Wind Turbine Design Evolution in Denmark

Denmark has a long of history of strong renewable energy engineering and sustainability. From very early on, many of the most important wind energy developments were made by Danish engineers. Come with me while I take a road trip with me through Denmark's Jutland peninsula, which was home to much of the modern wind turbine's development over the last century. We will stop at a number of historic and modern wind turbines and talk about the design evolution that has occurred and some of the mechanical engineering concepts and design tradeoffs that have caused wind power to evolve in the way that it has.
The sites visited are:
00:56 Lyngmøllen - traditional windmill from 1876
02:48 Vindkraftværket Tvindkraft - built 1975-78 and the world's longest operating wind turbine
03:32 Lattice tower turbines from late 1980s to early 1990s
04:58 Stall regulated turbines from the 1990s
07:01 Danish national test centre for large wind turbines in Østerild (Det Nationale Testcenter for Store Vindmøller) featuring modern onshore and offshore turbines
09:55 Rønland offshore windfarm, installed 2003
Mechanical engineering, aeronautical engineering and physics concepts discussed include:
01:13 The difference between a wind turbine and a windmill
01:36 Lift vs drag type wind turbines
01:54 Poul La Cour's contribution to modern wind turbine design
04:12 Tower design tradeoffs - lattice vs tubular steel towers
05:54 Wind turbine power regulation - stall vs pitch regulation
07:38 Why are wind turbines getting so big?
10:34 Wind resources - why are towers getting taller and why are turbines being installed offshore
For wind energy theory I recommend Burton's "Wind Energy Handbook."
Available to buy from Amazon (affiliate link), or your university library probably has it!
amzn.to/32Pb1fh
Video editing and animated intro by www.video-gestaltung.de

[@henrikberg4690]

As Danish Citizen I wellcome you to our windy country 😀 I really like your serious videos and good Work. More than 40 Years ago, when World shake there head in windmills, I worked with my programable Texas calculator on the effegiency for blades. At that time there was actual some serious studys from 1930 german engineer, i remember. And now we Arne here🤗thumbs Up for your Work and entrepreneurship 👍🙂 Henrik Berg, Denmark

[@choveskitchen3800]

What a great intro video Rosie, I hope lots of students will see this and be inspired to take an active role in the energy transition. 10/10 !!

[@EngineeringwithRosie]

Thanks so much Francesco, I hope so too!

[@daltonagre]

@@EngineeringwithRosie Here in Brazil, I liked your video.

[@jfan4reva]

Smiling like a true engineer when she's talking about how "you can get right up close to them and get a good look".

[@ivandasty277]

You are a great teacher . I like the way you speak , energetic and full of beautiful smiles . It's clear that you really believe in what you say and love your work .

[@iamfridaylee]

As a blade engineer , it's a honor to be there visiting the world's longest operating turbine , and thinking how amazing it is .

[@luisalmeyda2468]

I had a lot of fun watching this video! Ty for making it! Greetings from NJ, USA.

[@maxwellsmart3156]

Thanks for the trip through Denmark's wind turbine history. I hope you go back after they finish build their islands in the sea but it could be a while. I hope you would consider talking about the typhoon VAWTs from Japan. That seems interesting too. Congratulations on your increasing subscriber count.

[@ELMS]

I really enjoyed that. Learned a lot. You’re a natural!

[@Tore_Lund]

Through national subsidies since the 80'. Danish wind power had the resources to develop efficient blades and manufacturing techniques, before wind power saw any commercial interest. The Dansih technical university DTU, made the first fluid dynamics simulation ever of a turbine blade on their computer cluster around then too. LM -glasfiber, a Danish company manufacturing wings, now sold to GM was also a result of these 40 years of Danish development..

[@kasperkjrsgaard1447]

Tvind, a bunch of hippies but they’ve made an impression which basically lead to the forming of the Vestas we know by now. Interesting enough, when i started working in the wind business back in 2001 we made 27 meter blades which grew to 29 meter a year later. When i stopped in 2020 the blades had grown to 80 meters. Quite a change.

[@xxwookey]

@@acmefixer1 Rosie has made a couple of videos about that: kzbin.info/www/bejne/e36QmHasnbabhrc

[@thewheelieguy]

​@@acmefixer1 Rosie has now had a couple of videos addressing vertical axis turbines. It's essentially a matter of efficiency and cost. There have been lots of university projects trialing vertical axis turbines. It's not that engineers are unwilling to try them, it's that they don't work as well.

[@daltonagre]

Here in Brazil, I liked this video.

[@meredithbarnes5788]

Great video - so interesting to see Denmark's wind energy history!

[@EngineeringwithRosie]

Glad you enjoyed it!

[@jaswanthdala7331]

Thanks a lot for showing us different wind turbines.

[@surendersingal9122]

Rosie Gotra say, your personality n presentation ( on wind turbine) is also windy n happy. Thank you for giving insight into Denmark,s windy world..

[@slymartins]

Very entertaining and educational tour. Very well put together. Thanks for sharing.

[@EngineeringwithRosie]

Thanks so much! I'm glad you enjoyed it.

[@supremelawfirm]

Good on you, Rosie: I learned a lot, being a computer geek (retired too). Please do more videos: WE LUV ENGINEERS here (Oregon, USA, Earth, Solar System, Milky Way).

[@thewheelieguy]

More numbers, please! I was really wanting to hear nominal power outputs for these turbines.

[@Jeemus.]

Thanks for the video! I've just graduated university and am looking to enter the wind turbine industry so might go and check out a few of these locations this summer! It's awesome to see such a strong start to your channel and I hope it blows up! I'd be interested to hear more about the lifespan of the different turbines and how the local environment effects the type built if you are looking for topics to cover. Keep up the good work!

[@EngineeringwithRosie]

Thanks so much, I'm really glad you enjoyed the video. Get in touch if you need help finding any of the sites, but if you go to the test site at Østerild then you will drive past many examples of historic turbines, so it is pretty easy really! Thanks for the topic suggestions, design lifespan is a question I've been asked a few times so that one might have to be one of the next videos. And I'll add local environment to the list too. Best of luck with your career in the wind industry!

[@michaelklein807]

Water pujmp windmill on my farm worked the same way and looked like the ladder form you just showed us.

[@navigator902]

Excellent tour and intro... I'm now just installing some turbines and solar for the house. and love your explanations

[@hedgehog3180]

Hello from Denmark, wind energy is probably my second choice after locomotive design whenever I get to university.

[@EngineeringwithRosie]

I would suggest you try a "traditional" mechanical engineering degree, and take electives in locomotive and wind energy related topics (e.g. aerodynamics and composite materials). Then you will be able to move into whatever kind of industry you are interested in when you graduate. I had no idea what I wanted to do when I started university (actually I thought I wanted to be an astronaut). I'm glad I kept my education broad because those basic engineering skills can be applied to anything. The same is true for an electrical degree, or any of the traditional types of engineering. Just start by choosing the subjects that you enjoy studying and the job opportunities will become more clear as you progress in your degree and choose internships etc. Good luck with your studies!

[@hedgehog3180]

@@EngineeringwithRosie Thanks for the advise!

[@trueriver1950]

@@EngineeringwithRosie impressed by you taking the time to help someone get started ...

[@ImRShrivas]

Quite informative video about wind turbine and wind energy history. Keep sharing such details.

[@EngineeringwithRosie]

Thanks Rahul, I'm really glad you enjoyed it!

[@lunasun872]

Great video! Thank you for taking time to share this with us

[@malloott]

Most info dense 10m video ever? Loved it!

[@belomolnar2128]

All the turbines are in one 22 kV AC network connected. Great. P. F. 2021.

[@ddamianRC]

Great Channel and great job Rosie :)

[@EngineeringwithRosie]

Thanks for the visit!

[@ivanx4964]

Thank you for your explanations, I have leart quite a lot last days :)

[@Daniel-vx3ss]

Thanks for the sharing, very interesting.

[@AroundUs_2090]

Thank you Rosie for sharing this informative journey.

[@RonMar]

Thanks for the wind turbine videos! I've always wanted to know a lot more about them and, frankly, took them for granted whenever I saw them. "Oh look, some windmills." I would love to see a tour of a windmill and a ride up the interior elevator.

[@ricardoganem7902]

Thank you very much!! I really learn a lot !!

[@whitehorse1092]

Hi from Russia. We also strated the installation of wind generators. Danish Companies are the best

[@SheplerStudios]

Great explanation of the variations in wind turbine design. Learned a lot! Thanks.

[@michaelklein807]

And they are all still operating and being used!

[@davidgalloway266]

Excellent work. Look forward to seeing many more.

[@pipertripp]

Very nice programme! Your channel is growing fast ATM. Hope it continues. You deserve it given the quality of the content. Cheers!

[@EngineeringwithRosie]

Thank you very much!

[@frjn99]

Great video, thank you :)

[@cf9580]

Really interesting to learn about.

[@EngineeringwithRosie]

Thanks! I'm glad you enjoyed it 😊

[@johnaquilina3863]

Hello Rosie, I just watched your video. great information. I have been in the industry since 2006 and am always looking at how others communicate in the industry. You covered a lot while keeping it interesting. Great work!

[@thamho1352]

Awesome video. Thanks so much Rosie. I learnt a lot!

[@AleeEnt863]

Keep shooting videos, it is really enjoyable!

[@IBITZEE]

so nice to went to see the wind turbines with you... just sorry we didn't stop in a field so I could offer you a flower! ;-)

[@utubejdaniel8888]

Just found your channel and find it very interesting. My background is also ME with strong interest in low-speed aerodynamics - sailplanes and light aircraft. Keep up the good work!

[@EngineeringwithRosie]

Welcome aboard! Thanks for your nice comment.

[@utubejdaniel8888]

@@EngineeringwithRosie Looking forward to more on recycling issues and blade structures.

[@harveytheparaglidingchaser7039]

Poul la Cour, that was interesting!

[@lmifsud1000]

Great video telling a really interesting story. Just one thing to add - a sailing boat moves thanks to exactly the same forces that drive a wind turbine blade and aeroplane wing - flow over the sail creating lift - it's not "blown by the wind" as you say at 1:47 ! :-) Keep the videos coming, a really well done intro to wind technologies.

[@EngineeringwithRosie]

Hi Liam, thanks for your comment! I am not a sailor, as you have guessed, so I am certainly happy to be corrected 😁 I think I said old windmills were like a sailboat that is sailing directly with the wind, or something along those lines. In this case, wouldn't a sail be pushed by the drag force of the sail? If you are going in the exact same direction as the wind, your movement couldn't be caused by a lift force, since lift acts perpendicular to the flow direction, and if you're moving parallel to the wind, there's no perpendicular component. Now, perhaps it is the case that no one ever sails directly with the wind, because there isn't any lift force, so you're not really "sailing" and the drag force will get you where you're going much slower than if you criss-cross at angles always using a lift force over your sail. If you sail yourself then you would be better placed to answer this! I personally get very sea sick so I can't take up sailing even though I think it is a really cool sport (and verrry popular here in Denmark). In any case, I take your point that this is not the best example so thank you for pointing that out. Now I need to think of a different example for the next time I try to explain this concept 😋

[@OisinHiggins]

@@EngineeringwithRosie a great channel with interesting and useful videos. Sailor, windsurfer and engineer (structural, not aero or mechanical) here. Going with the wind (parallel) is known as running and yes you are correct, it's just the drag of the sail pushing you along. I would prefer not to sail on a run for a few reasons: - It's potentially unsafe: a slight change in wind direction or change in boat direction may result in the boom coming across (uncontrolled gybe, a skipper was killed on the 2015/'16 Clipper Race from this type on incident). - it's slow: sailing at an angle to the wind to get a perpendicular component as you surmised is quicker. Sailors call it apparent wind (boat velocity + wind velocity) and it's much more critical to lighter and faster vessels such as catamarans, windsurfers, kitesurfers, foiling boats such as the America's cup, MOD70s, Olympic 49er, International Moth etc. Running with a catamaran for example can cause the boat to cycle between acceleration and deceleration as boat speed cancels apparent wind speed. I'd only sail with the wind (running) when my course is constrained (by depth/water available or room to manoeuvre), if the vessel is so slow that apparent wind doesn't have a huge effect or when the wind is so light that the apparent wind has little effect on boat speed and velocity made good.

[@EngineeringwithRosie]

@@OisinHiggins Wow, great information! Thanks so much for adding this.

[@jonel5001]

Nice old fashioned mills. Can`t wait to see vertical axle, horizontal blade mills in future. They offer so much benefits they will come.

[@grommie]

Thank you !!! I like it !

[@muhammadafifhidayat2566]

Rarely virtual experiences 🤘

[@EngineeringwithRosie]

thanks

[@mikeklein4949]

Good stuff!

[@australianwindandsolar6274]

Great Videos Rosie 👍

[@EngineeringwithRosie]

Thanks!

[@chrischen82]

Very nice made short hisoric to present story :) Thanks and have a nice day :)

[@KiteTurbine]

Great series Rosie but you have to change to a wind powered van

[@pekkakorpi559]

You should go up to see tvind turbine in action, I have been there and that was awesome 🙂

[@_-martin-_]

I love your video - keep up the good work!

[@zubairahmad2430]

Educational & Informative trip with Rosie

[@EngineeringwithRosie]

Thanks! I'm glad you enjoyed it :-)

[@michaelklein807]

Thank you. Driving right hand drive auto I see.

[@SirHackaL0t.]

Loving your videos Rosie. It was a shame that you didn’t mention the generating capacity of each type of turbine. :)

[@EngineeringwithRosie]

Yes that would have been helpful, good point. When I recorded this I didn't know how to find those figures, though I do now. Denmark has a map of all their wind turbines and some specs. It's awesome. vindinfo.dk/kort.aspx

[@SirHackaL0t.]

@@EngineeringwithRosie ooh! Ta. :)

[@charlescamen5225]

Hi Rosie, Driving around Denmark in a right hand drive car is a bit irregular. The marvels of video editing. Is it not?. Another great video. Thanks.

[@b82s40]

The more I read about the wind turbines, the more I believe that the technology needs to be changed radically. Firstly the wind farms should give way to small clusters near the load points. We save on transmission to invest in more profitable storage. Secondly, the capital cost has low utilisation factor. We should use cheapest technology for collection before storage and optimize for use after storage. There may be many opinions but I believe the compressed air would be the best. It should be stored in the modified tower itself. The compressed air should be used directly for mechanical work using pneumatic technology to maximum extent feasible but could run a battery charger of minimum required size. Thirdly the tower as modified for storage will have substantial sunny area above tree lines.this should be used for installing photovoltaic panels and the product stored in lowest cost batteries available at the time. This should be used for lighting and electronics. Battery charging by compressed air could supplement this. Fourthly the design of vanes is unwieldy and presents problems in manufacture, transport, installation and maintenance. Perhaps invelox technology ducting the wind to ground and using the right size and number of vanes may be better. Vertical axis wind turbines with axis extending to ground level is also an option. One full sized energy tower as a prototype could prove the new idea.

[@EngineeringwithRosie]

Sounds really interesting Jagdish! I am looking forward to seeing your prototype 😀

[@acmefixer1]

You have some good ideas. But the many smaller wind turbines require more maintenance than a single bigger wind turbine. Other things complicate living close to the wind turbines. They're better away from urban centers.

[@samirpashayev5946]

great video! insightful! thanks 👍

[@filmic1]

That was really great!

[@aviphysics]

Though sails really do fly through the wind like a wing.

[@EngineeringwithRosie]

Yep, this analogy only works for non-sailors. I meant if you are sailing directly with the wind, then the wind is just pushing on the sail. But apparently that's not something you would ever really do, so bad analogy for real sailors.

[@richdobbs6595]

@@EngineeringwithRosie Sometimes you do go pretty much straight downwind during a triangular race, with some boat designs, but it is definitely when you are going the slowest. The apparent wind speed is really minimal. But I almost never did well when I was racing, which was 25 years ago now, so perhaps now days everyone tacks downwind.

[@DCockey]

​@@EngineeringwithRosie The "sails" in the old windmills work in a manner similar to sails of a boat sailing across the wind, not like parachutes. The difference with modern wind turbines is the efficiency, not the fundamental mechanics.

[@billybobwombat2231]

Hey thanks, awsome little vid, cheers 🤙🦘

[@DerAua]

Very interesting. Thank you!

[@DominikJaniec]

very interesting tour!

[@fjalics]

Excellent video. Lots of interesting information for how short it is. She never showed the outside of that car she was driving making me wonder if it was capable of being refueled by those wind turbines.😉

[@xxwookey]

Nope, it was an ICE vehicle.

[@aleksandrsnaumovs4277]

Great video!!! Can you please do one on foundations in the future? I's quite interesting to explore the foundation/stabilization issues/solutions for offshore and onshore windmills

[@EngineeringwithRosie]

Thanks for the suggestion. I'll see if I can find an expert to interview on that topic. It isn't something I know a whole lot about.

[@TheReykjavik]

I think one of the most important things in this video is those turbines that are 30 years old. It might be culturally worth it to keep the first one operating long after maintaining it costs more than the value of the power it generates, but the set from the late 80s doesn't have that significance. Even if we were willing to maintain an operating turbine from that period as an expense for the sake of history, we'd do it with one or maybe two examples, not a whole wind farm. But those turbines are still running because they still make more in revenue than they cost in maintenance, and that is some old tech, they are far from optimal by modern standards, but they keep producing. When they put those up, I doubt they ran the math on a 30 year timeframe, and today people might look at 5, 10, or 15 years out when planning a project, but in reality wind farms can be productive far longer than that.

[@EngineeringwithRosie]

Yes it's great to see those old turbines still going strong. Until recently the standard design life was 20 years, now it's pushing out to more like 30 years. And once that's up it's often possible to extend the lifetime.

[@kirstenspencer3630]

In the late 1970's the Danish government wanted to build a Nuclear power plant in Vindeby. Fortunately wind power came to the little village and as of 2003 the wind power produced exceeded what the nuclear power plant could have potentially produced. Happy power for the happiest people on earth. I am from in California and we will be paying for nuclear decommissioning for many year on my electric bill.

[@voxpopneverdies2025]

In the UK we have up to five sail corn Mills. No material though, all wood.

[@jamesb2059]

Great. learned a lot. Thank you.

[@mrgallbladder]

I'm curious what the rationale was for switching from lattice to tubular. I came across a fairly recent research article called: Lattice and Tubular Steel Wind Turbine towers. Comparative Structural Investigation, out of Aristotle University of Thessaloniki and University of Birmingham, UK. Their conclusion was that lattice towers are 40% lighter and cost 15% less while maintaining load-bearing capacity.

[@clydewolf2013]

You are so on target. I currently drive a seven year old electric which is great near home and I resort to renting an ice car for long trips do a lack of chargers where I need them.

[@aacowboy12]

Heppolt wind will be the new game in the wind industry 5 years testing completed by los alamos

[@EngineeringwithRosie]

Cool, I look forward to seeing the test results! I could only find really old information on the project when I searched, can you tell me where I can read about the current progress?

[@petergiessinger9617]

I had the idea: maybe the wind blows the bad mood away?

[@EngineeringwithRosie]

Ha, maybe! They do say the Danes are amongst the happiest on Earth 😀

[@fiegenfiegen]

Interesting video with a lovely host. Who can ask for anything more?

[@patrick247two]

Excellent.

[@trueriver1950]

10:44 in the UK onshore has problems with complaints from neighbours (close up windmills are noisy) and also from ppl who object to them "spoiling" the view. Those problems have almost stopped onshore in England though I am told Scotland is still building them

[@davidwilkie9551]

The Engineering teaching and learning aspects are excellent, dunno about the speculation that sounds too much like the muli coloured Hydrogen stories that have been around for so long they've got fossilised.

[@denismoran670]

Great, Rosie - thank you for that video. I wish we had independence such as Denmark has, so that windy Wales and the Mor Celtaidd could produce enough for Wales to be self-sustaining. Diolch yn fawr, Den Moran, Llangyfelach, Cymru.

[@take5th]

There’s nuthin like a Dane!

[@johnbavender9775]

Is it possible for engineers to think outside of the efficiency of the wind turbine and accept the cost is more important to any home installation.

[@PP.EKOTECH]

Good job ! :)

[@EngineeringwithRosie]

Thanks!

[@PP.EKOTECH]

;)

[@xaviermohmarc1100]

Hey Rosie, I've really enjoyed the videos you've produced. Please keep making them. I have a question, how would you calculate energy-output of a VAWT that features 3, 75m blades, versus a HAWT with the same length and number of blades; like the turbines in this video?

[@The_Bookman]

Really great vids. Have just discovered you and am very impressed. EVs are much more quiet for recording btw. ;)

[@The_Bookman]

SO different to the situation in Australia! I am convinced that a disturbingly large percentage of the population here have absolutely *no* idea how much the world has been changing, leaving us behind, while we are stuck in the 1950s with our recent administrations.

[@wjhann4836]

That old wind turbine: I'm wondering about the angle of the blades- is this turbine working "opposite" to modern ones? Will say- it seems, the blades are operating in lee of the mast.

[@georgepower8027]

Excellent introductory video with a lovely presenter.

[@abc-fq8gy]

excellent report i think wind will be more than 50% with solar due to not depend on sun so we need same extra energy as hydrogen to use it when we need it

[@fabiocavaleri]

but the pitch regulator one uses a governor just like a governor in the propeller of an aircraft?

[@MrAndrzejWu]

:) thank you, it was interesting

[@iblisthemage]

May I suggest that you make a video of batteries as well? Tesla’s Battery Day video and one of Tony Seba’s Energy Abundance videos could be a place to start. Basic hypothesis is that global battery production capacity has grown exponentially for quite some time, and will likely continue to do so for decades. Battery cost has dropped exponentially, and will likely have another 80% drop over the next decade. This will enable renewables in a magnitude that is hard to imagine today, and give us energy abundance (energy is almost free) over the next 50 years. Also Seba claims that current estimates of cost of fossile based energy forms is way to high, putting batteries + renewables below fossile already now.

[@worldinandaround]

informative video. hope you will one day visit LM wind assembly building if possible.

[@henrikedman8528]

Tanks for nice video. I have a question. Why are all windturbines going clockwise when you look from behind?

[@scottokeefe]

Is it true that painting one blade black will lower bird strikes . Love your posts . Thank you.

[@thakerharit9465]

What about job opportunity in wind power generation in Denmark?

[@trueriver1950]

World's longest serving wind turbine. Pity it is stopped in some of the shots... As are a few of the others

[@harryadams5651]

Why is the generator located on top of the tower. The rotational energy could be passed to generator by differential and shaft system which would allow easier,installation and servicing of generator

[@acmefixer1]

I've thought about this. The differential would cause torque on the nacelle thus causing it to deviate from pointing at the wind. Some kind of counter-rotating shafts would have to be used. Or maybe reciprocating rods on a crankshaft. But there are still problems.

[@jeffbertuleit5848]

Why are the now blades flying through the air instead of using the energy of the air like the original design that can extract more energy?

[@XanderTheGreat77]

Hey wanted to ask whether a 10kw HAWT wind turbine is good enough for pumping borehole water 270metres deep

[@florantedagaas1751]

I have a design for gearbox for wind turbines that can be implemented using a minimum of eight gears, not worm gears. Is there a simpler one?