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

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.

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.

Just thinking out loud again.

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...

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

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?

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.

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!

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.