New Bladeless Design for Wind Energy

[mheslep]

Betz still applies. Power(max) = (cross section)(fluid velocity)^³(fluid density). Economically useful wind velocity requires elevation of 30-50 meters, so a tower is required. The cost of a tower must be justified by significant power production. I'm skeptical that a device with a cross section a couple orders of magnitude less than than that swept by rotors can ever justify the cost of a foundation and large steel tower. Perhaps some of these Vortex devices can be affixed to existing high structures - tall buildings, stadiums.

 

[at94official]

I am not sure the claim they "only" capture 30% less energy than a bladed turbine is plausible. I have the feeling, 'On a good day, they can capture as much as 10% of a regular turbine,' would have been more accurate. Depends on how they're comparing them. Regardless, they strike me as the sort of design that would become cheaper and cheaper to manufacture the longer they had to work out the bugs and streamline the process.

I couldn't disagree more about this. It will absolutely help us generating electricity in a very innovative way. And the fact that you don't need a lot of space if you will have this 41 foot marvels for your wind farm.

 

[Jeff Rosenbury]

Betz still applies. Power(max) = (cross section)(fluid velocity)^³(fluid density). Economically useful wind velocity requires elevation of 30-50 meters, so a tower is required. The cost of a tower must be justified by significant power production. I'm skeptical that a device with a cross section a couple orders of magnitude less than than that swept by rotors can ever justify the cost of a foundation and large steel tower. Perhaps some of these Vortex devices can be affixed to existing high structures - tall buildings, stadiums.

One thought is to place them on top of light poles in car parks.

The poles would need to be taller, but with taller poles, we would need less of them (for lighting). Since it seems most of the U.S. is now a parking lot anyway...

 

[rollingstein]

The poles would need to be taller, but with taller poles, we would need less of them (for lighting). Since it seems most of the U.S. is now a parking lot anyway...

How tall a pole did you have in mind?

 

[Jeff Rosenbury]

How tall a pole did you have in mind?

The exact value would depend on how the equations worked out (cost, energy/meter height, etc.), but placing the lights at 12-15m seems about right. The vortex shredder (cool name, I just invented it) would start there. Of course that moves the electronics package up near the lightbulb... lots of trade offs.

 

[jim hardy]

And I can imagine the sync is because the pilot's eye needs to build a silhouette, or something like that, which would not be served by other patterns. But the effect on the ground is pretty brutal.

Not sure why synchronized though.

Imagine the view from above at night... synchronizing the lights makes it apparent where are the boundaries of the area to be avoided.
I've driven past those huge farms along I80 in Wyoming at night. You only have to see one cycle of the strobe to know how long is the string of windmills.

At the wind conference in Orlando last week the lighting manufacturers were showing off their new radar system that turns on the strobes only when it detects an aircraft in the vicinity.

http://www.nawindpower.com/issues/NAW1406/FEAT_05_Obstruction-Lighting-Advances-Make-Turbines-Better-Neighbors.html

A wind farm’s blinking red obstruction lights are a necessary safety measure to ensure wind turbines – which can measure from 400 to 550 feet in height – are visible to pilots and their aircraft. However, the intensity of these beams can also be an irritant to nearby residents, as the lights blink in contrast against the night sky. But thanks to advances in obstruction lighting technology, suppliers are introducing new products that flash only when necessary. The improvements are part of a growing trend to make obstruction lighting programs less intrusive.

and from
http://www.airporttech.tc.faa.gov/safety/downloads/TN05-50.pdf

 

[rollingstein]

Imagine the view from above at night... synchronizing the lights makes it apparent where are the boundaries of the area to be avoided.

I wonder how they synch all those lights? Any idea? An accurate timer?

Radio links? Master / slave flashing using a light sensor? Line freq. to synch?

 

[Jimster41]

I keep picturing cat-tails bobbing in a stiff wind.

I can imagine a specifically stiff pole (like a blade of grass, or a cattail), fixed at the bottom, with a ring of magnets around it's "ankle" (in a gimbaled weather resistant housing) .

I don't know squat about the physics of the energy conversion, but if it is just a pole with a vortex inducing shape that sticks up into the wind-velocity gradient, how does the estimation of energy conversion even work out? Thinking about the fluid process of a periodic vertical vortex development/shedding cycle, wouldn't you have to sort of integrate the force applied by the vortex over it's development cycle, against the vertical area of contact for that whole cycle, an area of contact that moves farther out the lever arm as the vortex grows (Assuming the vortex starts low and ends high). This seems like a pretty different process than an airfoil? I got the impression that Betz limit is is w/respect to an idealized disk processing wind. Doesn't the vortex process involve a thermal gradient also? I can imagine there are reinforcing non-linearities in the oscillator and the driving force, like vortices that are forced to develop faster by the return action from the last "separation". But the destructive harmonics that might prevent organized vortices from forming seem problematic.

Also I keep wondering how the problem is shifted if you are looking at an array of them processing the same flow in an emergent way - the way a stand of cattails will do.

If they are claiming no-friction, no moving parts, they can't be using a rotating motor design right?
Are there electric generators that are non-rotating, that can develop emf just based on linear oscillation?
Maybe the oscillation is rotational and not just linear. I mean cat-tails do more rotate (in long ellipses) than "bob". And that might help manage destructive fluid harmonics, a bit of stabilizing geometry in the feedback.

 

[Jimster41]

Imagine the view from above at night... synchronizing the lights makes it apparent where are the boundaries of the area to be avoided.
I've driven past those huge farms along I80 in Wyoming at night. You only have to see one cycle of the strobe to know how long is the string of windmills.

At the wind conference in Orlando last week the lighting manufacturers were showing off their new radar system that turns on the strobes only when it detects an aircraft in the vicinity.

http://www.nawindpower.com/issues/NAW1406/FEAT_05_Obstruction-Lighting-Advances-Make-Turbines-Better-Neighbors.htmland from
http://www.airporttech.tc.faa.gov/safety/downloads/TN05-50.pdf
View attachment 84174

Very interesting! We puzzled over exactly how they are synchronized for waaay too long. I think we gave up imagining anything clever, got to be some simple active control system?

Gotta love industry magazines! I find they record, in a nifty way, the simultaneous attempts to solve the economic and engineering problems. Very different from academic papers on theory (which are cool in a whole different way of course) and from books about the big picture. Industry rags have to be taken with salt, but I always get encouraged when I look at them, at all the different clever efforts out there... more importantly I think they represent a specific view of the "edge" of what's actually happening in a particular domain, that you just can't get anywhere else.

 

[mfb]

The exact value would depend on how the equations worked out (cost, energy/meter height, etc.), but placing the lights at 12-15m seems about right. The vortex shredder (cool name, I just invented it) would start there. Of course that moves the electronics package up near the lightbulb... lots of trade offs.

That does not work, the device needs a solid anchor that can handle the large torque. You would have to make the light-poles much more massive, which makes it impractical. You could mount the light at the top of a wobbling vortex device, of course, but that would have ... unfortunate side-effects.

 

[rollingstein]

That does not work, the device needs a solid anchor that can handle the large torque.

It is ironic how much effort goes in protecting Chimneys etc. from the effects of vortex shedding. All those strakes and tuned mass dampers etc.

I think people are underestimating the difficulty in scaling this up. Sure you can easily anchor a 20 feet fiberglass pole and allow it to sway but now you make that 60 feet tall and add the weight of the equipment etc, and you are looking at some very serious anchoring and stiffness / buckling issues.

If the promoters of the idea have thought these issues through it isn't clear from the stuff on their website at least.

 

[Delta31415]

seems like a good idea due to being cheap.

 

[jim hardy]

I think we gave up imagining anything clever, got to be some simple active control system?

i'd not have thought of synch-ing the lights with GPS.. Ahhh these young folks and their gadgets !

http://www.windpowerengineering.com/design/wind-basics/obstruction-lights-101/

An internal enclosure houses the flash circuitry and GPS synchronization circuitry, so it can synch up with other lights of the same model in the vicinity.

I don't know how (or if) they communicate with one another, but should be able to find out.As for working principle of this vortex shedder -

redwood trees pump water up hundreds of feet by something akin to peristaltic action in their fibers as they sway in the breeze, opposite sides of the tree seeing alternating tension and compression.
Similar alternate stretching and relaxing forces on opposite sides of their fiberglass pole as it bends could be mechanically transmitted into a magnetorestrictive mechanism to modulate a magnetic field...
i initially dismissed that in favor of modulating an air gap because i thought maganetorestriction would be utterly impractical for power generation
but as usual, when i looked sure enough somebody is doing it.

If you want to guarantee something will happen,
just publicly proclaim it impossible.

http://oscillapower.com/wp-content/uploads/2013/09/MTNotes_11-14.pdf

Our iMEC technology platform enables Fe-Al alloys to provide the required performance for power genera tion. The driving magnetomotive force is provided by permanent magnets, which typically make up less than 1% of the generator mass.
Tension changes on this circuit result in changes in magnetic permeability of the Fe-Al rods, resulting in changes in flux density within the circuit—all with no perceptible relative motion (less than 200 ppm of deformation). Electricity is generated by electromagnetic induction, using copper coils wound around the alloy rods.
The pre-compressed rods never go out of compression during normal operation. During extreme conditions that result in very high tension, safety bolts are engaged that pick up the excess mechanical load. These features are intended to eliminate fatigue-related failures. Magnetostrictive harvesters have been shown to have greater than 80% mechanical to electrical efficiency, a capability that should enable us to achievehigher efficiencies than have previously been demonstrated for wave energy converters (WEC)

see also http://revolution-green.com/magnetic-energy-harvesting-using-magnetostriction/

I don't know if that's what these guys are doing but it's plausible.

in light of above, i hereby publicly declare it impossible that i win the lottery.

old jim

 

[rollingstein]

For some probably idiotic reason there are huge FAA type signal lights on top of each one. And they all blink on at once. We pondered and pondered how this is achieved, and the why.. but the effect at night is... frankly hellish. I couldn't live with it. Good only if you wanted read a book to Satan, three words at time.

@Jimster41

Maybe this extract from the FAA Study explains why those lights have been fitted so bright & annoying.

"Nighttime wind turbine obstruction lighting should consist of aviation red-colored lights, either flashing or steady-burning, only. Minimum intensities of 2000 candelas for nighttime red flashing or strobe lights (L-864) are required. The standard FAA L-810 steady-burning obstruction light, with an intensity of approximately 32 candelas, is of very little use."

The wind turbine warning lights seem mandated to be approximately 60x as bright as a regular obstruction light for aviation.

I wonder why this rule is so?

 

[zoobyshoe]

...redwood trees pump water up hundreds of feet by something akin to peristaltic action in their fibers as they sway in the breeze, opposite sides of the tree seeing alternating tension and compression.
Similar alternate stretching and relaxing forces on opposite sides of their fiberglass pole as it bends could be mechanically transmitted into a magnetorestrictive mechanism to modulate a magnetic field...
i initially dismissed that in favor of modulating an air gap because i thought maganetorestriction would be utterly impractical for power generation
but as usual, when i looked sure enough somebody is doing it...

Something like this would be perfect for these oscillating poles. Come to think of it, they could incorporate this into any thing or structure that's under stress from wind, from street lights to skyscrapers.

 

[Jeff Rosenbury]

@Jimster41
I wonder why this rule is so?

As a guess I would think the rotating blades might cause a visual effect that looks similar to twinkling in low light conditions. This might mislead pilots into thinking the rotors are much farther away than they really are. With strong lights this would be mitigated, at least at close range where it matters.

 

[rollingstein]

As a guess I would think the rotating blades might cause a visual effect that looks similar to twinkling in low light conditions. This might mislead pilots into thinking the rotors are much farther away than they really are. With strong lights this would be mitigated, at least at close range where it matters.

Perhaps what we need is blade-tip integral lights. That would let them keep a low intensity (to not bother locals) as well as avoid the confusing twinkling effect.

In fact, I suspect you could get a nice, steady ring like effect due to the rotation.

Probably would have to be incorporated by the manufacturer during blade design to avoid any aerodynamic losses.

 

[Jimster41]

Perhaps what we need is blade-tip integral lights. That would let them keep a low intensity (to not bother locals) as well as avoid the confusing twinkling effect.

In fact, I suspect you could get a nice, steady ring like effect due to the rotation.

Probably would have to be incorporated by the manufacturer during blade design to avoid any aerodynamic losses.

maybe passive solar?

It is ironic how much effort goes in protecting Chimneys etc. from the effects of vortex shedding. All those strakes and tuned mass dampers etc.

I think people are underestimating the difficulty in scaling this up. Sure you can easily anchor a 20 feet fiberglass pole and allow it to sway but now you make that 60 feet tall and add the weight of the equipment etc, and you are looking at some very serious anchoring and stiffness / buckling issues.

If the promoters of the idea have thought these issues through it isn't clear from the stuff on their website at least.

I was thinking that all the electronics were near the ground. The stiffness and shape of the pole only has to solve the problem of motion under vortex development and shedding, durably?

 

[Jimster41]

I was wondering about how you would "feather" these things to dump wind in a storm for instance. And it occurred to me they could practically be flags, or sails?

 

[Jeff Rosenbury]

I was thinking that all the electronics were near the ground. The stiffness and shape of the pole only has to solve the problem of motion under vortex development and shedding, durably?

That might work as long as the electronics package keeps working and absorbing the energy. But when the electronics are shut down/broken, the pole is just another pole and needs to survive on its own.

 

[Jimster41]

That might work as long as the electronics package keeps working and absorbing the energy. But when the electronics are shut down/broken, the pole is just another pole and needs to survive on its own.

yeah, fair enough. That's what got me wondering about "soft" designs. Just a thin rubber mast up which you could run a stiff curved sail designed to create and dump vortices. Or a sail that folds at a pressure limit.

 

[zoobyshoe]

yeah, fair enough. That's what got me wondering about "soft" designs. Just a thin rubber mast up which you could run a stiff curved sail designed to create and dump vortices. Or a sail that folds at a pressure limit.

There's this other non-rotary design out there:

http://www.gizmag.com/saphonian-bladeless-wind-turbine/24890/

 

[nsaspook]

Seems full of hot air.
http://www.kcet.org/news/redefine/rewire/wind/bladeless-wind-turbine-too-good-to-be-true.html

 

[Jimster41]

Found this, I can't see the figures, sounds like Vortex.

http://www.google.com/patents/WO2012142563A1?cl=en

Pretty recent application... Northeastern Universtity, sleepers man, watch out.

 

[Jimster41]

Seems full of hot air.
http://www.kcet.org/news/redefine/rewire/wind/bladeless-wind-turbine-too-good-to-be-true.html

Yeah, doesn't seem to improve on the main complexity issue, at least not in a way that would appear to offset some amount of efficiency hit.

 

[jim hardy]

Seems full of hot air.
http://www.kcet.org/news/redefine/rewire/wind/bladeless-wind-turbine-too-good-to-be-true.html

Some folks harvest wind, others harvest investors.

 

[mfb]

Another concept
They all don't look very efficient. And this one even needs water.

 

[jim hardy]

Another concept
They all don't look very efficient. And this one even needs water.

from their link:

A mixture of 30% ethanol and 70% demineralized water appeared to be the most suitable spraying liquid.

It'll be perpetual happy hour downwind ! Got juniper ?

 

[RaulTheUCSCSlug]

Won't the alternator need some maintenance? I'm also curious to see how these structures hold up to rain. They seem very interesting, and wouldn't mind doing a DIY one in my backyard this summer for fun!

 

[Thermo]

Good news for birds.

 

[Jimster41]

Reminds me of that movie "Those Magnificent Men and Their Flying Machines".

Couple of thoughts keep recurring while reflecting on this thread.

Why has't nature come up with something as efficient as the rotating airfoil design? Lots of obvious answers follow on but it seems like an interesting way of thinking about the problem; to step back and look at it from a wider systems perspective.

How does per unit efficiency interact with system efficiency "footprint" in all relevant dimensions: size, cost of material, cost of construction, efficiencies of scale, durability and cost of maintenance over time, re-usability, quality of energy relative to use requirement, etc, etc? I would guess there are paradigms/tools for guesstimating. I am sure someone somewhere at some AE company has thought long and hard about how to enumerate those and get at some sensitivity matrix.

Or maybe it's a problem of identifying the key constraint to empirical discovery across what are actually impenetrably complex permutations. My guess is that the generator/alternator/storage mechanism is that. If someone could design a very cheap, incrementally scalable electric, or chemical, or electrochemical (or all of the above) energy converter that was not necessarily dependent on smooth high quality rotating mechanical energy, but more on any mechanical energy, natural mechanical noise, even if it was not terrifically efficient, then the question of how to "best" couple it to energy sources found in nature could be left as open as it probably should be.

The "compression engine" mentioned above is very interesting in this way.

 

[HyperTechno]

These too are bladeless wind electricity generators. What kind of mechanism is used here? That should be different from what mechanism used on pole generators.

 

[Jeff Rosenbury]

I like the one that looks like a cell phone. I assume it's a version of mfb's electrostatic generator.

I like it because it could be placed in fields and potentially used to irrigate crops or possibly in a water park as an artistic feature. In the southwest it might be used as a house cooler. It looks like it could be a nice, dual use generator.

 

[Dvorak]

In the long term, this is the future of wind power. They are cheap and look nice. They work similarly to trees swaying in the breeze which means they are environmentally sound.

In the short term, no numbers means all hype. The claim of no moving parts is unrealistic. The poles are supposed to vibrate, which means motion. Further vibrational movement is typically more damaging to equipment than circular movement. Permanent magnets lose magnetism when moved through fields repeatedly, and electromagnets need power. Their performance in storm conditions wasn't mentioned which can't be a good sign.

There are solutions to all these problems, but since the promoter didn't address them, I'm guessing he hasn't found them yet.

I hope they can get them to work, but I doubt they can.

This bladeless windmill works by movement of the pole due to the wind, then it is supposed to be flexible. What do you think is the material it will be made of? Secondly by the picture from the site we can know that it has less surface area, so the velocity of wind must be really high to make this windmill wag like the trees. Makes no sound is impossible, it is also probable that this new kind of windmill will make more sound than the one used presently, because the whole pole oscillates making its material move to and fro thus creating vibrations in the air.

 

[HyperTechno]

View attachment 85193 View attachment 85192 View attachment 85191
These too are bladeless wind electricity generators. What kind of mechanism is used here? That should be different from what mechanism used on pole generators.

Can someone please explain the mechanism of the wind electric generators that I've shown in my previous reply?