[RE-wrenches] ice accumulation

Sun Aug 17 07:41:08 PDT 2008

Hi Roger, It looks like you and I are the only early risers this morning.
You are 100% correct, I have very limited exposure to good wind
applications. There are at least couple of high profile installations here
in Saint Louis that are textbook examples of how not to do it. And to add
insult to injury, LEED awarded a platinum rating to one of these building
based (at least in part) on the points this very visible but almost
ineffective wind application provided.

My inappropriately applied experience regarding rotors stems from the rotor
being powered from the hub rather than extracting power from the airstream.
Two different situations that I will not knowingly confuse in the future.
Thanks for the time and effort in explaining the error of my ways.

This leads to another issue with the new division of the wrench list into
solar and wind divisions. Unless someone is properly versed in both those
technologies, and accordingly subscribes to both those lists, there might
not be the very interface we are having now and the opportunity to correct
some "common misconceptions". Of course you wind guys won't have to wade
through the foibles of solar electric much less solar thermal.

Best,

Bill Loesch
Solar 1 - Saint Louis Solar
314 631 1094

----- Original Message ----- 
From: "roger dixon" <roger.dixon at att.net>
To: "'RE-wrenches'" <re-wrenches at lists.re-wrenches.org>;
<daryl_solar at yahoo.com>
Sent: Sunday, August 17, 2008 7:44 AM
Subject: Re: [RE-wrenches] ice accumulation

> Hi Bill.  I have to take issue with your comment, "Certainly don't want to
> lose that shedding blade into the solar array".  Although you are in the
RE
> business, I have to admit, that sounds like a NIMBY comment to me.  I
> surmise from your "Solar 1-St. Louis Solar" sign off that you are a solar
> guy, not a wind guy.
>
> Let me help you out here.  What happens to a wind turbine rotor assembly
> when it starts to ice up?  It loses its airfoil.  There is less flow
> captured across the rotors due to the ice buildup and the rotors will slow
> down.  As the ice continues to build up, the rotors continue to slow down.
> Eventually, and sooner than later, they will stop rotating.  What is it
that
> is going to shed and throw a rotor any distance?  These are two different
> concepts anyway.  Rotors very rarely get thrown and I would submit the
ones
> that end up disengaged do so because of a lack of proper maintenance over
> time.  Back to "ice shedding".  Since we now understand that as ice builds
> up rotors will slow down to the point of stopping, what happens next?
> Whenever it gets warm enough to melt the ice it will drop straight down as
> it disengages from the rotor.  Due to gravity the heavier rotors will
swing
> toward the bottom and the lightest rotor will swing toward the top.  Until
> all the ice drops off those rotors the turbine it will not operate.
>
> I'm not sure this is a wind turbine application but only because it
appears
> from the pictures that once the ice arrives it may take awhile to melt.
> Will it melt any faster off the rotors than the PV panels?  Probably not,
so
> I am not sure a wind turbine will help resolve the problem.  However, that
> stems from the nature of the weather, not anticipated damage to the
> surrounding area due to flying ice, arcing rotors, broken equipment, etc.
>
> Dogs shed, not wind turbines :-)
>
>
> Roger Dixon
> Certified Wind Site Assessor
> Skylands Renewable Energy, LLC
> 908.337.2057
> roger.dixon at att.net
>
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Bill
Loesch
> Sent: Sunday, August 17, 2008 7:24 AM
> To: daryl_solar at yahoo.com; RE-wrenches
> Subject: Re: [RE-wrenches] ice accumulation
>
>
> Hi Darryl, Mark, Ron, et al,
>
> Those are some terrific and inspiring photos. If this is not an
application
> for RE, we might all go home.
>
> Special thanks to Mark for the good html sleuthing. Had I seen the photo I
> would have never suggested to mount fluid containers, Dole valves (and
more
> stuff) on the top of the rack.
>
> For the ice to accumulate as shown I am assuming there must be some really
> strong winds. More problems with adding wind machines than they solve?
> Certainly don't want to loose that shedding blade into the solar array.
>
> Here is another carry over from the transport category aircraft world -
add
> a shaker to the mount / module. Actuated by whatever you deem appropriate
to
> sense the ice accumulation. The shaker is most often a motor with a non
> symmetric weight on its shaft. Not exactly high tech. Hopefully less
energy
> intensive than the "clean" backflow heating.
>
> Again, my apologies for opening my mouth before I knew the scope of your
> situation. Absolutely great photos!
>
> Bill Loesch
> Solar 1 - Saint Louis Solar
>
>
>
>
> ----- Original Message ----- 
> From: "Darryl Thayer" <daryl_solar at yahoo.com>
> To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> Sent: Friday, August 15, 2008 8:24 PM
> Subject: Re: [RE-wrenches] ice accumulation
>
>
> > Hi all
> > This is for the far out ideas.  Most cooling and icing occurs on
> windshields and not on side windows, due to radiation to the night sky.
> What if a set of tempered glass were above the modules, such that the sun
> would pass underneath in the winter, and pass through in the summer.  The
> glass would serve as a radition sheild.
> >
> > Darryl
> >
> >
> > --- On Thu, 8/14/08, Bill Loesch <solar1online at charter.net> wrote:
> >
> > > From: Bill Loesch <solar1online at charter.net>
> > > Subject: Re: [RE-wrenches] ice accumulation
> > > To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> > > Date: Thursday, August 14, 2008, 9:39 PM
> > > Hi Ron,
> > >
> > > While you might put this into the same category as the
> > > RainX; I would
> > > consider using some type of glycol mix perhaps delivered by
> > > a Dole style
> > > (temperature sensing) valve. Glycol is what the transport
> > > aircraft community
> > > uses before launching an aircraft into current ice
> > > conditions. The Dole
> > > style valve only dispenses the gravity fed glycol when near
> > > freezing
> > > conditions exist.
> > >
> > > Bill Loesch
> > > Solar 1 - Saint Louis Solar
> > >
> > > ----- Original Message ----- 
> > > From: "Ron Young"
> > > <solareagle at solareagle.com>
> > > To: "RE-wrenches"
> > > <re-wrenches at lists.re-wrenches.org>
> > > Sent: Thursday, August 14, 2008 7:12 PM
> > > Subject: [RE-wrenches] ice accumulation
> > >
> > >
> > > > Hi Wrenches,
> > > >
> > > > I know this is a nice cool subject for these
> > > (hopefully) sun filled
> > > > days. I am working on a telecom system that has some
> > > issues with ice
> > > > accumulation on the panels that essentially shut the
> > > system down mid
> > > > winter. Wondering if anyone has suggestions to remedy
> > > the ice
> > > > buildup. It's an extreme mountaintop environment
> > > with very high winds
> > > > at times and the ice cakes up to 2" - 3" on
> > > surfaces. There are some
> > > > pics here: www.solareagle/temp/ice.html
> > > >
> > > > Access to the site in winter is totally out of the
> > > question so we are
> > > > hoping to find some ideas that might prevent or reduce
> > > the ice
> > > > accumulation. When the ice shuts the panels down the
> > > communications
> > > > go down.
> > > >
> > > > Someone suggested a slippery spray like RainX might
> > > help to prevent
> > > > accumulation but I think it would quickly be washed
> > > off/worn out and
> > > > I don't know the uv issues that might reduce power
> > > output.
> > > >
> > > >
> > > > Ron
> > > > earthRight Solar
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