NewWind Tree Turbine

[EEVblog]

This went viral on Facebook with 23M views:

s

Nowhere do they tell you the expected output per leaf, just "up to" figures, that's the tell numbers are being fudged here...


http://www.newwind.fr/wp-content/uploads/2015/08/Press_Kit_Interactive.pdf

[2N3055]

From brochure :

"Producing   an   average   of   2400   kWh   annually,   depending   upon   its   loca-on"

That is average power of 277.7 W  for a tree of 8 meter diameter... 

[hayatepilot]

It's always more efficient to build a large turbine instead of many small ones.
And cheaper too. 

But as a art installation it looks cool. 

[Someone]

The manufacturing is quite clever with the PCB integrated generators (commonly done for low cost motors) and the moulded plastic parts. It would have been interesting to experiment with a PCB inductions generator rather than the permanent magnets. Building these in volumes would be cheap and easy, it may well be a real innovation if you can add cheap wind generation capacity to the growing home DC infrastructure.

[2N3055]

The manufacturing is quite clever with the PCB integrated generators (commonly done for low cost motors) and the moulded plastic parts. It would have been interesting to experiment with a PCB inductions generator rather than the permanent magnets. Building these in volumes would be cheap and easy, it may well be a real innovation if you can add cheap wind generation capacity to the growing home DC infrastructure.

Again, 8 meter diameter, 270W average power (and that is as stated by them, with no number whatsoever to substantiate it..)
They don't even say what is power rating per individual microgenerator.. Not to mention, the tree will see only turbulence, even in good laminar wind, because of turbine interaction...

That is an art installation. I even like it as such, nice symbolism etc.. But as serious power generation device it's a joke..

[Someone]

The manufacturing is quite clever with the PCB integrated generators (commonly done for low cost motors) and the moulded plastic parts. It would have been interesting to experiment with a PCB inductions generator rather than the permanent magnets. Building these in volumes would be cheap and easy, it may well be a real innovation if you can add cheap wind generation capacity to the growing home DC infrastructure.

Again, 8 meter diameter, 270W average power (and that is as stated by them, with no number whatsoever to substantiate it..)
They don't even say what is power rating per individual microgenerator.. Not to mention, the tree will see only turbulence, even in good laminar wind, because of turbine interaction...

That is an art installation. I even like it as such, nice symbolism etc.. But as serious power generation device it's a joke..

They made a pretty art installation with it, so what? If they're churning them out for $50 a turbine I'll throw a bunch on the roofline of the house and enjoy it, it'll also keep the witches away (http://lancasteronline.com/features/finials-fact-and-fiction/article_31f54805-c6fe-5cdf-b496-db12af200521.html)

[ChunkyPastaSauce]

.....install these.....over actual trees?   

[Someone]

From brochure :

"Producing   an   average   of   2400   kWh   annually,   depending   upon   its   loca-on"

That is average power of 277.7 W  for a tree of 8 meter diameter... 

The numbers are all there, lets pull them out.

Installed capacity of 1 "tree" unit of turbines, 4100W
Around 60 "leaves" (turbines) on the pictured tree, ?70W each
Estimate of 2400kWh annually, which is a annual load factor of 13%
which is all very believable for such a system.

Yes, wind is a scarce resource in the urban jungle but you could put these in more favourable locations. But lets return to convenient rooftop installation:
http://web.wpi.edu/Pubs/E-project/Available/E-project-050410-163916/unrestricted/mc_rd_an_js_Rooftop_Wind_IQP_Report.pdf
Suggesting a 5% typical load factor in a urban environment.

5% annual load factor on 70W is 15kWh/year

My off the cuff estimate of a buy price @ $50 per leaf seems right on the mark if you can use them in better than average locations.

Some of us are about engineering and supporting good ideas, rather than rubbishing them without actually looking at the figures.

[2N3055]

From brochure :

"Producing   an   average   of   2400   kWh   annually,   depending   upon   its   loca-on"

That is average power of 277.7 W  for a tree of 8 meter diameter... 

The numbers are all there, lets pull them out.

Installed capacity of 1 "tree" unit of turbines, 4100W
Around 60 "leaves" (turbines) on the pictured tree, ?70W each
Estimate of 2400kWh annually, which is a annual load factor of 13%
which is all very believable for such a system.

Yes, wind is a scarce resource in the urban jungle but you could put these in more favourable locations. But lets return to convenient rooftop installation:
http://web.wpi.edu/Pubs/E-project/Available/E-project-050410-163916/unrestricted/mc_rd_an_js_Rooftop_Wind_IQP_Report.pdf
Suggesting a 5% typical load factor in a urban environment.

5% annual load factor on 70W is 15kWh/year

My off the cuff estimate of a buy price @ $50 per leaf seems right on the mark if you can use them in better than average locations.

Some of us are about engineering and supporting good ideas, rather than rubbishing them without actually looking at the figures.

Respectfully there are no relevant numbers in their brochure just some highly optimistic speculations.. Which is endemic for most wind energy industry, save for few respectable vendors..
So all you can is speculate and it has same significance as my laughing at them...

Missing numbers?

1. Size of the individual microturbine ?
2. Rotor efficiency ?
3. Generator efficiency, voltage and rated power  at specific wind speed?
4. Wind speed to power graph ?

All of that would be in fantastically perfect laminar flow.. so:

5. Study of turbine interference and loss of efficiency because of that.. If they claim they have a solution for turbulence problem, then comparison study how much they improved standard solution.
And yes, testing of that across whole wind speed range.

Funny numbers:
6. First they say solution scales from 500W to 3 kW, than tree has 4.1kW. Which is it?
7. Estimate of 2400kWh per annum correlates with a single, high efficiency (40% something) high speed vertical turbine with 8m diameter with good airfoil running at 10m/sec wind. They cannot achieve that efficiency, period, and 10m/sec is a speed that borders with a very bad weather with storm warning (that is between 5 and 6 on Beaufort scale).. No such wind in cities, except in gusts at storm time..
8. Their generator they are so proud of, is not very good exactly because of use of a PCB winding.. Classic winding has much better packing factor .. And voltage generated will be very low, few volts at best with huge currents, when you're lucky it actually  generates something..
9. 2 m/sec is funny too.. at that speed I see those kid rotating toys spinning too.. But they are not creating energy, just overpowering friction...  Wind energy is proportional to wind speed to third power, so if you have say, 125W turbine rated at 10m/sec, at 2m/sec that 5*5*5 less that 125.. Wait, that is whole 1 Watt!! ....... That is the reason no respectable vendor even bother with anything below 4-5 m/sec..
There is no energy to be had at that speed, so they optimize for better efficiency at higher speeds...

Also in the study you linked in summary criteria is listed as:
"..
The criteria we developed suggest that a potential building should be:
42
Above 150 feet tall (that is a 18-20 story building)
Have a roof at least 5,000 square feet
Supported by columns which the turbine can be attached to
Taller than buildings upwind
Not in a historic district
Not in or near an avian habitat
Connected to either a spot or radial network
Preferably commercial, waterfront, or industrial area
.."

That pretty much mean cca 10 locations in a city that I live...

And if I had more time, I could go on more but I guess it will suffice to explain what I had go trough my mind when I saw it.. So  based on that, I agree with Dave, and I call bullshit on this one..
This is one of those things that look and sound cool, it seems to have potential, but in reality, that money would be better spent on proven green technologies that we know that work.
With the hard data numbers that can prove it..

I'm not saying it will explode and will create no electricity at all, but I highly doubt it can generate promised specs...

If you have access to more numbers, I would like to see them and then we can calculate..
I really like idea of green energy and support it..
It's just I don't like con man and graphics designers posing as electrical engineers to pretend something works because it looks cool...

And as I already said, it does look very cool !!

Best regards!

[jonovid]

its Not original idea or New  , back when the renewable fad got started around 2006 the al gore movie,  I did try my hand at my own Wind Tree Turbine thing'o going for high air volume like a ships sail vs air velocity like a fan , mega torque vs rpm but come to the same conclusion. its all a bit , gone with the wind  

[Someone]

Funny numbers:
6. First they say solution scales from 500W to 3 kW, than tree has 4.1kW. Which is it?
7. Estimate of 2400kWh per annum correlates with a single, high efficiency (40% something) high speed vertical turbine with 8m diameter with good airfoil running at 10m/sec wind. They cannot achieve that efficiency, period, and 10m/sec is a speed that borders with a very bad weather with storm warning (that is between 5 and 6 on Beaufort scale).. No such wind in cities, except in gusts at storm time..
8. Their generator they are so proud of, is not very good exactly because of use of a PCB winding.. Classic winding has much better packing factor .. And voltage generated will be very low, few volts at best with huge currents, when you're lucky it actually  generates something..
9. 2 m/sec is funny too.. at that speed I see those kid rotating toys spinning too.. But they are not creating energy, just overpowering friction...  Wind energy is proportional to wind speed to third power, so if you have say, 125W turbine rated at 10m/sec, at 2m/sec that 5*5*5 less that 125.. Wait, that is whole 1 Watt!! ....... That is the reason no respectable vendor even bother with anything below 4-5 m/sec..
There is no energy to be had at that speed, so they optimize for better efficiency at higher speeds...

6 ) they didnt explain the lower end of the scaling, but as with grid connected solar you have some lower point where the economics dont work. You can buy solar panels of a few watts, residential solar installs are typically built with 200W panels, but they dont offer 200W systems for sale.

7 ) the 13% annualised load factor they imply is believable with good siting, I even think it'll pay in less ideal conditions. Its not assuming a wildly efficient system with the full swept area but something realistic like:
Lets pull some well known and relaiable numbers from "Sustainable Energy – without the hot air" for 6m/s wind (the average daily wind speed where I live) they estimate 140W/m2 available power and we can guess a typical efficiency of the cheaply made turbine to be say 25%. So with several square m of swept area the claim of the installed capacity being 4100W is believable and would only need a peak wind speed of 60km/h (believable). Oh look at 6m/s steady, that comes up with 1200kWh annual, contradicting your claims it needs all of more area, higher efficiency, and higher wind speeds than believable all at the same time to achieve the numbers. Back with "Sustainable Energy – without the hot air" they come up with an optimistic 600kWh annually for 1m2 of swept volume, so the 2400kWh annual for a tree install seems right on the money.

8 ) the PCB design is about cost reduction, this is the clever part. They're reportedly delivering systems for $500/leaf as art installations, so the guess of $50 in volume production I'm suggesting is again believable.

9 ) you on one hand dismiss that they havent shown and power profiles and then poke fun at the data they do provide, we've now got the cut in point for the profile, of course it produces very little power as does the cut in point of all wind generators.

The numbers are all within believable ranges, once they produce/share some more technical details it will be interesting but there is nothing here that is wildly difficult or impossible to achieve. The big innovation is building it cheaply in volume.

[2N3055]

6 ) they didnt explain the lower end of the scaling, but as with grid connected solar you have some lower point where the economics dont work. You can buy solar panels of a few watts, residential solar installs are typically built with 200W panels, but they dont offer 200W systems for sale.

Exactly my point.. they don't explain microturbines, no low end, no interaction, but simply multiply their number by some imaginary or idealized number and voila 4.1 kW at some wind speed..

7 ) the 13% annualised load factor they imply is believable with good siting, I even think it'll pay in less ideal conditions. Its not assuming a wildly efficient system with the full swept area but something realistic like:
Lets pull some well known and relaiable numbers from "Sustainable Energy – without the hot air" for 6m/s wind (the average daily wind speed where I live) they estimate 140W/m2 available power and we can guess a typical efficiency of the cheaply made turbine to be say 25%. So with several square m of swept area the claim of the installed capacity being 4100W is believable and would only need a peak wind speed of 60km/h (believable). Oh look at 6m/s steady, that comes up with 1200kWh annual, contradicting your claims it needs all of more area, higher efficiency, and higher wind speeds than believable all at the same time to achieve the numbers. Back with "Sustainable Energy – without the hot air" they come up with an optimistic 600kWh annually for 1m2 of swept volume, so the 2400kWh annual for a tree install seems right on the money.

Funny that.. from that same place "Sustainable Energy – without the hot air" , a quote :

 "...Chapter B (p263) explains how to estimate the power per unit area of a
wind farm in the UK. If the typical windspeed is 6 m/s (13 miles per hour,
or 22 km/h), the power per unit area of wind farm is about 2 W/m2...""

that exactly correlates with my numbers  and your 140W is a bit high... And that is for a large very efficient large turbine in good air.. Vertical microturbines have half of their efficiency, so 1W..
So I was actually optimistic..

8 ) the PCB design is about cost reduction, this is the clever part. They're reportedly delivering systems for $500/leaf as art installations, so the guess of $50 in volume production I'm suggesting is again believable.

Making it cheaper is moot point if it doesn't work well.. Bad generators give more energy loss and worse overall efficieny..

9 ) you on one hand dismiss that they havent shown and power profiles and then poke fun at the data they do provide, we've now got the cut in point for the profile, of course it produces very little power as does the cut in point of all wind generators.

Here I apologize to you for not being more clear.. What I meant was that they didn't provide and verified measured data taken professionally using scientific methods that prove their claims.
I don't know how deep is your knowledge in this topic, I don't want to be disrespectful, but they made few claims, that would make a revolution in the industry.. They claim they have a solution for turbulence (I'm sure every aerodynamics expert would want to know how), they claim have made better turbine that also is better that existing vertical design, they claim they made better generator by ignoring some well known rules of industry, and then they say they can do it cheaper than anybody...

And that brings us to last point:

The numbers are all within believable ranges, once they produce/share some more technical details it will be interesting but there is nothing here that is wildly difficult or impossible to achieve. The big innovation is building it cheaply in volume.

Confusion comes from the fact that their numbers are in believable ranges, BUT not for what they are doing. Large, vertical turbines have quite good efficiency, and  they claim they achieved pretty much same with a concept that regurgitates concepts that were rejected decades ago as not being efficient enough..
If they did what they claim, and can prove it, there are Noble prizes to be had.. Literally...  And frankly, I WISH they did...

But until they do prove it... To me it's just sleazy marketing of something really cool looking thing, by people that want to make money on "that green thing...", exploiting people's wish to make this planet a better place..

[Someone]

7 ) the 13% annualised load factor they imply is believable with good siting, I even think it'll pay in less ideal conditions. Its not assuming a wildly efficient system with the full swept area but something realistic like:
Lets pull some well known and relaiable numbers from "Sustainable Energy – without the hot air" for 6m/s wind (the average daily wind speed where I live) they estimate 140W/m2 available power and we can guess a typical efficiency of the cheaply made turbine to be say 25%. So with several square m of swept area the claim of the installed capacity being 4100W is believable and would only need a peak wind speed of 60km/h (believable). Oh look at 6m/s steady, that comes up with 1200kWh annual, contradicting your claims it needs all of more area, higher efficiency, and higher wind speeds than believable all at the same time to achieve the numbers. Back with "Sustainable Energy – without the hot air" they come up with an optimistic 600kWh annually for 1m2 of swept volume, so the 2400kWh annual for a tree install seems right on the money.

Funny that.. from that same place "Sustainable Energy – without the hot air" , a quote :

 "...Chapter B (p263) explains how to estimate the power per unit area of a
wind farm in the UK. If the typical windspeed is 6 m/s (13 miles per hour,
or 22 km/h), the power per unit area of wind farm is about 2 W/m2...""

that exactly correlates with my numbers  and your 140W is a bit high...

2W/m2 of land area, right now you're the one with the figures out by an order of magnitude or more. Do you want to have your debunking stamped with a "FAIL" ?

Aeroleaf looks plausible and more data will be interesting.

[2N3055]

7 ) the 13% annualised load factor they imply is believable with good siting, I even think it'll pay in less ideal conditions. Its not assuming a wildly efficient system with the full swept area but something realistic like:
Lets pull some well known and relaiable numbers from "Sustainable Energy – without the hot air" for 6m/s wind (the average daily wind speed where I live) they estimate 140W/m2 available power and we can guess a typical efficiency of the cheaply made turbine to be say 25%. So with several square m of swept area the claim of the installed capacity being 4100W is believable and would only need a peak wind speed of 60km/h (believable). Oh look at 6m/s steady, that comes up with 1200kWh annual, contradicting your claims it needs all of more area, higher efficiency, and higher wind speeds than believable all at the same time to achieve the numbers. Back with "Sustainable Energy – without the hot air" they come up with an optimistic 600kWh annually for 1m2 of swept volume, so the 2400kWh annual for a tree install seems right on the money.

Funny that.. from that same place "Sustainable Energy – without the hot air" , a quote :

 "...Chapter B (p263) explains how to estimate the power per unit area of a
wind farm in the UK. If the typical windspeed is 6 m/s (13 miles per hour,
or 22 km/h), the power per unit area of wind farm is about 2 W/m2...""

that exactly correlates with my numbers  and your 140W is a bit high...

2W/m2 of land area, right now you're the one with the figures out by an order of magnitude or more. Do you want to have your debunking stamped with a "FAIL" ?

Aeroleaf looks plausible and more data will be interesting.

I apologize for that omission.. You are correct in that that I quoted wrong... But your 140W is also very wrong.. That is theoretical power of wind at 6m/sec.
Betz's law say you cannot extract, ever, more than 59% of that energy.. In real life for best of vertical, large high speed turbines is a bit over 40%.. 
Savonius vertical rotor (this is a variant) is usually 20-30%. So we are talking about 25-45W.. 3 to 5 times less than you stated...

In addition to that you can't dispute other 100 sentences I wrote... And the fact that you so badly want to believe this marketing campaign to be hard scientific truth won't make it science and hard data and evidence..
And I agree with you it is possible.. Just not very likely and I doubt it....

So to quote you: I want numbers !!!  And not marketing brochure..

And since it wasn't me claiming outlandish scientific breakthroughs, it is not my burden to prove them wrong.. This is no human rights or criminal court .
In science, they have a burden (and obligation) to prove they are right, and then also, to submit data for impartial peer review to verify all the findings .

And if they all agree, then we salute the new king of the hill, and I promise I will in this very post publicly apologize and congratulate to people that made our world a better place..

Until then : it's all just marketing campaign by people that try to make money by swimming in a gray area... I heard that pitch too many times before and don't trust until they can show more than promises..

It is my obligation to be sceptic and theirs to prove they are right.

Either you prove unequivocally you are not selling bullshit, or you should stop selling bulshit.  Simple as that.

I don't want you think I have anything against you or your opinion. Nothing personal, you might know many things I don't know so I might be wrong.. I accept that possibility as I know full well I'm not that bright and don't have a PhD in wind energy. But I really dislike people exploiting good cause for their gain using shady schemes. It's simply I don't share your admirable enthusiasm for things somebody claims are made of gold without metallurgical analysis, by somebody else than a seller himself... 

 

[Someone]

I apologize for that omission.. You are correct in that that I quoted wrong... But your 140W is also very wrong.. That is theoretical power of wind at 6m/sec.
Betz's law say you cannot extract, ever, more than 59% of that energy.. In real life for best of vertical, large high speed turbines is a bit over 40%.. 
Savonius vertical rotor (this is a variant) is usually 20-30%. So we are talking about 25-45W.. 3 to 5 times less than you stated...

You again focus on the small details and fail to follow through with the larger picture.
140W/m2 is the theoretical power available in a 6m/s wind.

we can guess a typical efficiency of the cheaply made turbine to be say 25%. So with several square m of swept area

I put in the realistic 25% efficiency, and multiply it back by several meters of swept area. All their numbers add up, you just focus in on little parts and jump to conclusions.

2N3055 = debunking FAIL

In addition to that you can't dispute other 100 sentences I wrote

Your arguments are full of obvious holes, they dont stand up to examination. I've pulled some referenced numbers and checked that what newwind  are claiming is plausible with some short and simple figures. You seem stuck on this topic and are scrambling to find anything you can to discredit newwind and my analysis, not sure why but its your time wasted and now you're the one looking foolish.

[Someone]

Not often I'll draw in other threads, but its just too funny today:
https://www.eevblog.com/forum/chat/world-is-changing-we-need-to-readjust-the-attitude-or-perish/

And I really dislike people losing energy in trying to discredit something or somebody based on hate, prejudice and such..

[2N3055]

Unfortunately ,  it is only you that failed to have civilised discussion... 

You failed to prove anything than being a type of person that resorts to drama, personal insults and such when somebody doesn't believe that you are right based on , well, lack of data and wishful thinking... 

Also seems you like to presume things about people too, calling me hater of new technologies and green, better world..

Nothing can be further from the truth. I really wish them to make this microgenerator work, if they could make them make 50Wh in a day at 50$ price, I personally would buy and sell them in thousands... I have projects that need to be reliably supplied  with the small power, but off the grid and would benefit from it immensely. Also I designed, produced and installed electric vehicle charger, on my own time and money, to try prove that our government doesn't do enough to change in a right direction...

So my quote :" And I really dislike people losing energy in trying to discredit something or somebody based on hate, prejudice and such...." applies to your behaviour  too.. 

Also I start to suspect you have some financial or some other vested interest in this particular project that you're so staunchly protect despite any kind of proof they are not snake oil salesman...

I will repeat just one more time this in clear and simple language: I like anything green and good.. I don't hate anybody, but believe in truth and honesty. I don't protect lies and search for excuses when I do something wrong.

By the way you communicate I would guess you're much younger than I am and I'm going to write off your insulting and uncivilized tone (and outright screaming at me, darn you would think I killed somebody ) to youthful enthusiasm..
No problem, I was young once, I still remember how I was.. I actually like people with little fire in them..

But honestly, you should stop. Except insulting me personally, you didn't disprove any of my basic statements and general principle: They provide no data but marketing fluff, their data seem a bit too optimistic. That means they shouldn't be taken seriously until they prove all that with hard data. At which moment, to the victor go the spoils..

That is my argument, and it is absolutely perfect with no holes whatsoever.  I deliberately and openly stated I'm no expert and will not do any calculations anymore because I'm not sure I know how do them properly. And I left that to people that have PhD in physics. When manufacturer publishes actually any verifiable data...

It was you trying to prove something with quasi mathematics based on presumptions.. And at any cost, including personal attacks on a man who might be old enough to be your father...
 

And no I didn't do any debunking, so couldn't do fail at that. Manufacturers of said thing did perfect job by their own. Debunking would mean disproving of falsely stated data.. They provided none to speak off.

So please if you don't mind, I would like you to stop being rude to me.  I respect that you think I'm wrong, but I fail to understand why you insult me personally for saying simple fact that I don't believe in anything until proven true. That is a good life rule, trust me, it works.
I wasn't even talking to you, it wasn't addressed to you but to somebody else..

So this is the last from me on this topic, until they publish said data.

I wish you a good day.

[jonovid]

To give encouragement where encouragement is due,    just add blinking LED's & you have an outdoors Christmas Tree, 
or use as a hills hoist Ozy clothesline the rest of the year.      you never know,
Solar Roadways Incorporated may like idea of combining wind trees with a solar roadway,  so we can party like it's 1999 

[EEVblog]

They don't even say what is power rating per individual microgenerator.

They do, and even have a graph.


I have not run the numbers yet, but my guess is that unless you have say >10-12kmh wind for a good lot of the day, these things aren't going to cut the mustard for bang-per-buck.
Actually, I guess that regardless of wind speed these thing won't offer viable bang-per-buck for anything but arty type installations, or other dense urban installs.
But then, why not integrate this into a whirlybird for your roof and get roof cooling and generation into one. There is probably a reason hasn't caught on.

[2N3055]

They don't even say what is power rating per individual microgenerator.

They do, and even have a graph.


I have not run the numbers yet, but my guess is that unless you have say >10-12kmh wind for a good lot of the day, these things aren't going to cut the mustard for bang-per-buck.
Actually, I guess that regardless of wind speed these thing won't offer viable bang-per-buck for anything but arty type installations, or other dense urban installs.
But then, why not integrate this into a whirlybird for your roof and get roof cooling and generation into one. There is probably a reason hasn't caught on.

Thank you for that.. I didn't look hard enough I guess... So pretty much not useful as power generation.. If considered energy harwesting, I might even use it for some telemetry low power thing if they will sell it for a good price..

[jonovid]

Quote from: EEVblog on Today at 10:05:53 PM
Quote from: 2N3055 on Yesterday at 07:10:24 PM
They don't even say what is power rating per individual microgenerator.

They do, and even have a graph.

I have not run the numbers yet, but my guess is that unless you have say >10-12kmh wind for a good lot of the day, these things aren't going to cut the mustard for bang-per-buck.
Actually, I guess that regardless of wind speed these thing won't offer viable bang-per-buck for anything but arty type installations, or other dense urban installs.
But then, why not integrate this into a whirlybird for your roof and get roof cooling and generation into one. There is probably a reason hasn't caught on.

Thank you for that.. I didn't look hard enough I guess... So pretty much not useful as power generation.. If considered energy harwesting, I might even use it for some telemetry low power thing if they will sell it for a good price..

individual microturbines can be sold as Arduino kits or Hay Kids like stick one on you bicycle handlebars or something.

[Someone]

I have not run the numbers yet, but my guess is that unless you have say >10-12kmh wind for a good lot of the day, these things aren't going to cut the mustard for bang-per-buck.
Actually, I guess that regardless of wind speed these thing won't offer viable bang-per-buck for anything but arty type installations, or other dense urban installs.
But then, why not integrate this into a whirlybird for your roof and get roof cooling and generation into one. There is probably a reason hasn't caught on.

It would be a shame if they focused on the art market and didn't pursue cost reduction, as with most forms of renewable energy they all have their uses/sites/benefits but need to compete on price with the alternatives. These could be great for lighting at isolated sites where solar is the go-to now, public lighting already installs a tall pole so the incremental cost of adding some turbines would be small. The theoretical $50 price from above where it would be a commercial proposition seems possible, you can get a similarly sized and complex object at bunnings for that price retail.

[Simon]

I too saw these on Facebook and my first question was can I buy them individually and how much power do they produce. I think I did work out the 70 watt figure based on the figures they did give on their website but their website is more of a flashy advertisement than giving any technical detail. I too don't see these as being any more useful than an art installation unless you can buy the individual leafs quite cheaply as they could be quite easy to install for hobbyists.

Vertical axis wind turbines are already known not to be the most efficient in terms of mechanics and therefore are only useful in specific niche applications like this one. I would never tear down a tree to replace it with one of these arty farty things and I will always consider planting a tree rather than one of these arty farty things. There are places for trees and there are places for power generation. Sticking a load of these down a street with the expectation they will power the lighting regardless of the conditions would be quite silly. You would do better to plant trees which believe it or not are actually still useful to us as they do that weird thing called converting carbon dioxide back into oxygen, you know the stuff we rely on to live. Power generation is better done on a medium to large-scale unless you are talking about a technology that easily scales down like solar.

[2N3055]

I too saw these on Facebook and my first question was can I buy them individually and how much power do they produce. I think I did work out the 70 watt figure based on the figures they did give on their website but their website is more of a flashy advertisement than giving any technical detail. I too don't see these as being any more useful than an art installation unless you can buy the individual leafs quite cheaply as they could be quite easy to install for hobbyists.

There is a power curve diagram up there in the topic that Dave found on their site... If you quote power as most manufacturers do, at 10 m/s , than you would call it cca 25W generator.. So to reach claimed 4.1kW, you would need 150 of those on a tree.. I didn't really count, but as "Someone" (it's username ) said, seems to be 60-70 installed on the trees they show.. So that would mean they overestimated they claims..

For off the grid hybrid combined with a small solar panel, individual microturbine would be useful as a complementary energy harvesting solution, that would be good for off the grid low power telemetry stuff and such.It is compact, if it will be reliable and if priced really low, I would use it for such because I have need for such specialized equipment.  But they are marketing them as a viable alternative to other wind turbines.

[Simon]

Yes I would love to have a wind turbine as well and might solar panels as it would take over when the sun goes in or at night and my inverter does already have a second set of input sockets with a diode on each set for separation. Wind is indeed used for remote applications in conjunction with solar. Here in the UK there are a number of luminous road signs that are powered from a solar panel and a wind turbine, but surprise, surprise and I really can't think why the rushing out just escapes me... They are using horizontal axis wind turbines about 20 cm in diameter not vertical axis wind turbines. It's not like vertical axis wind turbines are anything new we have all seen for many years the triple egg cup turbine used on wind speed sensors. How strange they not be using the same type of design to generate power for a luminous sign that does not require much power and to be fair is probably mostly powered by the solar panel. Vertical axis wind turbines don't seem to have much real application they just look slightly better as in this application. I'm not saying I would not use one as it's simplicity of installation is about it's only advantage from what I understand. But if you want to do any serious generation with a single unit you were go for a horizontal axis and this is something I would now consider myself rather than the vertical axis.