Drake, One thing about those old modules is that the cells are incredibly thick. You can feel them on the back-sheet. They must be at least 1/16" thick. Wire-saw technology was just not that good in the old days. Module manufacturers say that the thickness of the cell has no effect on performance, but I guess we will just have to see. If we're still around in 2036, we can compare a set of 2009 modules with my old ones which will be 54 by then!
Brian -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Drake Chamberlin Sent: Friday, March 20, 2009 1:07 PM To: RE-wrenches Subject: Re: [RE-wrenches] Sunpower modules Allan and Brian Thanks for the answer to the problem. I think the Xantrex PWM chargers are going to be the most appropriate for these modules. The old Arco modules are incredibly long lasting. I hope the ones we are putting in today will last as long. Drake At 01:40 PM 3/20/2009, you wrote: >Drake, > >Just to add to Allan's excellent post, most of the Arco's made >before about 1985 had less than 36 cells. Some were 35-cell, most >were 33-cell, but there were also 32 and 30-cell units. > >You might want to look into rewiring the modules in higher voltage >series strings to get more "oomph" out of the MPPT controller, and >reduce transmission losses. However, be aware that many of those old >Arco modules had a sticker on them that said something like "do not >operate above 50VDC" > >I still have 12 Arco, 33-cell, model 16-2000 modules (16Vmp/2A) on >my off-grid house, wired in pairs for 24V and going through an >ancient Trace C-30A relay controller (not even PWM!). I've >contemplated wiring them for 36V and using MPPT, and I may someday, >but they have been working so well as is that I haven't bothered. >Even on hot days I often see 27.5V and 11-12A charging my 24V >battery bank, which I think is damn good performance from a set of >27-year-old modules. > >Brian Teitelbaum >AEE Solar > > _______________________________________________ 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
