How the biggest plane would supersize wind energy
wsj.com
wsj.com
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.
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.
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)
https://electrek.co/2023/09/05/worlds-largest-wind-turbine-r...
And it supposedly even did product 16MW average across a day, once! Albeit ahhh, they ran it during a typhoon!
> On September 1, the 16 MW wind turbine came up against wind speeds of a peak of 53mph in the face of Typhoon Haikui,*
If they've raised $100M+, I assume these questions have been asked, but I'm just generally skeptical that the math makes sense.
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.
Direct-to-tower delivery. Removes the need for transport on the ground for the last miles and the need for a crane.
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.
> 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.
By comparison a commercial jet takes ~20 years to emit 1 million tons of CO2. https://www.reuters.com/business/aerospace-defense/boeing-je...
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):
8TJ / (10[MW] * 25% * 3600[s/h] * 24[h/d])
"Simultaneously, Radia is developing a world-class portfolio of wind energy projects to leverage this solution"
So they just need to deliver one of those projects for the carbon to be offset.
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.
I'm pretty pessimistic about climate change. But the way wind and solar just keep getting cheaper and better gives me a certain amount of hope.
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.
At 150m above ground where there rotor hub sits wind blows all the time.
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!
(It's an honest question; you must have thought of it, of course.)
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).
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.
Of course, problems can scale faster the quadratically, transportation is one of them.
(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]"
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.
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.
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.
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.
It can fit multiple smaller blades but only 1 very large blade.
Slap them on a smallish fuselage, fly to the destination, truck the fuselage back.
It would need half the turbines to turn the other way around to have left/right wings, doubling tooling cost for production.
And it would need a runway of appropriate width, but maybe they could be mounted at significant v-shape.
Return trip not on the ground. The fuselage, engines, ... would still be massive, but with a set of small "normal" wings.
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.
Living near an Airbus factory I spot them frequently here. Impressive plane. Also pretty cute.
In my case is was the earlier Super Guppy https://en.wikipedia.org/wiki/Aero_Spacelines_Super_Guppy
Dad used to work at the British Aerospace Filton site. I absolutely loved getting to go to their family open day.
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 are starting from scratch.
- 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.
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.
As far as "turning a good profit", well, you might be right but that very much remains to be seen at this stage?
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.
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.
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.
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.
>Helicopters are more costly than airplanes, and flying with a dangling blade designed to catch wind would prove complex and dangerous.
Um, why not enclose the blade in a tube?
There are heavy-lift helicopters that can go 170 mph and carry 40 tons. No runway required.
Looking at the list below they mention that the helicopters can accomodate the weight in total but not externally.
So could be that the lifting mechanism is the limiting factor.
https://www.fairlifts.com/helicopters/the-top-10-heavy-lift-...
Seems like we’re pretty close.