solution, please link to it here by responding to this comment, and if you (yes, you) want to make a break-through in this space, solve any or all of issues 1 through 3, above.
Hi all the problems of the Savonius turbine can be solved everything from vibrations impulse stresses and low speed by dividing your stresses to diffirent positions. I did build a prototype . It excellerate very fast and there is no visible vibrations in the structure. I need funding to build a strong reliable model for testing and evaluating by univercities and research institutions
@@HendrikStander-v1l would love to see your solution!
Wow! Fascinating. I had pondered a question to myself about wind power and found you. I feel so informed. Thank you
Glad it was helpful!
One way to possibly increase the efficiency of VAWT systems could be by changing the surface structure of the blades to be more like a golf ball which uses the aerodynamics to increase some lift, reduce drag and effectively increase distance but that last factor doesn't much matter as much as the first two. Presumably, this could add to efficiency on the leading and trailing winds when applied relationally to the blade shape dynamics.
I recall seeing a video of a guy who 3d printed a golf ball textured computer fan and found that it was much worse than a regular fan blade.
The dimples have the specific purpose on a golf ball of generating turbulence to increase the amount of air flowing close to the skin around the ball which reduces the drag from the vacuum behind the ball. As well as help the backspin of the ball create lift.
But in a wing, turbulence reduces lift by making the air break away from the surface.
If you want to look up texture additions to help wings, look up whale fin bumps.
The major advantage of VAWTs are the low wind speeds required to start turning and produce energy vs the higher wind speeds requirement for HAWTs.
Great video. I’m exploring a portable wind turbine project and this was useful.
Thanks, I'm glad it was helpful for you 😊 Let me know when you make some progress on your portable wind turbine, I would love to see it! And tell me if there are any other topics you are having trouble finding information on, maybe I can help out.
@@EngineeringwithRosie Will do - might hit you up for hot tips on turbine design. :)
Pretty good description on the various turbines, and good info all around, I also came here from Just have a Think. Though the way you praise the horizontal axis makes it feel like the vertical ones would be used in the same space in the same spacing between them, but they wouldn't be. Since the ground footprint for a VAWT could potentially be the same as a HAWT, but the aerial footprint is much smaller because you don't need to worry about a huge rotation axis that's taken up only 30% of the time, so you can fit a lot more of the vertical turbines in a space than horizontal. So instead of worrying about turbines hitting eachother, you'd have to worry about too tight a spacing taking up the wind energy inefficiently. More turbines in less space means higher energy output, regardless if the efficiency is lower than that of the other type of turbine.
Something else to consider is not everybody has the space for a horizontal turbine, so even if it is much less efficient, it's still getting more energy out of it than otherwise possible. The more people adopt the technology, the faster it's efficiency will improve. A different tool for a different use.
Pretty good content otherwise.
Yes - we might put up a simple , vertical axis turbine on our narrowboat - to get some energy to top up the batteries without having the bother of horizontal-axis head-choppers. (Dot)
Greetings from across the Atlantic, Dr. Barnes,
As an engineer (discipline: electrical/electronics + systems) and inventor, dabbling now and then in renewable energy technologies particularly around the ocean, I happened upon your RUclips channel, thoroughly enjoying your video tutorials on wind turbines, and the sense of engineering balance of trade-offs. That appreciation and gratitude doubles for also presenting the Laws of Thermodynamics well in recognizing “green energy” scams. I shall especially recommend your channel to technical students and more vitally their undertrained teachers.
At your request, I suggest these topics for future videos:
1 - Turbine Gearing.
Electromechanical energy from turbines often exhibits regulated output as alternating current at a specific frequency - usually 50 Hz or 60 Hz, but shipboard this can be 400 Hz. Since wind and hydropower turbine-driven generators do not cycle so uniformly, doubtless there are some wondering how wind and hydropower turbines mechanically regulate their electrical output. I presume a continuously variable transmission or similar gearbox transmission gets implemented, or perhaps something more solid state electronic in a rectifier and DC regulator feeding a large AC inverter circuit. Mechanical friction a regular contributor to turbine inefficiency, this should include some methods used to reduce friction in wind turbine gearing. Of course, that could develop into a mini series of its own.
2 - Energy Density; Power Availability.
Like the Betz Limit for wind turbines or Bekenstein Limit for information holding capacity per the physics involved, the death knell for many proposed green energy technologies often proves the engineering economics of energy density. A close cousin of this with renewable energy sources (all forms) is power availability and reliability versus weather day or night, to wit: A wind turbine yields zero power when the wind is calm; photovoltaic panels only produce power when sunlight shines (starlight or moonlight at night, not enough to be useful - and so on. In terms of energy desnity, the more plentiful source of hydrogen is petrochemical hydrocarbons, not electrolyzed water - one reason why the petroleum industry does not fear hydrogen-powered stuff.
Thank you!
Blessings,
DSE
Isn't there also the issue that with vertical axis turbines, the shaft has to take up bending forces? This causes more friction in the best case but can lead to lower lifespans in the worst.
Bending forces, yes. Friction, no. The bending forces can wreck bearings, which is why it is nice that the main bearing for VAWT are at the bottom, easily accessible for replacement.
A good shaft can take some friction and bending 😋
Friction from bending can also be reduced if the bearing isn't fixed horizontal but can move the same way a constant velocity joint dose ( The CV joint at the end of car drive wheels)
@@stuartanderws5705 you lose efficiency with those, always something you try to avoid in design.
I would want to tether the top end to the ground from multiple points to resist that force
Thanks for the vid Rosie. Having worked in the small wind industry, selling over 2,000 small wind turbines, installing and servicing some 200 of them and living on a small wind turbine in my backyard the past 13 years, I'm very familiar with both HAWT and VAWT turbines. Some 10 years ago, an independent engineering firm did studies on various VAWT and HAWT turbines, at the same location, on the same tower heights and found HAWT's produce: 4-8x more energy than VAWT's, of comparable turbine ratings. Their study found that VAWT's were generating enough power to offer a: 80-160-yr. ROI while the average HAWT turbine offered: 20-25-yr. ROI. Most everyone loves the look and idea of VAWT's but they're simply yard art, they produce virtually no energy which is why the large, commercial wind turbines, never use them. In most cases, 1x 350W solar panel will far out-produce any VAWT, at a small fraction of the price.
Wow, that is really interesting! Do you have details of that study? I would love to check it out. I am hoping to do something similar on here, but I need to save up for all the turbines first! Maybe you can help me by telling me the most popular brands or turbine types you installed, so I can do those ones first.
I think in addition to making nice "yard art" they are also really fun educational engineering projects. So as long as we are not pretending they are a real part of our climate change efforts then I like them simply for being fun and educational and looking cool 😀
@@EngineeringwithRosie I think the question you posed as to whether VAWTs are not efficient enough yet for commercial use is due to a lack of development or an inherent inefficiency is a great question. It's not that they produce no energy; while it is certainly true that there is published data that shows certain VAWT installations did not performed well, these tend to be in poor wind sites where a HAWT would do no better. There is other data from large VAWTs in good wind sites that have produced a lot of energy quite reliably.
Stanford has a different approach:
[ruclips.net/video/56xW2535obY/видео.html]
[m.ruclips.net/video/RyOmwfH5GxA/видео.html]
One recomendation to your VT - place you VT into the tube to protect the VT against strong wind. You can than pull the tube down to “open” the VT. In case of emergency you put the tube up and your VT is save. Because the blades of VT you can not adjust according to wind
Extremely well made video, thanks so much!
One “efficiency” you didn’t mention. A v.a.w.t. can be much shorter, which costs less money, therefore giving you more bang for the buck. They can also produce power at lower wind speeds.
Yes, there is the efficiency of the unit, but what about: The amount of materials needed? The longevity of the unit as a whole? The ease/safety of maintenance? Recyclability of the spent materials at End of Life?
Thanks Rosie.
Wow, great question and I made this new video just for you on how those factors can all be combined to compare the overall cost of different generation types! (jk, I started making it months ago, but the timing of your question is impeccable) ruclips.net/video/6_BGHy4sfMs/видео.html
Congratulations Rosie, looks like your quality content has finally started getting attention it deserves.
Great video, thanks for helping understand the engineering aspects of wind turbines.
Although efficiency is a key parameter, I believe more important is energy/dollar. If the efficiency is 30% lower, but the cost is 50% lower, it may still be viable solution. Also, one should also add cost of "noise" and damage to the environment, e.g. killing birds
You also have the ongoing costs and replacement costs, in other words, total cost of ownership. If a VAWT is cheaper to build, cheaper to maintain and lasts as long or longer, then that would also change things. But I agree you need to actual, real examples operating to confirm the design.
@@brettbridger362
Problem is: Industry has committed itself to HAWTs therefore almost no money is invested into developing VAWTs.
@@maxmustermann9587 Yep. It tends to be human nature to assume your old assumptions are still valid. Not arguing for right or wrong of it, just that once industry is rolling down the hill it's unlikely anyone will ask are they rolling down the right hill.
@@brettbridger362 Nah, I think it's probably more about money. Greedy beasts we are ;)
There is something so much more beautiful about the shapes designers come up with for VAWTs and hopefully they do continue to develop and we get that big leap forward! Looking forward to the next video! Did you come across any biomimetic turbines in your research. I remember seeing some in very early stages based on hummingbird wings, trees and insect clap-and-fling. It feels a bit like wind turbine alchemy trying to overcome the betz limit but they're still interesting ideas!
It's great to see how your channel is growing and I hope you're enjoying making these videos as much as we enjoy watching them! Cheers to you Rosie!
I agree that there are some really beautiful VAWT designs out there, especially some of the Savonius ones. I think they are probably nice as public art projects, but we shouldn't pretend they are reducing emissions in any meaningful way when they put them on skyscrapers or median strips.
Biomimetics is an interesting topic, I want to do a video on that. I have heard people say that there are wind turbines based on hummingbird wings, or tubercles on whale fins. But I have to say I have never seen any major manufacturer interested in that. So I want to look into it more and make a video about it. Owl wings were the legitimate inspiration for the vortex generators that they put on blade tips to reduce noise, so I was thinking a visit to an owl sanctuary could be in order!
Thanks so much for your nice words about my channel, the support means a lot. I am enjoying the community that is growing around the channel and hope to do more community building stuff this year, with a newsletter and Patreon community. I am looking forward to a bit more growth so I can bring in some pro help to reduce my workload a bit, it is more work than I can sustain to do weekly videos on my own.
This is very informative Rosie! Thanks for explaining this. I'm working on a diy savonius rotor right now. It spins and I'm excited to make power with it soon. I'm trying first with a stepper motor, which has permanent magnets and does make AC voltage which is good for low-loss transmission to the batteries, for DC rectification. My comment was really gonna be about the question of efficiency. If there is some power to be had at my site, shouldn't I get what I can to top up my batteries. A simple, quiet VAWT is better than not having one at all. And homemade means it won't cost too much $. I look forward to the next video on design of VAWTs. DIY engineering is fun!
Sounds great! If you are enjoying making it then it is worth it! Share some photos/videos on my facebook or instagram pages when you're finished, I'd love to see it!
Nice introduction to VAWTs. In the 1980's to 1990's loads of work was done on VAWTs. There was a company in the UK called VAWT lead by Dr Ian Mays which eventually became the extremely successful Renewable Energy Systems. They built several large scale prototypes which were thoroughly tested in the field including in Carmarthen Bay and the Isles of Scilly. The big issue that resulted in stopping research was fatigue. It appears that VAWTs have a much worse fatigue environment than HAWTs. The British Library probably holds copies of the research reports.
HAWTS add multiple stress points in 3d vs a more 2d for a traditional windmill?
Thanks!🙂👍🏻
The lifetime maintenance cost remains to be evaluated, the temperature drop in Texas earlier this year caused a loss of electrical power that Horizontal axis(conventional wind turbines) froze and failed to deliver power does address other considerations. The simplicity of VAWT is compelling. The longevity of simpler engineering designs has been proven over time..
Simpler, maybe, but they also introduce more torque.
Texas didn’t invest in the anti-frost technologies that already exist. Presumably because its not cost effective if it doesn’t happen often but with climate changes they are likely to become more common.
@@alisonshellum9870 The last time that I looked, the Sun does not shine at night. The wind stops and starts presumably due to climate change. I think most people do not want higher energy costs, who does. I just received notification that our local power company will be raising rates due to the proposed tax hike on businesses. So much for people making less than $400,000 per year not getting a tax hike.
@@MrRickyw01 Thats down to your local politics and failure to tax fossil energy giants to cover future green investments. Other countries have been investing in renewables effectively for many years. Battery storage exists to help store solar energy in the daytime for use at night time and EVs with vehicle to grid will enhance this. Most younger people accept that we all have to pay for the mistakes of the older generations.
@@alisonshellum9870 You missed my point. The local power company is owned by the citizens of my city. Your right that it is an energy giant. However their only source of income is from the people using their electricity. When the taxes go up they have no alternative but to pass on the taxes and the cost of natural gas. They stopped burning coal many years ago. Germany did follow your thought. They currently employ an ex-German Prime minister to be nice to Putin, since Germany has become beholden to Russia for Energy.
Superb explanation as to the differences between HAWT and VAWT.
Thanks! 😃
Although efficiencies are important, when comparing the two types, it is surely profitability that is a more important factor viz initial cost + running and replacement costs per KW/hour of electricity produced under similar conditions. I believe VAWTs will always be less efficient at extracting energy from the wing but they do often work at lower wind speeds.
thanks for the video rosie!
very educating! water engineer here, learning a lot from you! all these years after my fluid mechanics course, still learning things!
I'm a power engineer. I work primarily with energy generation and exchange. I am genuinely curious here- doesn't the HAWT put an extreme amount of pressure and wear on the bearing holding the turbine shaft? Like, those turbine blades look to way several tons, and there is no counter weight on the other side of the bearing. Would this not seize bearings a lot? I deal with bearings all the time and don't see how this would work for more than say, a decade before the bearing fails.
Please let me know, anyone, if it's more resilient than I'm thinking.
Ultimate efficiency is a very important thing to understand - especially for large scale utility projects. But for most practical, smaller-scale installations, the more relevant factors include: initial investment & maintenance costs, noise levels, proximity to the use-case and to a way to store the energy produced. You may be able to get far better wind 50 meters up offshore; but that doesn't matter if you're trying to go off-grid on your own property, or hoping to increase your factory's power-failure resistance.
Great job! Curious to see what the efficiencies are when you factor in cost, not just to build, but operational lifetime as well. Also, presumably that efficiency loss can be made up by being able to place more in a given area?
Efficiency is simply the total amount of energy available, divided by the amount captured. Cost doesn't factor.
There is a concept LCOE - Levelised Cost of Energy that takes into account all the equipment and maintenance costs, divided by the amount of energy produced in its lifetime. Investors use that value rather than efficiency to compare options. And now we are going beyond LCOE to include value - how much can you sell the electricity for. I have a video coming up on that next week, so check back then!
But I need to note that so far, VAWTs all have higher LCOE than HAWT. Doesn't mean they always will, but it is not as easy to make a cheap and reliable VAWT as many people assume.
@@EngineeringwithRosie Can you do a short analysis on small VAHTs - like what someone would build as a camping generator? (using a battery pack) It has been a long time since I studied these, but I recall that VAHTs require external torque to start them up aerodynamically which would make such a machine overly complex. If not, then one could use pieces like wind surfing masts and sail cloth blades for a very light weight package.
@@kenhnsy a battened sail cloth savonius design would be very interesting. Although for backpacking I would be tempted to use electrolysis to store HHO in a bag for use later instead of a battery since the gas would be lighter than air even, whereas meaningful battery storage is heavy. But if you just mean for charging emergency devices and such I could see a small vaht generator design being plausible. Just wondering if it outweighs the benefit of a folding solar panel in terms of reliability.
That was very interesting. There seems to be in the countries I know about quite a lot of popular resistance to onshore wind, and often one of the arguments is noise. Perhaps vertical wind turbines could be a solution here, sacrificing some efficiency for public acceptance. You could also put them in towns and cities, producing locally produced power, even when the sun is not shining.
I would be curious to know your thoughts on the newer sail or kite wind power generation. That technology seems even more scalable/cost-effective than current generations of large utility turbines.
They should float them internal lift gas and a carbon fiber framework for rigidity.
more scalable - in what way? And how would they be more cost-efficient?
They require a lot more active control, require more airspace, have to be spaced further apart as the kites can freely move and could otherwise collide, and do not produce nice consistent power. And due to the nature of all the moving parts they also require more maintenance.
They do have the benefit of having a small footprint on the ground and producing a lot more power.
So while they can be really good for certain applications, they are not even close to being viable for the bulk baseload of power - which is the biggest problem we have with renewable so far.
Using them on a ship to decrease fuel-usage is a completely separate area but one were they can deliver their full potential, easily doubling their efficiency compared to when producing electricity.
Thank you for your effort this was really informative, after this video I'm excited to study more about wind turbine
Hi Rosie, Great video! I want to build one VAWT. It was very useful. Thank you
Great to hear Levan! There will be another video on VAWT design coming soon that you might find useful.
Recently had Electric solar installed with my water solar. I never really wanted a turbine but you might have sold me! The VAWT's aren't so ugly and quiet! And having a possible night time trickle charge would be nice. Thanks!
The best application i've seen for VAWT has been roadside energy capture along highways.
I read of a pilot where recaptured energy is fed to electrified roadbeds with electric vehicles using EM regenerative charging from the roadbed while in motion.
Great job, thanks for explaining this Rosie!
Have you considered the long term upkeep and maintenance into your efficiency calculations?
Hi Larry, great comment! Maintenance is not included in efficiency calculations which is purely the amount of energy extracted compared to the maximum. But there is a measure, LCOE (levelised cost of energy) which does include these very important considerations. I plan to make a video on that topic soon, it is much more widely relevant than efficiency on its own as you are clearly aware.
True energy efficiency of the design would be:
(Total energy required to manufacture/build/maintain/remediate structure @EOL)/Total energy generated over life of the structure
The differences in the design's nominal efficiency of energy extraction from the wind merely determine the area efficiency of the design, ie how much land you have to spread them over to meet your energy output target. Obviously the area efficiency is important, and will also feed into the total cost of the wind farm build, so may well override the energy efficiency due to initial investment requirements; it would be interesting to see how all the figures compare.
@@thecraggrat Great point! That is measured by Energy Return on Investment, EROI. en.wikipedia.org/wiki/Energy_return_on_investment
Want to see a video on that?
@@EngineeringwithRosie That would be the best. Thank you very much for what you do.
@@EngineeringwithRosie Yes please.
Hello Rosie, Thank you for your video. There is only one fundamental fact that you need to make clear on the difference between Vawts and Hawts, On the Horizontal axis wind turbine, All 3 blades (3 is the accepted best number) deliver an equal output into the wind in the instance. The prop can be balanced for high speed output., The numbers alone tell you that the Hawts are the clear winner.
On the Hawts , only one blade works at a time and its output is further resisted by the returning blades. You can draw it as many ways as you like but the returning blades do cause a drag. So you need a Vawt with a blade area 3 times the size of tbe corresponding Hawt, It is very simple.
There are a few more benefits for VAWT's as well. With lower speeds and more compact area's there would be less effect on birds and bats then HAWT's. Mainly I am looking at a compliment to my solar panels and batteries here in Canada and so I want a turbine I can build that is quiet and does not need such a large tower. VAWT's seem to be the better choice for this. Also I think they look so intriguing too. My plan is to convert an old honey extractor to a VAWT
Oh wow, a converted honey extractor? That sounds amazing! I hope you will share photos (tag me on Facebook or Instagram) as you progress!
Hi Tom, HAWTs are known to be destructive to airborne wildlife like bats and birds, as you said. Is there any evidence that VAWTs are safer for wildlife? If so, I'm sold!
Very interesting, I am currently designing my own high efficient vertical axis wind turbine, Thank you very much for the valuable information.
Lovely videos. Thanx for making them.
I would love to se a video on what type of turbine horizontal / vertical that would make the most sense for private use. I feel there the constraints might for different result as size and ease of use might become more of a factor. =) Keep up making more great videos. =)
Oh, my. Your notes just made me subscribe on the spot. Well, and the fact that you're so interesting and make it easy to understand!
I think VAWTs mounted horizontally at the top corners of tall, oceanfront buildings is one great application for them as the wind direction is generally constant and the horizontal mounting takes advantage of the vortices.
HAWT's: The variation in rotational speed along the blade's long axis, as well as the ljmiting factor if tip speed, is also a problem in Helicopter and Propellor driven aircraft blades as well. For example, if you get the tip speed going too high, the tip can cause small repetitive micro-burst shockwaves as they break the sound barrier. The air around them expands to the point it is no longer touching the blade, and then snaps back around it, rapidly, and it does this so violently that it causes cavitation localized on the blade tip. The blade, when it is in a point of no air (air voided from its surface by the sudden shockwave, basically) the TIP no longer has any air resistance and wants to spin faster than the rest of the blade, causing the blade to flex wildly in the forward direction of rotation. Then when the air smashes back together around the blade tip, it actually causes MORE air resistance at the tip than before the shockwave pushed away all the air, and thus slows the blade tip even further than it was before the air left the surface of the blade. This causes the blade to flick back away from the direction of travel (deflect/bend) even further than normal. This then happens... HUNDREDS of times a second, and you get blades flexing, bending, warping, wobbling, snapping, and shattering all over the place, and VERY rapidly turning into VERY fast moving shrapnel.
This is why long rotor blades for aircraft often have specialized tips and shape geometry, to break up the aerodynamics a bit or to cause the air to delay leaving the airfoil for juuust a fraction of a second longer than without the different geometry. This also helps to quiet the blade, allow the blades to spin faster, and provide MORE lift due to being able to spin faster and move more air overall. The same is true, relatively, for wind turbines. Your industry resolved part of this problem by chqnging blade geometry, but it also sort of solved itself, in that the wind turbines are not powered, but providing "power".
Fascinating. :-)
With the vawt being maintenance cost effective as well as space efficient wouldn't the loss of generation efficiency be overcome by just adding more vawt turbines and still come out more cost efficient maintenance wise?
Yes, as well as being able to put them in places you typically wouldn't. Like along high speed roadways to make use of that wasted energy.
I like this video! Good length, good detail level. Thanks for producing it!
you can fit more VAWT in the same space as HAWT. LIne the spine of your roof with a few along with solar and you should be off-grid pretty easily.
They would parasite from each other. Decreasing overall efficiency. That's why wind turbines are spaced away from each other.
With some very specialised exceptions like roof line vertical ones rotated to be horizontal. But then they become directional. So if your roof isn't angled just right they no reason to use them
@@CzornyLisek also I wonder what the implications are for many hundreds in an area, the ones downwind would be starved of wind
Wauw, usefull info and thank you for beeing this clear. I am interested in vertical, because i life in an urban area.
SeaTwirl is a Swedish company that makes revolutionary floating vertical axis wind turbines (VAWT), custom made for the conditions at sea. Very interesting.
Liked and subbed, thanks for the upload.
Fantastically compressed knowledge, I found answers to almost all questions I used to ask myself in relation to such types of wind turbines :)
Then you are easily to satisfy.
Area efficiency and monetary efficiency has not been investigated.
Thanks for a great video! I've always thought that turbine designs have more difference in efficiency. This opened my eyes. Simpler, more robust and easier to maintain, why would I choose the other alternative over 10-20% efficiency add?
Levelized Cost of Electricity. If 10% increase in efficiency costs you another $5000 upfront, but you make an additional $10,000 over the life of the system it's worth it. As a developer of Vertical Axis Turbines for hydro, the broad statements like "simpler" are misleading. Our systems are mechanical pretty basic, however the forces are way different than industry standard and the power electronics handle it differently. You trade simplicity one place to another.
@@Rokmonkey32 Thanks for your reply. I'm thinking about building my own system mostly out of junk lying around, something like oil drum savoniuses put up on old flag poles These things are just simpler to build and repair. Numbers you threw are out of my league and goal. I'm not about making or even using money. I'm trying to create atleast a little of power with something made out of repurposed stuff. Even 20Wh average is better than nothing when I did it myself out of almost nothing.
Echoing what Nate said. Cost efficiency should be the main thing you consider. In which case it's how much you pay vs. the total output of the unit over its lifetime. This in turn would be compared against what grid electricity costs, and with that total output, did you save money or make money.
I'm not big on wind for households unless solar isn't an option. They don't generate nearly the kind of power a modern household uses. You really need to be in a place where it's windy most of the year, AT your home. Plus, those smaller units for homes break, probably more frequently than the large wind turbines uses for powering the grid. Plus, you need a few to give power output you need for the home. So urban areas and residential areas are not very good places for these. Wind near ground level gets broken up, deflected, etc... and you would need the unit to be up above rooftops, probably by at least 20ft. for them to be effective. But even at that height wind is still being broken up by wind that comes up off a home by deflection. Anyone who lives in a residential area and then takes a boat to a nearby lake, large lake, can tell you the difference is pretty large. So in this case, a wind unit is these environments is probably giving you 25 - 40% of it's rating, and on rare days you get 100%. I'm pretty much in the path of the Texas wind corridor and it can be calm where I live at ground level, but go to the lake near by and there's white caps on the water, and I'm feeling the wind hit me pretty hard. Now, the tops of the trees are catching the wind near the home, but at ground level there's very little.
So if you can, solar if a better option for a home in those areas. If you have a good place for the panels they'll give you 100% of their rating much more often than a wind turbine will. So if you plan on buying a wind turbine for the home, do research, but there is no good wind data for where you live in particular, and the only way to get that info is for you to measure wind in about the same spot you would put the turbine, over an entire year.
If on the other hand you live in a windy rural location and you feel wind regularly at ground level, then much better odds they're worth the investment. But, I'd still rather have solar if the location is good for that. Single panel production, where a panel is about 1.5 x 1m, they give about 400W, some better, some worse. I also think the cost/watt (cont.) is lower for solar panels. In specific if I had a ranch style house where one side is south facing if I lived in the N. Hemisphere, those roofs EASILY have the space for enough panels to give you more energy than your house can consume. A central AC unit for instance uses somewhere between 3000 - 5000W, once again some being out of this range. An electric clothes dryer uses 2000 - 5000W. A modern gaming PC can have a graphics card that uses 200 - 300W and the CPU that drives the PC can use 60 - 200W. Then what if you use power tools, etc.... I wouldn't install panels to power both central air and a clothes dryer at the same time, unless you also have input from the power grid, but I would at least get up to about 9000W with panels, if I want to almost completely power my home or be off grid, and then not run central air when running a clothes dryer.
@@johndoh5182 Thanks for your time, there was lot of good info and great too.
Electricity price has more than doubled in the last two years so going off grid is my goal.
I live in north-east part of Finland where there is not so much sunshine but I still have some panels waiting to be installed. Six 250W panels, looking to double that when another bargain comes up. Just got used 4kW inverter that takes almost everything you feed her, solar or wind. 10kWh gel batteries also waiting to be in action.
I live on Russian border in an old house build after war and to nearest city is about 30 miles. Heat comes from burning wood and 90% of the electricity is needed to heat the water. 1600W water heater, of course it's only on use some of the time, our hot water tank is pretty well insulated. No need for air conditioning, our summer is rarely that hot and when it is, it does not last too long. Water comes from our own well using automatic electric pump, 700w, I think.
House is build on a hill on beach of a lake that is on the south side. Usually the strongest winds come from the south. Our house is surrounded by small fields with couple of taller trees giving shade. Fields are mostly not in use and offer lots of space to put up some wind generator poles/towers. +20ft is not a problem. Low average wind speed (7-9mph) is also not a problem when dealing with generators optimized for lower wind speed conditions. They generate less but they generate anyway.
I got a hold of 22kW AC electric motor. Sucker weights 440 pounds. Collecting strong magnets to convert it into permanent magnet generator. Time shows if the winds will rotate it or will it be something else.
You talked about modern house power needs. My house is far from modern with pretty low need of electricity. Cooking using burned wood is an option I often use. Couple of winters ago I realized I had not been using an electric stove for four months; did almost all my cooking in our big brick oven. My gaming laptop draws some power but nothing spectacular. No dryers for clothes here, we have ropes outside for that. Mostly we dry our clothes inside, moistens the air a bit. Fridge and deep freezer consume very little power and most of the year the freezer runs on fumes because it's on the cold storage room enjoying outside temps.
The only reason I would think of a solar system closer 10kW is an electric car. The prices here makes an electric vehicle a distant dream. Not that it works properly in our winter time when it's -30°F in recent technology.
The great thing about the place where I live; when it does not shine, it blows (pun intended). Solar, wind and gas generator in the heart of the winter is the plan. Been thinking about wood gas generator. The wood is plentiful and growing tree sucks much more carbon than it produces when burned.
Been gathering supplies and knowledge to start living my dream of being mostly self sufficient. Been growing some of my own food and spices, eating fish from the lake and meat from the forest.
Hard times are coming. I hope it's not too soon, I do enjoy the easier life.
Very well explained. Thank you. Brilliant.
I think putting these around lamp posts on the sides of motorways is interesting... closest to fast Lane and the air being pushed by cars would provide wind.
I think you bought up most relevant points. Vertical axis turbines are usually plugged by snake oil salesmen and have no use at all in utility generation. Distributed generation is about as much use as a chocolate fireguard. You're far better off, as an individual, taking shares in a proper turbine than installing a miniature one in your garden.
Don't forget that large vertical axis wind turbines have been trialled, and actually an issue not many people think of is bearing wear and gyroscopic effects. The out if balance loads on the main bearing are high, to say the least.
Generally these turbines are not self starting but that's not a problem for modern electronics and could even be an advantage for storm conditions.
"Sea twirl" is a business that seems to exist primarily to harvest money from gullable investors in return for computer graphics and promises if solutions to problems that don't exist. There will be others on the same bandwagon
Thanks for this vídeo. Very good
Nice video. Does it make any sense to funnel the horizontal wind into a vertical channel, and then use a conventional turbine blade? Thanks.
The logistics of such a thing would be a nightmare. The material, the design, the construction would all be tremendously expensive and difficult to manage. In fact, a lot of theoretical and doable constructions of literally any mechanic is superior to the commercial variants in efficiency but their cost offer diminished returns so they are not viable.
As a retired engineer, how about a combination of the two HWAT and VWAT? 💡
If you were to put a wind channeling and speed increasing by reducing the input/output diameter (funnel shape) that fed a HWAT on a vertical axis, you could get the best of both worlds. The wind capture funnel(s) would be required to be in a circular shape with a smooth curve that would not remove most of the wind force. but divert it upwards. The vertical axis mounted blades would then be able to have access to the speed increased air. The air flow would obviously be through the top with a screen across it to prevent animals from getting into the blades. Another way to think about this might be a water turbine. Basically the same principle with multiple sources of water.
This would increase the efficiency by increasing the wind speed being applied to the blades and also making it omnidirectional. The best of both worlds.
It seems that you are mistaken about the nature of Vertical Axis Wind Turbines...
Good explanation of vertical axis wind turbine. 👍👍
I think your video quality would increase a lot if you put up some towels or other sound absorbing material behind the camera :)
The shadows from your hands could also be removed with better lighting for a more proffesional look :) There’s a lot of videos on how to light up a scene, so it might be worth taking a look there :)
So sorry to hear that hand shadows somehow limit the enjoyment and / or usefulness of the video to you.
@@mahj the hand shadow is just a minor detal that could easily be improved, the real issue us the audi echo.
Where I live used to be characterised by its windmills, but ironically wind speeds are not consistent enough for utility turbine deployment today.
My house often has an onshore breeze and high wind in the winter, so a practical quiet way to harvest wind energy combined with solar and ideally energy storage would be interesting.
Hey Rosie, how about side by side tests for various wind turbines, see how they perform against each other at the same site. I mean like a competition. Much work I suppose... could be a fun project..
I see you're doing it Rosie, so cool! Would people donate, like send you their VAWTs?
I would like to do it, and have been thinking a lot about it, but the cost is a bit prohibitive right now. I don't think it will work well if I get them given to me by manufacturers, because then there is pressure to say nice things about the product I got for free. Maybe I can set up a Patreon or some other crowd funding and have people donate and vote on which models they'd like to see tested first.
One of the big killers of VAWT is the simple fact that the force acting on the blade (lift design) is only there during aprox ½ of each rotation. During the retreating and advancing portion of the rotation the lift is nullified. One way to possibly over come this is to use some type of variable pitch system.. maybe… look up voith drive (water tractor propeller system) it uses a constantly changing pitch system to maximize thrust in that case but something similar could be adapted to a VAWT
Hi Rosie! I'm an engineer like you! I appreciated a lot your video, I subscribed and posted a link to this video on a sailing Facebook channel. Cheers.
Love VAWTs for reasons I don’t quite understand! I heard somewhere that they are not self starting however... is that true?
Yes that's true, for some types. So then you need a bidirectional generator that can get them up to speed.
The rotor configuration is important to the self-starting characteristics of the rotor. The graceful curved blades on some Darrius-type VAWTs are not there to look nice, they actually improve the ability of the rotor to self-start because there is always some part of the rotor that is at the optimal angle of lift to start the rotor turning, and as that part of the rotor turns away from that angle, another part of the rotor is turning into that optimum angle. Self-starting behaviour is a particular difficulty with VAWTs, but it can be overcome with careful design.
Drag type VAWTs are self-starting. People have sometimes combines drag type and lift type to make the combination self-starting. It would be best to have a freewheel between them as the lift type will need to spin much faster to be efficient, I think.
I feel a mix of the two, where applicable, is best. Solar cost per watt is going down but efficiency is still not what it could be. HAVT will be best option for the vast array of wind conditions not suitable for HAVT. Medians on freeways. Urban industrial rooftops or plant towers. Commercial buildings.
Also the lack of transmission loss. Being closer to existing infrastructure is a huge factor beyond simple efficiency.
Great video.
Just off the top of my head, if for vertical turbines that each blade could rotate, you would design it so a blade catches the downwind, but when it is moving back around to being upwind, if I'm getting this right, that the blade has rotated to where it's not catching the wind, just like wind moving over a wing, you would have more efficiency. However you'd add complexity and cost, and the blades couldn't be too fancy like some of them are. The turbine would have to sense the direction of the wind which is easy enough, and then that would determine the way the blades orient.
Maybe this already happens without a blade rotating.
Vertical axis Wind turbine is safer than horizontal during tyhoon..
Are they? I haven't heard that before. I guess if they are smaller and lower to the ground that would make sense.
@@EngineeringwithRosie Also, seems savonius vawts kinda slow themselves down, self regulating I guess.
@@EngineeringwithRosie Lower to the ground will definitely help, but the rotor diameter tends to be lower, so the force at the tips is lower. VAWT tip speeds never reach the supersonic!
Interesting discussion of the pros and cons of the different types. It is good to hear from an engineers perspective why the 3 blade turbine is now the standard and most common form. I think a good topic for a future video would be about the impact scale has on the wind power produced by turbines, I would be interested to know if due to their small scale, whether domestic turbines can ever be effective and about the trends towards larger turbines, particularly offshore.
Great suggestion, thanks. I will start work on a video like that 😀
Really enjoyed the video. As an amateur engineer I have a plan in my head for a vertical axis turbine that gets round the problem of the blades rotating into wind and robbing efficiency. My idea involves a drum with blades that fold flush to the drum but come out for half a revolution to catch the wind. The timing of the blade actuation would be cam based. The positioning of the cam would be provided by a wind vane that always faced the wind thus ensuring the blades were always open at the right time. How that would work in reality I'd love to know. Keep up the good work.
I think that's a really fair assessment of the VAWT vs HAWT. In adding complexity to increase efficiency, potentially a variable pitch design similar to what cyclotech is developing for VTOL aircraft could capture more energy with a smaller cross sectional area.
There are now a number of papers that have shown that a set of counter rotating VAWTs can be packed much more densely than HAWTS, and so achieve better land use efficiency. They are counter rotating to make better use of turbulence cause by upstream turbines, thus boosting the energy efficiency of the grid as a whole, even though each individual turbine still has lower efficiency than a HAWT.
創意..贊
Thanks 😀😀
@@EngineeringwithRosie you speak Chinese?? Geez
@@SMD1999 ha ha, Google speaks Chinese! I can say two things in Mandarin "I don't understand what you're saying" and "I am stuffed full." I can't write them though
An advantage of VAWT is the ability to put several in a much smaller area. Also for off grid and RVers, quieter = better.
I'd like to see more comparisons along this line: amount of wind generation per physical area. Does placing more of the simpler, lower-cost VAWTs in the same physical area as a single higher-efficiency, more complex HAWT have a balancing point? And if so, what is that balancing point?
Thanks mate,, a windy day here on tge deck stuck in italy,, thought with the current govt 110% payback for energy efficient home improvements,, its a wind wind, bahaha
Scott McKie -- Hi Rosie -- very well done video. One topic that you might also think about adding in your section about vertical shaft turbines and their blades is the following, and it comes from being an aircraft pilot. The topic is named the "AOA" or "angle of attack" of the blade - as it interacts with the wind - which, because of the vertical axis -- is coming from only one direction at a time.
The maximum efficiency point of each blade / wing - is when the blade is just a little behind 90 degrees, i.e., "leading edge up", i.e., almost "in-line" with the direction of the wind. This position produces the maximum amount of "lift" - which is transferred to the vertical.
Also -- you did not explain the "percentage" of interaction with each blade - with the wind between the vertical and horizontal axis turbines.
A horizontal turbine -- has it's blades turned "into the wind" for 100% interaction, i.e., continuously produced lift - while the standard vertical axis turbine only has 100% efficiency as described above.
FYI -- the only vertical axis wind turbine that can come close to a horizontal shaft axis wind turbine - would be a design where each vertical blade would be gear driven off of the Ground connected stationary vertical shaft of the turbine itself. This way each vertical turbine blade would always be "turned into the wind" - for maximum efficiency on the windward side to the turbine -- but why do it.
@8:40 I'm not a great mech designer, but it seems simple enough to design a pivot on the VAWP blades so they lock with the wind direction (i.e. max push force obtained from wind) and pivot to show minimum resistance on the "into the wind" return path.
I wondered about that before, but I was thinking of a blade that isnt solid, but has a bar at each side connected by something like a bungee cord, inbetween the bars would be strong flexible material, so the push of the wind would also expand the blade whilst driving it, and when that wind energy is used it springs back to the closed position on its way back. i think if it worked at all it would have to only be small scale
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One efficiency only available to Vertical Axis Wind Turbines is in the use of magnets. You put polar opposite magnets in the base and the turbine, and can get close to a frictionless bearing. I've seen these for marine applications, where noise, vibration and maintenance are the key issues, Horizontal Axis Turbines are generally prohibitive to sleep on a sailboat and are almost always missed in favour of solar, but getting the real estate for the amount of solar on a small boat is a pain, especially with sails up. I'm hoping VAWT keeps developing well.
One point about savonious illustration was there is a design popular in the 1970 made from 55 gallon barrels usually three stacked high. The barrels were cut in half and instead of meeting edge to edge as shown here overlapped the axis so wind on the catching side was turned 180 degrees and pushed on the up wind side. The three barrels faced 120 degrees a part to even out the torque with three maximum points per revolution. Guess you could use more but point is the changing wind direction is more dynamic like a Pelton wheel compared to a water wheel with flat floates or paddles. It brings up a question how much more efficient would curved buckets on a wheel be than flat ones?
Great explained
for a home use , lower cost output unit , i would go vertical unit , 30% is better than 40% in the total cost of running an mainting the unit . i can understand why commercial units are hwt's , cause they dont want the cost of reinventing the wheel . great vid .thanks
I have a four part engineering puzzle you may find of interest.
First I watched part two to this vid first so I'ma reference it. I wrote about the use of a shield/scoop around the blades. It fixes many issues of Vawt's.
Second: you've heard of a blade less fan. Basically a wing shaped like a ring. Known to increase air flow over that provided by the internal fan by 15 X and more. A Dyson Fan.
Third: when I was in school, I learned about jet engine design from an 16mm military training film. We join the narrator at a fondue party or some whatever. A man sits across the room next to a shade lamp smoking a cigarette. The narrator points out how the smoke flows between the man and the lamp because smoke rises. The man turns on the lamp. When the lamp heats up the smoke is pulled to the inside of the shade then up. Yea we were taught with cigarettes. I assume you know why the smoke did as it did.
Fourth: I had a small blade less fan. One small flood later I had a toy to play with. I took the ring wing thing and made 4' legs for a 4' diameter ring. Painted it flat black and put it in the sun. It did generate air flow. Cutting slots near the bottom to provide air flow to the core it became a fan with no moving parts, If you placed a 6' diameter Vawt over it and kinda down and around the top edge it powered a bike tire dynamo enough to light the bulb. Kinda.
The blade pattern I used was like a conch shell. Fat end down. In my opinion this is the path grasshopper.
If you do poke around at it I would be interested to know how it goes.
I think the biggest benefit of a VAWT is that they can be placed a lot closer to each other, and in places that wouldn't make sense for HAWT. Like all along the sides of a motorway, which would have the benefits of capturing not only the wind, but vehicle air turbulence, and there is a lot of free real estate that could be capitalized just for that. Even a drop of 10% efficiency would be outweighed by the sheer number of turbines that can be installed
I have a design of a vertical wind turbine that works on compression and it has zero drag so a very small turbine can produce a lot of power. Vertical wind mills work on suction and you can only get a limited amount of suction. The vertical turbine under compression is far more efficient than a horizontal wind mill turned by suction. The pressure drop behind the blade on a horizontal is what can cause the blade to turn but once it is at zero pressure you can not get any more power from the blade. If you put a vertical turbine under pressure you can keep building the pressure thereby getting more power. This is how a car motor works. The piston is put under pressure and you get a lot of power from a small package. My friend has a v8 motor that can create 700 HP and small enough to fit in a F-150 ford from 1999. You increase the pressure on the piston to do this. You can never get that kind of power from suction (vacuum) . The air flow over an air plane wing creates a pressure drop and the wing is lifted into the space where the pressure drop happens. A pressure drop on one side of a surface can never be as great as a high pressure compressed air flow on the other side of the surface. I know a guy who said his wind turbine had a 3 to 1 compression ratio. I looked at it and It had many problems but was still better than any horizontal wind mill. My design has a 4 to 1 compression ratio and does not have any of the problems that his does ( he has to rotate the building into the wind with his and that is a big problem). He refused to believe that it is possible to get a 4 to 1 compression ratio, but my math can prove that mine will do that. Small package but will put out a lot of power. I know that some of you will want the plans but at this time it is classified.
I'm not sure if you are aware of Vertogen, but they are working on an self-governing variable pitch VAWT mechanism that might improve the efficiency of VAWTs significantly. It might be fair to say that "automatic variable pitch" is the holy grail of VAWT technology as it promises improved efficiency, improved self-starting and another layer of safety against overspeed. Only time will tell if the benefits outweigh the downsides produced by the complexity.
Thx for help ful info.
Suggestion: put some bookshelves or objects behind you…makes for more pleasing view
You smile so much for a serious thing, Mrs. Engineer, to explain something funny, how can it be then? Thank you very much🤘🤘🤘💛it