Ive installed a few systems with these laminates years ago, but havent kept up with performance much unfortunately. I have heard of the diodes going bad (which are glued into the laminate along the sides). Maybe thats your issue? Just speculating...
Roy Rakobitsch NABCEP Certified Small Wind Installer® NABCEP Certified Solar PV Installer® Certified Advanced Tower Climbing, Safety & Rescue Wind/PV Design Engineer Windsine LLC 631-514-4166 www.windsine.org On May 31, 2015 2:49 PM, "Allan Sindelar" <al...@sindelarsolar.com> wrote: > Luke, > I have never worked with Uni-Solar laminates, although I expect to for the > first time this summer, at 12,800' in the White-Inyo mountains, but that's > another story. I installed one small cabin system with US64s in 1999 (the > rancher wanted modules that would keep performing with a few vandals' > bullet holes, which never happened) and they continue to perform as new. > > So take my two comments with that disclaimer in mind. First, you measured > only 63% of rated output. That's pretty low at the controller, even if the > roof is hot. Could there be something else to search for as a cause? > > Assuming it's indeed simply weak voltage, consider a Midnite Classic 200 > or 250, to give the voltage window to allow repairing to a higher nominal > input, maybe 72 or 96 volts, so that the charge voltage will always be > higher than battery voltage. > > Allan > > > On May 31, 2015, at 11:55 AM, Luke Christy <sgsrenewab...@gmail.com> > wrote: > > > > Hello Off-Grid Wrenches, > > > > I recently made a periodic maintenance visit to a residential off-grid > system I take care of here in Southern CO, and discovered an interesting > problem. > > > > This system has an array of 48x Uni-Solar PVL-68 laminate modules > applied directly to standing-seam metal roofing. > > > > The data logging on the controller (Outback MX-60) indicated that the > system was having trouble completing a charge cycle and going to float. > Initially I assumed was due to heavy electrical use by the occupants > (renters). After a little checking, I noticed that the module string > voltage was only about 0.5V above the battery voltage! > > This was a cool late morning, with full sun, and the array was charging > almost 2kW at 54.5V. The module strings were running at 55V. I've noticed > the module voltage being lower than I'd like before, but it has never been > this low. I suspect this is the real reason the system hasn't been able to > complete a charge cycle. > > > > By removing the loads I was able to get an open-circuit voltage of 71V, > but that still seems pretty low. > > > > Has anyone else experienced a voltage degradation issue with the > Uni-Solar laminate? What was the expected annual voltage degradation for > this technology? > > > > These modules do have some age on them. The system was installed about > 15 years ago (by a competent installer who is now retired). The system was > installed before MPPT controllers were common, so I assume the modules are > wired in strings of 4 for 48V nominal. > > > > Any experiences or opinions are appreciated. > > Thanks in advance. > > > > -Luke > > > > > > Luke Christy > > > > NABCEP Certified PV Installation Professional™: Certification #031409-25 > > NABCEP Certified Solar Heating Installer™: Certification #ST032611-03 > > CoSEIA Certified PV Installer > > > > Solar Gain Services, LLC > > PO Box 531 > > Monte Vista, CO. 81144 > > sgsrenewab...@gmail.com > > 719.588.3044 > > www.sgsrenewables.com > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > List sponsored by Redwood Alliance > > > > List Address: RE-wrenches@lists.re-wrenches.org > > > > Change listserver email address & settings: > > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > > > List rules & etiquette: > > www.re-wrenches.org/etiquette.htm > > > > Check out or update participant bios: > > www.members.re-wrenches.org > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > >
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