Hi Bilal,

Honestly, for what its worth, I would say that if you want to design a wind
turbine, do it using existing aerofoil profiles and data for the moment at
least. Its best to leave aerofoil design and testing to people who've been
doing it a while and who have the expertise, experience, facilities, time
and financial resources for both the model building and wind-tunnel testing
required.  Aerofoils are notorious for not having read the same aerodynamic
texts as you have and don't perform exactly the same as even the best
simulation programs predict! Even wind-tunnel test results should be read
with caution. Read Prof. Michael Selig's stuff on how some of his best
design efforts sometimes perform brilliantly and sometimes just don't do
what they're supposed to! (See below for reference: Selig et al 1989 )

You should be able to find suitable existing profiles for your designs.
Main requirements are:

1) Ease of manufacture by whatever method you're using

2) Structural stiffness and strength

3) A good lift-to-drag ratio over the range you want

4) Gentle stall

5) Roughness insensitivity

Then if you really find that nothing 'off-the-shelf' fulfils what you need,
*then* get yourself involved in aerofoil design.

If you really want to go ahead, I have used a program called Xfoil. It was
written by Mark Drela of MIT, but I've lost the contact details for
obtaining it so you'll have to do a search.

Xfoil was written for the purpose of designing and/or modifying aerofoil
profiles and for simulating their characteristics and gives reasonable
results.  I used it purely for simulation.  You do need to have some
understanding of what boundary layers get up to in order to get sensible
results.  It was designed for, and has a good reputation for coping
reasonably well with, the peculiarities of low Reynold's number though it
is a few years old now.

However, you should not rely purely on simulated results from even the best
software when it comes to aerofoils.  You should only design your own
profiles if you have the expertise, facilities and resources to test them
afterwards in a  wind tunnel.

References for data on existing aerofoil profiles:

Abbott I. and von Dönhoff A.  'Theory of Wing Sections', Dover Publications
Inc., New York, 1947

Selig M.S., Donovan J.F. and Fraser D.B.  'Airfoils at low speeds',
Soartech 8, H.A.Stokely (publisher) 1504 North Horseshoe Corcle, Virginia
Beach, Virginia 23451 USA, 1989
This comes with the data on a diskette as well as in print - very helpful.

Giguère P. and Selig M.S.  'Low Reynolds number airfoils for small
horizontal axis wind turbines',  Wind Engineering Vol.21, No.6, 1997

Miley S.J.  'A catalog of low Reynold's number airfoil data for wind
turbine applications',  Rockwell International Corp., Golden, Colorado,
USA, 1982

Riegels F.W.  'Aerofoil Sections, Results from Wind Tunnel Investigations,
Theoretical Foundations' (Transl. fr. German),  Butterworths, London,  1961

Tangler J.L. and  Somers D.M.   'Advanced Airfoils for HAWTS'

For NACA/NASA data try:
http://www.mpa-garching.mpg.de/~tomek/CFD/refs/naca.html

Somewhere on the NASA server there's a page with data on all the NACA/NASA
profiles but I don't know the URL.  Try searching from here:
http://www.gsfc.nasa.gov/NASA_homepage.html  or here:
http://techreports.larc.nasa.gov/cgi-bin/NTRS

For other stuff about aerofoils for wind, have a look at:

Anderson R.F.  'The aerodynamic characteristics of airfoils at negative
angles of attack',  NACA Technical Note No. 412

Butterfield C.P., Scott G. and Musial W.  'Comparison of wind tunnel
airfoil performance data with wind turbine test data', Transactions of the
ASME - Journal of Solar Energy Engineering, Vol. 114 pp119-124, May 1992

Drela M. and Giles M.  'ISES; a two-dimensional viscous aerodynamic design
and analysis code'   AIAA Paper 87-0424, Jan. 1987

Drela M.  'Low Reynolds-number airfoil design for the MIT Daedalus
prototype: a case study',  Journal of Aircraft Vol.25 No.8 AIAA Inc. 1988

Griffiths R.T.  'The effect of aerofoil characteristics on windmill
performance',  Technical note, paper no. 251, Aeronautical Journal, July 1977

Jamieson P. and Rawlinson-Smith R. 'High Lift Aerofoils for Horizontal Axis
Wind Turbines' 16th Annual BWEA conf, Stirling ,Scotland,   1994

Wilson R.E., Lissaman B.S. and Walker S.N.  'Aerodynamic performance of
wind turbines',  Oregon State University, June 1976


At 18:46 05/09/01 +0500, "BILAL RAUF KHAN" <mian@...> wrote:
>respected group members,
>
>i am interested in software through which i can design the whole wind
turbine.
>i want calculate the profile of blades and output characteristics from
that software.
>if any body knew about this please let me know also.
>

	 end
-* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Dr. Julian Feuchtwang  (Academic Visitor)

CREST  (Centre for Renewable Energy Systems Technology)
AMREL Building, Loughborough University, Loughborough LE11 3TU, UK
'phone: +44 (0)1509 228140 email:j.b.feuchtwang@...
'fax: +44 (0)1509 610031 http://www.lboro.ac.uk/crest/eljbf.htm

I am new to your site. I am a mechanic by trade and have a reasonble
knowledge of automotive electronics.I want to build a 12 volt wind
charger to keep RV batterys up.My first question is the number of
blades used. I notice that 2 or 3 blades seem to be the popular
choice. I know from experiance that the heavey duty cooling systems
on gas engines will use 7 or 9 blades instead of 5 blades on the
normal duty cooling systems. Why not use more blades, catch more wind
and decrease the diameter? I did some testing with a GM altenator
with internal regulator and also a 12 volt farm tractor jenny and
regulator. I hooked each to a battery and hooked a volt meter to
each. I ran each with a 1/2 inch drill turning about 1000 RPM. They
both charged at about the same speed. I will want to get the same
results at under 500 RPM. I want to know how to get there. Perhaps
removing the wire from the armatures and replacing with magnets? I
don't need to produce anything over 10 amps. 12 volts. This will not
be in constant use, only occasionally. Thanx Arnie

Hi Ken

How about the Rutland 913 from Marlec ( http://www.marlec.co.uk/ ) ?   0.91
m diameter, maximum power ~90 W.  Very good start-up in low winds.  They're
very popular here in UK for boats and caravans.  I don't know about agents
in Canada but contact sales@... .

If you're worried about very severe conditions go for the 'Furlmatic'
version.

I have to say that unless your weekend retreat is up in the Arctic I'm very
sceptical about a 'constant 30 mph'.

Regards
Julian

p.s. Interest disclosure: I used to work for them so maybe I'm biased.


At 15:51 05/09/01 -0400, The Cory Family <corys@...> wrote:
>...SNIP...
>
>We have just purchased a camping trailer on a very windy lake. I'd say the
>wind blows constantly at about 30 mph at ground level from dawn to dusk.
>We'll only go there on weekends, mostly. The trailer has a standard marine
>battery, and the previous owners just charged it from their car. So what
>I'm looking for is a system that over the course of a week can charge the
>battery enough that we can run a few lights, a 9 volt music system, and the
>trailer's water pump for a couple of days. I'm guestimating that 20 watts
>would be loads of power for us, and the turbine, running all week, would
>only have to deliver 2/7 of that per day to charge the battery. Using
>Mike's formula, I figure that a 30 mph wind delivers about 870 watts per
>square meter to a perfect turbine, so it looks like a VERY small turbine
>will be enough for us. Do turbines this small even exist?
>...SNIP...

	 end
-* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Dr. Julian Feuchtwang  (Academic Visitor)

CREST  (Centre for Renewable Energy Systems Technology)
AMREL Building, Loughborough University, Loughborough LE11 3TU, UK
'phone: +44 (0)1509 228140 email:j.b.feuchtwang@...
'fax: +44 (0)1509 610031 http://www.lboro.ac.uk/crest/eljbf.htm

We are looking for the information on wind potential in
Uzbekistan and Turkmenistan.
If somebody has information on it, please inform us.

Thanks,

Wind Ltd.
DEI

I have a prototype wind turbine of unique design (see AIAA Journal of
Energy, v 5, No 6, Nov.-Dec., 1981). Because of design modifications there
is increased inertia in this prototype system and I need more capacity in
the electrical system. Currently I have a 240 v, 3 phase induction
motor/generator of 2.6 hp. I am looking for a 3 phase, 10 kw, 240/480 v
induction motor/generator preferably wound as a generator (ie higher
voltage) to provide the added starting and energy absorption (energy
output).

David Bailey
Tel (401) 789-6466
Fax (401) 789-8395


[Non-text portions of this message have been removed]

one or two 12 volt marine batteries and a 15W solar panel charger will
probably do the trick.

that's what i currently have on my fifth wheel RV.

Dick Stewart
ps:  of course, propane gas is used for the hot water heater and the
refrigerator.  the refrigerator fan is running off the battery as well.


----- Original Message -----
From: "David MacClement" <d1v9d@...>
To: <awea-wind-home@yahoogroups.com>
Sent: Friday, September 07, 2001 12:28 PM
Subject: Re: [a-w-h] Modest needs - 2 home-made wind-generators


At 15:51 5/9/2001 -0400, Ken Cory wrote:
>... power a full-sized house. I have more modest needs, and I wonder
>1) if I've come to the wrong place, and 2) if anyone can point me to
>a source of information about smaller power systems.
>
>We have just purchased a camping trailer on a very windy lake. ... what
I'm looking for is a system that over the course of a week can charge the
battery enough that we can run a few lights, a 9 volt music system, and the
trailer's water pump for a couple of days. I'm guestimating that 20 watts
would be loads of power for us, ... so it looks like a VERY small turbine
will be enough for us. Do turbines this small even exist?
>

· I'd think you might want to try making your own _very_ cheap
wind-generator.

· I've just uploaded to the awea-wind-home "Photos" archive, 6 images that
were sent to the group in Jan. & Feb. 2000, about easily home-made
wind-generators.

· I don't remember the original sender/owner's names, but the filenames:
MVC-017F.jpg MVC-021F.jpg MVC-023F.jpg (PVCpipe blades) w. sent 14/2/2000, &
P001007.jpg P001008.jpg P001009.jpg (metal blade, belt) were sent 10/1/2000

· The thumbnails are in the Album at:

http://photos.groups.yahoo.com/group/awea-wind-home/lst?&.dir=/

   and the first 3 above are at:

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=shaved-PVC-blad
es_dir-gen_side.jpg  {collect all of URL before trying it}

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=shaved-PVC-blad
e-dir-gen_front.jpg  {collect all of URL before trying it}

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=shaved-PVC-blad
es_dir-gen_dist.jpg  {collect all of URL before trying it}

   while the metal-bladed belt-driven ones are at:

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=metal-blade_bel
t-drive_front.jpg

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=metal-blade_bel
t-drive_side.jpg

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=metal-blade_bel
t-drive_rear.jpg

· Can someone tell us whose photos they are?

David.
(David MacClement) d1v9d@...
http://davd.tripod.com/GrRR-010907_titles.html#top
http://www.geocities.com/davd.geo/index.html#top
**************************************************


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----------------------------------------------------------
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. Join the list by sending a blank e-mail to:
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   (and read it on the Web), go to
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At 6:28 am +1200 8/9/01, David MacClement wrote:
>
>· Can someone tell us whose photos they are?

I recognise the first 3 as belonging to the judge.  randy young
judgeyoung@...
--
Hugh

http://www.ScoraigWind.co.uk

Hi all,

Thanks for all your good suggestions and advice. Another camper in the park
uses solar panels, and that's what I thought of first, but our site is
somewhat shady (weeping willow trees) and I wasn't sure if we'd get enough
sun to charge the batteries. I should go out there with a light meter and
make some measurements.

Thanks again,

Ken

At 15:51 5/9/2001 -0400, Ken Cory wrote:
>... power a full-sized house. I have more modest needs, and I wonder
>1) if I've come to the wrong place, and 2) if anyone can point me to
>a source of information about smaller power systems.
>
>We have just purchased a camping trailer on a very windy lake. ... what
I'm looking for is a system that over the course of a week can charge the
battery enough that we can run a few lights, a 9 volt music system, and the
trailer's water pump for a couple of days. I'm guestimating that 20 watts
would be loads of power for us, ... so it looks like a VERY small turbine
will be enough for us. Do turbines this small even exist?
>

· I'd think you might want to try making your own _very_ cheap wind-generator.

· I've just uploaded to the awea-wind-home "Photos" archive, 6 images that
were sent to the group in Jan. & Feb. 2000, about easily home-made
wind-generators.

· I don't remember the original sender/owner's names, but the filenames:
MVC-017F.jpg MVC-021F.jpg MVC-023F.jpg (PVCpipe blades) w. sent 14/2/2000, &
P001007.jpg P001008.jpg P001009.jpg (metal blade, belt) were sent 10/1/2000

· The thumbnails are in the Album at:

http://photos.groups.yahoo.com/group/awea-wind-home/lst?&.dir=/

   and the first 3 above are at:

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=shaved-PVC-blad
es_dir-gen_side.jpg  {collect all of URL before trying it}

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=shaved-PVC-blad
e-dir-gen_front.jpg  {collect all of URL before trying it}

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=shaved-PVC-blad
es_dir-gen_dist.jpg  {collect all of URL before trying it}

   while the metal-bladed belt-driven ones are at:

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=metal-blade_bel
t-drive_front.jpg

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=metal-blade_bel
t-drive_side.jpg

http://photos.groups.yahoo.com/group/awea-wind-home/vwp?.dnm=metal-blade_bel
t-drive_rear.jpg

· Can someone tell us whose photos they are?

David.
(David MacClement) d1v9d@...
http://davd.tripod.com/GrRR-010907_titles.html#top
http://www.geocities.com/davd.geo/index.html#top
**************************************************

http://www.bergey.com/Products/XL1.Tilt.IM.1.pdf

Is the tower manual for their new 1 kW turbine. The manual looks like a
rewrite of their 850 tower manual which used the same NRG tower. The
manual's been slightly rewritten and doesn't seem to have as many
illustrations--but I could be mistaken. Take a look at it.

Paul

Paul Gipe
208 S. Green St., #5; Tehachapi CA 93561-1741 USA; ph: +661 822 9150; fax:
+661 822 8452; pgipe@.... Wind Power for Home & Business, Wind Energy
Comes of Age, Wind Energy Basics, and Energía Eólica Práctica.
Wind Energy: http://www.chelseagreen.com/Wind/PaulGipe.htm
Wind Energy: http://rotor.fb12.tu-berlin.de/personen/paul.html
Electricity Feed Laws: http://invisibleuniverse.com/Juice/Wind/feedlaw.htm

At 3:51 pm -0400 5/9/01, The Cory Family wrote:

>
>We have just purchased a camping trailer on a very windy lake.

I recommend ampair.  Try Jack rabbit ads in HP mag or go www.ampair.com

>Do turbines this small even exist?

yes and smaller but you need an ampair.


--
Hugh

http://www.ScoraigWind.co.uk

Our side anchors are also offset for the same reason (in our case they're
slightly lower than the tower pivot point, same net effect). This works out
very nicely as it ensures the guys go slack as the tower is lowered but, as
Robert indicated, be sure on the first time up to GO SLOW and keep the guys a
little slack as you can buckle the tower the first time.

I also use the 'rope on the guy wire' thing, with a come along, usually two in
series. You can do it by hand but I'd rather not (again). I didn't have any
real problems doing it by hand, but you really need an assistant, and the
entropy factor is just a little too high. The come-along gives you positive
control (it wont ever sneeze, etc). Once the tower is past the 'wants to fall'
point, lower with a winch (as below, vehicle-only ups the entropy factor too
much for my taste). Leave the rope and come-along in place and it catches right
as it needs to on the way back up.

Our tower also lowers onto 4x4 bucks. This isn't strictly necessary (there are
actually left over from tower assembly on somewhat uneven ground) but it takes
most of the load out of the rigging in the down position, keeps the tower
steady when you're working on it.

That said, I can't emphasize caution enough working with these things. CHECK
EVERYTHING TWICE. I could have dropped the tower last time I brought it down
because I was so furious the miserable Whisper had failed again that I worked
too fast and thought I had everything set to crank it down but hadn't engaged
the pawls on the grip hoist (cable would have pulled right through - fast). I
was lucky enough to catch it, but only by virtue of being in the habit of
checking (and luck).

Its probably safer than climbing if you watch yourself but there are still far
too many ways to pull a Wile E Coyote with these things. BE CAREFUL. CHECK
EVERYTHING TWICE. (and stay the heck out from under it)

"Robert W. Preus" wrote:

> --- Robert W. Preus <rwpreus@...> wrote:
>
> I would add to your comments that the guys should be
> laid out so that they slack slightly during lowering. [...]

> Instead of a comealong to start the tower down, I
> attach a short rope about 15 or 20 feet up the down
> guy.  Pulling sideways on a guy wire with this rope
> generates lots of force.  If you leave the rope in
> place it is very quick and convenient.
>
> --- Michael Klemen <windy@...> wrote:
> > From: Paul Gipe
> > OK, having said that I have some reservations about
> > the tower raising
> > technique described. What do the rest of your think?
> >
> > Jon,
> >
> > I have raised and lowered these gin pole towers too
> > many
> > times to count, with wind turbines on top.  [...]

Thanks everyone--on and off list. I'll summarize the comments in my own words.

Paul

Paul Gipe
208 S. Green St., #5; Tehachapi CA 93561-1741 USA; ph: +661 822 9150; fax:
+661 822 8452; pgipe@.... Wind Power for Home & Business, Wind Energy
Comes of Age, Wind Energy Basics, and Energía Eólica Práctica.
Wind Energy: http://www.chelseagreen.com/Wind/PaulGipe.htm
Wind Energy: http://rotor.fb12.tu-berlin.de/personen/paul.html
Electricity Feed Laws: http://invisibleuniverse.com/Juice/Wind/feedlaw.htm

Hi all,

I've recently joined the list. I see that most of you folk are into systems
that can power a full-sized house. I have more modest needs, and I wonder
1) if I've come to the wrong place, and 2) if anyone can point me to a
source of information about smaller power systems.

We have just purchased a camping trailer on a very windy lake. I'd say the
wind blows constantly at about 30 mph at ground level from dawn to dusk.
We'll only go there on weekends, mostly. The trailer has a standard marine
battery, and the previous owners just charged it from their car. So what
I'm looking for is a system that over the course of a week can charge the
battery enough that we can run a few lights, a 9 volt music system, and the
trailer's water pump for a couple of days. I'm guestimating that 20 watts
would be loads of power for us, and the turbine, running all week, would
only have to deliver 2/7 of that per day to charge the battery. Using
Mike's formula, I figure that a 30 mph wind delivers about 870 watts per
square meter to a perfect turbine, so it looks like a VERY small turbine
will be enough for us. Do turbines this small even exist?

Ken

P.S. I live in Southern Ontario. At Pickering, Ont, just a few weeks ago,
they installed the largest wind turbine in North America.

How much does a wind turbine cost per kWH?

Yes I know it all depends, but lets assume for a standard site of say
10MPH and for the sake of comparison assume a non-battery storage use
such as .... water pumping or heating.

I would like to be able to draw a "fuzzy" graph from 50W up to >1MW
showing how the purchase price of a electrics effects the smallest
viable size of turbine.

I've managed to make some estimates for smaller turbines and utility
scale costs are fairly easily calculated, however I really do need
some help for the 10-100kW range.

--- Robert W. Preus <rwpreus@...> wrote:

I would add to your comments that the guys should be
laid out so that they slack slightly during lowering.
This is best accomplished by having the side guy
anchor points at the same level as the tower pivot
point but a couple of inches in the tilt down
direction from the tower pivot.  Then after raising
slowly the first time with no turbine on the tower,
(watching for over tightening) the guys can be
adjusted for a level tower and except for the lift guy
they are set.  Don't over do the offset (3 or 4 inches
is enough) or the tower will move side ways enough to
be scary.

Instead of a comealong to start the tower down, I
attach a short rope about 15 or 20 feet up the down
guy.  Pulling sideways on a guy wire with this rope
generates lots of force.  If you leave the rope in
place it is very quick and convenient.

--- Michael Klemen <windy@...> wrote:
> From: Paul Gipe
> OK, having said that I have some reservations about
> the tower raising
> technique described. What do the rest of your think?
>
> Jon,
>
> I have raised and lowered these gin pole towers too
> many
> times to count, with wind turbines on top.  The
> Whisper 4500
> with the 84 ft LMW&S tower does indeed have some
> large
> forces, but they can be minimized using a pulley
> reduction
> block between the gin pole and front anchor.  I've
> done this
> all winter long, and with a 3:1 pulley ratio, a
> parking
> brake, and a set of wheel chocks, and my front-mount
> winch,
> and haven't slipped once.  It's safe if done
> correctly.
>
> I agree with you, however, that I much, much prefer
> a winch
> than to pull with a vehicle.  It is much more
> predictable,
> and much easier on the tower.  I also would agree
> that a
> cable with pulleys will reduce the forces as
> compared
> with a rope.  I don't like the idea of a rope for
> towers
> that tall.  Ropes stretch.  Cables don't.  The force
> to
> overcome the friction to get the rope moving is
> pretty high.
> It might work, but I'd prefer a cable.  Cables,
> however,
> would probably require a pulley and not their
> recommended
> hardware.
>
> And for your comment #3, I would agree with SWP that
>
> the tower should be lowered and the side guys
> adjusted -
> if only for safety's sake.  If the forces on a tight
> guy wire were higher than you think, the whole tower
> can
> shift in the air.  I don't think I'd like that.
>
> Now, on to my comments.  These are given in the
> spirit
> of cooperation, and not as direct criticism to SWP.
> Perhaps
> they can use some comments in improving their
> manual.  The
> disclaimers at the front are very bold.  I haven't
> gone into
> great detail here, as I think Paul was more
> interested in
> general comments.
>
> Mike
>
> 1.  Perhaps I missed it, but I FIRMLY believe that
> anybody putting up a tilt-up tower for the first
> time
> should raise it once BEFORE putting the turbine on
> it.
> It's a great way to learn what you're doing before
> risking having the turbine on the tower top, with
> those
> extra forces.  If you make a mistake the first time
> (without
> the turbine), you only endanger yourself and the
> tower.  The
> turbine wouldn't survive a crash landing, but the
> tower may.
>
> 2.  I don't like the recommendation that you can get
> by with thin walled pipe.  I've downloaded high wind
> speed data for many states (haven't looked at it
> all),
> but 80 mph is not an unreasonable speed for ANY site
>
> in the US to see during a turbine's lifecycle (from
> what
> I have seen).  I would highly recommend anybody
> putting
> up the tower to use the stronger pipe.  Yes, it
> costs
> more, but it seems likely you will prevent a
> catastrophe.
>
> I don't understand the SWP rationale for even
> suggesting
> this as an option.  It's better to be safe than
> sorry.
>
> 3.  I would NOT recommend soldering your turbine
> wires
> to your tower wires.  Split bolt connectors are
> definitely
> the way to go.  They are removable!
>
> 4.  Rather than removing the top guy wire from the
> gin
> pole first, I would prefer to see them start from
> the bottom
> up, tightening as they go.  The tower will still be
> wobbly
> without the lower guy wires tight, so starting from
> the
> bottom up seems safer to me.
>
> 5.  I'm sure this is the way the towers were
> designed, but
> I don't like the idea of having the wires tightened
> by
> hand.  We pretension our guy wires on the LMW&S
> towers,
> and with the Whisper 4500 on top, in a good blow,
> even
> the downwind wire goes slack.  These towers will
> have
> more movement than I am used to in strong winds, but
> they were designed that way.  DO NOT pretension the
> wires in these kits.  I wasn't stating you should.
> These towers weren't designed for that.  I just
> thought
> I'd mention that movement of the tower top seems
> very
> likely.
>
> 6.  The manual states:  "If the tower is to be
> lowered, only
> unclamp the cables on the lifting wire side so that
> when the
> tower is re-erected only those cables will need to
> be
> readjusted."  Somebody forgot that as a tower is
> being
> lowered, the guy wires may TIGHTEN.  They may
> tighten on
> either the way up or the way down.  If this scenario
> isn't
> watched for, you can buckle the tower lowering it as
> well
> as raising it.
>
> 7.  I don't like their steps for lowering the
> tower...
> primarily #1 and #2... disconnect the wires from the
>
> controller and short them.  Apparently, they have
> removed
> the brake switch in the EZ-Wire.  This is not really
> a
> SAFE thing to do.  Sometimes you MUST stop a turbine
> when
> it is producing.  I don't want to be there to see
> sparks
> fly.  They will.
>
> 8.  They say to tip the tower by hand to get it to
> start
> coming down.  This may be stressful to some people.
> It
> may be easier to attach a come-along to one of the
> rear
> guy wires to get it to start coming down.  I will
> admit
> that I tip my 42 foot towers by hand, but use the
> come-along on our 84 foot towers.
>


__________________________________________________
Do You Yahoo!?
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Hi, Bilal.

You can see the profiles and calculations on:
http://amber.aae.uiuc.edu/~m-selig/ads/coord_database.html

Best disigns.

Fernando







BILAL RAUF KHAN wrote:

> respected group members,
>
> i am interested in software through which i can design the whole wind turbine.
> i want calculate the profile of blades and output characteristics from that
software.
> if any body knew about this please let me know also.
>
> regards,
> bilal.
>
> [Non-text portions of this message have been removed]
>
>
> ==========================================================
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From: Paul Gipe
OK, having said that I have some reservations about the tower raising
technique described. What do the rest of your think?

Jon,

I have raised and lowered these gin pole towers too many
times to count, with wind turbines on top.  The Whisper 4500
with the 84 ft LMW&S tower does indeed have some large
forces, but they can be minimized using a pulley reduction
block between the gin pole and front anchor.  I've done this
all winter long, and with a 3:1 pulley ratio, a parking
brake, and a set of wheel chocks, and my front-mount winch,
and haven't slipped once.  It's safe if done correctly.

I agree with you, however, that I much, much prefer a winch
than to pull with a vehicle.  It is much more predictable,
and much easier on the tower.  I also would agree that a
cable with pulleys will reduce the forces as compared
with a rope.  I don't like the idea of a rope for towers
that tall.  Ropes stretch.  Cables don't.  The force to
overcome the friction to get the rope moving is pretty high.
It might work, but I'd prefer a cable.  Cables, however,
would probably require a pulley and not their recommended
hardware.

And for your comment #3, I would agree with SWP that
the tower should be lowered and the side guys adjusted -
if only for safety's sake.  If the forces on a tight
guy wire were higher than you think, the whole tower can
shift in the air.  I don't think I'd like that.

Now, on to my comments.  These are given in the spirit
of cooperation, and not as direct criticism to SWP.  Perhaps
they can use some comments in improving their manual.  The
disclaimers at the front are very bold.  I haven't gone into
great detail here, as I think Paul was more interested in
general comments.

Mike

1.  Perhaps I missed it, but I FIRMLY believe that
anybody putting up a tilt-up tower for the first time
should raise it once BEFORE putting the turbine on it.
It's a great way to learn what you're doing before
risking having the turbine on the tower top, with those
extra forces.  If you make a mistake the first time (without
the turbine), you only endanger yourself and the tower.  The
turbine wouldn't survive a crash landing, but the tower may.

2.  I don't like the recommendation that you can get
by with thin walled pipe.  I've downloaded high wind
speed data for many states (haven't looked at it all),
but 80 mph is not an unreasonable speed for ANY site
in the US to see during a turbine's lifecycle (from what
I have seen).  I would highly recommend anybody putting
up the tower to use the stronger pipe.  Yes, it costs
more, but it seems likely you will prevent a catastrophe.

I don't understand the SWP rationale for even suggesting
this as an option.  It's better to be safe than sorry.

3.  I would NOT recommend soldering your turbine wires
to your tower wires.  Split bolt connectors are definitely
the way to go.  They are removable!

4.  Rather than removing the top guy wire from the gin
pole first, I would prefer to see them start from the bottom
up, tightening as they go.  The tower will still be wobbly
without the lower guy wires tight, so starting from the
bottom up seems safer to me.

5.  I'm sure this is the way the towers were designed, but
I don't like the idea of having the wires tightened by
hand.  We pretension our guy wires on the LMW&S towers,
and with the Whisper 4500 on top, in a good blow, even
the downwind wire goes slack.  These towers will have
more movement than I am used to in strong winds, but
they were designed that way.  DO NOT pretension the
wires in these kits.  I wasn't stating you should.
These towers weren't designed for that.  I just thought
I'd mention that movement of the tower top seems very
likely.

6.  The manual states:  "If the tower is to be lowered, only
unclamp the cables on the lifting wire side so that when the
tower is re-erected only those cables will need to be
readjusted."  Somebody forgot that as a tower is being
lowered, the guy wires may TIGHTEN.  They may tighten on
either the way up or the way down.  If this scenario isn't
watched for, you can buckle the tower lowering it as well
as raising it.

7.  I don't like their steps for lowering the tower...
primarily #1 and #2... disconnect the wires from the
controller and short them.  Apparently, they have removed
the brake switch in the EZ-Wire.  This is not really a
SAFE thing to do.  Sometimes you MUST stop a turbine when
it is producing.  I don't want to be there to see sparks
fly.  They will.

8.  They say to tip the tower by hand to get it to start
coming down.  This may be stressful to some people.  It
may be easier to attach a come-along to one of the rear
guy wires to get it to start coming down.  I will admit
that I tip my 42 foot towers by hand, but use the
come-along on our 84 foot towers.

I am new to this group. I would info on constructing a small wind
generator to charge my RV batterys. Thanx Arnie

Destiny has made Windmission wind work continue from the little (65 inhabitants)
island of Drejø, where I'm trying to establish a test station for small wind
turbines (and yes, the family is still intact). The authorities are positive,
but I must indicate noise levels. So far,  I have been operating 12 bladed super
windroses, which meet the Danish claims of 45 db(A) for poorly populated areas
in a distance of only 17 m from the turbine. However,  I'm also working on three
bladed third world kits. So, dear list fellows, any indications of noise levels
from your three bladed concepts will be more than welcome. Do not fear
competition, your turbines might well end up at the Drejø Vindstation.

All the best
Claus

***
Claus Nybroe, R&D
http://www.windmission.dk
Denmark

respected group members,

i am interested in software through which i can design the whole wind turbine.
i want calculate the profile of blades and output characteristics from that
software.
if any body knew about this please let me know also.

regards,
bilal.


[Non-text portions of this message have been removed]

At 10:33 am -0400 4/9/01, Clay, Douglas wrote:
>Hugh and others
>I am trying to build a brake drum generator, have you any suggestions as to
>the best and/or easiest method to attach the laminated core, specifically
>how to center it around the axle and get it parallel to the plane of the
>back-plate(?) (plate that attaches to the axel housing and has the brake
>shoes and brake cylinder attached)? The back-plate is not flat in the North
>American Ford components, and I presume not in the UK version.
>Thanxs in advance
>Cheers
>Doug

sorry it took a while to respond.

I have already put some suggestions about this on my page
http://www.scoraigwind.co.uk/brakeupdate
where I show the mounting lugs in more detail.  I use the flange to
which the brake backplate is bolted, and I weld pieces of flat steel
to this flange.  In the north american version he uses a number of
lugs radiating from the axle tube.

I will admit that my plans do not cover this process in any detail
and I get a lot of enquiries about it.

I can suggest you fit the stator within the magnets and put some
packing of suitable thickness in the air gap while taking on the
mounting lugs.  Use plastic sheet or thin aluminium.

Another approach is to mount the stator tentatively and use a piece
of wire attached to the rotor to check whether it is central.  spin
it slowly and check the clearance of the tip of the wire is always
the same.  Move the wire tip along the stator and try again to check
both ends.

To be quite honest, I don't remember exactly how I did it last time.
Next time I'll take notes and put it on the update page.
--
Hugh

http://www.ScoraigWind.co.uk

--- In awea-wind-home@y..., Paul Gipe <pgipe@i...> wrote:
> ...to explain power factor

is done easily enough with a little math (just for the record:)

Let the voltage be
 	 V cos (omega*time)

And the current
	 A cos (omega*time +phi)

And the instantaneous power
 	 P = Vcos (omega *time) * A cos(omega*time +phi)

With a little trigonometry this becomes
 	 P =  (VA /2) [  cos(phi) + cos(2*omega*time+phi) ]

Now if we take the time average
	 <P> = (VA/2) cos (phi)

Whenever phi is different from zero the time average of the power
<P>  is somewhat smaller than (VA/2) When voltage and current are in
phase, the <P> is maximum

Notice that the instantaneous power is negative twice pr cycle  if
phi is not zero.

Notice that power factor is an AC calculation. It makes no sense to
speak of DC power factor.

OK, all those who read to this point can claim their eyes did not
glaze over:)

----- Original Message -----
From: Paul Gipe
OK, having said that I have some reservations about the tower raising
technique described. What do the rest of your think?

The gin pole (or shear legs) is an old method to raise a mast or tower.  It
is attractive because it uses available equipment in place of a boom truck
or crane.  The down side to the  gin pole method is the amount of tension
needed to start the lift. If any anchor, hardware or line is not engineered
with enough working load limit to take the static and dynamic loads caused
by tower lifting (and lowering) you have a smashed wind turbine and tower on
the ground.  That said I have raised many anemometer poles (with no wind
turbine load at the top) with this method and up to say 30 meters (90 feet)
the forces are manageable.  Above that,40 or 50 meters (160 feet) the
hardware, cable, winch and force required becomes less manageable and in
fact frightening to me.  Your limits may vary.  My feeling is that the money
saved using this method in place of a boom truck is at risk if you drop the
tower and have to buy a new one.  Again you have your own comfort levels of
risk.  If I was installing a cheep turbine and a short tower, I would use
the gin pole method.

  Specific criticism of the SWP technique includes:

1.  The suggestion of using a tractor or truck as the source of pulling
tension provides much less control then using a powered winch drum or hand
operated winch.  The dynamic loads introduced from letting off the brakes
and rolling backwards before letting out the clutch out and pulling forward
and the lag in stopping at the point of  tower being vertical could cause
problems.

2.  Two parting the gin pole cable at the end of the gin pole and at the gin
pole anchor without a pulley or block is suggested.  This added friction
increases the line tension.

3.  When an adjustment of the side guys is required after the lift is
started it is suggested that the tower be lowered and the adjustment made.
The peak force on the lifting system is when the tower is parallel to the
ground being stopped from lowering.  I think that the side guys should be
adjusted if required, with the tower part ways up and then continue the lift

Jon Powers
mailto:calwind@...

I just made a judicious trade for a Wincharger 1222H. The
specification plate is partially torn off. I see 12 volts, can't read
the amps. It included about a 16 foot tower (I love the tower just as
art!). It has a couple of electrical pieces.
Any help on how to set it up?
It has about a 6 foot wooden propeller. I am a Radio Controlled
Sailplane fanatic and I am skilled at making carbon fiber over foam
wings, so I hope to design an extended span, tapered and twisted
blade in the future.

But for now, how do I wire it? Can anybody give me an estimate on
when it was built?

For background, I am 40 miles west of Portland OR, on the side of a
valley on the east foothills of the Coast range. I get a lot of wind,
but I would guess most of the time around 7MPH, ergo my desire for a
longer span for lower speed performance.

The windmill includes a centrifugal brake and apparently a rope to
manually brake it.

I look forward to your collective wisdom. No Nukes!

Thanks,
David Lombrozo
David@...

Andy had previously mentioned that SWP has posted it's tower manuals to
SWP's web site.

The manuals are easy to download and I took a look at the 65-foot tower for
the Whisper H40 as a possible replacement for my NRG 65-foot tower and BWC
850.

My hats off to SWP for posting the manuals. This and the tower calcs they
also have on their web site could be a real help to people.

OK, having said that I have some reservations about the tower raising
technique described. What do the rest of your think? You can reply to me
off list if you like--maybe be better actually. I won't influence anyone's
comments until others have a chance to read over SWP's procedure.

http://www.windenergy.com/SUPPORT/downloads.html

Paul




Paul Gipe
208 S. Green St., #5; Tehachapi CA 93561-1741 USA; ph: +661 822 9150; fax:
+661 822 8452; pgipe@.... Wind Power for Home & Business, Wind Energy
Comes of Age, Wind Energy Basics, and Energía Eólica Práctica.
Wind Energy: http://www.chelseagreen.com/Wind/PaulGipe.htm
Wind Energy: http://rotor.fb12.tu-berlin.de/personen/paul.html
Electricity Feed Laws: http://invisibleuniverse.com/Juice/Wind/feedlaw.htm

At 10:33 4/9/2001 -0400, Doug Clay <.-.-.@...> wrote:
>Hugh and others
>I am trying to build a brake drum generator ... method to attach the
laminated core, specifically how to center it around the axle and get it
parallel to the plane of the back-plate(?) (plate that attaches to the axle
housing and has the brake shoes and brake cylinder attached)?
> The back-plate is not flat in the North American Ford components, and I
presume not in the UK version.
>Thanxs in advance
>Cheers
>Doug
>

· I can't answer, but I suggest Hugh and others do, not only because of
general interest, but also because Doug works at the Canadian Government's
Agence des douanes et du revenu du Canada (Customs & Revenue Agency) :-
http://www.ccra-adrc.gc.ca , and it's good to have a wind-power advocate
with hands-on experience, in a government office.

David.
(David MacClement) d1v9d@...
http://davd.tripod.com/GrRR-010824_titles.html#top
http://www.geocities.com/davd.geo/index.html#top
**************************************************

Michael,

Just loved it. "Good luck putting that on your roof." Great Midwestern
understatement.

Jim,
Southwest Windpower peddles this idea, of putting a wind turbine on your
roof, because they don't want you to realize that a real tower costs money
too. Soooo, as Michael explained, don't believe everything you read and
more importantly don't believe everything you hear. There's some old adage
about that.

Paul

Paul Gipe
208 S. Green St., #5; Tehachapi CA 93561-1741 USA; ph: +661 822 9150; fax:
+661 822 8452; pgipe@.... Wind Power for Home & Business, Wind Energy
Comes of Age, Wind Energy Basics, and Energía Eólica Práctica.
Wind Energy: http://www.chelseagreen.com/Wind/PaulGipe.htm
Wind Energy: http://rotor.fb12.tu-berlin.de/personen/paul.html
Electricity Feed Laws: http://invisibleuniverse.com/Juice/Wind/feedlaw.htm

Hugh and others
I am trying to build a brake drum generator, have you any suggestions as to
the best and/or easiest method to attach the laminated core, specifically
how to center it around the axle and get it parallel to the plane of the
back-plate(?) (plate that attaches to the axel housing and has the brake
shoes and brake cylinder attached)? The back-plate is not flat in the North
American Ford components, and I presume not in the UK version.
Thanxs in advance
Cheers
Doug

Jim,

Here's the math:

P = Power available in the wind
rho = air density
A = swept area
V = velocity

P = 0.5*rho*A*(V^3)

The power available in the wind at 3 mph is
1.45 Watts per square meter.  A perfect turbine
would only convert 60% of that, or 0.87 Watts/m^2.

An average American home uses something like
6,000 kWh/year, so to generate that energy assuming
the wind ALWAYS blows at 3 mph would require a
continual output of 685 watts.  At 0.87 W/m^2,
that would require a 787 square meter swept area,
or for english units, 8,475 square feet.  That is
a 52 foot radius turbine.  Good luck putting
that on top of your house.

Sincerely,
Mike
http://www.ndsu.nodak.edu/ndsu/klemen


Jim Piper wrote:
>
> I have recently heard of a roof mounted wind generator that will
produce
> enough electricity to operate the average home from 3 mph wind.  As I
> understand it this system is not yet in production but has been tested
> and proven.
> Does anyone out there know any more about this system than I do?
> I would really like to hear from you.
> Jim Piper