Lenz turbine - Little to no noticable wind

[windstuffnow]

  I mounted the Lenz turbine on the roof as a test bed a couple days ago.  I've yet to see it stop turning.  Today there was a defining calm, I checked both my anemometers and both read 0.0 mph.  I went out to start another project and happened to glance up at it and it was still spinning.  Here is a video of the unit in wmv format... it's about 15 seconds long and about 475kb download.  Take note of the anemometer on the upper right hand corner of the turbine... if you watch real close you can almost see it move.

http://www.otherpower.com/images/scimages/15/Lenz_Turbine_low_wind.wmv

The best I've seen with it so far is 7 amps in a 15 mph wind.  With the seasons changing the winds should be kicking up a bit shortly.   It's going to be fun to see what it will really do on a windy day.

.

[rotornuts]

I'm nothing but impressed and very happy for your success Ed. I just posted a comment on MountainMans Darrius post saying how impressed I was with your latest design and now you give me even more reason. Those cups I was trying to get you to cover up before, I'd love to know what portion of this units success they are contributing. I know now that they are an important asset but further development will want to know how much. Ohh what I would do to see the lenz turbine in a wind tunnel with some flow visualization aids.

Mike

[electrondady1]

hey ed! thats a very efficient machine!  the roof might be giving you a boost.  

when larger winds begin do you think the geni will cause much vibration in the building?

you might not be interested but i've been experimenting lately with electrolisis. even at one volt you can get some bubbles forming. i was thinking it would be a good way to utilize the current produced at low speed , as in less than charging voltage

[windstuffnow]

 Hi Mike,

   Thanks for the kind words.  I agree, I'd like to find a wind tunnel ( that I could afford ) to really put it through some tests.  I'm sure my equipment and testing proceedures have a certain amount of error, a real wind tunnel would remove a large portion of the error for some nice clean data...

.

[windstuffnow]

  I'm sure I was getting something in the range of a 2mph turbulance across the roof.  It was running at about 28 rpm in the video.  I highly doubt it was making any collectable power, most likely just enough to overcome the bearing friction.  

  I've played with making h2, the low winds offer low voltage but you really need the amps to make any useable amount.  

  I've been leaning toward the idea of making a fairly large Lenz turbine to drive an eddy current heater submerged in water.  From playing around with some data I collected on an early experiment shows some real promise.  

  If nothing else, I'll learn something from it...

.

[electrondady1]

i'm not shure how an eddy current heater would work ed. sounds interesting

 why i asked about the vibration is i have a 9'x10' cabin  whose roof line is at 90% to the prevailing wind. it would make a nice booster. but i want to sleep in there this winter while i reno my house.

 we talked about this before but a very large lenz turbine would be a natural on one of your silos.

[MountainMan]

Ed,

Very cool.  Looking forward to see what sort of wattage you get from a genny of this size.  What sort of alternator are you using on it?

BTW, what is the strange thing on the roof to the left of the genny?  Kinda looks l ike you roped a baby seal and tossed it up on the roof!  Seems like the head is still moving.  Best be careful, it might attract some roof sharks.

Interesting that this contraption does not have the usual top and bottom "disks" that are typical of non-daerieus VAWTS.  Is that a trait of Lenz designs, or just your own special implementation?  If the latter, did you compare with and without "disks" with the same "cup" design?  Just wondering what part those pieces play from an aerodynamic rather than construction standpoint.

Any chance we could get you to try some shading experiments with this at some point?  Unless the "returning" cup is somehow providing a little bit of a lift vector due to its shape, I would think that shading it would create a significant boost in efficiency.  Seems like it would be fighting its way back upstream without shading it.  Myself and others have mentioned this before and some guys have shown plans for how to build a shade with a tail that points it properly.  Don't think anybody has actually shown results from such a thing though.  Perhaps shading would add just enough efficiency to give us VAWT proponents some bragging rights!  

BTW, your "accessible shaft above and below" design would lend itself very nicely to the installation of a self pointing shade.  One could even imagine some changes to the shade's tail assembly that would make the shade double as a furling mechanism in high winds.

thanks,

jp

[windstuffnow]

  MountainMan,

   The Lenz turbine uses a combination of lift and drag.  I posted a video a few weeks back of a test machine with one wing on it, starting from the back side of the machine the wing flies into the wing and back around again.  I experimented with diffusers or "shading" and it takes away from the output considerably.

   Here is the link to the single wing video, its about 1mb in mpeg format.  I'm still learing how to make these things smaller...

http://www.otherpower.com/images/scimages/15/upwind_wing.mpg

   All 3 blades play a part in extracting energy.

.

[BoneHead]

Oh WOW man. I had it all backwards! That's great!

I guess I'm a little think around the cranium. I thought the rounded ends were the ends that the wind pushed and the open side was on the inside with the bladed end cutting back on the return. I'm sorry, I had it all wrong. Just forget I asked half of those questions on the other thread. They just don't apply.

That's an awesome design. Congrats. I see how that shape will limit top speed but with a multi-stator low rpm alt, that things gonna rule. You should try and market that thing when you refine it. Be a nice way to pay the bills.

I can't get over that. It's a great idea. Without that movie, I would still be trying to figure out why you did things that you didn't actually do...lol. Good luck on that Ed!

[georgeodjungle]

i play a lot with hydrogen and o

please be very carful.

a 1/4 gallon of water is enough to take most of the windows out of a 1500 sq' house and not to mention mess up your hearing for a wile.

there's a lot of fun and cool stuff to do with it.

p.s.

nice genny

[BoneHead]

Have you hydrogen/electrolosis guys seen this?

http://jlnlabs.online.fr/bingofuel/html/bfr10.htm

[rotornuts]

You know Ed , I just had a thought. I'm speculating at the moment if the open wing design is (besides acting as a collector on the downwind side) perhaps ensuring no lift is generated on the outside of the wing on the upwind swing. With the 9 degree  positive wing angle you use and a symetrical profile if the wing was fully enclosed then the majority of the lift on the upwind side would be generated on the outside of the wing where the lift vector is pointed in the wrong direction. So at the cost of some drag I'm thinking you shifted the lift to the inside of the wing which is far outweighting the drag penalty. The penalty of the outside producing lift at those angles would be far worse than almost any drag (as you already know lift is far more powerfull than drag).

Just thinking out loud again.

Mike

[ghurd]

It always amazes me how fast you can get something from idea to roof.

(Fast is relative)

Let alone have a new idea work so well.

G-

[windstuffnow]

  Hi electron,

   I haven't heard any vibration through the roof so far.  You can, however, hear a very low grumble or humm when the unit is charging from the alternator.  You have to listen carefully for it.  

   Personally I wouldn't recommend anyone putting a turbine on their roof.   This is simply a quick ( inexpensive ) test bed for my turbine.  The turbine isn't in any way bolted to the roof, it's simply sitting on the roof.

   Sounds a bit scarry I know.   Simply a steel tube frame, held in place by sand bags and cables... photo below...

   There is 80 lbs of sand on each of 4 legs and the legs are 8 1/2 ft long, the unit stands 5 ft off the peak.  Lots of room for turbulance in its location.  Definately not an optimum test location.

.

[windstuffnow]

  Here's a fun comparison...  

My 500 watt unit was making 272 watts in a 20 mph wind.   The Lenz turbine was making 95 watts.  I decided to calculate the watts per sq ft to see how they compared.

The 500 watt unit was making 8.19 watts per sq ft while the Lenz was making 7.93.  I haven't calculated the efficiency of either as yet but I most likely will later when I have more time just for fun...

.

[SparWeb]

Ed,

I think you have inadvertently invented a new RE sub-culture: recovering energy from the convective currents rising from a hot roof.

I couldn't help but do the math: with a wind speed of nearly zero, your TSR is INFINITE! :^)

[hvirtane]

These results are very good indeed.

I think that some very successful

wind machinery will be developed

on these lines.

Unfortunately I cannot watch your video.

Could you anyhow put it there in

another format, too?

- Hannu

[electrondady1]

your right george , this stuff demands our respect. i never ignight it any more. just testing rates of production. i'm thinking lots of low power genies producing hydrogen / oxigen for immediate consumption in a generator.

[windstuffnow]

  Electron,

    Wouldn't it be more efficient to simply pull the power from the wind gennies?  Your converting wind to electric to H2 to mechanical power back to electric again.  The wind genny is about 40%, alternator 70%, H2 30%( this may be an optimistic figure ), fuel genny 25% into an alternator again at 70% or...

.4 x .7 x .3 x .25 x .7 = 1.5% efficient

The gennys .4 x .7 = 28%

Try a search on power balls.  Their fairly efficient.  Muratic acid and aluminum will produce a large volumn of H2 but the by product is hazardous ( don't breath the vapor ).  Aluminum absorbs H2 as it cools making it a great storage, unfortunately its expensive and most by products from it are difficult to re-use or dangerous.  Electrolysis is very inefficient.  That's the biggest problem with a H2 society is all the in-efficiencies converting it to a product we can use.  

I blew up a few jug's myself playing with the electrolysis.  A much safer fuel is methane.   A small slurry can produce a good volumn of fuel and all you need is anything organic to toss into the slurry.  Mow your lawn gather the clippings - any organic garbage you have - the neighbors cat, basically anything that will decay and dump it into the slurry , add a little water and sunshine and bingo fuel to run the genny, cook with or what ever.  Very simple, quite natural and much safer.

.

[pyrocasto]

Now that's awesome.

[electrondady1]

1.5% efficient, that's not so good. ed, your math has killed my dreams of power! lol

 this is fundamental knowlege to some but if i have 10 little mills producing 3 volts each in a slight breeze, how can the currents be combined into something useful?

 do i just shrug my shoulders and wait for a good wind to produce a charging voltage

[windstuffnow]

  Didn't mean to ignite your energy bubble ;o).  You must live in an area with fairly low winds. Do you have a good amount of sunshine?  

  If you rectify all the little turbines and wire the rectifiers in parallel you'll get the amps of all turbines together at 3 volts.  If you series them you'll get 30 volts at what ever amps is comming from the lowest one or an average of amps.

  .

[electrondady1]

oh no ed ! there is lots of wind around here! in fact we're having a bit of a wind event as i speak .  it's ripping the leaves off the trees and breaking some branches.

  typical fall weather.  

i'm on georgian bay / lake huron, thats about 300miles of open water.big wind? no problem!

 but i'd also like to harness the on shore breeze which is almost constant.

[Bruce S]

Ed;

Very nice machine!!

Have you considered using one of your smaller 150 - 200 watt "little" gennies on this VAWT?

I looked as a close as possible at the movie and couldn't see any gennie on it, or was this just up there to see how well it would fly?

Also , would it be more correct to measure the up draft coming from the roof if you turned one of the anemometers 90 degrees to see what is coming in a up draft?

  You are very correct about the eff. numbers, a bit high though.

I've taught our teenage daughter how to make H2 by just using old pencils and solar charged batteries and the best I've ever gotten on return was ~10% maybe. But , it is a good way to make use of those times when there is too much wind and all the batteries are charged. And would help when there isn't enough.

Cheers!

Bruce S

[Bruce S]

WAY OFF Topic of Eds unit, BUT

Read this a long time ago.

One thing they say but don't put proper emphisis on is that the carbon rods are the sacrifice items and they aren't cheap.

  There used to be a real good website that disclosed how this unit was actually built and the output with real numbers showing it not to be an OU item, but that it did in fact work and was built by more then one person. Out on the Keely BBS net I think.

Still way cool to look at though.

Just my 1/2 cents worth.

Bruce S

[nanotech]

I'm thinking of something along these lines for heating fuel.

Use wind power to generate the electricity, the electricity to make the "bingo fuel".

Store the "bingo fuel" for "on demand" useage by a converted natural gas furnace to heat the house.

[MountainMan]

Ed,

Is there very much force on the "cups" trying to change their shape when it is running in a fair bit of wind?  I'm trying to imagine some easier construction methods for something that is shaped very much like your machine.

Instead of taking the time to form the cups around the nice "spars" that  you created, would it work to go back to a "top plate and bottom plate" design, and cut appropriately shaped slots in the end caps to trap a piece of sheet metal and hold it in the same shape?  Just use a router to make a narrow slot in three places that is the same shape as the cross section of your "wings" or "cups" or whatever we are calling them? The sheet metal would to all the way through the disk, and then get fastened to the outside of the disk in some way

Some other contraption would be needed in the center to hold the end-caps in place and some good way to affix the sheet metal to the end caps where it passes just through them.  Maybe just cut the ends of the sheet metal into tabs and fold them back down onto the disks and screw the tabs to the disks.

Does this sound at all practical?  I'm sure it would work for a really short machine, but perhaps if one wanted to scale it up to 6 or eight feet long I fear there would be too much flexing of the sheet metal going on near the center.  Perhaps just another disk with the same slots that slides down into a middle position and gets affixed there.

Also, if you were to scale up your design (to a larger radius), do you think you would go for three larger "wings", or do you think you would keep the wing size similar and use more wings?

BTW, using your 8 watts/sq foot number (at 20 mph?), and keeping to readily available material sizes, one could do a 4 foot radius 8 foot long machine for 256 watts.  Placing these tightly along the North-South ridge of my eventual wood-shop building tightly packed, one could imagine approx. 30 ft * 8 feet * 8 watts/sqfoot = 1920 watts in a 20mph wind.  Not too shaby.  I know, I know, have to over build the shop buiding to handle it.  Probably also have to use some of those watts to run a noise canceling sound system when I'm in there working!

thanks,

jp

[ozetrade]

Hi Ed,

I've been researching the idea of creating some type of portable VAWT since a bad camping experience recently. When I say portable, I mean sits on the ground at the beach where we do most of our camping.

I have posted on this site http://www.fieldlines.com/comments/2005/10/14/92732/876/5#5 and also at http://www.thebackshed.com/Windmill/FORUM1/forum_posts.asp?TID=37&PN=1

Most reponses like the idea, but the general consensus is, my turbine has no hope of turning a F&P motor - even when decogged. I have been referred to your design by Gismo at Thebackshed.

I think I have read everything you have written so far, and I think I may be able to still keep it small and acheive the amps I'm after. I'n not familiar with loads and torque or anything else to do with wind generation, hence I turn to the experienced.

One of the things I've picked up in your discussions is taller does not mean faster, but wider improved torque. I believe a 3ftx3ft version of your VAWT might drive my F&P if it is geared correctly - well at least at enough rpm's to get the amps I need.

My power needs are a constant 5.5A full time for a 12v fridge, and a couple of 240v 8-11watt fluro globes, plus a few other items that will draw around 4-5A in total for 1-2hrs at night run from the 150W inverter - it draws .1A. At this time I have one 120A sealed wet deep cycle battery.

I'm on the east coast of Australia. We do our camping at the ocean on the beach where there is usually 10klm+ winds during morning and picks up to 15-20klm after lunch for around 4-5 hrs.

Could I get your thoughts on what I'm proposing.

Thanks,

Greg

[hvirtane]

Hi,

concerning portable wind machines,

have you seen this site:

http://www.shield.fi/turbine.html

You might also consider

a sail type HAWT.

I've heard about one guy, who has made

something like the above sail machine

as portable.

- Hannu