vertical axis generators

westbranch · June 2007

Hello, does anyone have any user info on a vertical axis generator? Have surfed and found a lot of listings from around the world and lots of manufacturers but they seem very new on the market. Prices cause one to hesitate on a relatively unknown product..

Eric

niel · June 2007

Re: vertical axis generators

no they are not new, but just aren't as popular. this could be because the efficiencies tend to be not as good on vertical axis types. there is a big advantage in that they don't need aimed as the horizontal types do. you still need them high in the air to take advantage of higher wind speeds up there just as with the horizontal types, but not as much need to worry about wind sheers and eddy currents with vertical.

westbranch · June 2007

Re: vertical axis generators

thanks Niel.

As you can see from my sign-on pic we have a clear shot at the lake and the wind . The mountains you see are just 60 miles in a straight line from the coast (west) and the valley is steep sided and funnels the winds quite well... too well at times and though I would like to tap into that endless resource I am afraid of the gusts that can exceed 60 mph. Last fall we were there and there were water spouts 200 feet in the air and the wind caused the entire roof (metal) to harmonically vibrate!!??!! from one end to the other (32')... thought it was about to rip off...

VA turbines seem to be a feasible option. I will be investigating the noise factor next. Read once that if you want to sleep never attach a HA turbine on your structure....

Eric

niel · June 2007

Re: vertical axis generators

sorry about the efficiency confusion as the vertical type aren't as efficient and i corrected it on my previous post. you will need to have the wind genny above the trees preferably at least 20+ feet higher or at least a wide swath of land without obstruction to the wind. this is especially true for the horizontal type as they have to shift direction and the eddy currents off of trees and buildings can do much damage to the wind genny. winds are more consistent higher up as well as being stronger.
you are correct that no wind genny should be mounted to a home as the vibrations can get bad. also, the stresses on the structure due to the wind genny on the home could cause a structural failure as the homes generally aren't made to handle this extra stress. even homes with pvs quite often need reinforced.
i believe the savonius is around the 20% mark in efficiency if i remember right. the darius(spelling) is a bit more efficient than the savonius, but does not self start so the 2 types are often used together. in any case the wind genny should have some provision to handle very high winds so as to limit damages and from the generator being overly driven.

BB. · June 2007

Re: vertical axis generators

Note: The following comments are directed at an article in Popular Mechanics that is almost a long form ad for PacWind about a future installation on top of Jay Leno's 17,000 sqft "garage" roof. While I am all for trying appropriate technologies for appropriate solutions--what little technical that is presented in this article seems to not bode well for an ultimately successful wind turbine installation. I am sorry if the comments were thought to have been directed at any earlier posts. -Bill

Well, I would think that if Jay Leno installs this vertical turbine on the roof of his 17,000 sqft "garage", he is probably doing just about everything possible wrong for renewable wind energy.

But what the heck do I know. Here is a link to the Popular Mechanics article:

http://www.popularmechanics.com/automotive/jay_leno_garage/4216780.html

http://www.pacwind.net/

-Bill

niel · June 2007

Re: vertical axis generators

bill,
read more closely what i wrote before being sarcastic as it was aimed moreso at the horizontal type for those requirements, but i will not go out on a limb and tell him it's ok for the verticals. it may be ok for that company's verticals as it seems they engineered them well. also, it's still true for getting the height no matter the type, but the verticals are not as prone to the sheers and eddy currents. it is not a guarantee there won't be any vibrations or structural stresses from verticals as this is not something i'd like to claim for them as they mechanically turn and winds do push on them. i'm sure they will do what is needed for leno and they aren't specific on all they will do for him in order to have them in place.

BB. · June 2007

Re: vertical axis generators

I probably should have posted the "Jay Leno PM" article summary/link first, then taken a shot at it--right now, my post could be construed as discussing the posts before.

I was "knocking" proposed the Jay Leno installation... Installing any wind turbine on a building it just asking for trouble. First the noise, vibration, and stresses will probably force the turbine off of the roof inside of six months. Second, unless his garage is set in the side of a mountain (which is possible since I do not know Mr. Leno), the wind flow will be very turbulent around the walls and turbine--and it would be difficult to extend the turbine 20' .

It is, slightly possible, that this company has solved some of the issues relating to mounting vertical wind turbines on his roof--but I doubt that.

I was more commenting based on some of that ads (such as for a company in the UK) that shows their standard horizontal turbines just bolted onto the side of a chimney a foot above the roof, or even below the roof's peak (of course, you had no idea of what "set me off" with the "PacWind" article placement in PM).

So--I was intending to support your statement of "...you are correct that no wind genny should be mounted to a home as the vibrations can get bad. also, the stresses on the structure due to the wind genny on the home could cause a structural failure as the homes generally aren't made to handle this extra stress..." in that the article was either over simplifying the Jay Leno installation (such as really building a freestanding turbine mount inside of the "roof line") or that it was just another over hyped 'solar is so easy--a caveman can bolt one to his roof' long form ad for PacWind.

Truly Sorry.
-Bill

niel · June 2007

Re: vertical axis generators

no problem, but if you hear more on his install, let me know as i'd be interested in how it comes out.

westbranch · June 2007

Re: vertical axis generators

Interesting comments, here is a link to a very advanced V-A T that I saw on the Home and Garden channel

http://www.mag-wind.com/mw1100.php

This is what got me interested in them. Another site quote.

The Mag-Wind VAWT wind turbine was invented in Canada by Thomas Priest-Brown and Jim Rowan. The magnetically-levitated Mag-Wind design solves 11 different problems that previously limited the development of vertical-axis wind turbines for generation of electricity. For more reading on the VAWT experiments, please vist the DOE.

which takes you to :
http://www.sandia.gov/wind/topical.htm#VAWTARCHIVE

some interesting titled articles ( and a very large list at that)

cheers

Eric

Eric

vertical axis generators

Comments

Categories