I want to make a small wind turbine

[Xringer]

I want to make a small wind turbine (about 2' OD) to put out in the backyard
as a wind speed indicator and something that might keep the birds away from
my solar mount experiment..

I've been looking at these vertical spinners..



One hour projects

Because they seem like the easiest to make.

My question is, does the 4 blade have any real speed or torque advantage over over the 3 blade design?

Just looking at the angles, is seems like the 3 blade would be less draggy
and spin faster in less wind.. But, I haven't a clue if that's true..

Thanks,
Rich

[Ryland]

Some basic rules for wind if you want to get any output out of it.

50 feet above anything within 500 feet.
Drag devices don't work well, a drag device being anything that is pushed by the wind rather then being an air foil.
My parents have a cup wheel style air speed indicator that is just above the roof line of the garage that is 20 feet away, I looked out the window one day to see if it was spinning and did a double take because the thing was spinning backwards! just for a few seconds then it stopped and started spinning the correct direction, the wind that low and close to the roof line was so turblulant that it was at times pushing on the back sides of all the cups strong enough that it really was spinning backwards.
There are times when that cup wheel is dead still, I can feel a light wind on my face and the turbine that is up the hill is spinning away putting out electricity like it should in a 10-12mph wind and every once in a while the wind speed indicator would show 2-3mph wind speeds on it's light up readout, so why did we even bother putting up that air speed indicator? the real reason was just to show people who ask why the we went to the work of putting a turbine so far away from the house on a tall tower, instead of putting it on the roof top.

[Xringer]

Don't need to make any power, unless it's a gimme. So a drag device will do just fine.
Since the 'pushers' can only spin as fast as the wind is moving, it can be my wind-speed indicator.
Plus, I think it might keep the birds out of the area where it's installed.

I've noticed that our little plastic penguin with propeller arms on the deck railing
does keep the birds away when the wind is over 2 MPH..


I was looking at the FG 'blades' I have and trying to figure out a hub piece,
and I think the 4 blade will be the easier to built, since it just needs
a square block to mount the blades to. Wooden 4x4 maybe?

[Ryland]

if you just want a worliegig that is of a large size I would say 3 is a good number as you have to push the return side back in to the wind, you can make a large cup wheel out of 55 gallon drums with a cut edge at the center, or 5 gallon buckets cut down the center with the open end towards the center.

[Daox]

Or a piece of PVC pipe. We had one guy here who made one like that... lemme dig up the blog post.

Here we go.
DIY Vertical Axis Wind Turbine | EcoRenovator.org

[Xringer]

I made the 3 wing model from the above drawing..



When I fan tested it, the results were poor.. Outdoor testing was disappointing too.

But, it was close to the house in a high turbulence area.. It just didn't want to self-start..


So, I added the Turbo mod..


36" of tape showing

Now, it self starts and turns pretty well (even in high turbulence).

So, the plan is to stick it up in the air, on a tree in back of the solar tracker
and see how it really works.

Something to do, while I'm waiting for the flooding in the basement to end...

Kinda looks like something that should be attacking Death-Stars..

[Daox]

Originally Posted by Xringer

Something to do, while I'm waiting for the flooding in the basement to end...

Haha, turbo mod, love it.

Ack, sounds like I'm not the only one. My sump pump died Thursday night and I had 6" in the basement in the morning. Alls well though, I'll have pics up just for kicks later on.

[Xringer]

Got a real heavy gust on the test stand..



It still works leaning sideways!

Check out the new lake just behind my yard!

[Xringer]

You might want to check your local weather data. There should be a wind speed history
you can access.

I know almost nothing about windpower, but I would 'guess' that you would want winds
of at least 12 MPH for at least a few hours a day.

And, of course the exact location and height of your turbine is extremely important.
For safety reasons, it can't be near the ground. And it's got to be high enough
to be clear of buildings and trees.

The turbulence and blockage from nearby hills, buildings and trees can render your
location useless for wind-power. Unless you can put up a very high tower.

My toy wind-turbine is still out there spinning occasionally when conditions
are just right.

You can see the wind toy, on a tall tree stump behind my tracker..