Light Weight Wind Turbine Project - as I build it.

[ghurd]

Yup, I sure do.
G-

[ChrisOlson]

So your bottom line suggestions have equaled "quit now" or "move somewhere where there is more wind and build a 10 or larger rig."

I felt it necessary to come back here and clarify a point.  I read thru the thread and nobody suggested any of the above.  It was pointed out that solar would be a better option than wind with your situation with the short tower.

What I have been trying to convey is that the amount of power available to a wind turbine increases with the cube of the wind speed.  However, the output of a generator is typically linear.  What this means is that a wind turbine will produce 8x more power at 12 mph than it will at 6 mph.  But only if it is designed correctly to be able to harvest it.

I tried to show you this by demonstrating how my 10 footer runs at only 28 watts @ 6 mph but it reaches 2.5 kW @ 28.  When you graph this and look at power output, long term, it is basically not even worth having the blades spinning at wind speeds less than 8 mph.  And that is why I let even my MPPT machines spin at extremely high rpm in light wind  - so it can respond by DECELERATING to optimum TSR when the controller loads it.  You get much quicker response to turbine loading by having it run fast than you do by running it slow.  When the rotor is running slow it has to try to accelerate to match its TSR with an increase in wind speed, and the airfoils go into immediate stall if they're already heavily loaded.

This should all be in the homebrew book.
--
Chris

[thingamajigger]

@Steadfast

Oh... I don't doubt the physics nor the advice for a second...

You should

It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.

---Mark Twain

I built my first 5m turbine when I was 13 years old, over 30 years ago, which was a standard dual belt driven design at the time turning a big old 52 Merc generator to charge batteries for the lighting in my shed/laboratory. It lasted about 8 months before gale force winds caused one of the blades to separate from the hub, this was not inherently due to the high wind but the fact the furling mechanism was unreliable and the paint at the root of the blades had worn away which caused water damage and weakening of the material. I found a five foot section of the blade about forty feet away from the turbine .

I would agree with most of what has been said in this thread to some extent and normally it is a good idea to plan for the worst in regards to mother nature. I would like to make one point concerning your short tower, that is a short tower is perfectly fine considering your turbine and its' use. In fact most people don't really understand why we always use high towers and never question why this is so. People install high and expensive towers which can be one half the cost of a system because the wind velocity is marginally higher at elevation however this is not the only reason why the towers are so high. The real reason is that none of the experts knows how to build a large diameter turbine which can consistently deal with the massive stress loads due to gusting high wind conditions usually found near ground level. This is also why we are seeing so many large commercial turbines routinely suffering catastrophic failures in the news.
Lol, the latest unworkable band-aid solution involves laser radar (Lidar) to detect the incoming gusting high winds to reduce stress loading despite the fact there is no way is hell they could possibly pitch the blades fast enough to actually make a difference nor that the pitching would likely induce as much stress as the gusting wind.

So my advice is to put her up and let her fly, see what happens and address the problems as they occur and solve them, not band-aid solutions you must solve the inherent problems. I never learned anything really innovative from a textbook because it's always just another flavor of the same old thing, real innovation usually involves a certain amount of risk.

@ghurd

Bending the tips does not change the physics.
That crap is a sales pitch that some people fall for.

Do you think this is why almost all new commercial/ business class jets and helicopters use airfoils with some form of winglet at or near the tips, just another sales pitch?. Lets do a little thought experiment, let's say we take these silly unproven bent tips and applied this thought to the whole of an airfoil, what do you suppose it might look like?. Well it may look something like this ---http://peswiki.com/index.php/Directory:WhalePower_Corp---, a 40% increase in angle of attack to stall, a 32% reducion in drag --- could a person ask for anything more. Which kind of adds a new wrinkle to all the numbers the experts like to throw around considering "the facts" doesn't it?, what are the facts when the facts keep changing, lol.

Regards

[fabricator]

. People install high and expensive towers which can be one half the cost of a system because the wind velocity is marginally higher at elevation however this is not the only reason why the towers are so high. The real reason is that none of the experts knows how to build a large diameter turbine which can consistently deal with the massive stress loads due to gusting high wind conditions usually found near ground level. This is also why we are seeing so many large commercial turbines routinely suffering catastrophic failures in the news.

Nothing like a ridiculous statement in your first post.

[thingamajigger]

@fabricator

Nothing like a ridiculous statement in your first post.

Is it ridiculous?, here's a question --- how long do you think a 130 foot airfoil or for the sake of arguement even a 20 foot airfoil would last if the air velocity at the outer 1/4 span regularly quadrupled in a matter micrseconds? I do not mean a 2D wing with laminar flow like many see in textbooks I mean in the real world where forces act in three dimensions through gradients. It is called wind shear and the term "shear" usually refers to what occurs to airfoils when they experience it.

It may help if you could explain in detail which part you found ridiculous.

Regards

[birdhouse]

I would like to make one point concerning your short tower, that is a short tower is perfectly fine

this post should be removed from this thread entirely.  it is FALSE and shouldn't be read by anyone. 

thingamajigger- are you one of those folks from missouri wind and solar??  because if you are, that would make a lot of sense with the rubbish you posted above. 

The real reason is that none of the experts knows how to build a large diameter turbine which can consistently deal with the massive stress loads due to gusting high wind conditions usually found near ground level.

even more rubbish!

nuf said...

adam

[windvision]

thingamajigger?

  Not sure where you get your information, but some of it is not realistically possible/probable. The type of wind shear we see and you speak of does not happen in microseconds. That would only occur after an atomic blast or a similar event. So your point is?

  Lidar is a tool. Just like many other methods to measure wind speed, turbulence, ect. Do you have first hand experience with Lidar, or are you just making hypothetical guesses as to its worth?

  I own 3 wind turbines. My 900 KW is the oldest. It changes pitch every 5 seconds. My 1.5 MW turbine changes pitch 10 times per second. My 2.5 MW turbine changes pitch at the top of the rotation and also at the bottom of the rotation because of the difference in wind speed at the different levels. Oh, did I mention the rate of change? 24 times per second.

  Getting back to the issues at hand. As I reread the entire post, no one said his combination wouldn't work. What they said is, it wouldn't WORK WELL.

  One more thing, I have met and talked with Stephen DeWar from Whale Power at the AWEA Conference in Dallas, Texas. Nice guy, great concept. Patent in hand for years now. If this is a game changer as you say, why don't we see the concept on every turbine produced? In case you don't know, the major turbine manufacturers are not beating down his door. Why don't you ask him why before putting all the links on the board?

 

 

[ghurd]

@ghurd

Bending the tips does not change the physics.
That crap is a sales pitch that some people fall for.

Do you think this is why almost all new commercial/ business class jets and helicopters use airfoils with some form of winglet at or near the tips, just another sales pitch?. Lets do a little thought experiment, let's say we take these silly unproven bent tips and applied this thought to the whole of an airfoil, what do you suppose it might look like?. Well it may look something like this ---http://peswiki.com/index.php/Directory:WhalePower_Corp---, a 40% increase in angle of attack to stall, a 32% reducion in drag --- could a person ask for anything more. Which kind of adds a new wrinkle to all the numbers the experts like to throw around considering "the facts" doesn't it?, what are the facts when the facts keep changing, lol.

Regards

A new wrinkle?  Not at all.
Skyscrapers laying sideways on the ground don't scrape the sky.

Swept area is swept area.
59.3% has NOT changed.

You have no idea what the pertinent facts are, or how to apply them.

[fabricator]

@fabricator

Nothing like a ridiculous statement in your first post.

Is it ridiculous?, here's a question --- how long do you think a 130 foot airfoil or for the sake of arguement even a 20 foot airfoil would last if the air velocity at the outer 1/4 span regularly quadrupled in a matter micrseconds? I do not mean a 2D wing with laminar flow like many see in textbooks I mean in the real world where forces act in three dimensions through gradients. It is called wind shear and the term "shear" usually refers to what occurs to airfoils when they experience it.

It may help if you could explain in detail which part you found ridiculous.

Regards

Basically the entire damn post, I've visited several large wind farms, and strangely enough I've never seen large stacks of spare blades or armies of maintenance people replacing the blades that must according to your post be destroyed daily if not hourly.

[thingamajigger]

@windvison

Not sure where you get your information, but some of it is not realistically possible/probable. The type of wind shear we see and you speak of does not happen in microseconds. That would only occur after an atomic blast or a similar event. So your point is?

Im not sure were looking at this from the same perspective, I think your refering to turbulence like we would find in close proximity to the ground which is like saying I throw a beach ball to you at 5mph and you catch it and you feel a force equivalent to 5mph. Simple enough, now I spin the beach ball CCW on it's axis so it has a surface speed of 35 mph then throw it to you again at 5mph only this time your left hand feels a force equivalent to 40 mph and your right hand a force equivalent to 30 mph. Now if the beach ball was a volume of air it is easy to see that there are two forms of motion present, one where a volume of air moves through a space at 5mph and another where a volume of air moves around a singular point at 35 mph +/- the ambient speed of 5mph. This is why a twister can level one house to it's foundation and not touch the house next to it because one volume of air acts independently from that around it through a boundary condition.

I don't imagine your big old turbines sitting in open ground will ever see anything resembling real turbulence on the other hand I have seen a 1m blade sheared instantly at its root, there was no apparent flexing as some might think the damn thing was just sheared off because I specifically placed the turbine in an area of turbulent air to test what would happen. It's called bluff or blunt body vortex shedding and is found most everywhere in nature.

One more thing, I have met and talked with Stephen DeWar from Whale Power at the AWEA Conference in Dallas, Texas. Nice guy, great concept. Patent in hand for years now. If this is a game changer as you say, why don't we see the concept on every turbine produced? In case you don't know, the major turbine manufacturers are not beating down his door. Why don't you ask him why before putting all the links on the board?

They say it takes 20 minutes to think of a better way of doing things and 20 years to sell it to somone else and unfortunately even in this day and age innovation is often dictated by economics and politics however we should not confuse the two. As well days after reading the first article I built and tested the technology for myself on a 1m airfoil so whatever the other turbine manufacturers may do or think really has no relevance to the fact of whether it works or not, you see I know as a fact it works very well. I guess the real question here is why wouldn't everyone do this?, rather than relying on second hand information and marketing hype if not baseless opinions why not just spend an afternoon proving the matter for ourselves?.

Regards

[fabricator]

I must just be lucky, I've had a 17 foot machine on a 25 foot "test" tower for four years now because of a local ordinance, there is a pole barn and 100 foot tall oak trees within 150 feet of the turbine, which has home carved white pine blades, it's been running since the spring of 09 without a problem, seems like I should have had at least one blade sheared off by now.

[birdhouse]

my 70' tower is barely above the trees, and i wish it was higher, because i do get some turbulent winds.  it sits in a wind zone 3/4.  i've seen it running balls out in very gusty turbulent winds.  my blades are still where i bolted them upon construction, and i have no worries about them staying where i bolted them.  each blade has a thick root, and is sandwiched between two 3/16" stainless plates with four 1/4" stainless bolts per blade (8.5' dia).

i think you may have design and or structural issues going on with your blade shearing.  why are you talking about beach balls when you can't even keep blades on a turbine?  again, design issues. 

everytime i drive to my ranch, i pass over 300 big boy wind turbines (200-250' dia) and i've never seen one with only two out of the three blades attached, or any signs of failure.  they've been up for 3+ years. 

adam

[tanner0441]

Hi

I don't understand the concern for micro second bursts or changes in wind speed and direction.  The sheer mass of even a tiny blade would not respond to microsecond changes in wind pressure, as for no-one knows how to deal with wind conditions at low levels..... Correct, and if all the brains and finances at the disposal of the companies able to study it can't work it out there is a fortune to be made by a first time turbine builder in a shed.

No one called you names, I have read through the complete thread now several times and all the comments have been to offer help and try to save you getting hurt, or someone else.

Suggestions have been put forward for what you should be looking at, but you have not even come back with a wind survey of your site, only what you want to do.  Some years ago in the UK was a company who were going to bolt a 6ft by 1Kw turbine to house chimneys. You never hear about them any more.

A suggestion you can try, tie bits of ribbon to the branches of all those trees and as many levels as you can climb to.  Then take a series of photographs and compare them, I bet every bit of ribbon on every photograph will be pointing in different directions, then ask yourself HOW in hells name a set of blades of any shape can respond when the pressure is never the same on any of the blades for more than a few seconds, and the bigger the blade the more it needs to be considered.

I look forward to the posts when you come onto the number of turns in the coils and the positioning of the magnets relative to the coils, and air gaps.

Pity your not in the UK. I would be happy to give you a traction motor from an electric go kart, a modified automotive alternator with the 6 wires brought out the back and a 24 V 240 W electric bike motor.  They are under my bench, they have all been strapped to a pillar drill and spun up to 1500 RPM. Not one of them produces enough power to charge a battery.  That is why they are under my bench and not on a pole in my garden.

Brian

[Norm]

I've read thru this whole thread and what I get is that you
 seemed to want answers to your questions....
.....Yet if you didn't like the answers you were gradually
starting to get more and more frustrated and go on the defensive?

.......but keep on posting your project....I'm anxious to see
how things turn out.

Norm.

[fabricator]

Tanner, I think you're mixing up the thread starter and this newbie.

[ChrisOlson]

Do you think this is why almost all new commercial/ business class jets and helicopters use airfoils with some form of winglet at or near the tips, just another sales pitch?.

I'm not sure I can agree with any of this where it relates to wind turbines.  The "winglets" used on aircraft wings only increase the aspect ratio of the wing.  Since the chord is rarely constant on aircraft airfoils the aspect ratio is the square of the span divided by the area of the wing planform.

The highest efficiencies in wind turbine airfoils have been achieved with slender, low Cd airfoils operating at extremely high tip speed ratios - they can approach 50%.  Not by cutting out a pattern on sheet aluminum with a trailing edge "winglet" and bending it in break.
--
Chris

[thingamajigger]

@Norm

.......but keep on posting your project....I'm anxious to see
how things turn out.

I hope steadfast will keep posting his progress as I'm anxious to see what will happen as well. I think everyone here should let him do this and I apologize in advance for the next time a get off topic because I probably will.
I have built a quite a few barnstormers in the past just to see them disintegrate in high winds and scatter there remains across my field and it was quite a bit of fun actually. It usually involved a few friends and a lot of beer and I knew there was no way in hell it was going to survive but it was always a good learning experience. There were even some machines which really suprised me because they didn't look like much but they were practically indestructable, I mean they were bending and shaking and making all kinds of god awful noises but they never failed.
Regards

[electrondady1]

thingamajigger ,
 perhaps if you  stick around and read up a bit you can get your mills to stay in  one piece. and then maybe you won't  drink so much.
 
steadfast ,
there are people here that are off grid.
they talk rough but are honest .
the people you buy your stuff from, talk smooth.
and tell you just what you want to hear,

i've been coming here for about 9 years
learning all the time
no one gets it right the first time

[fabricator]

thingamajigger ,
 perhaps if you  stick around and read up a bit you can get your mills to stay in  one piece. and then maybe you won't  drink so much.

ROTFLMAO

[tecker]

I assume you bought the Red delco ?

[Steadfast]

Since my PMA is being hand built, by the owner of the company, I am awaiting the completion and delivery of it... I simply have no new data to add at this point.

Except that during this weekend's new wooden shed's siding project, my two 6 volt golf cart batteries, have had no problem running my radio blasting my work music, all day long, while powering all of my power tools, including my circular Skill saw. And, that my two 140 watt solar panels have performed admirably at recharging those batteries that others here doubted would work. 


(This unflattering wood shed siding project photo, courtesy of my wife)

I added the shed onto the end of my chicken coop to give my riding lawn mower a new home out from my working shed and a better place to store the coop supplies.


Once the PMA is delivered, My father in law and I will devise a mount for it and mount it.  Then we will lower the pole and probably install some cables for further security.
Then we will raise it again, let her fly, and see what she produces...
 
I will take pictures when, and as I get the opportunity, to progress forward towards my project's completion.

[Steadfast]

Furthermore, this weekend, I also planted a raised 5 by 10' asparagus garden…

BTW: asparagus gardens truly, deeply and profoundly, SUCK to dig, plant, and build.
Just, look up the agonizing process...you'll see what I mean.



The wooden raised box was also made using power tools with the radio blasting away, all feeding off my shed's “sub-standard” battery system…

[dave ames]

Nice chicken coop there steadfast,

Absolutely nothing “sub-standard” with 280 watts of solar feeding ~220AH of battery...you even have room for a bit more battery (could double the size) and be OK.

For a while there I feared we lost you with our less than subtle critiques, so very glad to see you back.

Yikes! lots of work getting an asparagus garden established. ..be a few years now to see how you did 

Looking forward to more of the progress.

Regards, Dave

[ChrisOlson]

And, that my two 140 watt solar panels have performed admirably at recharging those batteries that others here doubted would work. 

You misunderstand what was said.  I pointed out that those batteries will only store a limited amount of power.  With 280 watts of solar feeding them, you can basically use about 130 watts continuous off them all day and they won't run out, and will stay near full charge.

Like somebody else stated, some of us have been living totally off-grid for years before you even thought about it.  And, yes, we might be a little rough around the edges.  But trying to "prove us wrong" is not going to work because it will eventually catch up with you, as we've already BTDT.

Like Dave says below, 280 watts of solar for that load is pretty decent.  If you want to see what your batteries really got, unhook the solar from them and use just battery power all day running radio, lights, power tools, etc., and see how much time you get from them before they dip below 12.0 volts (minimum safe voltage to prevent permanent damage to the plates).  I'd have to go back and refer to previous posts, but I believe I calculated they can store about 1,300 watt-hours of usable power.  280 watts of solar @ average 130 watts for 10 hours is 1,300 watt-hours, or 1.3 kWh.
--
Chris

[DanB]

'You misunderstand what was said.  I pointed out that those batteries will only store a limited amount of power. ,


Batteries don't store power (they store energy!)   sorry....  I just spend too much time worrying about how folks use those two words.

[ChrisOlson]

Batteries don't store power (they store energy!)

OMG.  My batteries store JUICE.  So cipher on that one for awhile.   
--
Chris

[JW]

So cipher on that one for awhile.

Difference Between Energy and Power

"Another difference is that energy can be stored whereas power cannot be stored."

[birdhouse]

orange juice or grapefruit?   

i like juice, both elctrically, and nutritionally!

[ChrisOlson]

orange juice or grapefruit?   

That's not specified.  It's just "juice".  Drink a lot of beer and you get juiced.  Touch the wrong wires and you get juiced.  Juice is universal   
--
Chris

[tecker]

Yep your heading off grid I think you'll run the gauntlet . I'ts not an exact science Trial and error is not what your mother would have wanted but she doesn't have any good ideas anyhow except the thing about clean clothes etc
I started a lot of projects at one time and then . The garden was in the mix so the garden is in and I'm back on the electrical . Chickens and garden is a good mix if you can keep them separated at times . I like it all hang in there.

[ChrisOlson]

I have a question though.  What do you do with asparagus?  Certainly not eat it, I hope?  I remember eating some when I was a kid, and only because my mom told I had to because it was "good for me".  Ever since then I've hated anything that's supposed to be "good for you".   
--
Chris

[Bruce S]

I have a question though.  What do you do with asparagus?  Certainly not eat it, I hope?  I remember eating some when I was a kid, and only because my mom told I had to because it was "good for me".  Ever since then I've hated anything that's supposed to be "good for you".   
--
Chris

Bacon wrap it and put it on the grill. !

[dave ames]

....What do you do with asparagus?  Certainly not eat it..

A power drink for energy perhaps?