Re: [RE-wrenches] Off-Grid Sizing Case

[Roy Butler]

Bob and all, I've heard that PV works better with full sun....my array's been in since '98 and I'm still waiting for that mythical 1,000 w/m2 to test that theory......yeah Bob, why do we live here? Seriously though.....I do agree with over sizing the array. But much as I hate running a generator on my off grid pv/wind system, it's a necessary evil where we live.....and it's even worse where Bob lives! Roy Butler NABCEP Certified Solar PV Installer® NYSERDA eligible PV & wind installer PA Sunshine Program Approved PV Installer Four Winds Renewable Energy, LLC 8902 Route 46 Arkport, NY 14807 607-324-9747 www.four-winds-energy.com Although no trees were killed in the sending of this message, a large number of electrons were terribly inconvenienced. robert ellison wrote: On this area of Northern New York i have not had over .30 KWH (300 watts) per day over the last week.... and thats the high day, most have been .10 or none, none being the most common. Thats off a 1400 watt rack of SW panels   Up here you size in a generator or go south for the winter.   Tell me again why i live here, any thoughts Roy? You can't be doing any better....   Bob On Thu, Dec 10, 2009 at 9:29 AM, Darryl Thayer <daryl_so...@yahoo.com> wrote: The system is way short on PV, and I would think that it is already a Gen with PV support.  I agree with everybody more PV is the way to go but the batteries must be cooked by now with this many Deep cycles.  BTW C/10 is not important, in fact I feel better if I charge slower.  I know fast charging is a good way to kill batteries.  Operating cost needs a high efficiency engine.  So until you can get the PV up to become the dominant source, a gen is probibly in order.  I tend to use smaller generators than most people, and the fuel efficency of a Honda inverter gen is hard to beat. --- On Thu, 12/3/09, wind...@wind-sun.com <wind...@wind-sun.com> wrote: > From: wind...@wind-sun.com <wind...@wind-sun.com> > Subject: Re: [RE-wrenches] Off-Grid Sizing Case > To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org> > Date: Thursday, December 3, 2009, 12:18 PM > > Off-Grid Sizing Case > > > > > > The rate of charging is not the > real problem in most > undersized systems, it is the fact that the batteries > seldom, if ever, get fully > charged. Given the ratio of PV vs battery capacity, I would > suspect that their > batteries have been chronically undercharged for ages. We > usually recommend > around 1 watt of pv per AH for a 12 volt system, 2 > watts for 24 volt > etc. >   > A generator is not usually the > answer, because it may > have to run for hours to get that final 5-15% of charge > into the batteries. > Generators are good for equalizing, not so much for general > > charging. >   > .................................................................................................. > Northern > Arizona Wind & Sun - Electricity From The Sun Since > 1979 > Solar Discussion > Forum: http://www.wind-sun.com/ForumVB/ > .................................................................................................. > >   ----- Original Message > ----- >   From: >   Mark >   Frye >   To: 'RE-wrenches' > >   Sent: Thursday, > December 03, 2009 10:56 >   AM >   Subject: Re: > [RE-wrenches] Off-Grid >   Sizing Case > > >   So being able to achieve C10 > charging from the PV is not so >   important? > > Mark > Frye > Berkeley Solar > Electric >   Systems > 303 Redbud >   Way > Nevada >   City,  CA 95959 > (530) 401-8024 > www.berkeleysolar.com  >     > > > >   From: re-wrenches-boun...@lists.re-wrenches.org > >   [mailto:re-wrenches-boun...@lists.re-wrenches.org] On > Behalf Of wind...@wind-sun.com > Sent: >   Thursday, December 03, 2009 9:51 AM > To: >   RE-wrenches > Subject: Re: [RE-wrenches] Off-Grid Sizing >   Case > > > >   I would go with #1. > The solar is obviously >   undersized for the battery bank he has. Another panel + > MPPT should give him >   about 25-40% more, depending on temps etc. >     > > .................................................................................................. > Northern >   Arizona Wind & Sun - Electricity From The Sun Since > 1979 > Solar >   Discussion Forum: http://www.wind-sun.com/ForumVB/ > .................................................................................................. > > > >   _______________________________________________ > List sponsored by >   Home Power magazine > > List Address: >   RE-wrenches@lists.re-wrenches.org > > Options & >   settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List >   rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out >   participant > bios: > www.members.re-wrenches.org > > > > -----Inline Attachment Follows----- > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org

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