Looking into small DIY wind turbines.

[spinningmagnets]

I recall finding a lot of useful info on DIY wind-gens at otherpower.com, and their chat-forum fieldlines.com

The way I remember it, it is useful to buy/rent a data-logging "weather station" that will log wind-speed, direction, and frequency.

Build a tall pole, and attach the weather station at 50 ft, then 60 ft, then 70 ft. This will tell you the lowest height that you can harvest useful amounts of wind. Robust towers are expensive, and the extra height costs are a significant factor. Mount the wind-gen 10-ft too low, and any money you saved on a shorter tower will be wasted on a system that generates very low watts.

Your cabin may be on the side of a hill, or by a stream (for fresh water and maybe a micro-hydro), but the wind-gen tower may be a better producer if it's located at the top of the hill. If yes, then there may be a benefit to generating AC with six wires (three phases) all the way down to the cabin, and put the rectifyer (AC to DC) which converts the six wires to two DC wires, next to the battery.

Also, buiditsolar.com has a DIY wind-generator section
https://www.builditsolar.com/Projects/Wind/wind.htm

 

[E1000]

otherpower.com fieldlines.com
...
Also, buiditsolar.com has a DIY wind-generator section
https://www.builditsolar.com/Projects/Wind/wind.htm

Thanks for the references to other sites! I will check them out. I found this site when searching for alternate energy and DIY wind turbines but all I found here was a bunch of pessimists and people who don't want to share their knowledge or help others.

 

[E1000]

topspeed posted tons of information about his VAWT over on fieldlines.com. Not sure why he won't post the same here? Oh well. Here is the link for anyone interested: https://www.fieldlines.com/index.php/topic,149820.0.html

No wonder it failed it is made from heavy plywood. And he has a weird obsession with RPM but no interest in watts which is odd.

 

[stan.distortion]

Get a weather station first and monitor your wind conditions. Not much point making any investment before having that data, if you're getting steady and consistent wind daily then it could be a worthwhile investment but if it's highly erratic and "all or nothing" then it's unlikely to give good results, you'll get practically nothing in the low periods and will probably have to put the brakes on in heavy periods.

 

[E1000]

Get a weather station first and monitor your wind conditions. Not much point making any investment before having that data, if you're getting steady and consistent wind daily then it could be a worthwhile investment but if it's highly erratic and "all or nothing" then it's unlikely to give good results, you'll get practically nothing in the low periods and will probably have to put the brakes on in heavy periods.

What if I am building it for free from spare parts and materials I've collected? What if I plan to make it portable and take it with me and set it up in the ideal spot in each location I take it to?

Maybe I am thinking too far out of the box for this forum.

 

[stan.distortion]

Get a weather station first and monitor your wind conditions. Not much point making any investment before having that data, if you're getting steady and consistent wind daily then it could be a worthwhile investment but if it's highly erratic and "all or nothing" then it's unlikely to give good results, you'll get practically nothing in the low periods and will probably have to put the brakes on in heavy periods.

What if I am building it for free from spare parts and materials I've collected? What if I plan to make it portable and take it with me and set it up in the ideal spot in each location I take it to?

Maybe I am thinking too far out of the box for this forum.

Not at all, I've spent years doing the maths on wind turbines and you've pretty much hit an ideal sweet spot square on the head with that idea. Something that can be towed behind a typical van or 4x4 and easily erected on site can put out usable power, give a good balance of cost/output and avoid planning/regulation complications. Go bigger and storage needs get out of hand, go smaller and output isn't high enough to justify costs (plenty of exceptions ofc, it's just a good ballpark figure).

3 meter diameter is a good size to aim for there but wind works out to be the least desirable of the 3 main options, wind, hydro and solar. If you've not got ideal wind conditions you get hamstrung by storage, the cost of the turbine is overwhelmed by the cost of storing enough power at the peaks to make it worth while. The ideal imo for wind is to combine it with hydro, pumped storage and that's only cost effective for a very limited number of locations.

 

[E1000]

Not at all, I've spent years doing the maths on wind turbines and you've pretty much hit an ideal sweet spot square on the head with that idea. Something that can be towed behind a typical van or 4x4 and easily erected on site can put out usable power, give a good balance of cost/output and avoid planning/regulation complications. Go bigger and storage needs get out of hand, go smaller and output isn't high enough to justify costs (plenty of exceptions ofc, it's just a good ballpark figure).

3 meter diameter is a good size to aim for there but wind works out to be the least desirable of the 3 main options, wind, hydro and solar. If you've not got ideal wind conditions you get hamstrung by storage, the cost of the turbine is overwhelmed by the cost of storing enough power at the peaks to make it worth while. The ideal imo for wind is to combine it with hydro, pumped storage and that's only cost effective for a very limited number of locations.

My plan is to use solar, wind, and water power to charge my EV for off-grid camping adventures. Locations will be chosen to maximize energy availability from all sources.

 

[topspeed]

I am going to build a small scale VAWT out of composite materials with the goal of charging an EV in wilderness areas supplementing solar and standard plug-in charging.

My initial plan is as follows. I would love to have comments and criticism and "I've tried that befores."

Basic design based on the FloWind 19m 3-bladed prototype discussed starting on page 34 of the attached Sandia National Labs document.

VAWT Flowind EHD.png

Goals:
-2-6KW power generation in 15mph wind.
-Low cost.
-Free standing rotor system without need for guy wires or braces.
-Low-maintenance operation to be used while I sleep or hike or do other activities.

Reasons for choosing a VAWT design:
-Goal of folding and portability. Heavy generator can be fix mounted to the roof of the vehicle or as an anchor on the ground and the lightweight blade assembly can be removed for stowage.
-DIYability. I have lots of experience with foam, fiberglass, carbon fiber, and balsa wood based RC sailplanes and I plan to use the same construction methods for the blades and rigid carbon tubes for the axles and struts.
-Omni-directional by nature. Can also operate well in turbulent or swirling wind areas without a consistent wind direction, i.e. mountain and canyon areas.
-Ability to operate in low wind conditions.

Design:
-Darrieus "eggbeater" VAWT with 6-10 foot blade length with top and bottom bent towards the axle. Size chosen based on trying to get best power generation while maintaining ability to pack up and store in a vehicle.
-3 blades to gain an additional torque impulse and aid in self-starting.
-Carbon fiber axle riding on ball bearings top and bottom.
-Carbon fiber mounting plates for the blades.
-Foam core blades with fiberglass or carbon fiber vacuum wrap. Possibly off the shelf RC sailplane wings.
-Possibly a small Savonius turbine mounted at the very top to maintain rotation in low wind but good efficiency in high wind. Also to aid in the self-starting ability of the system because Darrieus turbines sometimes need an initial rotation given to them to start.
-Transmission for optimum generator RPM, possibly with two speeds for high and low wind.

I chose this design because it seems like something an avid DIYer can build whereas a good DIY HAWT seems harder. A VAWT has all the heavy stuff down low which is something I think I can build. A HAWT would require me to purchase a high strength tower or weld something big and heavy and could be hard to setup in a primitive location. I think my VAWT could be mounted on the roof of an SUV with the blade assembly removable for stowage.

The only specific piece of hardware I currently have is a 10kw Manta motor/8kw generator. I plan to use this generator in my project because I got it for free and I think it is sized well for my application. I have the "Old Manta type #1" shown here: https://www.hydrogenappliances.com/manta.html

R/C plane wings won't last long....even solid wood systems sometimes seem to last around 10-12 years. This is a serious issue.

My aim is to test the system with "model plane" structure made outa ply and wood spars...but even that seems to start fading just in one sommer when instantly taken down and re erected the next day. It needs at least light coating of fibre glass.

The final product will be stainless steel system..that lasts 100 years.

 

[marka-ee]

I've been toying with the idea to make a wind turbine, conventional horizontal type, using a hub motor. So I looked at a lot of the sites and links I found, many dating back almost 2 decades. Sitting here in 2021, it's like I have a time machine to look at all these enthusiastic DIY projects. The 'time machine ' of the net lets me skip ahead to see what ever happened to said project. Sadly they mostly fizzle out. Poor engineering mostly. I'd love to see one that actually worked for more than a year and actually states the wattage per wind speed data. Most articles are so evasive about that damned wattage number. They seem to prefer RPM's or voltage output numbers. Useless.
I have a small grid tie solar system which offsets my utility meter by 500 watts. It just works. But playing with a wind mill just for the heck of it could be fun.

 

[Hwy89]

I went down this rabbit hole back in 05 and 06. I built numerous prototypes using Delco alternators rewound and fitted with permanent magnets. I got some worthwhile power and would have continued except that during a nasty storm one of turbines disintegrated. One blade went over the house and imbedded itself in the neighbor’s garden and I never found the other two. From that point on I’ve been a proponent of solar.

 

[Bradz estuff]

Hi,
I have mainly solar setup but mucked around a little with few turbines. They are ok as little bit extra but never going to put out sorta power get from solar unless you live in a constant tornado or something.
I live in Australia and don't have exceptionally high wind like right off the coast or anything but rarely do you see it making more than a trickle of power. When a storm going or something it does put out some decent power but its not often.
There's few things could do to improve its output ect but really unless you going to have some huge turbine in optimum conditions then its really more for the knowledge and understanding how it works rather than the huge amount of power each turbine is going to be putting into your batteries. I don't regret installing it and learn alot from it ect but It prob bring in less power than if had just added 1 more solar panel onto system, just it cost about the equivalent amount as 3 panels would cost and plenty of time setting it all up and getting to point it all 100%.

 

[topspeed]

I went down this rabbit hole back in 05 and 06. I built numerous prototypes using Delco alternators rewound and fitted with permanent magnets. I got some worthwhile power and would have continued except that during a nasty storm one of turbines disintegrated. One blade went over the house and imbedded itself in the neighbor’s garden and I never found the other two. From that point on I’ve been a proponent of solar. 1FF951F2-2388-4FBD-B306-9B5D547B48E6.jpeg

Yes...there are dangers here involved. The pitch controlled HAWT is now little over 100 years old innovation.

 

[topspeed]

Small polish turbine factory delivers 74% efficient VAWTs ( only in small winds sadly ).

https://www.youtube.com/watch?v=EM-gCvhQhPU

 

[Hillhater]

Small polish turbine factory delivers 74% efficient VAWTs ( only in small winds sadly ).

What does this mean exactly ?
74% of max generator capacity in optimum wind conditions ?

 

[topspeed]

Small polish turbine factory delivers 74% efficient VAWTs ( only in small winds sadly ).

What does this mean exactly ?
74% of max generator capacity in optimum wind conditions ?

That is what ANEW company claims of putting electricity into network for their B1 turbine at 5.25 m/s wind.

https://www.energy-xprt.com/downloads/anew-model-b1-vertical-axis-wind-turbine-brochure-823378

 

[stan.distortion]

That will be 74% of the theoretical maximum impeller efficiency which is only about 45% so in reality actual efficiency would only be around 30%. I'm guessing that's total efficiency though, electrical output because they wouldn't be making a big deal about it otherwise seeing as you can get over 40% impeller efficiency with a few bits of carefully cut drainpipe for blades. The output at a steady wind speed has little relevance for the vast majority of cases where wind power is considered although, in fairness, the few cases that have consistent wind speeds are the only ones viable for wind power without masses of storage and the ability to capture much higher wind speeds than current turbines are capable of.

 

[topspeed]

That will be 74% of the theoretical maximum impeller efficiency which is only about 45% so in reality actual efficiency would only be around 30%. I'm guessing that's total efficiency though, electrical output because they wouldn't be making a big deal about it otherwise seeing as you can get over 40% impeller efficiency with a few bits of carefully cut drainpipe for blades. The output at a steady wind speed has little relevance for the vast majority of cases where wind power is considered although, in fairness, the few cases that have consistent wind speeds are the only ones viable for wind power without masses of storage and the ability to capture much higher wind speeds than current turbines are capable of.

No they claim 74% of the wind energy into network...that is an exuberant claim. There are several studies which do confirm that Betz limit is only valid on propeller type turbines.

OTOH they have only 10 year warranty for the blades.

 

[Hillhater]

No they claim 74% of the wind energy into network...that is an exuberant claim. .

So they are calculating a theoretical energy input ...swept area, wind speed, air density , etc etc ....at a optimum speed....
...and then comparing that to electrical energy output ?
With no reference to generator max capacity, or performance at other wind speeds ?
That is a pretty limiting specification.
I wonder Why they do not use the industry convention of generator “nameplate” rating , vs, energy output over a typical operating period , days, or months ?..
...to give a reference Capacity Factor,...for a given location.

 

[topspeed]

No they claim 74% of the wind energy into network...that is an exuberant claim. .

So they are calculating a theoretical energy input ...swept area, wind speed, air density , etc etc ....at a optimum speed....
...and then comparing that to electrical energy output ?
With no reference to generator max capacity, or performance at other wind speeds ?
That is a pretty limiting specification.
I wonder Why they do not use the industry convention of generator “nameplate” rating , vs, energy output over a typical operating period , days, or months ?..
...to give a reference Capacity Factor,...for a given location.

Yes many wonder also if the readings are accurate.

----------------------------

Seen this yet : https://www.youtube.com/watch?v=7RgyLDVlAg4

 

[topspeed]

Modest developement on my version 4 today of the prototype.

Yellow wing on the back is from the old set up with 1 m shorter moment arm.

 

[topspeed]

No they claim 74% of the wind energy into network...that is an exuberant claim. .

So they are calculating a theoretical energy input ...swept area, wind speed, air density , etc etc ....at a optimum speed....
...and then comparing that to electrical energy output ?
With no reference to generator max capacity, or performance at other wind speeds ?
That is a pretty limiting specification.
I wonder Why they do not use the industry convention of generator “nameplate” rating , vs, energy output over a typical operating period , days, or months ?..
...to give a reference Capacity Factor,...for a given location.

6-12% above Betz's limit is plausible ?

https://iopscience.iop.org/article/10.1088/1742-6596/753/2/022056/pdf

 

[topspeed]

My wings look like this day before yesterday.

 

[SlowCo]

That looks more like wings for a plane then windturbine. :wink:
Curious to see how this turns out.

 

[topspeed]

That looks more like wings for a plane then windturbine. :wink:
Curious to see how this turns out.

Yes H-darrieus VAWTs are like this.

Here is the wing tip / winglet.



Final aspect ratio will be 8.

 

[ynot]

Easy to build 'drag' machines, but designing and building blades that generate lift is very difficult and requires matching generators with blade design.