New Bladeless Design for Wind Energy

[zoobyshoe]

Sounds pretty good:

Vortex claims that energy produced by its turbines will cost around 40 percent less than energy made from wind turbines that are operating today. A large part of that cost reduction comes from maintenance — since the Vortex doesn't have moving parts or gears, it should last longer and it won't require periodic lubrication. The simpler design also means that manufacturing costs are about half that of a traditional wind turbine (those massive blades are expensive). That said, Vortex tells Wired that its bladeless design captures around 30 percent less energy than a regular turbine. The company does note, however, that it's possible to fit more of the Vortex models in the same area. And, as a bonus, the bladeless turbines are silent.

http://www.theverge.com/2015/5/16/8...s-wind-turbines-shake-to-generate-electricity

I like this particular idea a lot. With no blades, these take up much less space, and the claims about them being 50% less expensive to make, and lower maintenance, seems completely plausible. They would be a good design for powering cold outposts that are frequently overcast, but windy. The thing I would most like to find out about them at this point is how they're affected by snow. Ever since I experienced Minnesota, I've been mulling over the idea of a device to generate extra electricity from the cold winter winds, which is when you need it the most there. The trouble with every idea I had was clogging from snow and ice build up. These look like they'd shake it off.

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.

 

[Ryan_m_b]

The lower maintenance seems quite interesting. I'd like to see some proper figures of how much energy they can produce and what a farm of them could do given minimum separation distances. I half-hope that this could get round the weird Nimbyism a lot of people here in the UK have because they find the spinning turbines ugly. Conceivably these could be any colour, paint them brown and stick a few fake branches on them and they'll blend right in with the view.

 

[zoobyshoe]

The lower maintenance seems quite interesting.

Yes, they look intriguingly simple.

I'd like to see some proper figures of how much energy they can produce and what a farm of them could do given minimum separation distances.

Absolutely. The problem with most of these inventions is that the inventors grossly over-estimate the efficiency. The things works, but ends up not being worth the effort to implement.

I half-hope that this could get round the weird Nimbyism a lot of people here in the UK have because they find the spinning turbines ugly. Conceivably these could be any colour, paint them brown and stick a few fake branches on them and they'll blend right in with the view.

Hah hah! But then you might get complaints about an introduced species.

 

[Jeff Rosenbury]

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.

 

[zoobyshoe]

Further vibrational movement is typically more damaging to equipment than circular movement.

Very good point. That didn't occur to me.

Permanent magnets lose magnetism when moved through fields repeatedly...

From ferroceramic magnets forward to rare Earth types, this is not a problem. These kinds hold their magnetism beautifully and were engineered with that issue in mind. Loss of magnetism was only ever an important problem back in the days of high carbon, hardened steel magnets.

and electromagnets need power

Not necessarily. There is the phenomenon of the "self-exiting dynamo".

Modern generators with field coils are self-excited, where some of the power output from the rotor is used to power the field coils. The rotor iron retains a magnetism when the generator is turned off. The generator is started with no load connected; the initial weak field creates a weak voltage in the stator coils, which in turn increases the field current, until the machine "builds up" to full voltage.

http://en.wikipedia.org/wiki/Excitation_(magnetic)

In the short term, no numbers means all hype.

Yep.

 

[stedwards]

This device seems to rely on vortex shedding to keep it wiggling. Does this imply a very narrow range or Reynolds number?

On top of that, do you need to go around whenever the wind conditions are optimal and give them a kick-start with a stick?

 

[rollingstein]

How are they actually generating energy with a small amplitude vibration motion? All the efficient, commercialized generation technology I've known is rotational.

To put this in perspective, I don't think they even have a one kW prototype demonstrated in a on field test. Too early for all the hype. I'm very skeptical that the capex scales favorably. A typical wind turbine is in the hundreds of kW range.

If they try and scale this up the foundations needed to resist the impact / stress of those oscillatory vibrations would need to be quite robust?

 

[QuantumCurt]

I really like this idea, but some questions persist. It seems to me that there would be seasonal fluctuations in their generation of energy. In colder temperatures, the towers are going to be less flexible, meaning a smaller amplitude of oscillation. It seems plausible to me that such a fluctuation could exist. I wonder if compensation for such a likelihood has been factored in. As previously mentioned, it seems likely that snow and ice buildup would have an effect on these as well, although that could easily be addressed with a simple heating element to keep ice from building up on the surface.

The fewer maintenance needs is appealing, but comes with a drawback: jobs would be lost. The regular maintenance of wind turbines has resulted in the creation of many jobs. A lot of people in my area have gotten certified to work on wind turbines in the last ten years or so, and it's become one of the better jobs around here. If the current wind turbines were replaced by these, it doesn't seem likely that all of these people would be keeping their jobs.

One potential large bonus I can see is that I think people would be less resistant to these than many of them currently are to wind turbines. Personally I think wind turbines look awesome. Not only for the engineering involved in them or the fact that they generate clean electricity, but I also find them to be quite aesthetically pleasing. This is a personal opinion though. Not everyone will agree. However, one of the complaints that I've heard most about conventional wind turbines is that shadow flicker can cause epileptic seizures, which is a legitimate complaint in some cases and an empty point of argument in other cases. As the blades spin around, they cause shadows to periodically flicker. In some cases, poor placement has led to these shadows being cast into peoples' houses. I think this is a very valid complaint, but is easily resolved by proper offsetting to avoid it. Another complaint is that the turbines often interrupt the flight paths of migrant birds. Turbines are located such that they take advantage of naturally occurring air currents; the same air currents that birds take advantage of when they migrate. There have been many instances of birds being killed after flying into the blades of a turbine. I think this is in some respects a valid complaint, but personally I think the sacrifice of a few ducks and geese is well worth the cleaner energy that is produced. And the people making these complaints often don't consider how many birds fly into the windows of a typical skyscraper every year.

 

[jim hardy]

How are they actually generating energy with a small amplitude vibration motion? All the efficient, commercialized generation technology I've known is rotational.

To put this in perspective, I don't think they even have a one kW prototype demonstrated in a on field test. Too early for all the hype. I'm very skeptical that the capex scales favorably. A typical wind turbine is in the hundreds of kW range.

Work = force X distance so if the displacement is small the forces must be large.
Well, given that tall tower with generator at its bottom they sure have plenty of mechanical advantage.
I'd guess they use some sort of wobble plate to vary reluctance and modulate a magnetic field.

Extracting energy will damp those 'resonant oscillations'..

Call me a curious skeptic... If they can do a megawatt i know somebody who needs a couple hundred of them.

 

[A@bhishek]

Sounds pretty good:http://www.theverge.com/2015/5/16/8...s-wind-turbines-shake-to-generate-electricity

I like this particular idea a lot. With no blades, these take up much less space, and the claims about them being 50% less expensive to make, and lower maintenance, seems completely plausible. They would be a good design for powering cold outposts that are frequently overcast, but windy. The thing I would most like to find out about them at this point is how they're affected by snow. Ever since I experienced Minnesota, I've been mulling over the idea of a device to generate extra electricity from the cold winter winds, which is when you need it the most there. The trouble with every idea I had was clogging from snow and ice build up. These look like they'd shake it off.

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.

 

[zoobyshoe]

Work = force X distance so if the displacement is small the forces must be large.
Well, given that tall tower with generator at its bottom they sure have plenty of mechanical advantage.
I'd guess they use some sort of wobble plate to vary reluctance and modulate a magnetic field.

Extracting energy will damp those 'resonant oscillations'..

Call me a curious skeptic... If they can do a megawatt i know somebody who needs a couple hundred of them.

Yes, it would be nice to have an explanation of exactly how the generator part works, but you are right that this is a long lever and a small force at the top end will be amplified a few times at the bottom. That said, though, you're also right about the damping.

 

[rollingstein]

Call me a curious skeptic... If they can do a megawatt i know somebody who needs a couple hundred of them.

Me too! Intensely skeptical. Their first 10 feet tall unit is designed to generate 100 Watts.

Other than aesthetically pleasing designs there's not much hard data on that website to chew on.

 

[rollingstein]

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

I want to see how efficient they can make this transformation.

 

[Jeff Rosenbury]

I want to see how efficient they can make this transformation.

I don't foresee a big problem making them efficient, at least to reasonable rates (~50%).

In air magnetic fields are poorly understood at this point. There's plenty of science, but engineers have concentrated work in cores. They will need a good magnets engineer and those are rare at this point. I can foresee some design issues with EMF noise as magnetic fields go all higgly-piggly.

There are lots of problems to solve and lots of work for engineers.

We should push this technology as an engineering jobs program.

That was sarcasm. I would never push an uneconomical project just to line my own pocket. Still, if GE has a bunch of engineers sitting on their hands, there are worse slot machines needing feeding.

 

[anorlunda]

Call me a curious skeptic... If they can do a megawatt i know somebody who needs a couple hundred of them.

Count me as a skeptic along with others in this thread. But I disagree with Jim on that point. A 100 watt DC generator with low complexity, low maintenance would be welcome in many third world locations. It could power LED lights, and charge cell phones at night when solar panels don't work. But its cost would have to be comparable to a 100 w solar panel, something less than $100.

We need to think of electric power in terms of the law of dimishing returns. The very first increment from none to some is very valuable. That is very different from adding another increment on the top of a previously developed society. Considering the cost benefit curve, the difference in slope between the first and last increments could be on the order 10^4.

 

[rollingstein]

A 100 watt DC generator with low complexity, low maintenance would be welcome in many third world locations.

Diesel / Gasoline operated generators seem ubiquitous in whatever parts of the third world I've seen. Some very poor & backward regions too. Besides the expertise to repair & maintain them seems quite accessible in rural third world mechanics.

Although generators can be finicky they also take quite a lot of battering very well. Parts can be poached off vehicles etc. I've seen lots of improvisation. The technology overlaps a lot with vehicles. The basic technology is largely unchanged for decades so the penetration & knowledge base is high even in remote areas.

Any device trying to supplant them will have a very high bar I think. I'm not sure I see the third world as a good market for a novel wind device.

 

[Jeff Rosenbury]

I agree the third world cannot support the non recoverable engineering costs of this technology. But in the long run this technology is little more than a pole and the cost should be minimal; even minimal enough to out-compete generators.

Getting from hype to mature technology is a big, expensive problem.

 

[rollingstein]

I agree the third world cannot support the non recoverable engineering costs of this technology. But in the long run this technology is little more than a pole and the cost should be minimal; even minimal enough to out-compete generators.

A pole & pretty substantial foundations?

A 42 feet tall pole intentionally optimized for vortex shedding. I'd be curious to see what sort of anchor forces they expect in a gale.

 

[bhobba]

For me its a no brainer. Here in Australia we have had a number of investigations about the health effects of the noise regular turbines make. That they make no noise has a huge political advantage even if the health effects of the noise is exaggerated - people will always, if their is the slightest hint of health problems, work long and hard to scuttle it.

Thanks
Bill

 

[Jimster41]

Complex parts near the ground +
Simple construction +
Lower efficiency per unit -
Higher efficiency per unit area ?+

Mechanical durability does seem scary. But I can imagine that physics of using EM fields to stabilize more of a "vibrating" mechanical system, while siphoning off the work done against the stabilizer - could turn out to just be about clever circuit design.
Existing wind turbine generators use some type of magnetic field generating system, and it's at the top of a big skinny pole.

There is a large wind farm near my father's farm. Two problems that mean NIMBY for me.
Low frequency noise. It is there, and it get's to you (it does me anyway). And I suspect it varies in a high density field in a way that is non-linear. I'd be curious if these are worse or better in that regard.

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.

Those concerns aside (problems that need to be solved), I am gung-ho for wind power, and re-newables in general.

 

[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.

To avoid a Cessna getting sliced? Not sure why synchronized though.

 

[Jimster41]

To avoid a Cessna getting sliced? Not sure why synchronized though.

The idiotic part is how ridiculously bright the effect is. Not the fact there are signals on them. Of course you need to make it hard to fly a plane into them accidentally. 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. My sense is that it would probably work to just reduce the luminosity. It's just not a light scheme tuned to the use case - which is the kind of stupidity that kills good ideas.

 

[rollingstein]

The idiotic part is how ridiculously bright the effect is. Not the fact there are signals on them.

Can you post a photo? Would be interesting to see.

I suppose there are Codes about this sort of thing. Maybe someone has screwed up.

 

[Windadct]

Having looked at some wave energy projects, this has a similar power profile, it is not continuous it will be oscillating. From a power conversion standpoint this is very big technical hurdle. Every oscillation is a thermal cycle - this destroys the electronics in relatively short order.

 

[rollingstein]

Why are these things noiseless anyways? Isn't this like a huge vibrating reed? Is it just that the freq. is lower than the range we can typically hear?

 

[Jimster41]

Can you post a photo? Would be interesting to see.

I suppose there are Codes about this sort of thing. Maybe someone has screwed up.

My guess was that someone looked up the code, and it was for a pole over x feet high, = y-lumens and z-frequency. I think you could put a (much) fainter non-strobing light on them, and it would probably be just fine, maybe safer, and maybe even pretty. The spinning of the blades makes them "strobe" to some degree but it's a fairly random effect. That's what had us confused about what we were seeing for awhile. But it became pretty clear they are synced.

I've emailed to see if he's got a video.

 

[Jimster41]

Having looked at some wave energy projects, this has a similar power profile, it is not continuous it will be oscillating. From a power conversion standpoint this is very big technical hurdle. Every oscillation is a thermal cycle - this destroys the electronics in relatively short order.

Yeah, that makes sense.
Hybrid systems, with storage, could be more interesting though right - with storage sort of used as a super-inductor?

It's such an interesting problem. I'd like to know more about it. I mean EM fields are infinitely tough right, it's just about protecting the harness?

I've done some work on combined cycle plants. At one they were looking at adding storage to sell more "ramp rate" (they can currently move @100MW/min). This is in a market with lots of variable wind power. Turns out they were as interested in getting the state subsidy for commercial scale energy storage implementation.

It seems cynical on one hand, but then if there is no price on carbon, fracked natural gas is 2$/MMbtu (really), there is no economic incentive whatsoever to answer the questions around large scale renewables through trial and error - which is how good ideas become usable designs (IMHO). And the economic strangle-hold of fossil combustion goes on.

 

[Windadct]

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.
Super-Conductor / Inductor .. of course some new technology may help the technical problem - but only adds to the cost.
Large plants also see wear and tear in the thermal cycle of ramp up and ramp down - so the discussion of ramp rate also takes a lifetime toll on those assets.
As for the displacement of the carbon/ gas - the issue I see is those industries ARE also subsidized and always have been, and the environmental impact, while debatable in scale, does exist, we do not "pay" for these costs at the meter ( I am particularly critical of the treatment / abandonment of the workers and towns in the coal mining regions - left on federal / state subsidy and healthcare, this is technically a federal subsidy to the coal industry and the cost is not included in the price per ton of coal) . In NJ in the summer there are a bunch of peak load diesel generators, every afternoon in the summer they load these up and you can just see the pollution -- basically a greenish-purplish exhaust on days when the smog already limits visibility to about 5 mi. So there is the need to improve - we do not need today to be beating the lowest cost energy source, we need to piece by piece eliminate the highest cost and worst impact sources.

 

[Jimster41]

I couldn't agree more @Windadct

basically a greenish-purplish exhaust on days when the smog already limits visibility to about 5 mi. So there is the need to improve - we do not need today to be beating the lowest cost energy source, we need to piece by piece eliminate the highest cost and worst impact sources.

yeah, "NOx" haze (as you probably know) is the yellowish green part of that (particulates the rest).

 

[rollingstein]

Having looked at some wave energy projects, this has a similar power profile, it is not continuous it will be oscillating. From a power conversion standpoint this is very big technical hurdle. Every oscillation is a thermal cycle - this destroys the electronics in relatively short order.

What does the actual power conversion device look like in this (waves / vortex wind) case? It isn't a regular alternator is it? There's no rotary motion but more a linear oscillation.

Do we have the converse of a linear motor? In this case they say it is moving part free so I suppose the don't even have any conversion of the oscillation to a rotary motion.

 

[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.