alt.hn

5/19/2025 at 7:58:59 AM

Tallest Wooden Wind Turbine

 https://modvion.com/

by Bluestein

5/23/2025 at 9:59:13 AM

"Making net-zero wind power possible"?

Is that trying to tackle the non-problem that was spun up a while ago by oil companies in propaganda pieces like the Landman show on TV?

It's a non-problem. The lifecycle assessment of wind turbines today, which is the accounting for the actual emissions of the lifetime of a wind turbine, factoring in: creation, installation, maintenance, even the disposing of it, was clocked to be offset after 5.3 months of running the turbine (according to this study: https://pubs.acs.org/doi/full/10.1021/acs.est.9b01030 ; and every other one I could find finds the same ballpark)

by sebstefan

5/23/2025 at 10:26:39 AM

Please note that the study takes the energy that the wind turbine produce and calculate how much green house gases a natural gas-fired power plant would create producing the same amount of energy.

by belorn

5/23/2025 at 10:40:08 AM

Without having checked the study because I can't open the link on this machine: does it also take recycling of the metals into account? There's also cost in placement (which are very significant in places like the North Sea for instance), and digging up the rare earth minerals and such.

by once_inc

5/23/2025 at 11:12:51 AM

No, no mentioning of recycling. It only look at average energy output, converts it into what a natural gas power plant would do to get the same amount, and compare it to an estimation of green house emissions from producing the turbine. They do mention creating the estimation of production emissions from 28 wind turbine LCA studies of 22 on- and 6 offshore locations, so it sound like they include placement costs, but I can't say for sure. on- and offshore turbines may not be built identically.

The fundamental question that the study ask is if the wind turbine would replace an existing natural gas-fired power plant, how much less green house gases would it produce compared to keeping the natural gas-fired power plant, and how does that compared to the production emissions of the wind turbine.

by belorn

5/23/2025 at 1:42:10 PM

Why not a nuclear power plant? And how about the battery backup that the wind power needs to be reliable?

by cyberax

5/23/2025 at 1:54:33 PM

Nuclear is so expensive the only reason anyone builds them is governments wants a source of nuclear trained people around for military purposes (either bombs or navy ships).

Battery backup isn't a needed as much as many thing in the real world. Those gas power plants we already have are not going anywhere, so we still use them when there isn't much wind. Though battery is something we should be building instead (and are).

by bluGill

5/23/2025 at 2:24:51 PM

Wait, what? There are also a number of countries that operate nuclear plants purely for civilian electricity production. Military applications are not the primary motivator.

Instead, civilian energy demands and energy independence are the motivating factors. Look at how Ontario leveraged its electricity supply in the early days of the trade war.

by xattt

5/23/2025 at 3:13:21 PM

I said build not operate. The world situation has changed, 50 years ago nuclear power was a good idea to build. If you have a working nuclear power plant I'd generally keep operating it, and do small upgrades over time. However building a new one is something you should only do if you have military needs. (note that showing off is sometimes a military need)

by bluGill

5/23/2025 at 9:25:24 PM

CANDU 9 and Advanced CANDU reactors were developed and built during a time when Canada had no active military nuclear program.

by xattt

5/23/2025 at 2:27:25 PM

In most of Europe, nuclear is cheaper than anything else but coal, natgas, and classic hydro.

When you also add the cost of battery backup.

Spain and Portugal have just experienced the first taste of that fact.

by cyberax

5/23/2025 at 5:41:15 PM

Most of the cost of nuclear is in construction so extending the life of existing nuclear power stations as long as possible makes sense. However new nuclear in Europe has been much more expensive and even France has lost the ability to build new nuclear capacity cheaply.

by laurencerowe

5/23/2025 at 4:55:39 PM

Nonsense, by that logic Lithuania should have been a #2 military power long time ago (having built nukes from a civil nuclear reactor) (it used to operate #2 largest nuclear reactor in the world, now it would be #4).

by mndgs

5/23/2025 at 4:02:17 PM

You can do the same with a nuclear power plant and calculate how much power it generate and how much green house gases that represent if it was produced by a natural gas-fired power plant. Fuel cost is a thing, but to my knowledge they are fairly minor in terms of greenhouse emissions when compared to burning fossil fuels.

Batteries/storage do not produce energy so they don't displace any energy in this kind of calculations. They can be viewed as a small efficiency increase of existing wind turbines, in which case they do have a form of greenhouse gas payback time, although the energy must not be counted twice for both the turbine and battery, and the increased wear and tear on the wind turbine may impact the result.

Wind generally has an production rate of around 50%, which mean that countries like Denmark that has already reached over 100% wind production still only have energy for half of their consumption. This mean the storage need is fairly massive, which they currently solve by importing energy from fossil fueled thermal power stations, nuclear and hydropower from nearby countries. Constructing more wind power at this point does not seem economical for power companies, and any storage solution like lithium, reverse hydro, and so on are also not economical (as in, there is basically zero investment into it outside of government subsidized initiatives). As such, wind has in that location seem to have reached its ability to displace any more fossil fuel.

by belorn

5/23/2025 at 3:14:13 PM

Because nobody is lobbying to build nuclear power plants instead of windmills because of the lifecycle emissions of the windmill production.

by delusional

5/23/2025 at 4:58:51 PM

It would be laughable to compare nuclear with any alternative based on the cost of externalities.

by motorest

5/23/2025 at 11:00:35 AM

so... that estimate should be even shorter, since we're replacing primarily coal stations?

by NooneAtAll3

5/23/2025 at 1:16:42 PM

Turns out gas is just as bad as coal when you account for leaks

by mavhc

5/23/2025 at 1:21:44 PM

if you believe the carbon equivalency metrics for methane

by throwawaymaths

5/23/2025 at 2:14:28 PM

Why would you not believe that?

by virgildotcodes

5/23/2025 at 4:30:24 PM

there's a lot of unmeasured assumptions and if you read what is described to the public its usually scientifically wrong. usually it's one of:

- methane has a higher absorption than CO2

incorrect. CO2 has a dipole moment amd c-infinity-v symmetry so it absorbs way more

- methane has higher absorption in open windows of IR frequencies

also incorrect. the water band don't overlap with CO2

- methane has a longer atmospheric half-life

incorrect. you can look up the numbers on this. i believe it was believed to have a longer half life a few decades ago but detailed isotopic studies have disproved it?

you have to dig really deep to figure out that there is I think? an estimated self-shading effect of CO2 that changes the marginal absorbance of a single molecule. but this assumes a uniform distribution of CO2 in the atmosphere and no scattering. anyways i think this is not spoken of because it also reminds that the effect of Co2 is logarthmic (A = log(T))

by throwawaymaths

5/23/2025 at 10:03:20 AM

> The lifecycle assessment of wind turbines today, which is the accounting for the actual emissions of the lifetime of a wind turbine, factoring in: creation, installation, maintenance, even the disposing of it, was clocked to be offset after 5.3 months of running the turbine

Very informative. Thank you.-

by Bluestein

5/23/2025 at 6:31:27 PM

But are there any iron mines, steel plants etc that actually work on electricity?

Otherwise you can calculate any offset you want, but it'll be a paper exercise.

by Scarblac

5/23/2025 at 6:19:25 PM

They still need conventional power plants for backup which will make the life-cycle electricity emissions of the whole system much dirtier.

by cbmuser

5/23/2025 at 8:12:43 PM

But building and installing the wind turbine still requires some emissions.

The wind turbine doesn't remove carbon from the air, so the offset you are talking about is not a real offset, it's only relative to how much CO2 wasn't released in the atmosphere by a more polluting source of power that would have been used instead.

Wooden wind turbines would allow sequestrating carbon (in the cut trees that make their structures) and potentially compensate the carbon necessary to assemble and install the wind turbine, if the trees are replanted.

by thrance

5/23/2025 at 10:30:13 AM

At least wood is more recyclable, so why not.

Thanks for the study link!

by jiehong

5/23/2025 at 10:38:12 AM

Is it though? Steel is very easy to recycle. Engineered timber that is full of various glues and fire retardants not so much.

by twelvechairs

5/23/2025 at 10:48:17 AM

I thought the main problem with recycling them were the fiber composite blades? If they keep those but just swap the metal tower with a wooden one they've achieved exactly nothing in practice.

by moffkalast

5/23/2025 at 11:40:04 AM

Well replacing the tower reduces embodied emissions from the steel. Sure that's not as big as an issue if the steel was already recycled (and would be recycled again) using an electric arc furnace powered by renewables, but the wood is actually negative since it's storing carbon while it's not decomposing.

The blades themselves isn't really much of an issue if you actually compare it to fossil fuels - for example, coal fly ash was 18% of all waste generated in Australia around 2019 (this is likely a bit less now as one or two major coal plants have since been decommissioned).

I think it's astronomically unlikely that wind turbine blades would ever be that kind of proportion of a country's waste, but it was just a normal thing for coal. And gas and oil have a similar problem, it's just harder to see since it's fine particulate matter belched into the air instead of heavier ash that you have to deal with!

1. https://www.abc.net.au/news/2019-03-10/coal-ash-has-become-o...

by stephen_g

5/23/2025 at 4:53:51 PM

"The research indicates that there will be 43 million tonnes of blade waste worldwide by 2050" https://www.sciencedirect.com/science/article/abs/pii/S09560...

by nabla9

5/23/2025 at 5:46:43 PM

Which just isn't very much. The US currently produced 120 million tonnes of coal ash per year.

by laurencerowe

5/23/2025 at 12:03:29 PM

This is not just wood though. This is wood fibers mixed with some sort of resin.

by cinntaile

5/23/2025 at 10:13:40 AM

What about more complex and expensive infrastructure required for balancing uneven electricity output?

by anticodon

5/23/2025 at 11:44:03 AM

A bit more complex, but it doesn't have to be more expensive...

I think this is massively overblown, it was actually hard to manage a grid with baseload generation, since you still needed peaker plants for the morning and afternoon peaks and then had massive amounts of excess power overnight.

It's just that that's what people were used to, not that it's actually the best or easiest model for managing grids.

Highly variable sources bring some different challenges than the old status quo, but we also have much more sophisticated technology in the power space now anyway. And that new and sophisticated tech can produce new opportunities that outweigh the challenges if anything.

So I take arguments like yours with a massive grain of salt. How you put it is not really the case.

by stephen_g

5/23/2025 at 10:25:03 AM

The same as for the wood turbine.

It also matters before asking the question of batteries how much turbines it's going to take before the problem actually needs to be tackled

The problem doesn't arise immediately in the duck curve. It depends on how much of the energy mix of the place is composed of controllable sources alongside your wind and solar

I recall seeing that the need for batteries is tiny if you accept a 10% share of carbon emitting energy across the year - so all in all, another non-problem, or at least first you should focus on building the turbines to reach the problem, then think of whether or not it's worth getting batteries for the rest.

by sebstefan

5/23/2025 at 10:39:04 AM

"Uneven electricity output"?

The variation on output is over a matter of hours (wind powerful enough to spin entire wind farms is not something that comes one second and is gone the next), and large grids with import and export capabilities are largely self-regulating.

Cost fluctuations in the electricity market regulate whether e.g., power storage sites will charge or dump power, whether district heating plants will source more heat from giant electric kettles, when EVs will start to charge, when private smart water heaters will preheat, when people decide to schedule washing machines and dishwasher, whether offline fossil fuel power plants will be fired up to sell as the rate becomes more lucrative or shut down as power becomes too cheap, whether any "idle" plants will throttle up or down, and whether windmills will engage brakes and turn away from the wind or release brakes and turn into it.

Power grids have also always had the ability to load shed by dropping customers off the grid, starting with factories that have special agreements, in case the combined local production and import is insufficient, and can detatch from neighboring grids and countries if there are import/export issues that could destabilize the grid.

The grid needs to change when supply or load conditions change significantly (e.g., every house in a city suddenly having an EV or heat pump, every house in a city suddenly having solar cells and supplying a ton of power, a power plant or wind farm being built somewhere power has not previously been routed), and can be optimized (e.g., power storage, smart load scheduling), but that is entirely orthogonal to windmills.

by arghwhat

5/23/2025 at 10:15:26 AM

yes - RE Spain a month ago ..

by WinstonSmith84

5/23/2025 at 10:23:57 AM

Was a root cause done on that? Was it due to wind power?

by coolcase

5/23/2025 at 11:02:16 AM

Trigger suspected to be one substation https://www.reuters.com/business/energy/power-generation-los... The blackout itself is suspected to be amplified by ren https://montelnews.com/de/news/96607ac1-dd73-4c23-bb47-a7c2a... "Die Experten betonen, dass erneuerbare Anlagen das Problem nicht nur nicht abfedern konnten, sondern möglicherweise verstärkt haben."

by Moldoteck

5/23/2025 at 10:48:18 AM

https://en.wikipedia.org/wiki/2025_Iberian_Peninsula_blackou...

The root cause is not known, but Spain was producing excess power (primarily solar) at the time around the disconnect. Some fluctations were seen, then supply started to disconnect from the grid in Spain, leading to sudden loss of 2.2GW of power. In Spain, automatic load shedding then happened to try to recover, but it was too little too late as neighboring countries detached from Spain to protect their own grids.

Nothing about this sounds like an issue with renewables.

by arghwhat

5/23/2025 at 10:47:07 AM

No, the study is still ongoing. I can't find the link (and Google is functionally useless for finding original links) but Spain's power authority held an update last week where they gave a summary of events (where the failure first happened, where it spread to, etc) and if I understood correctly will have non-Spanish/French/Portuguese experts do the full investigation.

Still a ways away from understanding what happened

by passwordoops

5/23/2025 at 1:16:04 PM

https://en.wikipedia.org/wiki/2025_Iberian_Peninsula_blackou...

not strictly because of wind power but few denies that wind power hasn't been a contributing factors - politically it's too sensitive so it's going to be "under investigation" for a long time. Alledgedly too little inertia / rotating power ... there is a parallel to the Australian blackout 10 years ago, where the solution was to build large batteries

by WinstonSmith84

5/23/2025 at 1:08:09 PM

does that number take into account the area of nature paved to create roads for transporting those huge masts?

by internet_points

5/23/2025 at 1:20:49 PM

Because they require so little, infrequent, maintenance it makes very little sense to pave asphalt roads to wind tower locations.

For the vast majority of wind farms, dirt or gravel roads connect masts to pre-existing infrastructure.

The largest wind farm in the US is the Alta Wind Energy Center: https://maps.app.goo.gl/rPjUGSTN979dfUoDA

The largest wind farm in Europe is the Markbygden Wind Farm: https://maps.app.goo.gl/ETVeMXpf1uPieTct8

Dirt and gravel roads.

I'm not saying that there have never been roads paved to create wind farms.

I am saying that the number of roads that have paved is so small that it is irrelevant.

by os2warpman

5/23/2025 at 9:21:46 PM

Can't speak for the US, but that is not the case in Norway.

There have been massive protests due to the amount of nature destroyed. There are some before-after sliders on

https://www-nrk-no.translate.goog/dokumentar/her-er-norges-s...

(scroll around for "wind") that give an indication, although the most striking difference is experience by the people who used to go for hikes in remote places where there are now immense wind parks. The wind companies love building them up in the previously-untouched mountain regions since I guess height = more power, also less NIMBY neighbours.

https://www.google.no/maps/place/Buheii/@58.6554134,6.887061... had zero roads a decade ago, now it's all roads. And with roads come traffic and people and cabins and tourism and more roads.

Now they're saying we need more wind parks for AI data centers (a few years ago it was for crypto). We're tearing down nature so we can keep growing our energy use while staying "green".

by internet_points

5/23/2025 at 2:22:15 PM

looking at the wind farm from a certain elevation reminds me of west texas where each of the dots is a gas well instead of a turbine. then my brain went hard left and imagined the wind turbines being used to pump gas in some insane reason

by dylan604

5/23/2025 at 1:57:50 PM

Why should it? We already have all those roads as they were built for all our other transport needs and have plenty of spare capacity for the few wind turbines (1 every 5 minutes is not much use on a modern road) we are building.

Unless you are talking about the last 100 meters - but as the other reply pointed out, those are not roads. Most of the ones I've seen are grass - the roads are used so little we don't need gravel and they don't even turn into dirt.

by bluGill

5/23/2025 at 2:19:49 PM

"Steel is very strong per volume, so steel is a good choice when strength per volume is one of the main constraints. However, wind turbine towers are essentially empty inside so there is room to increase the volume by making the walls thicker. The Laminated Veneer Lumber (LVL) material in a Modvion tower has higher strength per weight and higher strength per cost than steel alternatives."

Strength per volume versus strength per weight is an interesting trade-off. They're arguing this could let towers get taller.

by jbms

5/23/2025 at 9:12:41 AM

What does "net-zero" mean in this context?

I would have assumed of course that wind turbines are net negative emissions, even factoring in the construction and materials.

Do they mean net-zero in materials and construction alone? Because that sounds impossible.

by aqme28

5/23/2025 at 9:25:29 AM

What they seem to be claiming is that because the wood itself contains more carbon that is used to produce the turbine, they have net negative carbon emissions before accounting for actual energy production.

That seems pretty dubious to me. After the turbine’s thirty year life, what happens to that carbon?

At any rate, if it’s true that it takes 90% less carbon to produce in the first place, setting aside the whole “wood contains carbon” thing, that’s pretty cool.

by mistercow

5/23/2025 at 9:38:51 AM

That’s a great project and kudos to the team, meanwhile :

> After the turbine’s thirty year life, what happens to that carbon?

Those curved boards are probably mixed with epoxy or another polymer, making it a bad candidate for recycling in other wood application (paper, osb boards…), compared to first hand row trees. We’ll probably "valorize" it in incinerators.

by aziaziazi

5/23/2025 at 9:43:05 AM

I think they plan to cut down the tower and saw it into joists basically. The tower wall should be thick enough to allow for that. You will loose some material ofcourse but most of it should be possible to use in construction.

by wizardOfScience

5/23/2025 at 10:20:12 AM

Would the epoxy not have degraded over time? Making it quite a bit weaker?

by peterpost2

5/23/2025 at 4:54:19 PM

Probably doesn't matter all that much, especially for interior material that wasn't exposed to the elements. Worst case you're probably talking strength on th order of chip board which is still useful.

by potato3732842

5/23/2025 at 9:38:26 AM

If you build enough of these sustained, the total amount of CO2 bound it them could be significant. Similar to growing forests or restoring peat bogs. But yea, growing forests is equally suspicious as a lot of carbon sink forests have turned out to be cut down...

by boxed

5/23/2025 at 11:03:48 AM

"what happens to that carbon?" - biomass))

by Moldoteck

5/23/2025 at 10:10:26 AM

Presumably they mean that the CO2 captured in the wood of the tower can offset the manufacture of blades and other components at some point in the future. Not that reaching net zero in wind power is an important milestone or anything. From their technology page:

> The life-cycle emissions from modern wind power plants made of steel are about 4–7 grammes carbon dioxide per kWh. Building the tower in wood lowers the emissions from the wind power plant by approximately 30 percent per kWh.

That would put wind power some 50-100x below fossil fuels already. Additional improvements are always nice to have, but not really a big selling point.

by mppm

5/23/2025 at 9:36:15 AM

> I would have assumed of course that wind turbines are net negative emissions, even factoring in the construction and materials.

It's net much-less-than-coal and much-less-than-oil, but it's not zero and certainly not negative.

I think you're confusing "if we add this to the grid we subtract the carbon emissions compared to the current system" with "this pulls carbon from the atmosphere". Those are very different things.

by boxed

5/23/2025 at 5:14:46 PM

I listened to a podcast titled "Taming the hydrogen hype" [1] that suggests things like nuclear power plants and wind turbines don't follow the same cost reductions as solar and batteries because they can't be fitted in a shipping container:

> So, most industrial things have big economies of scale, right? There's this imaginary world where, "Oh, I'm going to shrink down the cost, but the cost per unit is also going to go down." That requires magical thinking. It requires making it so small that you can make it in a factory and ship it in a shipping container.

Based on what I read on the site the turbine components can be transported using normal lorries. However, it would be interested to know:

1. If they can be shrunk even further and be transported in a container.

2. Would this help reduce costs.

1. https://open.substack.com/pub/davidroberts/p/taming-the-hydr...

by kieranmaine

5/23/2025 at 5:22:30 PM

Wind turbine power output scales by the square of rotor length so like nuclear power tend to be cheaper per unit power produced the larger they are.

by laurencerowe

5/23/2025 at 9:03:52 AM

From what I understood the main ecological issue with wind turbine are more due to the blades than the tower, I wonder if they're doing something on that side.

by Bric3d

5/23/2025 at 9:22:32 AM

Those blades are a major engineering challenge. Have a friend who's a materials scientist who works on those blades. Those things experience crazy stresses because they're so huge. Failures can be pretty catastrophic. I don't think the ecological issue with those blades is all that relevant given the huge ecological benefits of wind power over any other form of electricity generation.

by elric

5/23/2025 at 9:39:08 AM

Any? Solar and nuclear would like a word :P

by boxed

5/23/2025 at 1:14:35 PM

Solar actually has over twice the footprint of onshore wind, considering the energy needed to produce the panels, but it's irrelevant in the grand scheme of things, as all those mentioned sources, if they were to form the majority of the mix, would make electricity a much smaller chunk of the overall footprint than, say, food.

In 2024 France electricity was responsible for an equivalent of 16.1Mt of CO2 - largely due to gas peaker plants, which together contributed to a single digit percentage of overall electricity consumption.

That's 235kg of CO2 per person, or 2.5-7.5kg of beef in terms of environmental impact.

by Tade0

5/23/2025 at 12:13:02 PM

That feels like a disingenuous take. If the composites in wind turbine blades are an environmental problem, then so is nuclear waste and so are the semiconductors in solar panels.

by elric

5/23/2025 at 3:16:50 PM

i partly agree, but the fact that those blades cant even be recycled [0] but are instead dug down in the ground after use will probably be an ecological issue relatively soon.

edit: [0] https://www.bloomberg.com/news/features/2020-02-05/wind-turb...

felt like i read that article yesterday. 5 years ago, wow. has any progress been made there?

by lkmill

5/23/2025 at 12:24:25 PM

It's a relatively very minor challenge compared to burning massive amounts of gas, coal or oil for the same energy of the blades over the lifetime. The big picture is that wind turbines are a massive improvement over that.

There's a very minor challenge (compared to decades of coal/gas related emissions) of what happens to the blades after their useful life ends. Mostly you are just putting something that doesn't naturally degrade very well in a landfill where it sits and doesn't degrade very well. It might be leaking some toxic stuff slowly over a very long time. Compared to all absolutely massive amounts of other stuff we dump in landfills, what happens to the blades is probably not the most urgent thing to tackle from an ecological point of view.

Of course, windmill construction at scale involves a lot of steel, concrete, and blades. So if would can do the same job and perform well, that's still interesting to do. We take something that's already amazingly good and make it even better.

by jillesvangurp

5/23/2025 at 9:39:32 AM

Check out these guys! https://voodin-blades.com/

by wizardOfScience

5/23/2025 at 10:51:33 AM

We're officially back to classic wooden windmills.

by moffkalast

5/23/2025 at 9:08:53 AM

Maybe they can use cross-laminated wood or the compressed wood that was on hacker news the other day.

by Onavo

5/23/2025 at 10:57:42 AM

It's that, and the tower's concrete base (which is huge, and virtually indestructible, which means no-one is going to remove it. It'll stay in the ground forever, essentially sealing it (even if there is a meter of dirt covering it). See [1] for a picture to understand the dimensions:

[1] https://www.sserenewables.com/news-and-views/2021/09/concret...

by DocTomoe

5/23/2025 at 2:26:02 PM

There has been lots and lots and lots of attempts to replace steel with wood in construction. These attempts have gone nowhere. So what is to say that this time it will be different? If wood is so good for tall construction why isn't it already used in skyscrapers?

by bjourne

5/23/2025 at 2:44:25 PM

The best thing in their favour is how standardized and simple a wind turbine tower is. They know the requirements and their customers. It's much easier than a skyscraper, and it might let them start to scale production of the materials so they become more attractive to other applications.

However there is growth in mass timber construction generally. People are competing to build taller and taller timber skyscrapers.

by jbms

5/23/2025 at 3:16:56 PM

Most traditional constructions in Asia (and to be frank anywhere else in the world) has been with wood, stone and dirt. Steel is only possible since we extract enough iron and burn in with coal, something we're not sure to be able to do at the same price (=rate =quantity) as we did for the last 100years. Still, here's some contemporary "skyscraper":

105m - Thailand - 1981 | https://en.wikipedia.org/wiki/Sanctuary_of_Truth

85m - Norway - 2019 | https://www.moelven.com/mjostarnet/

87m - US - 2020 | https://www.ascentmke.com

350m - Japan - 2041 | https://www.nikken.co.jp/en/projects/highrise/w350.html

by aziaziazi

5/23/2025 at 7:56:11 AM

I never understood why wind turbine towers are built as hollow, tapered cylinders. Isn't the best mass-to-strength ratio acheived with truss/grid type structures, like in construction cranes?

by svantana

5/23/2025 at 8:55:00 AM

A wind turbine tower is essentially a cantilevered beam resisting the bending moment from lateral wind loads. The loads can come from any direction. Bending induces stresses in any beam that increase with distance from the centre. A thin walled hollow tube is the most material efficient design theoretically as it concentrates the load bearing materials along the perimeter of the beam. Any deviation from this incurs material that is not fully utilised.

by wizardOfScience

5/23/2025 at 5:06:08 PM

This is almost a "spherical cows" level gross over simplification. If you weren't defending it in other replies I'd think you were satirizing people who only have book learning and no real world experience.

At the limit the failure of your statement obvious. If instead of a thick walled wood tube hundreds of feet tall this structure were an orders of magnitude wider cylinder of thin plies the same height it wouldn't even be able to hold itself up, it would flop over, tear and all fall down under its own weight if not from manufacturing variances then from the wind and differential expansion/contraction from the sun and if by some miracle it survived that it would flop over

The material has to support itself and tolerate undefined small (relative to the main load) loads in other directions as well as point loads from fastening it to whatever you are using it to bear the loads of, going all in on "large and thin" fails to optimize for this for more or less the opposite reasons that going all in on "solid" does.

by potato3732842

5/23/2025 at 8:49:37 PM

The parent is explaining why it’s hollow instead of being a truss. They accurately explain that the hollow tube is optimal to counter the wind loads. Your criticism is that they didn’t discuss gravity loads, but that wasn’t “in the prompt” — the gravity load doesn’t explain why they’re a hollow cylinder. There are a wealth of other irrelevant things that could be discussed, but have been neglected because they are irrelevant to the question.

Frankly your comment disappoints me. wizardOfScience gave a _great_ answer, that would make any solid mechanics professor proud.

by pinkmuffinere

5/23/2025 at 9:01:33 PM

You're strawmanning bot me and the comment I'm replying to. Whether you're using a truss design or a solid material wall what I'm saying holds true. You can't just go all in on "put the material at the perimeter" because it'll have other problem. Gravity is just one of those problems.

by potato3732842

5/23/2025 at 9:30:11 AM

Your explanation raises the follow-up question, which svantana already hinted at: Why don't construction cranes use hollow tubes instead of their typical truss structures?

by adwn

5/23/2025 at 9:36:50 AM

The crane manufacturing business case is not driven by material efficiency to the same degree. It is a tool that needs to be reliable and have performance in operations. Limit the need for man hours through ease of use etc. It should also be able to take many assembly/disassembly cycles.

Thus does the amount of material not matter as much in a crane.

For wind turbine towers the material cost can be >>50% of the installed cost.

by wizardOfScience

5/23/2025 at 4:47:32 PM

Working for a crane manufacturing company. While raw material costs are maybe not that drastic, we consider material efficiency the most important metric for cost and a lot of brain power was spent to optimise the amount of steel used. There are multiple reasons for this. The ones I can think of are:

  * The margins for cranes are thin and steel is expensive.
  * Thicker steel is harder to work with, increasing manufacturing cost.
  * Each kg of dead weight may decrease the performance of your product, e.g. max. Live load. This is especially true for the jib.
  * More weight at the top of the crane may necessitate a sturdier structure below, amplifying cost even more.
  * More weight may require more ballast blocks, which are costly (especially transport)
  * More weight means higher transport costs
  * More weight means more wind area, which is the critical factor for high constructions.

by majoe

5/23/2025 at 10:59:23 AM

Because at cranes the force is not the wind that comes from any direction, but the directed payload hanging at the crane arm. Almost all cranes I now moving also the pole around.

by Aldipower

5/23/2025 at 9:36:38 AM

Certainly makes them easier to disassemble and move elsewhere.

by IsTom

5/23/2025 at 2:50:20 PM

Yeah it's pretty essential that construction equipment be pretty easy to construct and deconstruct. There are some videos [1] which are worth checking out.

[1]: https://www.youtube.com/watch?v=vx5Qt7_ECEE

by dguest

5/23/2025 at 10:42:30 AM

My guess: They want the wind to pass through the crane, while they want wind turbines to capture the wind.

by carlosjobim

5/23/2025 at 4:58:29 PM

This is the answer.

Interestingly, wind/storm loads are oftentimes the limiting factor for the configuration height of a crane.

This is because, when adding another tower segment, not only the total area increases but also the wind forces. The other loads stay roughly the same

This is the reason why bottom-slewing cranes, which are commonly used for small buildings, sometimes are built with solid walls. Top-slewing cranes, which are used for high buildings, always use a steel framework.

by majoe

5/23/2025 at 9:07:55 AM

This is what I come to HN for, kudos

by Onavo

5/23/2025 at 8:17:07 AM

The forces acting on the wind turbine tower are mostly perpendicular, i.e. the wind hitting the blades and the structure. Ideally, the blades have maximum wind resistance (up to a point).

The construction crane rarely experiences that kind of wind load, because the truss structure is hollow and allows air to pass through. Ideally, the structure has zero wind resistance (down to a point).

by cluckindan

5/23/2025 at 8:00:59 AM

https://gicon-hoehenwindrad.de/ They test-building a 380m wind turbine in such a style now.

by looofooo0

5/23/2025 at 8:21:40 AM

I know it's a test project and one shouldn't be to stoked about a test project, but for the last year I have again and again searched for updates about it. Unfortunately, they keep it (understandably) low. Let alone the story of the 90+ year old engineer that envisioned such a project (and they are only implementing 20% of it) is so awesome. Looking forward to when it finishes and hopefully changes our view on wind power for good!

by patall

5/23/2025 at 8:50:37 AM

UK has moved from open grid style to a cylinder style for electricity pylons. Presumably there's an advantage to it, but I don't know what it is: https://www.nationalgrid.com/national-grid-energise-worlds-f...

by flir

5/23/2025 at 5:09:52 PM

I can't speak to the UK but in the US things like electrical towers and highway signs mostly go to tubular construction for labor cost reasons.

Tube gets manufactured in a facility specializing in doing it in a low labor way (rolling or whatever). Flanges get welded on, they get slapped on cribbing and trucked to you and then assembled with minimal labor.

Contrast with the lattice. Cheaper material inputs, a whole bunch of cheap channel with holes punched as needed, but all that punching, and then all that bolting, takes way more labor, a lot of it can be done cheaply, but it adds up, and when it does get to site there's more pieces to pick and connect, etc.

Basically the more expensive material saves you quite a bit of human labor at each step. Same reason huge rolled steel and welded tubes displaced riveted construction.

by potato3732842

5/23/2025 at 10:15:29 AM

No, the optimal shape is a thin dense shell with a stiff low-density interior.

Optimization only leads to trusses if you constrain the design to have no low-density elements.

In practice this leads to things like a thing CFRP surface wrapped around balsa or stiff foam.

by impossiblefork

5/23/2025 at 8:00:28 AM

I’d be interested to hear the answer to this, but don’t really want to see it. Wouldn’t it look terrible?

by lostlogin

5/23/2025 at 10:47:28 AM

It is likely that ,while a truss would be lighter and stronger, to counteract the forces encountered by a turbine it would also require a cross section so large, as to interfere with the blade travel, rendering the proposal, impossible. There are small wind turbines useing truss style towers, but they all have a "stub" tower on top, and they are under 10kw......10-15'blades. the wooden tower under discussion, is also "small" by todays standards, and unlike steel towers that can be made by any half respecting medium sized fabricator, will require a specialised industrial facility that cant make anything else usefull, and so the one that is doing this, is funded at great expense from government grant funding. kinda cool,kinda cringe

by metalman

5/23/2025 at 8:42:48 PM

Love wind turbines they look great and feel like the future. Don't understand the hate for them

by rcpt

5/23/2025 at 8:44:10 PM

Have you actually looked into the arguments?

by frainfreeze

5/23/2025 at 8:27:47 AM

Would be great if someone could build wind turbines to look like the windmills of old

by norome

5/23/2025 at 9:11:31 AM

Those are really short and therefore much less efficient. Wind power scales as a cube with speed, and speed scales as a power with height. A little more height can make a big difference.

by aqme28

5/23/2025 at 2:15:45 PM

What type of windmill of old? They look like a scaled up Jacobs wind system from the 1920s. No surprise, Jacob's wind got a lot of things right back then.

If you mean the old water pumps used in the American west (they are still made today!), those are good for water pumping because they produce high torque in low winds, but they make less horsepower and that is what we care about.

If you mean the Dutch style windmills/houses, we could do that, but the big house blocks a lot of wind and so it is not efficient.

I can't think of any other style of old windmill. However if you can the answer to your question is likely because that style is much less efficient.

by bluGill

5/23/2025 at 8:53:41 AM

Why? Presumably we’re trying to optimise on generated power?

by robin_reala

5/23/2025 at 9:58:17 AM

It's not a viable proposition, I agree, but one thing it would get around is NIMBYs in the UK who seem to love vintage windmills, but not wind turbines!

by frereubu

5/23/2025 at 9:42:00 AM

Huh?! I don't see this as a viable challenge to the extant business model and they never reveal the numbers, let alone a basic model, behind their "net-zero" marketing claim.

They also still haven't solved the main issue of non-modular turbine blade transport and assembly. Modular and stepped blades are the next frontier. Not tower construction.

Quite frankly, the tower is trivial.

The cost of the tower construction and materials is a small percentage of the initial blade, transmission, and generator assembly costs and on-going maintenance. Even the lubrication flow sensors and lubricants are highly specialized for the unusual duty-cycles and variable loading of a wind turbine.

by calmbonsai

5/23/2025 at 9:57:44 AM

I feel very strongly that if a wind turbine is made of wood, you have to call it a windmill even if it's not powering a mill.

by lupusreal

5/23/2025 at 9:51:57 AM

[dead]

by aaron695

5/23/2025 at 10:30:42 AM

I think this is modern Nordic engineering in a nutshell: Some of the smartest people you can find working on some of the dumbest projects you can think of.

For any of you wondering why would anybody do this, the full explanation is in the site footer: "This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 959151."

by carlosjobim