Rooftop wind doesnt work

[B529]

Fabricators recent post regarding roof mounted turbines made me think of this article written by Mick Sagrillo. It shows data of various turbines. It's really no surprise how little these trubines produce. Unfortunately one of the negatives of the green movement is the scoundrels who come out and take advantage of the uneducated.
https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B349-y-LeFJPNDdlZGQ2YjAtMjA3OC00ZDgwLTk4NWMtYWU0ZDFlZDgyNjM3&hl=en

This is live data from a Bergey 10k a friend installed here in Eastern Colorado. http://www.secrcd.org/Page.aspx?PageID=5127 This is what a properly installed turbine in a good wind site will produce.

Tinkering around with VAWTS and roof mounting turbines for ourselves is one thing, companies/installers scamming people out of their hard earn money with VAWTS, roof mounted turbines... is criminal.

[harley1782000]

Excellently explain!!!  If there is a fool out there, there is money to be made.

Jim

[Bruce S]

Nice write up, the only thing i wish he had done was in the subtitle NOT put "Wind Doesn't Work" , there are those that will use this against wind power without any real reference to roof top mounted corporate built units.

Bruce S
 

[JW]

Hi Guys,

Nice write up, the only thing i wish he had done was in the subtitle NOT put "Wind Doesn't Work"

Have been considering this since this morning.  "Wind Doesn't Work" is a bad title. It would be no problem  for one of us to edit the title for Kevin.

I agree with Bruce, ive done my share of admin duties    And it is possible for someone to use this post as a platform, to rail against wind power, generally these type of folks, often miss the true intention of such an article...

Also, I helped B529 by creating a link to the document, and arranging that it was not hosted on the database here(hosted with google), as it is, about 16mb.

Im glad the link worked properly. It took some work on my part, but was not really a big deal, its no problem for me to helpout users, with this sort of thing, resize picture etc. After I produced the link, Kevin went ahead and posted, works good for me. I see no problem "tweaking the title" alittle, if necessary.

JW

[keithturtle]

Yeah, we know wind works.  It's just that their variety of rooftop wind doesn't.  Or more accurately, can't.

Maybe "Rooftop wind doesnt work" might be better

Turtle

[Bruce S]

Yeah, we know wind works.  It's just that their variety of rooftop wind doesn't.  Or more accurately, can't.

Maybe "Rooftop wind doesn't work" might be better

Turtle

turtle;
 Actually "Doesn't Work As Well" would be better. I've had a great time reading into the past post of Windstuff and a couple others.
For VAWTs and related units , because of the much lower normal RPMs they would work "marginally" BUT no where near like anything a lot of "corporations" would have people believing. Jay Leno's unit comes to mind. Funny how you don't hear much about that unit so much.

Ed however did a lot of testing back in '03 '05 ish and his units could work, and I believe he even had one on his rooftop with nothing but sand bags holding it in place, with them working in the 20% eff range,     <IF my math works right>. 

Cheers
Bruce S
 

[JW]

Hi Guys,

B529 pm'd me and gave the all clear, if you guys want to change the title. Im with you guys on how you feel best to proceed. 

JW

[hayfarmer]

LESS FILLING (in to battery string) but looks great, looks more like it to me. my 2 hawt 's  are cooking with gas this week. been great winds this winter.

[Bruce S]

Hi Guys,

B529 pm'd me and gave the all clear, if you guys want to change the title. Im with you guys on how you feel best to proceed. 

JW

JW;
That was nice of B529, but I'm not a big proponent of changing titles and such, it can quickly become a slippery slope. The PDF is the one I was referring to, sorry should have made that more clear. IT was and remains to me a well done set of slides. I liked that fact that towards the end, one place actually used commonsense and did their homework BEFORE spending $$$$ and looking goofy.

Cheers
Bruce S

[B529]

I view VAWTS, roof top mounts as not working. Until someone can show me some real world numbers, I stand firm. I guess technically they work, but so does a solar panel in the shade.

Once again having fun with various designs of VAWTS for personal use, hey that's cool.

Bruce, it's not just "corporations". About three weeks ago while at a rifle range of all places, the guy next to me started chatting. He asked what I did for a living, asked him what he does for living. He's a one man show RE dealer/installer. Told me he had installed 3 "new technology" VAWTS. He started going on about how great they are, don't have to be on tall towers, can power an average home, start up in low winds......we know the rest of the BS.

When I first read Sagrillo's article, I kind of wondered about the title. Then I thought maybe he's looking down the road at the future of small wind, if this type of crap continues to be sold, it may take a while, but the word will be "wind doesn't work". No doubt in due time the three rifle range guys customers will come to that conclusion.

I question if the green movement, tax credits........is good for the future of small wind?
 

[keithturtle]

Yeah, we know wind works.  It's just that their variety of rooftop wind doesn't.  Or more accurately, can't.

Maybe "Rooftop wind doesn't work" might be better

Turtle

turtle;
 Actually "Doesn't Work As Well" would be better. I've had a great time reading into the past post of Windstuff and a couple others.
For VAWTs and related units , because of the much lower normal RPMs they would work "marginally" BUT no where near like anything a lot of "corporations" would have people believing. Jay Leno's unit comes to mind. Funny how you don't hear much about that unit so much.

Ed however did a lot of testing back in '03 '05 ish and his units could work, and I believe he even had one on his rooftop with nothing but sand bags holding it in place, with them working in the 20% eff range,     <IF my math works right>. 

Cheers
Bruce S
 

Indeed, work as well is the operative phrase.  But when you compare the real output of solar panels to an equivalent rooftop wind unit dollar for dollar, "rooftop wind doesn't work" worth a hoot.   Both are costly, but at least one has a payback, even on windless days

Turtle

[DamonHD]

Though on days with deep dark clouds or snow my solar PV isn't catching enough photons to push the virtual needle on the generation meter off the zero stop...

Rgds

Damon

[electrondady1]

i can't say i really understand what this thread is pointing to.
i don't know who Mick Sagrillo is.
is he famous or something ?

is it surprising that corporations of any sort, mislead people into purchasing their  product or service ?
your expecting windmill manufacturers to hold themselves to some higher standard than say,
 oil companies,  processed food producers,  automobile companies or banks ?

the last image in the link says, " we know how to make wind work".
and shows three images of hawts on 80' towers out in the countryside.

that's not going to help the vast majority of people that live in urban settings.

[Perry1]

Mick has been around wind for a long time and installed or flown just about every type of turbine. He is referred to a lot in Paul Gipes book.

Not that we want to hold wind to a higher standard, just stamp out the blatant lies. Those need to go,

I think the last line you refer to is kinda self evident. Sorry to say but wind doesn't work for people in tight urban areas. That's the cold fact these guys don't want the public to know. If you want to use wind to make power and 'work' (I take that to mean you can meet your loads and pay the turbine off in a reasonable amount of time) you need a big rotor way up in the wind.

I would say that the HAWT's you refer to DO help people in urban settings because they are able to consume power that was made without using a 'dirtier' means.

Perry

[DanB]

the last image in the link says, " we know how to make wind work".
and shows three images of hawts on 80' towers out in the countryside.

that's not going to help the vast majority of people that live in urban settings.

I think Mick was dead on when he gave that presentation at the Small Wind Conference in Wisconsin a couple years ago, and it was nice to finally see a little bit of real data on some of these very expensive (some payed for with our tax dollars) rediculous installations.

No - and it's not going to help the vast majority of people that live in urban settings.  Best shot those folks have it to conserve energy and if they want 'wind power' it's going to get piped in from very large wind turbines that are on tall towers in very windy places that are remotely located!  From everything I've read and seen, and I have been interested in this topic for most of my life.... rooftop wind doesn't work well.  And - it's fairly cheap to move electricity from places where it does work well... to places where it doesn't.  I wonder why people keep trying...  the facts are out there, the numbers just don't add up favorably.

[Tight Yorky]

Hello gents,

I have been reading the varied opinions on building mounted wind generators. I thought you might be interested in the results of study posted by the Energy Saving Trust here in the UK.
The link is below..

http://www.energysavingtrust.org.uk/content/download/1834470/5058917/file/EST%20Location%20Location%20Location%20Report2.pdf

Page 13 mentions some grid tied, building mounted installations actually consumed more power than they generated due to the inverter power consumption.
There must have been a good sales man involved in those installations. Perhaps he previously sold snow to Eskimos. 

Regards.
Clive.

[fabricator]

The plain unvarnished truth for the vast majority of urban dwellers is that solar is the way to go if you are passionate about RE, however, if you are able to build and install your own turbine and can get by local zoning requirements and go in with your eyes wide open, go for it.

[electrondady1]

http://www.youtube.com/watch?v=eogwoFSiqqY

this is closer to what  i imagine  when i think of "urban" wind power on a roof..
when your in a less than ideal location, swept area is all that's left to play with.
some kind of wind wall is needed.

a single  4-6ft. hawt bolted to a roof won't cut it.
especially if it costs 14,000 dollars.

[fabricator]

Wow! they need some kind of guards on those things.

[bradyaero]

It works if the turbine is designed for the roof....

<a href="http://www.youtube.com/watch?v=PMOQtOhFN2M" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/watch?v=PMOQtOhFN2M</a>

[B529]

It works if the turbine is designed for the roof....

<a href="http://www.youtube.com/watch?v=PMOQtOhFN2M" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/watch?v=PMOQtOhFN2M</a>

What happens when the wind changes direction? Looks like a tiny swept area?

Sure it's spinning, doesn't mean it's producing. Output numbers?

Solar would look good on that roof!

[DamonHD]

One video of one turbine spinning on one roof for a few minutes does not contradict the general truth that urban wind is --- to be technical here --- generally crap due to all the obstacles, and the actual space round a roof will be extra turbulent.

No amount of wishful thinking will make that general issue go away: suburbanites wanting to do RE should almost always consider solar in preference (or hydro for example if they have the resource).

I have a MotorWind turbine which is a nice bit of kit designed to exploit the same sort of cliff/barrier effect as in that video and it only even turns about 10% of the time at best.  I have the typical problem that I can't put it high up and anyway the surrounding terrain is rough (houses and trees) and also I'm in a dip.

Rgds

Damon

[Beaufort]

It works if the turbine is designed for the roof....

<a href="http://www.youtube.com/watch?v=PMOQtOhFN2M" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/watch?v=PMOQtOhFN2M</a>

Nice idea, but it's much too low to make use of the "sweet spot" that occurs on roofs like that.  They're getting a decent amount of non-laminar flow being that close to the roof; putting it up another 1-3 feet gets closer to where the fastest, laminar flow occurs.  Giving the wind some room to flow under the device would also help quite a bit.  A simple CFD analysis would get them much better results....until the wind changes direction

[Bruce S]

It works if the turbine is designed for the roof....

<a href="http://www.youtube.com/watch?v=PMOQtOhFN2M" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/watch?v=PMOQtOhFN2M</a>

What happens when the wind changes direction? Looks like a tiny swept area?

Sure it's spinning, doesn't mean it's producing. Output numbers?

Solar would look good on that roof!

Nice looking unit though.
 In the video he says ~14V @ ~4amps so not bad, even if it's a 20mph wind.
I'd like to see it with true viewable numbers, like a anemometer and  display of both Volts and amps during the tests.
I mic up on the roof for noise and one in attic for sound from vibrations would be nice too.

Cheers;
Bruce S

 

[dnix71]

I don't get the hate for small wind here. I don't need gigawatts of power. A steady 20 watts would be just fine, esp. at night. 20 watts doesn't sound like much but if it's at night when the sun isn't shining it's 1/4 kwh/day of power I wouldn't have had otherwise. I do not expect to live off-grid like I could on grid. It won't happen.

As long as the output is not misrespresented and it doesn't cost $1000's of dollars, it can be useful. Even if all it did was light the property at night, that would be worth something.

Mounting it on the roof is probably a bad idea. A pole in the ground tied in one place to the side of the building should be okay, though. I can't put up a tower high enough to reach clear air, If it fell it would land to or three houses away.

If battery technology ever gets 'good' solar will be enough. I already make more than I can properly store. What I need is a battery that is affordable and will not sour if left in a partial state of charge for a long time. Maybe one day the NiMH packs from hybrid cars will come down in price. Right now at $500 for a used Prius pack the cost per kwh of storage is still about 5 times that of Pb acid.

[Bruce S]

I don't get the hate for small wind here. I don't need gigawatts of power. A steady 20 watts would be just fine, esp. at night. 20 watts doesn't sound like much but if it's at night when the sun isn't shining it's 1/4 kwh/day of power I wouldn't have had otherwise. I do not expect to live off-grid like I could on grid. It won't happen.

As long as the output is not misrepresented and it doesn't cost $1000's of dollars, it can be useful. Even if all it did was light the property at night, that would be worth something.

Mounting it on the roof is probably a bad idea. A pole in the ground tied in one place to the side of the building should be okay, though. I can't put up a tower high enough to reach clear air, If it fell it would land to or three houses away.

If battery technology ever gets 'good' solar will be enough. I already make more than I can properly store. What I need is a battery that is affordable and will not sour if left in a partial state of charge for a long time. Maybe one day the NiMH packs from hybrid cars will come down in price. Right now at $500 for a used Prius pack the cost per kwh of storage is still about 5 times that of Pb acid.

ALL very good points, I don't understand the bad vibe's either, but could be due to all the incorrect numbers given out by LLCs and the hype pushed by J.Leno and Pacw.. and similar others.

20 watts from one for me would be nice too. Windtsuff ED has a nice unit that'll do that as an Radial Air core. Plus its a good way to learn stuff.
As an Urbanite I cannot put up a 10 foot pole without a permit due to high power lines than run through our alley.
For usage of stored power < what Little I get from current 90watts of PVs> I have for the coffee pot and other cool little things that could add up on my electric bill.
Ohhh and the cool factor of having lights and coffee when the mains goes out.

ONE thing that may not be completely understood is the need for people to understand what they're getting into with small VAWTs or lower power or roof units. Could be instead of reading wild claims made by "SALESMEN" people should read and understand more of what they're looking at.

I'm hard headed enough to try building one of Ed's 3-phase radial air core units using 65 turns 22ga wire, 1x2x3/4" ceramic mags and #10 sized tins cans TIG welded together about 4 high  . I should be able to charge a few AAs for the lawn lights and scare the black birds out of my Apple trees 


I like my cute little NiCds, they forgive me when I drain them to near death, kinda like a mutt dog, they just come back wanting to play some more.

HAVE FUN!!
Bruce S


 

[ghurd]

I like small wind.
The problem is while 20W does not sound like much, most peoples typical wind speed and a steady 20W all night takes a machine bigger than most people expect.
G-

[B529]

I don't get the hate for small wind here. I don't need gigawatts of power. A steady 20 watts would be just fine, esp. at night. 20 watts doesn't sound like much but if it's at night when the sun isn't shining it's 1/4 kwh/day of power I wouldn't have had otherwise. I do not expect to live off-grid like I could on grid. It won't happen.

As long as the output is not misrespresented and it doesn't cost $1000's of dollars, it can be useful. Even if all it did was light the property at night, that would be worth something.

Mounting it on the roof is probably a bad idea. A pole in the ground tied in one place to the side of the building should be okay, though. I can't put up a tower high enough to reach clear air, If it fell it would land to or three houses away.

If battery technology ever gets 'good' solar will be enough. I already make more than I can properly store. What I need is a battery that is affordable and will not sour if left in a partial state of charge for a long time. Maybe one day the NiMH packs from hybrid cars will come down in price. Right now at $500 for a used Prius pack the cost per kwh of storage is still about 5 times that of Pb acid.

You are missing the point of the post. The hate is not aimed at small wind. It is aimed at companies/installers grossly misrepresenting output, mounting VAWTS on roofs, and charging thousands of dollars to do so.

So what size roof-mounted VAWT (swept area) and wind speed would you need to get a steady 20 watts output?

[JW]

"Small wind" is something different than "Hyped up Roof Wind"

but could be due to all the incorrect numbers given out by LLCs and the hype pushed by J.Leno and Pacw.

J.Leno and Pacw

Respectfully, can we leave these guys out of this?

As far as im aware these "end users" have publish nothing, also we dont need to pressure them into publishing any numbers...

The hate is not aimed at small wind. It is aimed at companies/installers grossly misrepresenting output, mounting VAWTS on roofs, and charging thousands of dollars to do so.

Although this is a good topic, everyody needs to "chill"

I think its great if we can say this softly...

Im going to "echo" whats been said already, if your getting into wind-power just for the fun of it, thats fine, enjoy and have fun 

JW

[Madscientist267]

from current 90watts of PVs> I have for the coffee pot and other cool little things

LOL 90 watts and you're going to waste it on making a pot of coffee? LOL It takes all day (and maybe then some) to get the kind of power out of a PV array of that size to run a coffee maker for even one pot!

More power to you tho (no pun intended), nothing says that what you use the energy for has to be one thing or another... LOL

Steve

[bradyaero]

It works if the turbine is designed for the roof....

<a href="http://www.youtube.com/watch?v=PMOQtOhFN2M" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube.com/watch?v=PMOQtOhFN2M</a>

What happens when the wind changes direction? Looks like a tiny swept area?

Sure it's spinning, doesn't mean it's producing. Output numbers?

Solar would look good on that roof!

Nice looking unit though.
 In the video he says ~14V @ ~4amps so not bad, even if it's a 20mph wind.
I'd like to see it with true viewable numbers, like a anemometer and  display of both Volts and amps during the tests.
I mic up on the roof for noise and one in attic for sound from vibrations would be nice too.

Cheers;
Bruce S

 

You can't put a f'n hawt on a roof.... but a hawt designed for a roof works quite well.
14 volts at 4 ams in < 20 mph wind that was not directly aimed at the roof.  Zero noise.  Turbine is 8 feet long by 42 inches wide.

There ya go, Dexatron

[Madscientist267]

I think this argument is pointless.

From what I can tell, traditional HAWTs don't do well with turbulence.

VAWTs do better with it, or it's never at least as much an issue.

Turn a VAWT on it's side, stick it in the right place, and it seems to do what it does.

To say it doesn't work, well, maybe not on a grand scale, but 14V @ 4A on something is more than my 2c PV panels will throw out into the real world, and in maybe close to about as much space?

Something needs to give between the VAWT and HAWT people.

I think it was said best earlier in the thread... 'if you're having fun'...

Steve
 

[Beaufort]

Something needs to give between the VAWT and HAWT people.
 

Yes, a side-by-side comparison of a VAWT and HAWT in the same conditions.  This isn't to encourage a right/wrong decision but to address the myths of both designs.  To date, I haven't seen two machines rated for the same power being tested.  I've been watching AWEA, SWCC, NREL, and other oganizations scramble to come up with standards and spending millions in the process, but nobody has done the Pepsi challenge with VAWT and HAWT. 

Does a VAWT capture more energy in variable/turbulent winds?
Is a HAWT more efficient than a VAWT?
Is a VAWT quieter than a HAWT?
Do less birds get killed by a VAWT?
Which has a better $ per kW?