I really wish they were a more teachers like you while I was growing up. This is how math should be taught. You are an inspiration. I feel so sorry for today's students.
Or you could change the equations completely by switching from Wind to Water? Only need to handle the environmental and corrosion problems.why water is 750 x more dense and although generally much slower it is more predictable.
Great vlog Rosie. I'm so lucky to be working in the industry. I have travelled to many of the wind farms and watched the skill of moving the blades, towers and Narcelles. The real understanding of the size is when you get up close to the turbines under construction, the size of the newer turbines is mind blowing. I think you engineers designing these turbines are incredible, as are the technians that are putting them together. One factor that you didn't talk about is wind, turbines are built in places with lots of constant wind. When erecting a turbine you really want to put the tower up in one go and then the blades in one go, the bigger the turbine the longer it takes to erect . The last thing you want is wind, so you need favourable weather windows. The longer the weather window you need the fewer that are available. It will be fascinating to see how the industry evolves over the years to come.
I wrote my PhD several years on ago a particular hydrodynamic challenge to having larger and larger diameter tubular towers on offshore wind turbines (the 'ringing' phenomena). As for everyone who has ever written a PhD, spending so many years of my life doing research on the topic gives me the impression that it's the most important issue ever and all wind turbine engineers all over the world should spend at least half their time designing tubular tower with that into consideration. But I won't fall into the trap of writing a RUclips comment just talking about my research! (oh crap, maybe I just did?)
Well. We're busy in Denmark with those everbigger windblades. Do you think it's a good idea with those 'megawindmillls'. With long blades. And a high tower. Yes or no? (Challenging the ph.d. engineer to simplify?)
I have a PhD too. My job is to finance these. We don't care. It all comes down to one number. Internal rate of Return (IRR). If that is high enough, we will finance it as long as somebody else is taking the technology risk if it doesn't work. Towers, nacelles, blades, foundations, ships, cables. That isn't our problem. I have never seen an offshore wind turbine close up and very few of the people that finance them have either.
One key parameter you didn't mention is the energy return on energy invested (EROEI or EROI). Not only does the parts get heavier and cost more, but they take more energy to make a large wind turbine. But also the power produced goes up as the square of the disk radius. Also the EROI is determined with the total energy produced over the lifespan of the system. Wind turbines have a operating life span of 20-25 years. So EROI is the amount of energy produced by the wind turbine over its total lifespan divided by all of the energy that went into making all of the parts plus the energy required to transport and install the wind turbine and lastly the energy expended to during maintenance Of course the higher the EROI the better since the amount of energy that is available for use is hopefully many times greater than the energy that it took to make, install and operate the wind turbine. In the limit a EROI of 1.0 as low as one would go since you would only get back energy exactly equal to the energy you put into it. So which increases faster with radius, the sum total of power produced over its lifetime or the amount of energy that it took to make and install thicker walled and taller steel masts, heavier gearboxes and blades. invested
Many have been found to have a lifespan well under the 20-25 year prediction. Some are lasting less than 10 years due to leading edge abrasion and delamination of the blades. This is especially the case in coastal locations and offshore installations.
Those brief clips of unusual turbine designs at the very end of the video were fascinating! Perhaps worth a future video? I'm especially curious about the airborne types, having previously gone down the wikipedia-research-rabbit hole!
I did a livestream on airborne wind about six months ago. Planning an update and a "proper" (shorter) video on the topic soon. Here's the livestream ruclips.net/video/2vdcfrfsyKg/видео.html
Super cool video. Combining this one with your 'Why do (most) wind turbines have three blades' gives super interesting insight into different challenges and ideas for the future
Thanks! Hey by the way, I was thinking it would be cool to collab with you guys for a livestream sometime. I'll get in touch later in the year if that sounds interesting to you.
Another great video. I didn't know you had a PhD as well. Your formal expertise in these fields is far greater than you have let on, so it is Dr Rosie from now on. :) As for the future of wind turbines, if blades that can be assembled on site, arrive in two or more pieces, can't be competitive priced, then I can't see many onshore wind projects having larger turbine blades. As you pointed out, the challenge isn't just going to be the problem of the logistics of the length, but the cross section or diameter at the base of the blade is going to be a major limitation too. Off shore wind turbines has a greater potential to keep getting bigger as the logistics are less of an issue, but the handling cost is surely going to become more expensive as they grow in size. The only question then is what the rate of increase of these costs are compared to the energy returned. Sure the squared vs the cubed does help, but at some point the returns will diminish, however I think we are a long way from that point.
I really like the deeper dive into the engineering that you take, compared to other vids on all these topics. Although, admittedly, much of the math goes RIGHT over my head! :D Keep up the good work.
Thanks for the feedback! I tried to keep the maths short enough that whoever didn't want to follow that part wouldn't get so bored they'd stop watching! Let me know if I succeeded, or if you'd rather less equations on a video like this. That will help me find a good balance
I like the current balance. I get the concepts from the dialog and diagrams, and have enough math knowledge I can see where its going, even if I get lost in the details of the formulas. However I can imagine the more mathematically inclined would get value from the formulas too, and maybe I'll crack some books and try to catch up.
I'm a structural engineer and Rosie did a great job of explaining the math and theory, I definitely wouldn't have been able to explain this as well as she did.
@@EngineeringwithRosie any audience is a mix of people who like what they see so stay & people who are just passing through, they'll watch one or 2 videos & move on. So the question is, do you like the audience you've got? If you like your audience the way it is just keep the mindset & formulas you're currently using. There's around 4 billion internet users so a few thousand will always follow you but is it the particular few thousand you want? I like what I see so I'm staying. :-) You're showing me more about things I want to know more about & you deliver it with a pleasant voice & demeanor. Thank you for being you.
Another excellent and informative presentation Rosie. I saw an interesting development in wave power by a company here in Australia. The Wave Swell Energy Uniwave 200 is apparently operating off the coast of King Island and generating 200kW - it is a form of windpower generated by waves. That looks interesting too. Perhaps you can take a look?
I saw that too, looks cool! I talked with those guys a while back when I made a few waves energy videos, they weren't at a stage they wanted to talk about their tech publicly at that time but I'll try again. I would looooove to visit King Island, and plenty of other video possibilities on the island besides wave energy.
Great video! Really nicely explains the tradeoffs. One other benefit for big turbines particularly onshore is in wind farm design. If you have bigger wind turbines, then you can concentrate more power on the windiest points on your site, wake efficiency improves and land costs go down. So even if the cost of energy from bigger turbines stops decreasing at some point, bigger turbines could still reduce wind energy costs overall.
Very good. I play in small (micro) wind energy ~ I do a bit of writing and sometimes teach workshops on the design and build of small wind electric systems. Size often comes up and I always have to point out the advantage of height (which often comes with larger machines) ~ and the fact that energy harvested is related to the cube of diameter while the weight of the rotor, and the alternator is roughly related to the cube of the diameter. With small, direct drive alternators I usually use about 8x the magnetic material and 8 times the copper, if I double rotor diameter. (4x the power at half the rpm) I love your channel.
There's a you tube video somewhere about the world's largest mining dragline, it was perfectly feasible to build and operate , but the maintenance costs were off the scale because everything was just too big to comfortably service - so downtime was huge , It was abandoned -
Great videos on wind turbine design, very informative. I particularly enjoy the ones on VAWT’s as I got involved in a VAWT start up after I retired, but subsequently left the business for reasons outlined below. Without giving too much away wrt proprietary design which is being patented, we were trying to boost power output by manipulating (increasing) native wind speed impinging on the blades of an H blade VAWT (though it could also be applied to spiral blades). Ref the wind speed power equation, the two easiest elements to modify to increase power are obviously swept area and wind speed. In one of your VAWT videos you cover why increasing VAWT swept area comes with increased costs and technical challenges, and why the Betz limit effectively rules out trying to become more efficient than HAWT’s as a credible performance improvement avenue. So that leaves wind speed, which because it’s cubed in theory offers by far the best chance to increase power output. However, increasing native wind speed requires external intervention / interception and we found via patent search numerous examples of VAWT designs employing external devices to do this, eg, cowlings, Venturi’s, funnels, diversions, channels, etc, but what was also obvious was that none of these seem to have ever been effectively commercialized, suggesting they either don’t work or more likely don’t work well enough to warrant significant development investment. As we progressed through TRL design and testing we did find some wind speed increase that would require VAWT / blade design optimization to capture maximum benefits, but it wasn’t enough to likely challenge and replace the dominance of HAWT’s on the market. HAWT’s dominance effectively meant breaking into the wind power generation game would require significantly more power (wind speed) increase than we had seen to warrant an investment risk on a new tech start up as opposed to a less risky ROI through simply making bigger HAWT’s! After much consideration it was the observed experimental limited wind speed increase potential, slow and expensive pace of development and extreme business challenge that caused me to make my decision to leave, but it was still a very interesting project to be involved with. The business is still working on trying to improve the concept! So this brings me to my technical question to you, in your opinion why do you think attempts to increase native wind speed before hitting the VAWT all seem to fail, or at least not work well enough to warrant further investment, and finally achieve commercialization? Maybe a good topic for a video?
Hello. Good, but there are some little points - hmm: "Kevlar" is Aramide. And under pressure it's much worse than under tension (The same for HM-Carbon fibre not mentioned here.) Next important point: The gearbox growth is exactly by cube with diameter: If you double all dimensions of a WT, with a constant tip speed you end up 8 times of the torque. That's in fact the same machine (except minor aerodynamic incluence in this sizes- bigger is better - as in real life). So if you have the direct-drive Enercon E126 with 400 tons of Nacelle- try to made a 200 m rotor :-) A rough estimation ends up at 2000 tons. I assume you'll kill additionally all the frequencies of the tower. Therefore: gearbox- machines- maybe. But direct drive has stopped already. And to compare strong-wind and low-wind-machines isn't as easy. That's apple with pairs.
Likely be "floating" turbines to reach those 50+MW figures. Gets them up high and negates many of the transportation problems. Just need material science to resolve the carbon nanotube at scale problem. Super easy, barely an inconvenience. 🙂
What rules out making the tower with cables. Cables allow the tower to mostly deal with the vertical force while the cables keep it standing up. This seems a natural way to go taller without making things too big to go down a road.
Thank you for this brilliant Video. Dr. Hansen published a paper in which he and co authors mentioned Super Storms. I concluded that off shore windparks must be able so withstand Hurrikane windforces. Larger fields with not too tall towers can withstand extreme weather and protect coasts by breaking waves and softening winds. But my remark should not do injustice to your extremely bright work and presentation.
As an electrical engineer with some structural and heavy equipment background, your math and graphics ratio were perfect. What a great example of a typical engineering problem - optimizing many design variables. And scaling is such a wonderful way to prove design concepts but can be problematic in certain engineering areas such as fluid dynamics if I recall. Scaling, and ignorance of resonance, (as someone else commented here), was the downfall (literally) of the Tacoma Narrows bridge.
Or maybe blades will change. Airplanes went from 2 blades to 3 to 4 to 5 as more power was applied. Then there's exotic designs like scimitar blades. Maybe wind turbines will do something equivalent. And generators could go with superconducting coils/magnets. Lots of room for improvement.
Three blades is optimum. As l understand it you have to allow the wind to pass through - more blades and the wind will take a path around. Anyway there's actual experts have made videos about this.
@@DavidOfWhitehills I've watched those and more blades also mean lower speeds for same torque, therefore quieter, and less air speed difference between the top and bottom blades.
@@DavidOfWhitehills Why were the first aircraft 2 bladed? Same with ships screws. Look at the development of submarine screws. These things usually boil down to current technical capability and costs. Those change with time.
Would you comment on the idea of multi rotor contra rotating turbine hubs. I understand wind turbulence from adjacent wind turbines in a wind farm is a consideration in efficiency. However many propeller based aircraft designs over the decades have successfully used contrarotating propellers accepting any inefficiencies for the advantages of smaller diameter and ground clearance and high engine power absorption. It would also seem that the upstream rotor is adding some kind energy in the form of turbulence to the air stream that the downstream rotor could possibly be designed to take advantage of. The common understanding of wind farm inefficiency due to air turbulence of nearby turbines does seem to get a little more interesting when the accepted use of contra rotating propeller aircraft is introduced in to the conversation.
One thing you didn't mention is the increasing height related to airspace. The FAA already imposes limits on how tall a structure may be based upon the distance to the nearest airport. At some point, the possibility of conflict with aviation may become more important than the physical stresses on the blades or towers.
I'm eager to see an "offshore VAWT" video if you've got one coming up! There's a lot that's different and I'm curious how it could impact the designs and sizes
9:25 I've always observed this while driving... I wasn't sure if it was actually what I was seeing. My Dad was an engineer and he 'didn't know'... THANK YOU. I can put this to rest!
Excellent video, Rosie. And I must say, being a Dutch guy with 24y in the industry, that the anniversary speech topic, including embarrassed laughter, is not restricted to the Danes.
I remember reading a few years ago about magnetic gearboxes, the idea being they were supposed to be simpler to maintain, were lighter and had fewer power losses. I wonder if anything came of it?
I saw somewhere that Vestas has some cooperation with a company that makes segmented towers out of wood. Solves both the diameter problem and the issue of lots of steel being needed for towers.
Another great video Rosie!I find turbines fascinating and have pondered this question before. Two thoughts came to mind whilst watching the vid: - might it be possible to construct a pressurised blade? In the same way that a paraglider's wing stays formed during flight, a pressurised blade (with a compressor near its 'root' and electrically powered) would help maintain the form of a partially 'flimsy' shell. This could reduce manufacturing and transportation costs. - Thinking about when the wind is not blowing, is one large inoperative turbine better than 5 smaller inoperative ones? Or is it better to spread the risk of no wind?
Hm, a pressurized blade seems like a good idea, until the pressurization system fails. In the 1980s, there was a trend of building stadiums with super lightweight membrane roofs weighing a fraction of conventional truss supported ones. They were held up by a slight overpressure in the building and were of course much cheaper to build. Eventually they all failed due to environmental conditions and/or failure of the overpressurization machinery. All but one have since had major structural work done, aka explosive demolition. Great in theory, not so great in practice. There's also the problem of pumping air from a stationary compressor into rotating structures. I'm a structural engineer, not mechanical, but it doesn't sound easy.
@@drecksaukerl Thanks for your answer! My thought was that the compressor for each blade is built into the base of the blade, electrically powered by a 'ring' electrical connection through the turbine's axis and possibly also the pitch mechanism. Re: compressor failure - I guess this would depend on air leakage through the blade and whether the brake mechanism could halt the blades' rotation quickly enough to prevent serious damage and if a pressure connection to adjacent blades would be worth consideration.
I would love a 50 min video where you go over the data of one particular type, curve fit all the laws using real world data and just run and discuss one of these optimization models.
Dr. Barnes, Has anyone investigated toroidal blades? It should be more efficient and structurally stronger. Fabrication on site can avoid the critical transportation issues. Thanks for being a voice of engineering clarity!
Great video!! Very educational!! . You said something about new designs and I agree with you there too. There’s a wind machine design out there that instead of going up in the air is going down to the ground , in fact it’s going to be under ground. The designer thinks this machine could produce hundreds of megawatts per machine and produce power 24/7. Could be installed near the consumers, thus saving on transmission lines. Very interesting design. It is a super wind machine.
How does foundation size scale? Not only does a bigger rotor increase the wind load, but the higher tower increases the lever force on the foundation? Will floating wind turbines mitigate that?
Hey Rosie, great overview. Check out the Lagerwey self climbing tower for another method to build high towers without the need for a large crane. Lagerwey has been taken over by Enercon so they have that technology now. This method of installation has already been proven on many installations in the Netherlands and in Europe.
I'm at 2:30 and going to make a couple predictions to see how they bear out with your analysis before watching the rest: 1 - turbines will continue to grow in size for some time as our materials science improves because of the efficiency returns of making turbines bigger and taller 2 - turbines will hit the tyranny of the rocket equation and the same kinds of problems as megafauna as the ever-increasing structure sizes demand more structure to hold the structure up which demands more structure to hold up that extra structure, amplification of resonant forces will come into play....TL;DR - at some point, the material capabilities of the turbines will start to hit efficiency limitations where you CAN go bigger but it will become more expensive in LCOE to shore up such colossal turbine structures than to just build 2 turbines. But we're not there yet. 3 - eventually the advancement of wind harvesting will shift towards finding ways to make turbines (or non-turbine) megastructures that are more and more efficient at harvesting wind as we'll hit practical efficiency caps at just building bigger and bigger crap.
Some new info for you,,, a wind farm in my area was sold to the landholder after it had been in operation for 23yrs. Now the landholder has since sold his farm because he found the costs to maintain the wind farm was larger than the returns it earned. SO THE INSTALLERS RECOVERED THE COSTS TO FIT THE SYSTEM AND A HANDSOME RETURN ON TOP & NO COSTS TO REMEDIATE THE AREA AND PROFIT FROM ITS SALE !! yes thats the game watch it roll out in your area. AND remember 27 years and the costs rise fast as an average
Excellent as always. I enjoy your forays into the formulas and principles without tipping over into total geek speak. You tread that line well. How to different soil structures figure into foundation design? More importantly, does it significantly affect the cost. BTW, any reason for eating cake yet?
No celebration cake for me yet, though being 41 weeks pregnant has led to a few cake cravings I will admit (assuming that's what you meant by the cake comment!) And I'm glad you thought I got the balance right between showing the important formulae but not making it an engineering lecture. It's a tricky balance! I don't know a whole lot about foundation design, but that could be a cool topic for a livestream if I can find an expert to get on as a guest. There have been a few foundation failures in the news recently, it works be nice to find out more about what that's about.
The other issue is a rather practical one. There are simply not enough wind turbine installation vessels large enough to install large numbers of 15 MW turbines. The owners of these vessels are simply not willing to keep building bigger ones as turbines get bigger because they can't be sure they will not be become redundant before they get the return on the investment. These vessels cost $500 million and that is a big investment without certainty about future revenue. Put simply, planning to build a 15 MW sized wind installation vessels now is futile. Investors have to build 20 MW sized vessels but by the time they are built in 5 years time the manufacturers might be planning 25 MW turbines
How about a discussion of wind turbine other than blades. I have seen vertical helical wind turbines, horizontal system on roof tops and barrel shaped wind generators. The barrel shape I most recently saw was used in Okinawa Japan and reportedly survived a direct hit from a Cat. 3 Typhoon. Lets look at more options for various condition where a blade system might not be appropriate.
Thanks Rosie. Your video got me thinking (the best compliment 🙂) is the air mass of anabatic and katabatic winds sufficient to support power generation? I live near a coastal mountain that has a cliff face with tremendous winds (in both directions) I sometimes wonder if very large axial fans of efficient design, bolted to the cliff face, could overcome the tower issues?
Here is a different direction for wind technology: Pluvicipia creates wind inexpensively and with primarily positive side effects. In that case, it seems big is unnecessary: Produce faster currents onto your field, the energy sources, potential temperature, is better than free, using it helps to cool the planet and absorb C02, as well as produce water and food, etc. Sounds too good to be true because it is the energy source for the next era in human development. Check it out; you will love it. It will return on the market soon; I'm trying to complete numerical modeling before republishing the revision. At this point, the best I got is prior mathematical models and quick AI design revision. But it will be out there again soon.
It's a brave pundit who would make predictions about the size and design of anything in this age of rapid material science advances. The 'next big thing' may well be very different to what we're working with today.
I have the solution! Since a big part of the expense is taller towers and their associated costs simply dig a big trench for the blades to travel through on the lower part of their revolution. This would allow you to only have to elevate the hubs just above the ground thus saving a fortune!
The opponents of wind turbines often show a beautiful American bald eagle with one wing cut off. But we also know cats kill 10x as many birds as wind turbines. We are not going to makes cats extinct to save birds. Why don’t we hear about new technology to save birds? What progress have we made on saving birds in the past 10 years?
When I was still in the power industry (Los Angeles, California) I had to decipher a term from Palo Verde nuclear station (LA is a participant): BOP - turned out to be “balance of plant” Nuclear engineers and Navy people would already know that
Rosie,engineering is one of mankind’s greatest achievements. We have not as yet been able to the summon the elements on command however. Wind on demand isn’t within our remit. The meerkat proposition is simples. Until you can control the wind,turbines remain totally weather dependent. In other words the lack of predictably renders the investment wasteful,unless you are a subsidy harvester,snake oil salesman. 1x0=0 1000000x0 =0
A few thoughts: Are these very large machines already a 'hazard to navigation' for aircraft & if not how big can you go? What do you do about different wind speeds & directions at different heights? Can you end up with a machine that's big enough to launch satellites off it's blade tips?
Onshore they are a hazard, at least for small recreational aircraft. Offshore its not a problem as no aircraft flies at 200m above sea level. Commercial aircraft usually cruise at 10,000m above sea level.
A great presentation. I think you could, though, perhaps have made the point that the optimum size for offshore and onshore turbines is very different because of the fabrication and transport challenges of very large blades for inland ones (shipyards are designed to fabricate huge structures, and you don't need to worry about bends and clearances on the water). For inland ones, therefore, the optimum size is mostly set by these constraints while for offshore ones it is set by the scaling issues you detailed so well here. Of course offshore has its own expensive issues (eg getting the power back to shore), but the point is the size considerations differ.
just a thought, what you build a hub with a Long interconnected arms like a bicicle so you use the same blade but with a 15 to25 meters more, and you could even have a different sleeve in the first part so the pitch can be adjusted in the Ruth and the tip independent, transport will be easier and it will work in a wider range of wind speed.
Another aspect is the windspeed every cross section sees. Near the hub - most if not all design is for strength and are probably not adding power. Further out is a transfer to an actual aerodynamic profile while the windspeed crossing the blade is not much more than the wind a pixed point sees. But at the wing tip the wind across the blade is extreme, I imagine it may be close to what a aircraft have. At some point of scaling turbine blade up - I think the wingtip is more drag than adding power. What do you think?
As she mentioned in the video, the rotational speed is reduced with increasing diameter, so the tip speed stays the same for optimal aerodynamic performance.
Great explanation, I think most systems have a 'sweet spot' size wise and it's not always just about what's theoretically possible. Something I'd therefore be very interested to know is what are the life limiting factors and components for wind turbines? Currently life expired turbines usually get completely replaced (re-powered) after 20-25 years because larger and more efficient turbines have become available since they were installed. This does obviously increase efficiency of the particular wind farm but it's arguably not a good use of carbon intensive materials (or costs) to do a complete replacement. So it would be interesting to know what will happen once most turbines achieve an optimal sizing, as suggested. Could these turbines be maintained and run indefinitely? What parts would need to be replaced, and what parts could be reused? Foundations and grid connection are a major part of the cost, so I would guess big savings should be possible if these can be reused, and both should be good for 100+ years.
I remember seeing a report that Europe currently has power capacity of around 950 GW. If the economic forces ever tip to favor the 1GW designs, I can only imagine how much power we’ll have. Also I suspect that given the relatively few number of them that would need to be built, that they’d either be built on site or the parts would need to be flown in through a team of helicopters. That would be a sight to see.
@@RonTodd-gb1eo It's usually blowing somewhere in the world, and Europe as a whole is increasingly interconnected powerwise so even if it's dead in Ireland if it's windy in Denmark, Ireland will have power.
this was a lot more interesting than i thought a phd video could be. My only question is that you didn't mention upper atmosphere winds. I read that the main reason why turbines are getting bigger was because they get to reach higher velocity wind higher up in the atmosphere. you approached this video without any consideration that wind will change direction, change speed, or on average have higher wind speeds farther off the ground
If we ever build space loops or space orbital rings (forget elevators, those are ridiculous in comparison), I'd love to see giant wind turbines hanging part way up the tethers. Though at that point we'd have access to a huge amount of 24hr space solar.
I seem to recall, about five years ago, watching a news piece about a prototype and research wind turbine that was kite-based. "No more pesky unwieldy blades" "smaller airfoil in a larger area of sky can harvest more power than traditional" types of claims. With, if I recall correctly, its fatal flaw being that the best use cases are not anywhere near populated areas. Rosie, have you heard of that type of wine turbine? I'd be interested in someone with your background highlighting this technology, its pros and cons, and hearing your take on what came of their research and product development.
I did a livestream on airborne wind about six months ago so you can check that out if you're interested. I'm planning a follow up in the normal short format sometime soon, so let me know if there's any specific questions you think would be interesting to cover 😊
maybe I missed it, but one of the biggest concerns for even larger wind turbines, at least for offshore purposes, is the required infrastructure and installation vessels. with each increment you need to design and construct new infrastructure (ships, ports, factories) that can build these new larger wind turbines, but that's not cheap at all and has inherent financial risks. sometimes the perfect is the enemy of the good. I too want to see neverending fields of 50MW wind turbines out in the sea, but if this doesn't make financial sense we won't see it.
Hi Rosie, have you seen the recent Harmony Turbines spot on Disruptive Investing here on YT? They have some very interesting developments on their version of a Savonius Vertical Axis Wind Turbine. Well worth a watch.
I always enjoy your video’s. I have often wondered if we will get to a point where a manufacturer will “lock in” to a particular design and if there would then be scope to decrease cost due to economy of scale?
On topic, BIG is the Engineering term, "BIG" is the let's get as many of these as is possible, on the Mine Sites and Refineries as can be arranged as a matter of urgency. If a certain Canadian Mining group has a genuine method of CO2 sequestration in Tailings from Nickel Mining, and the same can be applied to all Metal Mines, this is the serious solution to Sequestration. (For the same CO2 reduction reason, SMRs are required urgently, I'm not biased, much) ***** Apparently Queensland Nickel is to be resurrected, they need direction for full Electrification, and vastly improved Refining methods. After the new baby is settled in, "someone" should organise some crowd funding to work out the sustainable redevelopment plan. A common sense objective in common is the quickest way to get Voters back together and make use of University Training.. etc.
Well done. I think there may be a "skyscrapers in NYC" aspect to this, in that all the space above the turbine is "wasted". There's certainly an incentive to grow vertically for greater "density" in the same area.
@@garrykanter5773 higher wind turbines are harder to hide, louder, have longer shadows, kill more birds and bats. Anti wind energy initiatives grow faster than the hub hights of wind turbines. This costs a lot of money in the planning phase of a windfarm. And if someone has to spend money, someone else will profit. Don't you agree?
really cool explanation, what i miss at the end of the vid, is something like a curve showing we could not have reach more than N kW with older fiberglass wing design, without raising the cost by MWh produced, and the same with the Carbon Fiber. I left the video with no clear clue of what will happen ? more than 16 MW by pole, or are we today at a maximum ? As we know we have nowadays nothing really best than epoxy/carbon fiber, it could have led to a max, where higher means a higher MWh ?
A question please 😊 I’m mystified At how fast the blades go, the outer portions many hundreds of KPH . I’m wondering how this intense speed of the outer portions of the blade can actually be helping generate power, in my way of thinking it’s a burden on the system as the prevailing wind is vastly slower ? (My humble comparison is only with cars, where wind resistance when you go over 200 kph is like hitting a brick wall) Thanks
If someone built a helicopter that was a hundred times bigger than the biggest helicopter that currently exists, then transport would no long be a problem. We could have wind turbines on land that are as big as the offshore ones.
Here's another thought... a 12mw weighs 650 tons and can melt enough metal for 1000 other turbines in 25 years of service, and a 1.5mw weighs 165 tons and can only melt enough metal to build 400 of itself in 25 years.
l would imagine crane size is one of the biggest factors that will dictate wind turbine size also transport will play a part. Cost and manufacturing versus output in MW and maintenance factors such as parts replacement will play a role. l really enjoyed this one you went into small detail and you showed confidence in the subject including ways to build bigger. Public opinion will also play a part going forward into the future. The positions of wind turbines and solar farms is a contentious issue in Australia with size annoying some people also. l prefer as much power generation in one location as possible to cut down on public hostility and increase efficiency... The bottom line is still cost versus MW no matter how big the turbine, also the ability to recycle parts is coming into play at the moment....
How does the operational window for wind turbines change with increasing size? My guts tells me that with larger size there's more mass to rotate and the amount of energy needed to initiate rotation from standstill is larger. I would therefore assume that you would need higher wind speeds before it could start. Is this correct?
09:23 Bending due to self-weight For the ascending blade, isn't its weight compensated (and exceeded) by very aerodynamic lift turning the turbine? But then again, the descending blade suffers combined forces of its own weight and aerodynamic force. Perhaps steering the angle of the blade on its way down could keep this force constant, to reduce dynamic stress? To reduce weight of a blade, as well as work around the transportation problem, don't build them as solid structures. Perhaps you could use the trick flying insects use in their wings: supporting skeleton made of a mesh of tubes filled with pressurized liquid. Some of the insects (e.g. dragonflies) use liquid which hardens after the wings are fully unfolded, and so could wind turbines, as there is usually no need to retract the blades (... until the end of their operational life, that is). Another option would be blades made as inflatable structures. Related to that, inflatable blades could be filled with lighter-than air gas to achieve neutral buoyancy in air. Since they are connected to the hub, the blades can't catastrophically fail like airships did, but construction and operation must make provisions for any case of sudden reduction or loss of lift, etc.
Keep exploring at brilliant.org/EngineeringwithRosie
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Alright. Still toughed about 'miniRosie' on the way. Congratulations. From Copenhagen.
I really wish they were a more teachers like you while I was growing up. This is how math should be taught. You are an inspiration. I feel so sorry for today's students.
do they make wind turbine blades thin so they dont work very well!
will you marry with me>?
Or you could change the equations completely by switching from Wind to Water? Only need to handle the environmental and corrosion problems.why water is 750 x more dense and although generally much slower it is more predictable.
Great vlog Rosie. I'm so lucky to be working in the industry. I have travelled to many of the wind farms and watched the skill of moving the blades, towers and Narcelles. The real understanding of the size is when you get up close to the turbines under construction, the size of the newer turbines is mind blowing. I think you engineers designing these turbines are incredible, as are the technians that are putting them together. One factor that you didn't talk about is wind, turbines are built in places with lots of constant wind. When erecting a turbine you really want to put the tower up in one go and then the blades in one go, the bigger the turbine the longer it takes to erect . The last thing you want is wind, so you need favourable weather windows. The longer the weather window you need the fewer that are available. It will be fascinating to see how the industry evolves over the years to come.
I wrote my PhD several years on ago a particular hydrodynamic challenge to having larger and larger diameter tubular towers on offshore wind turbines (the 'ringing' phenomena). As for everyone who has ever written a PhD, spending so many years of my life doing research on the topic gives me the impression that it's the most important issue ever and all wind turbine engineers all over the world should spend at least half their time designing tubular tower with that into consideration. But I won't fall into the trap of writing a RUclips comment just talking about my research! (oh crap, maybe I just did?)
Well. We're busy in Denmark with those everbigger windblades. Do you think it's a good idea with those 'megawindmillls'. With long blades. And a high tower. Yes or no? (Challenging the ph.d. engineer to simplify?)
Time for cake!
As long as you don't recreate your dissertation here in the comments you're good.
You have now given us the teaser, and now I need a psychology degree to predict where you will post your first chapter.
I have a PhD too. My job is to finance these. We don't care. It all comes down to one number. Internal rate of Return (IRR). If that is high enough, we will finance it as long as somebody else is taking the technology risk if it doesn't work. Towers, nacelles, blades, foundations, ships, cables. That isn't our problem. I have never seen an offshore wind turbine close up and very few of the people that finance them have either.
One key parameter you didn't mention is the energy return on energy invested (EROEI or EROI). Not only does the parts get heavier and cost more, but they take more energy to make a large wind turbine. But also the power produced goes up as the square of the disk radius. Also the EROI is determined with the total energy produced over the lifespan of the system. Wind turbines have a operating life span of 20-25 years. So EROI is the amount of energy produced by the wind turbine over its total lifespan divided by all of the energy that went into making all of the parts plus the energy required to transport and install the wind turbine and lastly the energy expended to during maintenance Of course the higher the EROI the better since the amount of energy that is available for use is hopefully many times greater than the energy that it took to make, install and operate the wind turbine. In the limit a EROI of 1.0 as low as one would go since you would only get back energy exactly equal to the energy you put into it. So which increases faster with radius, the sum total of power produced over its lifetime or the amount of energy that it took to make and install thicker walled and taller steel masts, heavier gearboxes and blades.
invested
Many have been found to have a lifespan well under the 20-25 year prediction. Some are lasting less than 10 years due to leading edge abrasion and delamination of the blades. This is especially the case in coastal locations and offshore installations.
Those brief clips of unusual turbine designs at the very end of the video were fascinating! Perhaps worth a future video? I'm especially curious about the airborne types, having previously gone down the wikipedia-research-rabbit hole!
She has a video on the subject.
I did a livestream on airborne wind about six months ago. Planning an update and a "proper" (shorter) video on the topic soon. Here's the livestream ruclips.net/video/2vdcfrfsyKg/видео.html
Super cool video. Combining this one with your 'Why do (most) wind turbines have three blades' gives super interesting insight into different challenges and ideas for the future
Thanks! Hey by the way, I was thinking it would be cool to collab with you guys for a livestream sometime. I'll get in touch later in the year if that sounds interesting to you.
@@EngineeringwithRosie wow what an honor, that would be awesome!
@@AshesWindTurbineSimulation great! I'm taking October off, I'll get in touch after that to arrange it.
Another great video.
I didn't know you had a PhD as well. Your formal expertise in these fields is far greater than you have let on, so it is Dr Rosie from now on. :)
As for the future of wind turbines, if blades that can be assembled on site, arrive in two or more pieces, can't be competitive priced, then I can't see many onshore wind projects having larger turbine blades. As you pointed out, the challenge isn't just going to be the problem of the logistics of the length, but the cross section or diameter at the base of the blade is going to be a major limitation too.
Off shore wind turbines has a greater potential to keep getting bigger as the logistics are less of an issue, but the handling cost is surely going to become more expensive as they grow in size. The only question then is what the rate of increase of these costs are compared to the energy returned. Sure the squared vs the cubed does help, but at some point the returns will diminish, however I think we are a long way from that point.
I really like the deeper dive into the engineering that you take, compared to other vids on all these topics. Although, admittedly, much of the math goes RIGHT over my head! :D Keep up the good work.
Thanks for the feedback! I tried to keep the maths short enough that whoever didn't want to follow that part wouldn't get so bored they'd stop watching! Let me know if I succeeded, or if you'd rather less equations on a video like this. That will help me find a good balance
I like the current balance. I get the concepts from the dialog and diagrams, and have enough math knowledge I can see where its going, even if I get lost in the details of the formulas. However I can imagine the more mathematically inclined would get value from the formulas too, and maybe I'll crack some books and try to catch up.
I think that you have struck the right balance for a general audience.
I'm a structural engineer and Rosie did a great job of explaining the math and theory, I definitely wouldn't have been able to explain this as well as she did.
@@EngineeringwithRosie any audience is a mix of people who like what they see so stay & people who are just passing through, they'll watch one or 2 videos & move on.
So the question is, do you like the audience you've got? If you like your audience the way it is just keep the mindset & formulas you're currently using. There's around 4 billion internet users so a few thousand will always follow you but is it the particular few thousand you want?
I like what I see so I'm staying. :-)
You're showing me more about things I want to know more about & you deliver it with a pleasant voice & demeanor. Thank you for being you.
A video I was very much looking for
Great video! Even as a retired rocket scientist I had great pleasure looking at your video. Very pedagogical.
Another excellent and informative presentation Rosie.
I saw an interesting development in wave power by a company here in Australia. The Wave Swell Energy Uniwave 200 is apparently operating off the coast of King Island and generating 200kW - it is a form of windpower generated by waves. That looks interesting too. Perhaps you can take a look?
I saw that too, looks cool! I talked with those guys a while back when I made a few waves energy videos, they weren't at a stage they wanted to talk about their tech publicly at that time but I'll try again. I would looooove to visit King Island, and plenty of other video possibilities on the island besides wave energy.
Great video! Really nicely explains the tradeoffs.
One other benefit for big turbines particularly onshore is in wind farm design. If you have bigger wind turbines, then you can concentrate more power on the windiest points on your site, wake efficiency improves and land costs go down.
So even if the cost of energy from bigger turbines stops decreasing at some point, bigger turbines could still reduce wind energy costs overall.
You had me at cake. Very interesting video.
Very good. I play in small (micro) wind energy ~ I do a bit of writing and sometimes teach workshops on the design and build of small wind electric systems. Size often comes up and I always have to point out the advantage of height (which often comes with larger machines) ~ and the fact that energy harvested is related to the cube of diameter while the weight of the rotor, and the alternator is roughly related to the cube of the diameter. With small, direct drive alternators I usually use about 8x the magnetic material and 8 times the copper, if I double rotor diameter. (4x the power at half the rpm) I love your channel.
should build one of these... ruclips.net/video/kye6AFjYayE/видео.html
Wow, such clear and succinct explanations! Another excellent video. Thanks, Rosie.
From a Vestas guy, I say keep up the good work Rosie! Really like your videos you are an excellent science communicator.
There's a you tube video somewhere about the world's largest mining dragline, it was perfectly feasible to build and operate , but the maintenance costs were off the scale because everything was just too big to comfortably service - so downtime was huge ,
It was abandoned -
Excellent video.
Extremely valuable all the references provided with the description.
Great videos on wind turbine design, very informative. I particularly enjoy the ones on VAWT’s as I got involved in a VAWT start up after I retired, but subsequently left the business for reasons outlined below.
Without giving too much away wrt proprietary design which is being patented, we were trying to boost power output by manipulating (increasing) native wind speed impinging on the blades of an H blade VAWT (though it could also be applied to spiral blades).
Ref the wind speed power equation, the two easiest elements to modify to increase power are obviously swept area and wind speed. In one of your VAWT videos you cover why increasing VAWT swept area comes with increased costs and technical challenges, and why the Betz limit effectively rules out trying to become more efficient than HAWT’s as a credible performance improvement avenue.
So that leaves wind speed, which because it’s cubed in theory offers by far the best chance to increase power output. However, increasing native wind speed requires external intervention / interception and we found via patent search numerous examples of VAWT designs employing external devices to do this, eg, cowlings, Venturi’s, funnels, diversions, channels, etc, but what was also obvious was that none of these seem to have ever been effectively commercialized, suggesting they either don’t work or more likely don’t work well enough to warrant significant development investment.
As we progressed through TRL design and testing we did find some wind speed increase that would require VAWT / blade design optimization to capture maximum benefits, but it wasn’t enough to likely challenge and replace the dominance of HAWT’s on the market.
HAWT’s dominance effectively meant breaking into the wind power generation game would require significantly more power (wind speed) increase than we had seen to warrant an investment risk on a new tech start up as opposed to a less risky ROI through simply making bigger HAWT’s!
After much consideration it was the observed experimental limited wind speed increase potential, slow and expensive pace of development and extreme business challenge that caused me to make my decision to leave, but it was still a very interesting project to be involved with. The business is still working on trying to improve the concept!
So this brings me to my technical question to you, in your opinion why do you think attempts to increase native wind speed before hitting the VAWT all seem to fail, or at least not work well enough to warrant further investment, and finally achieve commercialization? Maybe a good topic for a video?
Hello. Good, but there are some little points - hmm:
"Kevlar" is Aramide. And under pressure it's much worse than under tension (The same for HM-Carbon fibre not mentioned here.)
Next important point:
The gearbox growth is exactly by cube with diameter: If you double all dimensions of a WT, with a constant tip speed you end up 8 times of the torque. That's in fact the same machine (except minor aerodynamic incluence in this sizes- bigger is better - as in real life).
So if you have the direct-drive Enercon E126 with 400 tons of Nacelle- try to made a 200 m rotor :-) A rough estimation ends up at 2000 tons.
I assume you'll kill additionally all the frequencies of the tower. Therefore: gearbox- machines- maybe. But direct drive has stopped already.
And to compare strong-wind and low-wind-machines isn't as easy. That's apple with pairs.
Thank you for the dive in wind turbine engineering, really interesting.
Likely be "floating" turbines to reach those 50+MW figures. Gets them up high and negates many of the transportation problems.
Just need material science to resolve the carbon nanotube at scale problem. Super easy, barely an inconvenience. 🙂
What rules out making the tower with cables. Cables allow the tower to mostly deal with the vertical force while the cables keep it standing up. This seems a natural way to go taller without making things too big to go down a road.
Thank you for this brilliant Video. Dr. Hansen published a paper in which he and co authors mentioned Super Storms. I concluded that off shore windparks must be able so withstand Hurrikane windforces. Larger fields with not too tall towers can withstand extreme weather and protect coasts by breaking waves and softening winds. But my remark should not do injustice to your extremely bright work and presentation.
As an electrical engineer with some structural and heavy equipment background, your math and graphics ratio were perfect. What a great example of a typical engineering problem - optimizing many design variables. And scaling is such a wonderful way to prove design concepts but can be problematic in certain engineering areas such as fluid dynamics if I recall. Scaling, and ignorance of resonance, (as someone else commented here), was the downfall (literally) of the Tacoma Narrows bridge.
Or maybe blades will change. Airplanes went from 2 blades to 3 to 4 to 5 as more power was applied. Then there's exotic designs like scimitar blades. Maybe wind turbines will do something equivalent. And generators could go with superconducting coils/magnets. Lots of room for improvement.
Three blades is optimum. As l understand it you have to allow the wind to pass through - more blades and the wind will take a path around. Anyway there's actual experts have made videos about this.
@@DavidOfWhitehills I've watched those and more blades also mean lower speeds for same torque, therefore quieter, and less air speed difference between the top and bottom blades.
@@tsbrownie So why aren't they being built with more blades?
@@DavidOfWhitehills Why were the first aircraft 2 bladed? Same with ships screws. Look at the development of submarine screws. These things usually boil down to current technical capability and costs. Those change with time.
@@tsbrownie Hmm. If you obstruct the wind you lose the wind, it will just go around or over.
Would you comment on the idea of multi rotor contra rotating turbine hubs. I understand wind turbulence from adjacent wind turbines in a wind farm is a consideration in efficiency. However many propeller based aircraft designs over the decades have successfully used contrarotating propellers accepting any inefficiencies for the advantages of smaller diameter and ground clearance and high engine power absorption. It would also seem that the upstream rotor is adding some kind energy in the form of turbulence to the air stream that the downstream rotor could possibly be designed to take advantage of. The common understanding of wind farm inefficiency due to air turbulence of nearby turbines does seem to get a little more interesting when the accepted use of contra rotating propeller aircraft is introduced in to the conversation.
One thing you didn't mention is the increasing height related to airspace. The FAA already imposes limits on how tall a structure may be based upon the distance to the nearest airport. At some point, the possibility of conflict with aviation may become more important than the physical stresses on the blades or towers.
-No wind today, so we don't get any electricity
-That's why we need more wind turbines!!
I'm eager to see an "offshore VAWT" video if you've got one coming up! There's a lot that's different and I'm curious how it could impact the designs and sizes
You're right, I should do a video like that. There are so many new companies trying to get into that space.
Who needs Brilliant, as Rosie is nothing but brilliant? 😁
9:25 I've always observed this while driving... I wasn't sure if it was actually what I was seeing. My Dad was an engineer and he 'didn't know'... THANK YOU. I can put this to rest!
Thanks Rosie. That is the least I can say. Glad that I found your channel.
Excellent video, Rosie. And I must say, being a Dutch guy with 24y in the industry, that the anniversary speech topic, including embarrassed laughter, is not restricted to the Danes.
Do you guys do the cake too? Or Stroopwafel perhaps?
This one just popped into my feed, really well done and great insights and analysis.
I remember reading a few years ago about magnetic gearboxes, the idea being they were supposed to be simpler to maintain, were lighter and had fewer power losses. I wonder if anything came of it?
I saw somewhere that Vestas has some cooperation with a company that makes segmented towers out of wood. Solves both the diameter problem and the issue of lots of steel being needed for towers.
Another great video Rosie!I find turbines fascinating and have pondered this question before. Two thoughts came to mind whilst watching the vid:
- might it be possible to construct a pressurised blade? In the same way that a paraglider's wing stays formed during flight, a pressurised blade (with a compressor near its 'root' and electrically powered) would help maintain the form of a partially 'flimsy' shell. This could reduce manufacturing and transportation costs.
- Thinking about when the wind is not blowing, is one large inoperative turbine better than 5 smaller inoperative ones? Or is it better to spread the risk of no wind?
Hm, a pressurized blade seems like a good idea, until the pressurization system fails. In the 1980s, there was a trend of building stadiums with super lightweight membrane roofs weighing a fraction of conventional truss supported ones. They were held up by a slight overpressure in the building and were of course much cheaper to build. Eventually they all failed due to environmental conditions and/or failure of the overpressurization machinery. All but one have since had major structural work done, aka explosive demolition. Great in theory, not so great in practice. There's also the problem of pumping air from a stationary compressor into rotating structures. I'm a structural engineer, not mechanical, but it doesn't sound easy.
@@drecksaukerl Thanks for your answer! My thought was that the compressor for each blade is built into the base of the blade, electrically powered by a 'ring' electrical connection through the turbine's axis and possibly also the pitch mechanism. Re: compressor failure - I guess this would depend on air leakage through the blade and whether the brake mechanism could halt the blades' rotation quickly enough to prevent serious damage and if a pressure connection to adjacent blades would be worth consideration.
That was super interesting! Thanks for sharing your insight with us!
Beautiful engineer overview, thanks!
I would love a 50 min video where you go over the data of one particular type, curve fit all the laws using real world data and just run and discuss one of these optimization models.
Dr. Barnes,
Has anyone investigated toroidal blades?
It should be more efficient and structurally stronger. Fabrication on site can avoid the critical transportation issues.
Thanks for being a voice of engineering clarity!
I love your channel, Rosie! You have great content. I learn so much every time I watch your vids.
Great video!! Very educational!! . You said something about new designs and I agree with you there too. There’s a wind machine design out there that instead of going up in the air is going down to the ground , in fact it’s going to be under ground. The designer thinks this machine could produce hundreds of megawatts per machine and produce power 24/7. Could be installed near the consumers, thus saving on transmission lines.
Very interesting design. It is a super wind machine.
How does foundation size scale? Not only does a bigger rotor increase the wind load, but the higher tower increases the lever force on the foundation? Will floating wind turbines mitigate that?
Hey Rosie, great overview.
Check out the Lagerwey self climbing tower for another method to build high towers without the need for a large crane. Lagerwey has been taken over by Enercon so they have that technology now. This method of installation has already been proven on many installations in the Netherlands and in Europe.
I'm at 2:30 and going to make a couple predictions to see how they bear out with your analysis before watching the rest:
1 - turbines will continue to grow in size for some time as our materials science improves because of the efficiency returns of making turbines bigger and taller
2 - turbines will hit the tyranny of the rocket equation and the same kinds of problems as megafauna as the ever-increasing structure sizes demand more structure to hold the structure up which demands more structure to hold up that extra structure, amplification of resonant forces will come into play....TL;DR - at some point, the material capabilities of the turbines will start to hit efficiency limitations where you CAN go bigger but it will become more expensive in LCOE to shore up such colossal turbine structures than to just build 2 turbines. But we're not there yet.
3 - eventually the advancement of wind harvesting will shift towards finding ways to make turbines (or non-turbine) megastructures that are more and more efficient at harvesting wind as we'll hit practical efficiency caps at just building bigger and bigger crap.
I'm no engineer but I don't think I did too bad. I think you did a much better job than me though!
I'm looking forward to whenever a wind turbine becomes the tallest structure in Europe.
Some new info for you,,, a wind farm in my area was sold to the landholder after it had been in operation for 23yrs. Now the landholder has since sold his farm because he found the costs to maintain the wind farm was larger than the returns it earned. SO THE INSTALLERS RECOVERED THE COSTS TO FIT THE SYSTEM AND A HANDSOME RETURN ON TOP & NO COSTS TO REMEDIATE THE AREA AND PROFIT FROM ITS SALE !! yes thats the game watch it roll out in your area. AND remember 27 years and the costs rise fast as an average
*Crocodile Dundee: **_"That's not a wind turbine. THIS is a wind turbine."_* 😉
Excellent as always. I enjoy your forays into the formulas and principles without tipping over into total geek speak. You tread that line well. How to different soil structures figure into foundation design? More importantly, does it significantly affect the cost.
BTW, any reason for eating cake yet?
No celebration cake for me yet, though being 41 weeks pregnant has led to a few cake cravings I will admit (assuming that's what you meant by the cake comment!)
And I'm glad you thought I got the balance right between showing the important formulae but not making it an engineering lecture. It's a tricky balance!
I don't know a whole lot about foundation design, but that could be a cool topic for a livestream if I can find an expert to get on as a guest. There have been a few foundation failures in the news recently, it works be nice to find out more about what that's about.
Respect for your career. That's pretty cool.
Add more blades, and put on sliding tips, if the wind is lighter they go at the end? With strong wind they are nearer the axis.
Excellent video! Thank you.
The other issue is a rather practical one. There are simply not enough wind turbine installation vessels large enough to install large numbers of 15 MW turbines. The owners of these vessels are simply not willing to keep building bigger ones as turbines get bigger because they can't be sure they will not be become redundant before they get the return on the investment. These vessels cost $500 million and that is a big investment without certainty about future revenue.
Put simply, planning to build a 15 MW sized wind installation vessels now is futile. Investors have to build 20 MW sized vessels but by the time they are built in 5 years time the manufacturers might be planning 25 MW turbines
I know someone that said in the future we will build wind turbines in space :D
How about a discussion of wind turbine other than blades. I have seen vertical helical wind turbines, horizontal system on roof tops and barrel shaped wind generators. The barrel shape I most recently saw was used in Okinawa Japan and reportedly survived a direct hit from a Cat. 3 Typhoon. Lets look at more options for various condition where a blade system might not be appropriate.
Thanks Rosie. Your video got me thinking (the best compliment 🙂) is the air mass of anabatic and katabatic winds sufficient to support power generation? I live near a coastal mountain that has a cliff face with tremendous winds (in both directions) I sometimes wonder if very large axial fans of efficient design, bolted to the cliff face, could overcome the tower issues?
Incredibly interesting. Thanks.
Wow, thanks Rosie.
Much to think about....
Here is a different direction for wind technology: Pluvicipia creates wind inexpensively and with primarily positive side effects. In that case, it seems big is unnecessary: Produce faster currents onto your field, the energy sources, potential temperature, is better than free, using it helps to cool the planet and absorb C02, as well as produce water and food, etc. Sounds too good to be true because it is the energy source for the next era in human development. Check it out; you will love it. It will return on the market soon; I'm trying to complete numerical modeling before republishing the revision. At this point, the best I got is prior mathematical models and quick AI design revision. But it will be out there again soon.
It's a brave pundit who would make predictions about the size and design of anything in this age of rapid material science advances. The 'next big thing' may well be very different to what we're working with today.
I have the solution! Since a big part of the expense is taller towers and their associated costs simply dig a big trench for the blades to travel through on the lower part of their revolution. This would allow you to only have to elevate the hubs just above the ground thus saving a fortune!
The opponents of wind turbines often show a beautiful American bald eagle with one wing cut off. But we also know cats kill 10x as many birds as wind turbines. We are not going to makes cats extinct to save birds.
Why don’t we hear about new technology to save birds? What progress have we made on saving birds in the past 10 years?
When I was still in the power industry (Los Angeles, California) I had to decipher a term from Palo Verde nuclear station (LA is a participant): BOP - turned out to be “balance of plant”
Nuclear engineers and Navy people would already know that
Rosie,engineering is one of mankind’s greatest achievements. We have not as yet been able to the summon the elements on command however. Wind on demand isn’t within our remit. The meerkat proposition is simples. Until you can control the wind,turbines remain totally weather dependent. In other words the lack of predictably renders the investment wasteful,unless you are a subsidy harvester,snake oil salesman. 1x0=0 1000000x0 =0
Another great video! Thank you.
Perhaps use climbing crane technology and build the towers like a skyscraper.
Fun design talk.
Counter rotating blades? Too much vibration?
A few thoughts:
Are these very large machines already a 'hazard to navigation' for aircraft & if not how big can you go?
What do you do about different wind speeds & directions at different heights?
Can you end up with a machine that's big enough to launch satellites off it's blade tips?
Onshore they are a hazard, at least for small recreational aircraft.
Offshore its not a problem as no aircraft flies at 200m above sea level.
Commercial aircraft usually cruise at 10,000m above sea level.
Thanks, very interesting and well presented. Having lived in Norway for several years, I really get the cake and speech thing!
A great presentation. I think you could, though, perhaps have made the point that the optimum size for offshore and onshore turbines is very different because of the fabrication and transport challenges of very large blades for inland ones (shipyards are designed to fabricate huge structures, and you don't need to worry about bends and clearances on the water). For inland ones, therefore, the optimum size is mostly set by these constraints while for offshore ones it is set by the scaling issues you detailed so well here. Of course offshore has its own expensive issues (eg getting the power back to shore), but the point is the size considerations differ.
I agree, and I thought I did say that! Not very clearly obviously...
A hard limit to blade length is tip velocity approaching Mach 1.
Solid video, subscribed.
just a thought, what you build a hub with a Long interconnected arms like a bicicle so you use the same blade but with a 15 to25 meters more, and you could even have a different sleeve in the first part so the pitch can be adjusted in the Ruth and the tip independent, transport will be easier and it will work in a wider range of wind speed.
Another aspect is the windspeed every cross section sees. Near the hub - most if not all design is for strength and are probably not adding power.
Further out is a transfer to an actual aerodynamic profile while the windspeed crossing the blade is not much more than the wind a pixed point sees.
But at the wing tip the wind across the blade is extreme, I imagine it may be close to what a aircraft have.
At some point of scaling turbine blade up - I think the wingtip is more drag than adding power. What do you think?
As she mentioned in the video, the rotational speed is reduced with increasing diameter, so the tip speed stays the same for optimal aerodynamic performance.
Great explanation, I think most systems have a 'sweet spot' size wise and it's not always just about what's theoretically possible. Something I'd therefore be very interested to know is what are the life limiting factors and components for wind turbines? Currently life expired turbines usually get completely replaced (re-powered) after 20-25 years because larger and more efficient turbines have become available since they were installed. This does obviously increase efficiency of the particular wind farm but it's arguably not a good use of carbon intensive materials (or costs) to do a complete replacement. So it would be interesting to know what will happen once most turbines achieve an optimal sizing, as suggested. Could these turbines be maintained and run indefinitely? What parts would need to be replaced, and what parts could be reused? Foundations and grid connection are a major part of the cost, so I would guess big savings should be possible if these can be reused, and both should be good for 100+ years.
I remember seeing a report that Europe currently has power capacity of around 950 GW. If the economic forces ever tip to favor the 1GW designs, I can only imagine how much power we’ll have.
Also I suspect that given the relatively few number of them that would need to be built, that they’d either be built on site or the parts would need to be flown in through a team of helicopters. That would be a sight to see.
None when the wind is not blowing.
@@RonTodd-gb1eo It's usually blowing somewhere in the world, and Europe as a whole is increasingly interconnected powerwise so even if it's dead in Ireland if it's windy in Denmark, Ireland will have power.
this was a lot more interesting than i thought a phd video could be. My only question is that you didn't mention upper atmosphere winds. I read that the main reason why turbines are getting bigger was because they get to reach higher velocity wind higher up in the atmosphere. you approached this video without any consideration that wind will change direction, change speed, or on average have higher wind speeds farther off the ground
That was explained at 2:56.
If we ever build space loops or space orbital rings (forget elevators, those are ridiculous in comparison), I'd love to see giant wind turbines hanging part way up the tethers. Though at that point we'd have access to a huge amount of 24hr space solar.
I seem to recall, about five years ago, watching a news piece about a prototype and research wind turbine that was kite-based. "No more pesky unwieldy blades" "smaller airfoil in a larger area of sky can harvest more power than traditional" types of claims. With, if I recall correctly, its fatal flaw being that the best use cases are not anywhere near populated areas.
Rosie, have you heard of that type of wine turbine? I'd be interested in someone with your background highlighting this technology, its pros and cons, and hearing your take on what came of their research and product development.
I did a livestream on airborne wind about six months ago so you can check that out if you're interested. I'm planning a follow up in the normal short format sometime soon, so let me know if there's any specific questions you think would be interesting to cover 😊
@@EngineeringwithRosie awesome, I'll check it out and if I think of any specific questions, I'll be sure to ask!
maybe I missed it, but one of the biggest concerns for even larger wind turbines, at least for offshore purposes, is the required infrastructure and installation vessels. with each increment you need to design and construct new infrastructure (ships, ports, factories) that can build these new larger wind turbines, but that's not cheap at all and has inherent financial risks. sometimes the perfect is the enemy of the good.
I too want to see neverending fields of 50MW wind turbines out in the sea, but if this doesn't make financial sense we won't see it.
Hi Rosie, have you seen the recent Harmony Turbines spot on Disruptive Investing here on YT? They have some very interesting developments on their version of a Savonius Vertical Axis Wind Turbine. Well worth a watch.
I always enjoy your video’s.
I have often wondered if we will get to a point where a manufacturer will “lock in” to a particular design and if there would then be scope to decrease cost due to economy of scale?
On topic, BIG is the Engineering term, "BIG" is the let's get as many of these as is possible, on the Mine Sites and Refineries as can be arranged as a matter of urgency.
If a certain Canadian Mining group has a genuine method of CO2 sequestration in Tailings from Nickel Mining, and the same can be applied to all Metal Mines, this is the serious solution to Sequestration. (For the same CO2 reduction reason, SMRs are required urgently, I'm not biased, much)
*****
Apparently Queensland Nickel is to be resurrected, they need direction for full Electrification, and vastly improved Refining methods.
After the new baby is settled in, "someone" should organise some crowd funding to work out the sustainable redevelopment plan.
A common sense objective in common is the quickest way to get Voters back together and make use of University Training.. etc.
Incredible video
Well done.
I think there may be a "skyscrapers in NYC" aspect to this, in that all the space above the turbine is "wasted".
There's certainly an incentive to grow vertically for greater "density" in the same area.
You forgot that the space above a small wind turbine does not come for free.
@@janwinders I did?
Who gets paid?
@@garrykanter5773 yes, you did. Lawyers, officers and researchers get paid for it.
@@garrykanter5773 higher wind turbines are harder to hide, louder, have longer shadows, kill more birds and bats. Anti wind energy initiatives grow faster than the hub hights of wind turbines.
This costs a lot of money in the planning phase of a windfarm. And if someone has to spend money, someone else will profit. Don't you agree?
@@janwinders Since I have no idea what your point is, I do not.
very good work
really cool explanation, what i miss at the end of the vid, is something like a curve showing we could not have reach more than N kW with older fiberglass wing design, without raising the cost by MWh produced, and the same with the Carbon Fiber.
I left the video with no clear clue of what will happen ? more than 16 MW by pole, or are we today at a maximum ?
As we know we have nowadays nothing really best than epoxy/carbon fiber, it could have led to a max, where higher means a higher MWh ?
A question please 😊
I’m mystified At how fast the blades go, the outer portions many hundreds of KPH . I’m wondering how this intense speed of the outer portions of the blade can actually be helping generate power, in my way of thinking it’s a burden on the system as the prevailing wind is vastly slower ? (My humble comparison is only with cars, where wind resistance when you go over 200 kph is like hitting a brick wall)
Thanks
Wasn‘t there also a problem with blade tip speeds getting into the transsonic region at some point?
Isn't the additional fatigue caused by the greater flex of a bigger blade offset to some degree since it is rotating more slowly?
If someone built a helicopter that was a hundred times bigger than the biggest helicopter that currently exists, then transport would no long be a problem. We could have wind turbines on land that are as big as the offshore ones.
Here's another thought... a 12mw weighs 650 tons and can melt enough metal for 1000 other turbines in 25 years of service, and a 1.5mw weighs 165 tons and can only melt enough metal to build 400 of itself in 25 years.
What happens to the air ( wind ? ) pattern downwind of a large wind farm ? Are there any local climate effects ? Any research done on this ?
Love the cake story Rosie, loads of cake consumption at VESTAS offshore 🎂 and fun times..Chris
l would imagine crane size is one of the biggest factors that will dictate wind turbine size also transport will play a part.
Cost and manufacturing versus output in MW and maintenance factors such as parts replacement will play a role.
l really enjoyed this one you went into small detail and you showed confidence in the subject including ways to build bigger. Public opinion will also play a part going forward into the future.
The positions of wind turbines and solar farms is a contentious issue in Australia with size annoying some people also.
l prefer as much power generation in one location as possible to cut down on public hostility and increase efficiency...
The bottom line is still cost versus MW no matter how big the turbine, also the ability to recycle parts is coming into play at the moment....
How does the operational window for wind turbines change with increasing size? My guts tells me that with larger size there's more mass to rotate and the amount of energy needed to initiate rotation from standstill is larger. I would therefore assume that you would need higher wind speeds before it could start. Is this correct?
09:23 Bending due to self-weight
For the ascending blade, isn't its weight compensated (and exceeded) by very aerodynamic lift turning the turbine? But then again, the descending blade suffers combined forces of its own weight and aerodynamic force. Perhaps steering the angle of the blade on its way down could keep this force constant, to reduce dynamic stress?
To reduce weight of a blade, as well as work around the transportation problem, don't build them as solid structures. Perhaps you could use the trick flying insects use in their wings: supporting skeleton made of a mesh of tubes filled with pressurized liquid. Some of the insects (e.g. dragonflies) use liquid which hardens after the wings are fully unfolded, and so could wind turbines, as there is usually no need to retract the blades (... until the end of their operational life, that is).
Another option would be blades made as inflatable structures. Related to that, inflatable blades could be filled with lighter-than air gas to achieve neutral buoyancy in air. Since they are connected to the hub, the blades can't catastrophically fail like airships did, but construction and operation must make provisions for any case of sudden reduction or loss of lift, etc.
A very long and interesting way to say "I don't know, it is complicated and future will tell".
Spoiler alert: that's the answer to every question about future technology development!