New Bladeless Design for Wind Energy

[Jimster41]

it is a short time power cycle, every oscillation goes from 0 to about 10X average power - 2 x per cycle. So if you want 100KW avg output many of the components need to be sized to handle 1MW peak power...a significant cost driver - and then there is lifetime - determined by the Temp Swing in the devices, delta T of 60-80C not uncommon -- with a 1-2 Second oscillation you get to millions of thermal cycles very quickly, all you can do is throw more silicon at it. Even putting the energy into a battery would "work" but they also have finite life. Even traditional wind turbines have power electronics lifetime much shorter then expected due to sub-harmonic power surges.

Is there are circuit/control design that is standard in such a high voltage? high variance input situation. I'd love to have a better sense of where the state of the art is in terms of unit and system control for these kinds of machines. Like is anyone using them in an "integrated array" to distribute load variance across a wider field, reducing per unit variance? Anything crazy like that? maybe another thread though. Any reference pointers would be welcome.

 

[Windadct]

In general the motion is converted to a traditional rotary motion for a number of reasons, but cost, efficiency and availability are big. Any back and forth motion develops mechanical stress, more so than the rotating machines( even humans - there are 6-7 hour bike races but not too many 5 hour running ones). As for the circuitry - typically convert to DC and then invert to AC for Grid tie... really is no magic there - complexity adds cost. To "spread out" the load just means you are adding silicon, increasing cost and in many cases losses.
I like stepping back and looking at the whole system and say - does this make sense... case in point http://www.oceanpowertechnologies.com/apb-350 - look at the average power and then the weight!
In this case for remote (middle of the ocean) power source you have a serious premium and can "afford" this - but I have never seen a large scale roll out on this that makes sense.

 

[dlgoff]

I'd guess they use some sort of wobble plate to vary reluctance and modulate a magnetic field.

My guess was maybe something like they use here.

 

[Jimster41]

Their website is pretty vague on the power conversion technology. But I only looked a little. Wonder if there are any papers out there attributable to founders etc.

They claim no moving parts, No friction.

Mabye it's a magnet that just wobbles in an electro-magnetic field? The mechanical resistance powering the oscillator would really be contained in the stiffness of the pole (pretty durable right)? And the main mechanical action would be in immobilizing the fulcrum of the pole (also pretty simple and likely durable)? But it does seem like it would be a very dirty signal, unless the oscillation is attracted to some stable period above a minimum level of input, and zero below.

Put up a few of different sizes, connect their fields, hmm...

 

[Windadct]

Wave action is incredibly dynamic and random, and then the marine environment. Wave energy has great potential, but due to the challenges IMO the ultimate solution will be a work of art - creative, not a brute force mechanical structure. When someone has a good solution - it will be so clearly elegant everyone will look at it and know.
Renewables are a funny field - I personally am 100% for true renewable solutions - but the amount of nonsense only hurts the mission(in EE parlance we call this noise) - solar highways, wave energy (today), alternative wind solutions, they are all sucking in large scale dollars for what should be small scale research and it drives me crazy - giving the whole mission a very bad name.
In the end there is no perfect solution - there are a LOT of Texas ranchers today in love with wind that 10-15 years ago would have almost spit in your face if you proposed such liberal garbage on their land.

 

[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.