Author Topic: For the VAWT inspired (Read 3413 times)

Warrior · « **on:** September 10, 2007, 01:55:40 PM »

Stumbled into this webpage.

http://mariahpower.com/index.php?option=com_content&task=view&id=13&Itemid=35

Warrior

DanB · « **Reply #1 on:** September 10, 2007, 08:18:23 AM »

Another one that I'm very skeptical of.

No product... but you can reserve yours today!

'investors click here'

'1KW output from a machine that sweeps 40 square feet'

Nice webpage though!

feral air · « **Reply #2 on:** September 10, 2007, 09:58:27 AM »

"affordable pricing" and "$3,995.00" don't really go together.

TomW · « **Reply #3 on:** September 10, 2007, 10:57:54 AM »

Warrior;

I have to agree with feral air and DanB on this puppy.

Still hoping one of you VAWT guys pull off a next level VAWT, however.

Cheers.

TomW

iamdewayne · « **Reply #4 on:** September 10, 2007, 11:02:21 AM »

'1KW output from a machine that sweeps 40 square feet'

I see that too...

Rated at 1kwh... they talk about 12 mph, but the specs say its rated at 25mph

maybe it can hit a kw at 25mph, I sure wish they would just come out and say that.

by their figures, it makes about 214 watts per hour average in 12 mph winds if I'm reading it right ( 1880 kwh per year divided by the 8760 hours in a year). Here in Dallas, Texas thats about 260 dollars a year off my bill ( they only offer the grid tie version waiting list for now )

At a cost of 4000 dollars and a 15 year payback, I think I'll stick to solar....

I'm still searching for a good 200 watt vawt for my roof.... even if it was a pair of 100 watt machines.....

Dewayne

Warrior · « **Reply #5 on:** September 10, 2007, 12:05:23 PM »

Oh I agree with Dan on this too. I'm a HAWT guy 100%.

For me it's easy, if VAWT had similar performance as a horizontal, then the major manufacturers would already be using them. I just don't have faith in them; they are all snake-oil to me

I just posted it to share with the vertical axis guys, maybe they can get some ideas.

Warrior

feral air · « **Reply #6 on:** September 10, 2007, 01:44:50 PM »

You should build a small vawt and then maybe they won't seem so snake-oily.

feral air · « **Reply #7 on:** September 10, 2007, 01:49:41 PM »

Could you settle for 10, 20watters?

That may be the best way to go if you plan on putting them on your roof. The big guys tend to wobble or vibrate because they're harder to balance. A bunch of smaller vawts would cancel eachother out and there's less mass behind them.

Just a thought.

DamonHD · « **Reply #8 on:** September 10, 2007, 02:06:20 PM »

What does a 20W VAWT look like? Any photos (or price lists!)? I'm after something around that power.

Rgds

Damon

Slingshot · « **Reply #9 on:** September 10, 2007, 03:05:05 PM »

Actually, it appears they are claiming 217 watts @ 12 MPH, and 1 KW at 25. But still it's vaporware, even if it's potentially-possible. "Looking for investors" is usually a dead giveaway.

feral air · « **Reply #10 on:** September 10, 2007, 03:25:41 PM »

I have no idea, sorry if I got your hopes up! I was just trying to point out that bigger (on your roof anyway) may not be better.

I've tried finding something in the 20w range too but all I've been able to find is sketchy homebuilt stuff with numbers I just can't take at face value.

I'm guessing a 4ft tall vawt made from 10inch pvc pipe would be able to put out around 20watts, if it was well built. If a steel barrel vawt can do 50-80watts...? I'm still pretty new to these things though so that's a WAG.

Sorry.

DamonHD · « **Reply #11 on:** September 10, 2007, 03:32:08 PM »

OK, well having gotten my first milliJoules of wind energy today I'm all over-excited! B^>

Rgds

Damon

CmeBREW · « **Reply #12 on:** September 10, 2007, 06:01:41 PM »

Yeah I just saw it on youtube lastweek:

http://www.youtube.com/watch?v=AnhpeJAS9gY

On the positive, it looks good.

But on the other hand, I'm skeptical also. My guess would be HALF that power at best-- like most other commercial units out there and there fantasyland ratings.

At 30 feet high, I wonder how it don't bend the shaft and/or prematurely tear up the bearings in high winds! I can flip a car over with the leverage from a 30 foot long pole!

The whole thing must bend in high wind I quess or it would destruct I would think. That design seems impractical. Perhaps there will be more detailed info later on it.

CmeBREW · « **Reply #13 on:** September 10, 2007, 08:20:25 PM »

On the other hand though, (thats right, i have 3 hands!) the good thing about that design is it self-regulates in high winds. I see now the blades are actually 20' high. I can only flip over a Yugo with a pole that short!. If they would extend the spacing on the bearings, and give more accurate,truthful power ratings, I still suspect it might make a useful moderate power VAWT. It is interesting. Of course cutting that price in half would help. I think we have all flipped around ideas like this using long pieces of PVC pipe. I thought about doing something like that attached to each corner of my house. (4 seperate, 8 ft. high, pvc Vawts- from the spouting down to the ground)

Bearing at the top and alternator down at ground level.

Fun to think about!

I wonder when and if they (Federal government) are going to pass a law that requires ALL (including China made) residential turbine manufacturers to get ACCURATE and TRUTHFUL power ratings using an INDEPENDANT testing source such as UL

I wonder if they already do? I actually don't know.

TomW · « **Reply #14 on:** September 10, 2007, 08:53:01 PM »

Cm;

Bearing at the top and alternator down at ground level.

Zubbly and I discussed using a motor conversion for both bearings. That would give you great control and the conversions become multitaskers as bearing and alternator in one piece.

We never tried it just talked it out. Seems to be a viable idea yet. I like the idea on the corner and roof edges of buildings, too. That seems a good location and might bypass "no turbine" problems. It is not a wind turbine, it is an active wind load deflector with electronic braking..

Cheers.

TomW.

Cheers.

TomW

tecker · « **Reply #15 on:** September 11, 2007, 04:19:03 AM »

Unless the shaft goes down the tower 10' the stress on the bearing has got to be massive.

wooferhound · « **Reply #16 on:** September 11, 2007, 06:55:54 AM »

I like Electric Eds idea about shrouding a VAWT . . .

http://www.fieldlines.com/story/2003/6/17/73839/3388

This would work really well on a Horizontal VAWT as suggested above.

feral air · « **Reply #17 on:** September 11, 2007, 09:05:55 AM »

It's easy to add a shroud on s-hawts (or you can mount them just-so) but on s-vawts it's not really worth it, imo.

The extra complexity and added cost outweighs any minor efficiency gains.

If it was a mass-produced vawt with a shroud then yeah, ok...I'd probably buy that one over a similar one without a shroud. But when you're building these yourself it's just not worth the hassle.

CmeBREW · « **Reply #18 on:** September 11, 2007, 05:27:52 PM »

Good Idea Tom. I wish I had way more time to learn more about those motor conversions and the 'F & P' motor conversions. I am beginning to have a big interest in all that now. Thats my main problem now with Vawts is making or converting something that will have a cut-in at only 30rpm (!!) and raise in AMPS as QUICKLY as possible with the slow rpms!!(Usual range of only 30-120rpm) So it seems to me, conversions and alternators for Hawts are different, since the amps raises SLOWER (to avoid 'stall') as the rpm increases ALOT.

My knowledge of conversions and 'F&P's' is still somewhat limited. I believe the 'F&P's' need to be rewound with smaller GA. wire to bring cut-in WAY DOWN to where I need it. Correct me if I'm wrong, but I don't think a conversion will work in this LOW of RPM range.

On the other hand, 'Gearing' is another option I am flipping around-- since perfectly 'matching' an alternator for a Vawt may be difficult. At least with gears, I can simply put different size spocket on there until I get it 'matched' good enough to the vawt rotor.

Concerning those 'corner of the house' Vawts, I like the idea of one conversion at the top and one at the bottom as you said, since you could have essentially TWO (electrical) 'gears' to switch back and forth to, instead of only one. The second one comes on during a stronger gust. I'm not sure how to do it though. I get decent breezes and good turbulant wind on the corners of my house. I stand there all the time. As we all know, its not the BEST place, but where my house is, its probably about the same as on top of my roof.(but less noticable)

I find these Vawts quite interesting--and I know I'll get SOMETHING out of 'em!!

TomW · « **Reply #19 on:** September 11, 2007, 05:55:57 PM »

Cm;

Thats my main problem now with Vawts is making or converting something that will have a cut-in at only 30rpm

Well,Zubbly assured me that a conversion could be wound to reach cut in at pretty much any RPM. I have no idea on how but thats what he said. Maybe he will pop in with a comment on that.

Cheers.

TomW

vawtman · « **Reply #20 on:** September 11, 2007, 06:00:06 PM »

Tom,

Still hoping one of you vawt guys pull off a next level vawt.

It seems over the last couple years im the only one that has been inside a real vawt to understand the power available but struggle to harness it.

Im not the type to throw in the towel.However spend my limited time here and thinkin.But love it and all the great advice i get along the way.

The wheel is on the testbed.Cool when spun at 60rpms the mags are blurry.

Sure i felt like giving up many times.

Not afraid of failure but you cant fail until you try,right.

One thing that bugs me is nonbuilders pickin on a vawt design.Not aimed at you.

CmeBREW · « **Reply #21 on:** September 11, 2007, 06:43:16 PM »

I suppose doing ALOT of turns with something like 24 ga. wire in a conversion would bring the cut-in WAY DOWN to 30rpm, but the question is, will the AMPS raise very quickly as I need them to. I mean, at cut-in I would start producing 1 watt@30rpm. But will 60rpm only be a measly 2 watts or will it go way up to like 20watts or more as I would like??? I do not know.

I have the same question with the alternator stator I'm making right now. The stator is only going to be 3/16" thick. Mag to mag gap, just over 1/4". This is to get as strong of flux as I can get with these smaller 1"dia.(1/4"thick) magnets. I already made and tested a test coil out of thin 24ga. wire / 170 turns. The cut-in will be about 30rpm, but I have no idea if the AMPS will raise quick enough??? It may only do 2 stinkin watts at 60rpm! I'm hoping for 5-10 watts or more at 60rpm and at least 20 watts or more at 100rpm. Like I said, my knowledge is limited I'm afraid. But I AM learning thru good Ol' 'trail and error'. I know what I'll have to do if it DON"T work. Either gear up or save up --and purchase MUCH BIGGER ($$$) magnets and make a whole new alternator.

DamonHD · « **Reply #22 on:** September 12, 2007, 01:36:46 AM »

I know nothing OK, but provided resistance is not a limiting factor then I guess there's one of two things that we might expect from doubling the rotation rate:

We double the current/power output in the obvious way (coils cutting twice as many field lines in the same time).
We double (or more) the voltage and current simultaneously and therefore the power goes up closer to available power in the wind, ie nearer speed cubed.

Just a thought, from a largely empty head.

Rgds

Damon

finnsawyer · « **Reply #23 on:** September 12, 2007, 09:51:37 AM »

I have been surprised that none of the VAWT builders have decided to investigate my alternator design. Using that design the prediction is that you would get at least four times the peak voltage out at the same rpm using the same number of the same magnets and identical, although more of them, coils. So, one could drop from a cut-in of 120 rpm to 30. There is a resistance penalty, however, as the the resistance would be three times as great. On the other hand, by going from a single winding to two in hand, the resistance drops by a factor of four and the voltage by two, meaning the cut-in could go from 60 rpm to 30, as compared to the three phase alternator. This increase (in power really) is made possible because the rotor diameter has about doubled, which doubles the rate of change of flux per coil, and the number of coils increases by 50%, which results in all the magnets working to produce power all the time, so you would have 12 coils producing voltage at any time rather than just six.

The rate at which the current increases after cut-in when charging a battery will depend on the alternator resistance. You don't want this current increase to be so great that the power into the battery exceeds the power available from the wind, as this will result in stall. At cut-in the current will be very small. At some point above cut-in you will reach one amp. The current will increase rapidly from that point, as will the power into the battery. You want to avoid stall. I believe that Flux had some good advice about that. You might check his Posts and comments.

CmeBREW · « **Reply #24 on:** September 12, 2007, 09:58:15 AM »

Well, I will find out soon enough. We all know that going with more turns of much smaller wire means MUCH greater RESISTANCE, which means it will LIMIT the current from raising quickly, which is seemingley the exact opposite of what I need. But I have no choice in order to get a cut-in of only 30rpm.(with those 40 / 1"diam. mags)

But the other principle is, the closer the mags (air gap) are to each other, the stronger the flux, which means (I believe) the greater the raising volts AND amps will be per RPM with any given coil. So I hope it will offset what I had to do with the high resistance. So I still may get some OK little watts in breezes for many hours a day for my small system. That is what I am after is more of a low power BREEZE Vawt for my small system. Most days in the summertime, there is only a little breeze, and my big VAwt only usually goes 30-100rpm.(but with alot of torque) If it don't work, I'll use 18ga. coils and gear up. It will be very interesting to study Zubbly's conversions. When I test the whole stator in the Vawt I will post a story soon.

feral air · « **Reply #25 on:** September 12, 2007, 01:56:38 PM »

Could you build a little vawt and give it a whirl? Alts are beyond me for now. I'd need detailed instructions or I'd probably screw it up.

My "quick vawt" diary post is about a simple S-vawt that should be fairly cheap and easy to duplicate on a slightly larger scale. A 2 or 3 footer would be pretty awesome if it had a halfway decent alt design to go with it.

That's just big enough to be useful but not so big that it would look out of place in a backyard...

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Author Topic: For the VAWT inspired (Read 3413 times)