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You can see technical drawings of their device in their patent (US 11391262): https://patentimages.storage.googleapis.com/26/02/b1/f9004c8c6a47fb/US11391262.pdf

by mrb 4y ago

You can see technical drawings of their device in their patent (US 11391262): https://patentimages.storage.googleapis.com/26/02/b1/f9004c8c6a47fb/US11391262.pdf https://patentimages.storage.googleapis.com/26/02/b1/f9004c8... The article calls it "motionless" and "bladeless", but this is patently (hah!) false. There are actually spinning blades... See figures 16c, 16d, 19 in the patent: the blades are in the turbine underneath the central body element. At first sight, given the quantity of material used in the device for the foils and central body, relative to the small turbine size, it's hard to intuitively picture how or why it can be more efficient than a regular wind turbine built using the same amount of material which could, therefore, have much larger blades. Edit: in fact the inventor of the device, Carsten Hein Westergaard, previously published results from a prototype https://iopscience.iop.org/article/10.1088/1742-6596/2265/4/042065/pdf https://iopscience.iop.org/article/10.1088/1742-6596/2265/4/... in which he claims the prototype achieved an efficiency of 42% of Betz limit, which is inferior to standard utility-scale turbines (Wikipedia claims 75-85% but I haven't checked sources: https://en.wikipedia.org/wiki/Betz%27s_law#Betz's_law_and_coefficient_of_performance https://en.wikipedia.org/wiki/Betz%27s_law#Betz's_law_and_co... ) so that seems to confirm my intuition.

foxyv 4y ago
I think they mean that the blades are not visible from ground level. A big problem with wind turbines in residential areas is the motion is really distracting and shadows on windows can be annoying as heck. Although looking at the patent, this thing would be stopped up with dead squirrels on my house in ten minutes unless they added some grating to the inlet.
- hoosieree 4y ago
  The blades are spinning so fast cleanup becomes a simple matter of wiping off the red mist.
taftster 4y ago
Just to ask. Do you think the housing of the turbine would somehow "channel" the wind it collects into the blades? And therefore increase the performance or yield against the size of the blades? Maybe in this way, the comparison is legitimate, that a smaller turbine blade (as in this case) can collect more wind? I'm honestly not sure if that holds up properly, like from a true physics point of view. But it kind of makes sense from intuition. It would seem you'd get quite a fast moving turbine blade with this configuration.
- mrb 4y ago
  That's entirely the point of Aeromine's invention: the foil and body channel the wind (by decreasing air pressure between the foils) and this increases the speed of wind at the turbine. But per my edit, it doesn't seem sufficient to beat the efficiency of traditional wind turbines. I suppose that's why the company tries to focus on other advantage (less noisy, better aesthetics).
  - earleybird 4y ago
    If I remember correctly they claim something like 40% of a conventional turbine, so it doesn't beat a conventional turbine in a classic setting however it may work well enough in a residential/light commercial setting. It really seems like a reverse Dyson bladeless fan.
    - nerpderp82 4y ago
      Dyson Jet https://www.youtube.com/watch?v=jbXJa8osys0 https://www.youtube.com/watch?v=jbXJa8osys0 'Bladeless' airplane turbine https://www.youtube.com/watch?v=bPZI6XoHi10 https://www.youtube.com/watch?v=bPZI6XoHi10
    - merely-unlikely 4y ago
      > 40% of a conventional turbine If I'm not mistaken, a conventional turbine can turn to face the wind but these can't. That could significantly impact actual performance.
  - saalweachter 4y ago
    I could see another advantage for residential use -- you should be able to make the failure mode for this style safer, because you are already wrapping the turbine in metal. It should also be easy to close the channel and stop wind from getting to the blades which is also not possible with traditional designs. But yeah, I'm leaning with the other comments in this thread that these guys sound too shifty in the way they're promoting this, and it makes me suspicious of the utility of the product.
- 4y ago
cbhl 4y ago
Sounds like the inverse of those "bladeless" dyson fans where the blades are hidden inside the body/base. Might still be a net safety improvement?
abc_lisper 4y ago
This is like the Dyson fan in reverse. Look ma, no blades - well there are, just not behind/facing the wind.
laverya 4y ago
There's a difference between thermodynamic efficiency and cost efficiency. Extracting 40% of the energy in the wind for $500 is very often going to be better than extracting 70% for $5000.
- dzhiurgis 4y ago
  Yes but then location comes into play - offshore power needs to be delivered!
rootusrootus 4y ago
> inferior to standard utility-scale turbines But isn't this supposed to be a rooftop wind turbine? I'm curious how it compares to other small turbines that I could conceivably put on my own property.
Obi_Juan_Kenobi 4y ago
> efficiency of 42% of Betz limit, which is inferior to standard utility-scale turbines That isn't surprising at all; wind generation scales very very well with larger size. If it actually achieved 42% at that size, it would still be a major innovation. But that's also a strong claim that requires very strong evidence. The reasons for inefficiency at smaller scales are fundamental: higher drag to lift. Essentially what they're doing is using the existing building as part of the device to direct wind. This is not a new idea, and in favorable conditions you can get some impressive numbers. But in real life.. https://www.renewableenergyworld.com/storage/small-wind-turbines-driving-performance-52701/ https://www.renewableenergyworld.com/storage/small-wind-turb...
7952 4y ago
But it is not about power per kg of materials but power per $ spent. You may be able to fabricate the wing elements out of cheaper and heavier materials using simpler methods.

by mrb 4y ago

foxyv 4y ago

I think they mean that the blades are not visible from ground level. A big problem with wind turbines in residential areas is the motion is really distracting and shadows on windows can be annoying as heck. Although looking at the patent, this thing would be stopped up with dead squirrels on my house in ten minutes unless they added some grating to the inlet.

hoosieree 4y ago
The blades are spinning so fast cleanup becomes a simple matter of wiping off the red mist.

taftster 4y ago

Just to ask. Do you think the housing of the turbine would somehow "channel" the wind it collects into the blades? And therefore increase the performance or yield against the size of the blades? Maybe in this way, the comparison is legitimate, that a smaller turbine blade (as in this case) can collect more wind? I'm honestly not sure if that holds up properly, like from a true physics point of view. But it kind of makes sense from intuition. It would seem you'd get quite a fast moving turbine blade with this configuration.

mrb 4y ago
That's entirely the point of Aeromine's invention: the foil and body channel the wind (by decreasing air pressure between the foils) and this increases the speed of wind at the turbine. But per my edit, it doesn't seem sufficient to beat the efficiency of traditional wind turbines. I suppose that's why the company tries to focus on other advantage (less noisy, better aesthetics).
- earleybird 4y ago
  If I remember correctly they claim something like 40% of a conventional turbine, so it doesn't beat a conventional turbine in a classic setting however it may work well enough in a residential/light commercial setting. It really seems like a reverse Dyson bladeless fan.
  - nerpderp82 4y ago
    Dyson Jet https://www.youtube.com/watch?v=jbXJa8osys0 https://www.youtube.com/watch?v=jbXJa8osys0 'Bladeless' airplane turbine https://www.youtube.com/watch?v=bPZI6XoHi10 https://www.youtube.com/watch?v=bPZI6XoHi10
  - merely-unlikely 4y ago
    > 40% of a conventional turbine If I'm not mistaken, a conventional turbine can turn to face the wind but these can't. That could significantly impact actual performance.
- saalweachter 4y ago
  I could see another advantage for residential use -- you should be able to make the failure mode for this style safer, because you are already wrapping the turbine in metal. It should also be easy to close the channel and stop wind from getting to the blades which is also not possible with traditional designs. But yeah, I'm leaning with the other comments in this thread that these guys sound too shifty in the way they're promoting this, and it makes me suspicious of the utility of the product.
4y ago

cbhl 4y ago

Sounds like the inverse of those "bladeless" dyson fans where the blades are hidden inside the body/base. Might still be a net safety improvement?

abc_lisper 4y ago

This is like the Dyson fan in reverse. Look ma, no blades - well there are, just not behind/facing the wind.

laverya 4y ago

There's a difference between thermodynamic efficiency and cost efficiency. Extracting 40% of the energy in the wind for $500 is very often going to be better than extracting 70% for $5000.

dzhiurgis 4y ago
Yes but then location comes into play - offshore power needs to be delivered!

rootusrootus 4y ago

> inferior to standard utility-scale turbines But isn't this supposed to be a rooftop wind turbine? I'm curious how it compares to other small turbines that I could conceivably put on my own property.

Obi_Juan_Kenobi 4y ago

> efficiency of 42% of Betz limit, which is inferior to standard utility-scale turbines That isn't surprising at all; wind generation scales very very well with larger size. If it actually achieved 42% at that size, it would still be a major innovation. But that's also a strong claim that requires very strong evidence. The reasons for inefficiency at smaller scales are fundamental: higher drag to lift. Essentially what they're doing is using the existing building as part of the device to direct wind. This is not a new idea, and in favorable conditions you can get some impressive numbers. But in real life.. https://www.renewableenergyworld.com/storage/small-wind-turbines-driving-performance-52701/ https://www.renewableenergyworld.com/storage/small-wind-turb...

7952 4y ago

But it is not about power per kg of materials but power per $ spent. You may be able to fabricate the wing elements out of cheaper and heavier materials using simpler methods.