If the plane really is task built that would be super cool. Huge plane (108m/356ft), carrying pretty light cargo all in all (blades of this length weigh probably 20~25T), that ideally can land and takeoff on short runways (to maximize the number of airports it can deliver to). By compare, a 777 will be either 60 or 75m long and carry 220t, and itself weigh 160t. Neat idea. Being able to get bigger blades to sites would be great. It also would enable centralizing the production better, which could be an efficiency win; a couple big factories cranking out blades. There's a lot of practical scale-out this would enable.
The plane really is pretty wildly proportioned. I'm not sure what the total internal volume/cross section is expected to be but that's a long plane! Carrying not much weight! The blades are big but not colossal: by compare, the offshore Vestas V164 10MW turbine has 160m blades (weighting 35t); this is being designed for ~100m.
It's definitely good to ask what else such a craft might be useful for. The low capacity is an obvious downside, but if it can access lots of airfields that could be quite enticing.
Edit: Missed this: With a capacity for 80 tons. That's a lot more than I expected! It doesn't seem to make sense to me, for the payload it'll carry.
Also: The WindRunner includes shoulder-height tires and has the ability to land on a packed-dirt 6,000-foot runway, which would need to be built for each project. Well, that's neat & potentially immensely useful for a lot.
> The blades are big but not colossal: by compare, the offshore Vestas V164 10MW turbine has 160m blades (weighting 35t); this is being designed for ~100m.
That's the part I really struggle with: I could easily imagine value in taking a new approach to blade transport as radical as this if it allowed on-shore installations to get on par with off-shore rotor sizes. But if the result is the same as what's already established, just achieved in a different way, it feels like a microoptimization hardly worth the engineering.
Wow, thanks for posting. That really shades what they're going for differently, much more ambitious than I'd first thought.
So this will be bigger than 10MW that Vesta. Blades will almost certainly have to be >35t. For compare the largest turbine now is China's 16MW turbine (note that a couple m of the diameter is in the hub not the blades, but still):
> Goldwind’s GWH252-16MW intelligent wind turbine has a rotor diameter of 252 meters (827 feet)
Thanks, missed that detail. So the plane, when it becomes available, would be almost long enough for blades deployed off-shore today. (e.g. Siemens-Gamesa SG 14, 108m and 115m)
Work with me, here: dedicated seaplanes for megasized offshore windmills. This would put TailSpin one step closer to being real. Clearly a civilizational win.
I think you would want to pack it with anything on the return trip to the factory to pick up more blades. Otherwise it's just an empty trip, might as well move some large equipment to help offset the cost.
How much more energy can these large blades produce that it's worth inventing a new kind of airplane (and apparently a purpose-built airstrip for every destination) to ship them? And if they ever break and need fixing, do you have to go pick them up, take them in for repair, and bring them back?
If they've raised $100M+, I assume these questions have been asked, but I'm just generally skeptical that the math makes sense.
> (and apparently a purpose-built airstrip for every destination)
Having built a 64-turbine windfarm back in the 2000's (so they were likely smaller than they are now) a goodly chunk of the work involved was site prep in building access roads traversable by the cranes required to set everything up, and the massively over-length trailers carrying the blades. Things like maximum grade, radius of the turns, breakover angle etc were hugely important.
Grading out and paving an airstrip when you already have an appreciable contingent of heavy earthworking equipment onsite and, likely, also a concrete batch plant to reduce the travel time for the concrete you're using for the foundations really isn't too big of a stretch!
Why can't the blades be broken down into managable segments and assembled on-site? The military folds and unfolds airplane wings all the time on aircraft carriers.
(It's an honest question; you must have thought of it, of course.)
The tips of the blades travel close to the speed of sound. The blades are quite difficult to manufacture as it is, it's a big challenge to add intentional weak points and/or weight by making them foldable.
The tips of fighter aircraft wings travel faster than the speed of sound, deal with far more stress (from turns, explosions, etc.), and the wings I expect are more complex and difficult to manufacture - but they fold.
I'm not saying you are wrong, but by themselves those factors aren't entirely convincing to me.
(Also, the wings need to fold and unfold repeatedly over their lifetime; the blades could just be, in theory, shipped in pieces and then assembled once).
Fighter aircraft also have a very short lifespan measured in thousands of flight hours and enjoy constant maintenance compared to a wind turbine expected to work 24/7 for decades with minimal maintenance.
Landing strip construction could work well as part of overhead line construction. You have an existing design that favours long straight lines and a need to build a haul road. Although the scenario where this was actually useful might be fairly unique.
Their website says it can land on a packed dirt airstrip, 6000ft long. I wonder if they would park all the nearby windmills during takeoff/landing, to avoid creating swirly air.
The alt energy transition needs some SERIOUSLY LARGE scale. I wish I had a super-caps lock for that.
The fact that a custom transport plane and dedicated landing strip for massive wind farms is economically feasible should give you a hint as to what is at stake.
For review, both wind and solar, allegedly with storage bundled in and without subsidies, is cheaper than the next cheapest (and fossil fuel based) generation method: natural gas turbine, per LCOE numbers from Lazard LAST YEAR.
Natural gas turbine is basically topped out in terms of efficiency and cost, I believe they have already exceeded Carnot efficiency with downstream exhaust heat capture and other maximization techniques. They can't go lower. Wind? Likely has a decade of gradual cost improvement. Solar? Successful integration of perovskites might drop prices 50% or more in the next decade, plus usual economy of scale improvement.
The economics are basically settled. The details are massive scale, load leveling, grid adaptation.
Well, yes. If you have a combustion engine or a turbine, Carnot tells you exactly the maximal efficiency you could achieve. But the exhaust still can be used for residental heating. So while the generator doesn't get any more efficient at producing electricity, you can use the heat which drives up the overall gain of operating the generator.
We are headed for 20 MW now, so a wind farm with five 20 MW turbines is a typical size for many gas power plants; 100 MW.
In the EU, there's testing facilities that are checking these at this 20 MW size now. Commercially at this point there's up to 17 MW operating in the North Sea.
Very different things. There is basically only one solar panel size on the market. Which starts at $100. Making large solar installations means just getting more panels. This is great for cost reduction, as that most of the times goes along with ramping up production numbers. The production of the single panel doesn't get more complex though.
Wind energy is also getting constantly cheaper, both due to cost reductions and due to making the wind generators larger and thus more efficient. Onshore wind energy is the cheapest in Middle Europe and if they could grow further, costs would go down accordingly.
But even if production can deliver, getting the blades gets more and more difficult, so here we area.
Wind is just different too. There are subtle advantages to scaling up wind: fixed costs increase but capacity factors do too (taller turbines means they’re turning more % due to more consistent wind speeds at higher altitudes).
Just remember gas plants run continuously at the rated capacity whereas wind capacity factor is 30-40%, so a like for like comparison probably involves storage.
> Radia estimates the larger turbines could reduce the cost of energy by up to 35% and increase the consistency of power generation by 20% compared with today’s onshore turbines.
Not sure what that translates to in terms of energy output over time.
As for the sibling "Why not airships?" question, the article says:
> Blimps can’t land in windy conditions. Helicopters are more costly than airplanes, and flying with a dangling blade designed to catch wind would prove complex and dangerous.
Does this cost reduction factor in the cost of making a new airplane company? If they transport a million blades then the cost per blade is not that high. But if they only make 10,000 blades then it becomes more of a factor (especially if the useful life turns out to be not as long as predicted).
If they move 3,000 blades for ~10MW turbines then a 20% improvement in capacity factor alone is worth 3,066,000 metric tons of CO2 year. Edit: (Ops 10Mw * 1,000 turbines * 0.5 tons from natural gas /MW * .35% capacity factor * 20% improvement * 24 * 365 hours, coal is roughly double that.)
Assuming: 500tons of fuel for the transport of the 3 blades (comparison: AN225 with higher max payload weight guzzled ~15tons/hour).
You could have used that energy to produce 500000kg * 40MJ/kg * 40% = 8TJ.
The turbine would need ~40d to produce this (~25% capacity factor, 10MW nameplate power):
The existing option is semi trucks traveling in daylight with additional vehicles supervising and special self steering trailers, local PD stopping traffic if necessary, new roads being built or existing ones improved.
The financial side is not just about energy output alone but includes other constraints and opportunities. A developer may get access to cheaper land and untapped wind resource or grid connection opportunities. A single project like that could make a lot of money. And critically it could be packaged into an opportunity that could be sold to banks and investors. Opening up new opportunities could easily justify a few tens of million in delivery costs.
Support become very costly, because need very large hangars and special machines for large craft (Ukrainian Ruslans and Mriya was designed as off-road, and carry few tons of special equipment onboard, which is not good for economy). Second problem landing strips, which also are limited (limited length, limited width).
As example, for small size and narrow-body planes, in US there are more than 6000 private airstrips, so they could nearly substitute automobiles, but if need landing strip for something large, they are only at very large airports and in special places, like military airbases and space centers, so just few for whole country.
In the world, things are worse than in US, so most Antonov planes was designed to fly from ground road, and carry special equipment on board, but this made them less effective.
That is problem. You sure could make tiny strip (10m x 250m), nearly everywhere, even at the center of old city.
But large planes need much larger strips, for example typical international airport have strip 30m x 1600m.
Why so much difference, because economy. It is much more effective to make large strips in large cities (or near them), than to make off-road planes (google Bush plane) which will have much more expensive cost to transport weight-kilometer or passenger-kilometer.
From where become expensiveness. Well, most effective planes flight fast at high atmosphere (because speed of sound is significantly higher in low pressure), but they also have high landing speed, and unfortunately, brakes (very similar to automobile) need to dissipate all energy from speed, calculated from simple formula (m*v^2)/2, so with double speed have quadruple energy.
Energy dissipation from plane brakes is really big problem, so big that nearly all big planes have special "thermo-accumulating" weights inside landing gear, which considered to heat fast when braking and then few hours dissipate heat. Extreme example was Concord, on which brakes cooling about 11 hours after landing. Bush planes are slow, so they don't have this problem.
Second problem, because of engineering considerations (physics), large planes usually are tall, but not too wide inside, and very big loads are just considered to transport in "horseman" configuration, mean load placed on top of plane, so need special crane to load/unload.
When wind is faster than their maximum speed. Chances are they can take much higher wind speed than the elaborate truck ballet required to transport huge blades on the ground. Wind turbine installation isn't exactly an all-weather project as is.
And real nimby impact (as opposed to the impact imagined) scales much less than quadratic, because larger rotor implies lower rpm and rpm has a huge impact on perception. Small rotors emit a very strong "presence" when you are anywhere near, whereas the tallest ones feel as if they are on a different plane of existence even when you are standing right at the base. Certainly not quite as disconnected from reality as airliners passing by at cruising level, but it's a similar effect.
Thats linear scaling [1] so its still scaling quadratically. Ax^2 + Bx is a quadratic, after all!
(Also, shouldn't the first order approx should neglect wind speed as a function of height?)
[1] actually worse. From Wiki entry for "Wind Gradient"
"Although the power law exponent approximation is convenient, it has no theoretical basis.[18] When the temperature profile is adiabatic, the wind speed should vary logarithmically with height,[19] Measurements over open terrain in 1961 showed good agreement with the logarithmic fit up to 100 m or so, with near constant average wind speed up through 1000 m.[20]"
What is the smaller version of this? Just like I can buy a small solar panel that is able to charge a battery that I can then use to charge my phone. Is there a small windmill I can buy that can do a couple hundred watts?
There are small windmills available for purchase. For a while campers and sailing yachts would use them. But they seem to go out of fashion. The problem is: the efficiency goes up with the size also, there is more wind the higher you go. On top of all of that, windmills are quite noisy. You really cannot use them in residential areas. Solar cells are much easier these days and also cheaper.
At the risk of asking a dumb question - why do wind turbine blades need to be transported in one single impossibly large piece?
They are all composite materials, right? Can't they be manufactured in a couple pieces and fused together properly on-site, using technology that is a more economical as compared to designing and building new types of aircraft?
However, I understand that doing a composite/chemical joint basically involves setting up a mini-factory, since your joint quality will depend very much on being able to control the conditions. Mechanical joints require less on site infrastructure, but have an efficiency penalty (https://www.nrel.gov/docs/fy23osti/84397.pdf).
In any case, I imagine Radia is betting on getting enough volume to make the development cost irrelevant. In the end, you had to transport the roughly the same amount of material onsite anyways, in roughly the same form factor. The cost of a fleet of aircraft can be amortized over a huge geographic span wind farms, while also being attractive from the perspective of delivering replacements.
I definitely think segmented blades are a way forward, but I can also see Radia's argument. I can totally believe that the "real winner" is going to a combination of situation and execution.
I have no expertise of any sort but I would assume a contiguous fiber material would have higher strength and the fuse joint would be considerably weaker.
I dont have any expertise either, but wouldnt it be more feasible to make a mobile factory that can be built on site? Power shouldnt be a problem, a huge cable needs to be laid anyway. Just turn it around after the job is done.
Just have a traveling circus with a large construction tent. Trailers that connect to each other etc. Sound more feasible than a plane to be honest.
That's an approach explored by many it seems, and success on this front would certainly have to be considered a risk of investment in novel transport solutions. As far as I know, factories heat-treat (and pressure-treat) those composites in one go, in a huge oven enclosing the entire blade. On-site manufacture would either require those huge heat treatment units built locally or somehow made transportable, or a process that does without.
It might be a bit of a chicken/egg situation, the materials science required to do without the full-size oven not being worthwhile without a transportable implementation of all the assembly and layup arrangement that would have to be done before, and the logistics not happening without a solution on the materials side.
I like this kind of crazy thinking. I wonder if there are also scenarios where blades can be shipped by truck 95% of the way, but the "last mile" is by helicopter.
I doubt it. Federal highway infrastructure mandates only 14.5 ft clearance. These things are larger than that in diameter and must go on a flatbed (that is itself 2' off the ground or so.) Turning radii on highways are not sufficient for something 300 feet long either, I don't believe anything over 80' can be towed. Many states have lower limits than the federal government on length.
The real question is how will it get from wherever that plane lands (which I assume must only be large airports, unless they plan on building private runways near installation sites, which I guess might not be cost-prohibitve relative to the cost of flying the world's biggest plane in once for each blade) to wherever it is going? So it may still be last mile by helicopter, I don't know how else you'd move it.
Wind projects often need to re/build a lot of roads, bridges and other road infrastructure anyways. They often need to build concrete production facilities on site to support the construction. In comparison, 2 km of packed dirt runway, which the plane is specifically meant to land on, is nothing.
It really doesn't seem like it could pencil out, as it carries only one blade at a time, that's three trips for each turbine - and most windfarms would have more than one. But I guess they think it does. Perhaps they can also deliver to offshore farms, which already have contracts. I know there is a shortage of the specialized ships to float their huge blades out.
Also, I hope they've done their homework on NIMBY pushback on land which is pretty effective against wind farms even with regular sized turbines.
Started too early I guess. Ten years later and the blade transport use case would have come in at just the right time to salvage the investment. Back when Cargolifter shut down, rotor sizes were still in a range where ground transport isn't all that challenging.
Take twelve blades, run the generators as motors and, uuuh, attach an 40GW CNG power plant? Suddenly clearing out thay landing strip for Windrunner does not seem all that hard ;)
The least-unrealistic approach to go full Munchhausen on getting rotor blades airborne might be assembling them in pairs or triplets and then lifting the contraption with some form of flying tugs that attach near the tips and pulling them into rotation once sufficiently clear from the ground. Like a tip jet rotor tailless helicopter, but with external propulsion units, and powerful enough for static lift during start and touchdown. Would still need per-blade pitch control through the rotation cycle to compensate for the lift difference between forward-going blade and backward-going blade while non-stationary (or compensating wind). Still wildly unrealistic, but other "use the blades to fly themselves!" are even further out I think.
Right, in a windmill they're mounted at an angle for generating rotation. When you mount them on the fuselage you just set them at an appropriate angle for the aircraft.
The airspeed will vary along the length of the blade, necessitating a twist to control the angle of attack for efficiency. A blade/wing that would fly would be stalled at the root and/or supersonic at tip, efficient in only a small ring. That's the twist.
It's interesting that they chose to design a fully enclosed cargo airplane. There was a proposal a while back for a flying "flatbed truck" which could carry bulky cargo on an open platform behind a pressurized cockpit. It seems like a similar design might work here. Fuel consumption would be high due to the extra drag but cargo operations would be easier.
This reminds me of the massive planes that Airbus use to transport wings etc around Europe. I remember seeing one of the early generation many years ago when my dad worked for British Aerospace (who were the British part of the consortium before they sold of their civil division). It was immense.
to appreciate the scale of this new plane, the current (recently destroyed) record holder for the largest cargo plane was An 225 that could hold 70m objects lengthwise. It seems that the newly proposed plane can hold > 100m objects, so that is approximately 50% increase in cargo length. The additional ability to land on packed dirt strips is also a huge plus.
I suspect that the final business model, as hinted by the last sentence in the article, may include significant revenue contribution from transporting other machineries. The recently lost An 225 had a long running operation transporting these, including another jumbo jet. Now that the An 225 is gone, there could be more market for this interesting beast of a plane.
- They have no build facilities, no supply chain, hardly any aircraft design team to speak of.
- They are developing an oversized aircraft for 1 very specific type of cargo, meaning of little use for anything else.
- They raised $100 million.
Sorry, no. This is absolute nonsense, and a waste of money.
To bring a bit of perspective, the development of the Airbus Beluga XL, according to Wikipedia, cost €1 billion. And that was with a design team with years of experience, starting from a fully certified design they knew inside-out, with an existing supply chain, and with knowledge of all the design pitfalls of such a design as they had, you know, already built a Beluga type aircraft before.
There is a reason why the industry says it costs about $10 billion for a clean-sheet aircraft design. And that is for experienced design teams. Agreed, this plane will not have to care for passengers, but that will not reduce the development costs by 90%.
And then we haven't addressed the elephant in the room: the usefulness of an oversized airplane designed to carry an oversized, lightweight cargo, that will probably be of absolutely no use for anything else. It will be extremely costly, and they will not be able to amortize that cost by offering their services to carry different types of cargo.
Sidestepping the discussion about the billions in subsidies that SpaceX got or didn't get, and the technology transfers they might have, or not have benefited from, SpaceX actually has a broad market they can leverage to turn a good profit with the excellent product they designed.
That will not be the case here, at all. Aircrafts are designed for very specific payload/range configurations, and are a lot less competitive once out of that optimum.
A 100 m plane designed to carry 80 tons of blades over 2000 km is of little use to anybody else. It's not anywhere close to the loading capacity of a 747 they are comparing themselves with, and it can't even cross the Atlantic. And that is if they even hit their payload targets at all, which is easier said than done.
And no, it is not magically going to carry 130 tons over 6000 km with a bit of tweaking. That's not how planes work.
Everybody can claim that they are going to make rockets and planes, talk is cheap.
Two of the main benefits startups claim to have is that:
- They can use their small size to play loosely with the rules, move fast, break things, and run around in circles around the sclerosed, unwieldy established players.
- Said established players have left, by their inefficiencies, plenty of low-hanging fruits the new players can use to gain critical mass.
Building and certifying a new aircraft of that size is a multi-billion dollars endeavour because it is difficult, not because the market has consolidated itself to the highest level of inefficiency.
Hitting your payload and range targets is surprisingly difficult, even for companies with decades of experience. And being a few percent off in the single digit range means the difference between something that is usable, and a design that is literally good for the scrapyard.
To compound the problem, playing fast and loose with the rules in that business is when people start dying, with the 737 sagas being the perfect, very actual, illustration of this.
Or A Very Large Quadcopter, because they already know a thing or two about making large rotating airfoils with a hub full of neodynium and coils?
My guess would be range is the limiting factor, helicopters struggle keeping themselves in the air for more than a few hours, before taking into account any meaningful payload. Fixed wing aircraft can achieve so much more range.
Well, there are no large blimps/airships in production. Also, they are quite sensitive to windy conditions, and you want to errect the turbines in very windy places...
On the other side, building a small amount of rather simple airplanes should be quite doable in todays day and age.
Land and sea logistics will always use less carbon per ton than an airplane. Using a ship to move offshore cargo is probably going to be 1/100th of the carbon footprint of an extravagant airplane.
Well, certainly there will be soon the wish to transport even larger blades. But if the first gen works out and is successful, then they could build an even longer airplane. As most of the Airplane is basically an aerodynamic fairing around the blades, I don't see why not.
I would think a 'fleet' or swarm of lifting vehicles, airships, drones, etc would make more sense than pioneering an entire custom airplane of such scale.
Given that lifting fleets/swarms don't exist, I think that scaling up a conventional aircraft is actually lower risk. Aside from the technical risk getting lifting fleets/swarms certified would be an extremely novel development. Super jumbo aircraft should have a much more smooth regulatory pathway.
While the physical scale of the aircraft is huge, its actual lift capacity isn't groundbreaking. They quoted 80 tons. That's well within the capacity of today's military strategic lift (C-17s can lift 85 tons). And in terms of size comparison, compared to the An-225 (RIP), the quoted dimensions are 108m (Windrunner) vs 84m, 24m high 18m, 80m wingspan vs 88m.
Certainly a non-trival increase in linear size, but it's not a magnitude leap either.
This was one of my own first two thoughts on TFA, the other being that given this as a proposal, one clear advantage of offshore windfarms is that transporting construction modules to the site should be vastly more straightforward: ship or barge towers and blades directly. This could work for farms both in ocean waters or large lakes.
But other than that, the idea that blades might be shipped by some other mode (overland, barge, special-purpose rail, possibly) to a proximate location, then drone-ferried to the actual construction site ... seems a more viable option.
And yes, drone lift-swarms comprised of multiple units yoked together and lifting a blade or set of blades ... seems more viable. Distances travelled should be relatively short (roughly, 10s to a few 100s of km), transport speeds need not be high, and flight profiles could be quite low altitude.
Even if not drones, a ferry aircraft that could transition between vertical and horizontal flight modes, similar to the Bell Boeing V-22 Osprey, but, say, with an open cargo frame, might be a better fit. These could take off from a standard runway if desired, but also land and take off vertically from a cleared landing zone (potentially a barge or floating dock, in the case of offshore farms).
Airships might be another option, though the ballast problem (as cargo is offloaded, an equivalent weight of ballast would need to be onboarded to prevent the airship from floating away), and poor handling in even modestly windy conditions (likely around wind farms) would probably prove problematic.
Same here. I understand it would be dangerous to transport something so large, exposed to the wind. But couldn't they partially assemble it and then do the last parts on-site?
A turbine blade isn't something that you can partially assemble. They looked into building temporary blade factories on site but the analysis indicates that a custom airplane is cheaper and less risky.
Just that the strongest helicopter on the page can only lift 20 tons. Of course, it would be sufficient to lift a single blade in one go. Still, that would be a very complex operation requiring very good weather.
