[RE-wrenches] techno-poetry! (Matt Lafferty)

Thu Oct 29 02:09:25 PDT 2009

Techno- poetry of the highest quality. 

Love it. 

For a brighter energy future,

Geoff Greenfield
President
Third Sun Solar & Wind Power Ltd.
340 West State Street, Unit 25
Athens, OH 45701

740.597.3111     Fax 740.597.1548
www.Third-Sun.com

Clean Energy - Expertly Installed

----- William Korthof <wkorthof at eesolar.com> wrote:
> Why bother with the DC converters if you only have 2 strings?
> 
> Get a wide-range, dual-channel inverter (Power One 5000) and plug in  
> the modules
> however you like. The bypass diodes in the modules will bypass the  
> shaded module
> sections as appropriate for the conditions, and rest of the modules  
> (not shaded) will
> contribute power used by the wide-input MPPT at the optimal string  
> voltage.
> The input channels are separately controlled, so they both operate at  
> their optimal
> MPPT voltage at all times.
> 
> The input voltage range is extremely wide, 90 to 550 Vdc (Mppt), with  
> a startup
> voltage of 200 Vdc and a maximum Voc of 600 Vdc. That's extremely  
> flexible gets
> you very close to harvesting 100% of the available module output.
> 
> Cost, performance, and reliability seem far better with a PV/inverter  
> combination
> than what you get if you add DC converters to each module.
> 
> /wk
> 
> 
> >
> > Date: Wed, 28 Oct 2009 16:29:56 -0700
> > From: Matt Lafferty <gilligan06 at gmail.com>
> > To: "RE Wrenches" <re-wrenches at lists.re-wrenches.org>
> > Subject: [RE-wrenches] Shade Mitigating DC Device Application
> > Message-ID: <F3827D62F9FA4F1E983C525A44F44CE8 at GILLIGONE>
> > Content-Type: text/plain; charset="us-ascii"
> >
> > Esteemed Wrenches,
> >
> > Your collective wisdom & conjecture is sought in resolving the  
> > following
> > riddle:
> >
> > There once was a home in the hills.
> > With morning sun the roof is filled.
> > Blasted mountain rising in the west,
> > Makes a shady mess at very best.
> >
> > "Onward! Fear not!", sayeth the man.
> > "Twenty-four modules. Not one less!"
> > "Black box of magic for every one."
> > "And string inverter plus Island of Sun!"
> >
> > With fifty-one hundred watts of DC.
> > Two series strings of four times three.
> > Black boxes of magic, but not by that name.
> > At quarter the price are they really the same?
> > 'Tis not the matter, least not today.
> > To you the group... What do you say?
> >
> > For greatest performance over time to yield...
> > 2 balanced strings of shade and of sun,
> > Or put worst shade all onto one?
> > Snake-oil merchants say not to worry.
> > Magical boxes change dark to light in a hurry.
> > What say ye, from out in the field?
> > Balance the strings, or not?
> > <End>
> >
> > Some factors to consider.... The site is shade-challenged, primarily  
> > in the
> > afternoon. There will be two strings of 12 modules each feeding a  
> > single
> > inverter. Enphase is off the table for now. Homeowner specifically  
> > wants to
> > do back-of-module DC shade mitigation. The array layout is such that
> > configuring the strings so there is a dominant sunny one and  
> > dominant shady
> > one is possible. It is also possible and almost as easy to configure  
> > the
> > strings so they are more balanced with each other. Assuming that  
> > each module
> > is equipped with a black box, will it make any difference which
> > configuration gets used?
> >
> > I have my theory on the subject and am interested in yours. Thanks in
> > advance for any and all feedback.
> >
> > Pray for Sun!
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
> > URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20091028/7546620a/attachment-0001.htm 
> > >
> >
> > ------------------------------
> >
> > Message: 3
> > Date: Wed, 28 Oct 2009 18:21:14 -0600
> > From: Mick Abraham <mick at abrahamsolar.com>
> > To: gilligan06 at gmail.com, RE-wrenches
> > 	<re-wrenches at lists.re-wrenches.org>
> > Subject: Re: [RE-wrenches] Shade Mitigating DC Device Application
> > Message-ID:
> > 	<3dff9f8c0910281721r3a729f1er48806fe6aa5a1cba at mail.gmail.com>
> > Content-Type: text/plain; charset="iso-8859-1"
> >
> > This jester must ask, with a hint of glee...
> > is this off the grid, or is there u-til-i-tee?
> >
> > Mick Abraham, Proprietor
> > www.abrahamsolar.com
> >
> > Voice: 970-731-4675
> >
> >
> > On Wed, Oct 28, 2009 at 5:29 PM, Matt Lafferty  
> > <gilligan06 at gmail.com> wrote:
> >
> >> Esteemed Wrenches,
> >>
> >> Your collective wisdom & conjecture is sought in resolving the  
> >> following
> >> riddle:
> >>
> >> There once was a home in the hills.
> >> With morning sun the roof is filled.
> >> Blasted mountain rising in the west,
> >> Makes a shady mess at very best.
> >> **
> >> *"Onward! Fear not!*",* *sayeth the man.
> >> *"Twenty-four modules. Not one less!"*
> >> *"Black box of magic for every one."*
> >> *"And string inverter plus Island of Sun!"*
> >>
> >> With fifty-one hundred watts of DC.
> >> Two series strings of four times three.
> >> Black boxes of magic, but not by that name.
> >> At quarter the price are they really the same?
> >> 'Tis not the matter, least not today.
> >> To you the group... What do you say?
> >>
> >> For greatest performance over time to yield...
> >> 2 balanced strings of shade and of sun,
> >> Or put worst shade all onto one?
> >> Snake-oil merchants say not to worry.
> >> Magical boxes change dark to light in a hurry.
> >> What say ye, from out in the field?
> >> Balance the strings, or not?
> >> <End>
> >>
> >> Some factors to consider.... The site is shade-challenged,  
> >> primarily in the
> >> afternoon. There will be two strings of 12 modules each feeding a  
> >> single
> >> inverter. Enphase is off the table for now. Homeowner specifically  
> >> wants
> >> to do back-of-module DC shade mitigation. The array layout is such  
> >> that
> >> configuring the strings so there is a dominant sunny one and  
> >> dominant shady
> >> one is possible. It is also possible and almost as easy to  
> >> configure the
> >> strings so they are more balanced with each other. Assuming that  
> >> each module
> >> is equipped with a black box, will it make any difference which
> >> configuration gets used?
> >>
> >> I have my theory on the subject and am interested in yours. Thanks in
> >> advance for any and all feedback.
> >>
> >> Pray for Sun!
> >>
> >> _______________________________________________
> >> List sponsored by Home Power magazine
> >>
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> >>
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> >>
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> >>
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> >> www.members.re-wrenches.org
> >>
> >>
> >>
> > -------------- next part --------------
> > An HTML attachment was scrubbed...
> > URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20091028/561affab/attachment.htm 
> > >
> >
> > ------------------------------
> >
> > _______________________________________________
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> > End of RE-wrenches Digest, Vol 2, Issue 1107
> > ********************************************
> 
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