[RE-wrenches] Charge Control in AC coupled system
Wrenches, Howie, good to see you probing this issue. I have an upcoming system as well that is considering a micro-grid approach. My question would be, is the Outback not able to sell back and charge at the same time. I understand that with power present on the ac output terminal the inverter will try to charge the battery. But doesn't the unit also try to sell back on the AC output terminal. Most Outback systems will sell down to the float voltage in a battery back up situation that is grid connected. Does all of the DC connected array stop selling back with the Sunny Boys going full steam. For example. Lets imagine we have 4 kW connected to an Outback dual inverter grid connected battery back up and then add 4 kW connected to a Sunny Boy in a micro-grid format. When the sun is shining---and all the loads in the critical panel are being met---that the Sunny Boy overpowers the Outbacks and 1. Charges the batteries and 2.(my question) overpowers the Outback's ability to sell to grid in its traditional format? As always the guidance of the "List" is greatly appreciated. Thanks Doug Wells The Solar Specialists www.thesolarspecialists.com 802-498-5856 ___ 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
[RE-wrenches] Generator for off grid
Randy, I have seen issues with Kohler's as well. But some of them perform well. When Kohler changed their warranty I had a meeting with the company owner that installs and services their units. We decided on a middle ground. Rather than moving all off grid systems to a different genset, we install Kohlers in their territory. They back the Kohler -in house- with one year P @ L and or 2000 hours. Might be an option for you. Doug Wells The Solar Specialists Morrisville, VT 05661 NABCEP Certified Solar Heating License www.thesolarspecialists.com 802-498-5856 ___ 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
[RE-wrenches] Heavy Duty Modules?
Wrenches, Can anyone recommend a panel that is built with more strength or ability to handle greater load. I am installing on a shallow pitched roof and am concerned about snow build up in this particular location. I know you guys out in the Sierra's get a lot more snow than we do. What modules are up to the challenge? Are there any new military spec modules like the old MSX 120's? Any experience or guidance is appreciated. Doug Wells Morrisville, VT 05661 NABCEP Certified PV Vermont Solar Partner The Solar Specialists www.thesolarspecialists.com 802-498-5856 ___ 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
Re: [RE-wrenches] Tall L-feet
Jim, Ecofasteners makes a variety of feet attachments. At one point they made up to 6" feet. Worth a shot if your looking for prefab. http://www.ecofastensolar.com/ Doug Wells The Solar Specialists www.thesolarspecialists.com 802-498-5856 ___ 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
[RE-wrenches] Insulated Roofing Approaches
Wrenches, We have a project that will involve installing arrays on storage units. The roof is metal, over 1 1/2" rigid insulation, over 2x8 rafters. We have come up with a couple solutions, but thought it wise to consult here. Has anybody else installed on this type of roofing? What was your approach? Thank you for any insight or experience. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] calculating low string voltage
Ray, I agree with what you have calculated, but the temp. coef. listed is for a Voc. For voltage sag, the temp. value would be a Vmp value and I don't know how much of a difference that makes. I have seen some manufacturers offer a temp. coefficient for Vmp as well as Voc. Not sure what the difference would be, but if it gets down to a few volts with the PE, it is would be worth checking. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com On Nov 29, 2011, at 5:55 PM, Ray Walters wrote: I'm prepping for a class on this very subject tonight, so I'll just wrap up everybody's good points: V min = Vmpp x (1- temp diff x Temp coefficient) So first, I'd take your ambient temp from ASHRAE Extreme Annual Mean Maximum, then add Scott's adder (ie roof mount off 6" = +30C) so let's say the ASHRAE # is 35C, then you have 30 + 35 = 65C cell temp then, 65C - 25C(STC) = a differential of 40 deg C from standard test conditions The Aug/ Sept 2010 edition of Solar Pro shows the coefficients for numerous modules, Solar world for example is -0.33 %/degC With a 40 degC differential then, the voltage would change by 40 x .33, or 13.2% So just assuming Vmpp = 35v, the adjustment would be 35v x (100%-13.2%), or 86.8% of 35v, which gives a Volt min of 30.4 v Somebody please correct my math if I got that wrong. Also probably more interesting is the actual Power coefficient, which shows the total power losses from higher temperatures, not just voltage. The calculation would be similar. Ray On 11/29/2011 2:07 PM, Darryl Thayer wrote: > > I am on road so I have no texts with me, but the same formula applies about > 0.4% per degree (less voltage) or use the module label voltage coefficent. > However you must use the MPPT voltage and the temperature = (temperature > ambient (2% high) plus roof temperature warming) The roof temperature is > hard to find good values because it depends upon spacing between roof and > module. I add 15 deg C for most situations. > > Best I can do from memory. > DT > > From: Kirk Herander > To: RE-wrenches > Sent: Tuesday, November 29, 2011 1:48 PM > Subject: [RE-wrenches] calculating low string voltage > > I am in debate with a PE over calculation of low voltage of a series string > on a hot day. He insists that an arbitrary high cell temp is factored in, not > just ambient temperature. Could someone please give an accepted formula for > this calculation? Thanks. I cannot find a clear reference to low voltage > calculation on a hot day (but every reference material is clear on how to > calculate high voltage on a cold day). > > Kirk Herander > VT Solar, LLC > dba Vermont Solar Engineering > NABCEPTM Certified installer Charter Member > NYSERDA-eligible Installer > VT RE Incentive Program Partner > > > ___ > 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 ___ 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
[RE-wrenches] federal credit clarification
Roger, I don't have any definitives either. Have been hounding the IRS for a while now. I did hear this weekend that the grant will be 80% of the credit value. Again, this is not a definitive, just what I hear. Makes sense I guess. What this will do is allow some of my clients to get loans for a period of one year on the amount of the grant. They can then pay off that part of the loan next year, and leave the balance in a low interest program. That is if Uncle Sam ever cuts the checks. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] module frame separation
William, I have done the procedure before. I used RTV silicone. The hard part was cleaning out some of the old sealant in the frame. After seeing enough modules that look like they were sealed by preschoolers, you might end up with a longer lasting seal than the manufacturer. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
[RE-wrenches] Broken Modules
Wrenches, I am curious what other installers are doing with broken modules? I know some manufacturers are starting recycling programs. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] grounding of hot water collectors
Kirk, What is his logic? Are you running the circulator with PV mounted on the collectors? Is the house plumbing grounded? Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] NABCEP
William, I agree that the value of NABCEP is mixed. I would like to think that it is still a benchmark. To me the importance of NABCEP has not been the test, but the prerequisites to take the test. A test is just a test and I have always felt that they have limited value. But experience is different. When I applied you had to have 3 years of experience installing(in my track). And the jobs that you used had to be lead installs. Not just, "yeah I was on a crew for a couple jobs. Or I have "some experience" installing. I feel it important to understand the job from beginning to end. Design, Safety, Installs and Commissioning. The more they water down the experience component to fast track eager installers, the less the certification will mean. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] single string of batts: must the interconnects be inverter size cables?
I have always used 4/0 through out the bank. I guess that I have had to replace to many dead batteries at this point. If you are under sizing the parallel strings, what happens when a cell fails? or 2 cells fail. Now all the current would be carried by one string. If you are running equal lengths to a buss bar, it might make sense to put a current limiting fuse on each parallel run before the bus. However, this would pretty much negate any money save on downsizing the copper. So what is really gained? Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] SWH - mixing valves
Kelly, I have also seen mixing valves get leaky over time. Many mixing valves are designed for controlled input from a boiler at steady 140 degree temps. It is not uncommon for SHW tanks to reach 180+ degrees in certain conditions. If exposed to these higher temps the valves can begin to loose accuracy. Usually they are designed to "fault" into the cold position, so the begin to leak in a little cold and the client will complain about low temps at the faucet/shower. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com On May 19, 2010, at 2:14 AM, Kelly Keilwitz, Whidbey Sun & Wind wrote: Thermal wrenches, I'm having an ongoing issue with mixing valves in my own system not keeping a steady mix domestic HW temperature as the tank temperature varies with solar heating. If I set it for (say) 122˚F mix when the tank is 135˚, it seems to hold that differential at all tank temps - i.e. when the tank is hotter the mix is too hot (sometimes dangerously so), and when colder the mix is too cold for a comfortable shower. Thus, I need to change the setting all the time. I'm now using a Honeywell valve with a 90˚ - 145˚ range. This is a replacement for a valve with a wider range that acted the same way. Any ideas, suggestions for better valves, or? This has me wondering how many of our SWH customers are experiencing a similar thing, but just aren't bothered enough to say anything. We seem to have encountered many plumbing situations where the mixing valve allowed weird backflow or siphoning situations to mess with system operation, especially with HW recirculation. I thought I had all such causes eliminated on my system, but maybe not. Thanks for sharing your experience with such matters. -Kelly Kelly Keilwitz, P.E. Whidbey Sun & Wind Renewable Energy Systems ke...@whidbeysunwind.com 360-678-7131 ___ 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
Re: [RE-wrenches] double-insulated PV wire
Marco, Last we purchased both from USA wire and cable in Austin. Under $5 per mated pair and pins for oversized MC4. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & 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
Re: [RE-wrenches] Mike Holt Solar Video - LIVE in your town, limited time only
Richard, I agree. I caught part of the streaming as well. Thanks for sharing. Bringing lightning protection into the discussion is a whole other can of worms. He made a variety of assumptions. 1. That the auxiliary rods were not bonded. For instance, I was trained in the exact opposite manner for ground mounts and off grid. Installing a rod at each pole mount, inverter and generator. But then bonding all of these rods together, with the intention of keeping all metal, modules, etc in the entire system at the same potential. This approach seems to really be echoing his own comments of keeping everything underground bonded. The important part seems to be having the DC electrical bonding, GFI etc and the AC neutral bond in only one location. 2. Ground lightning strikes will create differences in potential on all conductors. The insulation on most conductors buried in conduit is only good to 600 to 1000 volts at best. If there is a strike creating 100,000's of volts then all conductors will surely see current and voltage spikes. This is why we always install Surge Arrestors. 3. While I can appreciate the physics of lightning protection, I have it on my house, I am not so sure about its impact on a large PV array. I have a hard time accepting that a 1-2 foot spike of metal on the roof connected directly to ground will handle anything near a direct strike like he showed in the picture. Unfortunately, in that regard you get hit, or you don't. In fact, some lightning folks will admit that lightning protection can encourage the passage of some strikes. But the question here seems to be ---1. Is 1000 ft2 of aluminum rectangles, racking and wire, less conductive than a 2 foot metal spike. And is the extra 20-100 feet that the grounds pass to the rod, really enough to resist current in a strike. 2. If logic holds that a lightning protection system has merit, then wouldn't bringing every rail to ground at multiple points and then bonding them all together do the same thing. I am not saying that this is the way it should be done, but making the point that it is essentially the same thing. So, I respect Mike and what he is trying to do for many people, which is provide clear and accurate training materials. However, I agree with Richard that I would like to hear from all the voices in the industry that have their minds around this as well. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com On Dec 9, 2013, at 9:21 AM, Richard L Ratico wrote: I watched most of the streaming video of Mike Holt and six PV industry professionals this weekend. The most interesting aspect of it was Mr. Holt's very dramatic build up to the Sunday discussion of Article 690.47(D) which brings back the requirement for an auxiliary grounding electrode for PV arrays. He used everything short of drum rolls to build anticipation for this part of the presentation. Having personally contributed a short piece on this subject for SolarPro magazine along with Bill Brooks and John Wiles in 2008, I looked forward to this discussion. Finally, midday Sunday, instead of a discussion of an important and controversial part of the 2014 code, we received a rant by Mr. Holt demanding an immediate and unprecedented withdrawal of the article. Prior to his remarks, in contrast to the preceding article discussions, Mr. Holt asked that the guest panel not make any comments that would explain how the requirement came to return to the code after being eliminated in the 2011 edition, or any comment that might "confuse" the issue. To my very great surprise and disappointment, they complied, uttering not a single word, nodding their heads and moving on to the next article. After all the buildup by Mr. Holt, the "discussion" amounted to his monolog, which if parsed, though stated to be for safety concerns, seemed primarily an exercise designed to sell his books, videos and consulting services on grounding. This was of course expected. The weekend live streaming was generously offered free of charge, a rare opportunity to hear current PV expert opinion on the NEC. My concern is that Mr. Holt's control of the process here inhibited the dialog that should have taken place. There are significant implications of allowing his opinion to go unchallenged. Is there, or is there not, any merit in 690.47(D)? Could the language be better? Could the requirement be modified to make it better rather than simply discarding it? Does accepting his argument mean all those systems installed according to the 2008 code are unsafe? Mr. Holt explicitly stated his desire to create a groundswell of opinion to immediately eliminate this requirement of the code. Would it not be better to carefully think through and discuss the issue, in contrast to what was permitted on his "show"? Dick Ratico Solarwind Electric --- You
Re: [RE-wrenches] Outback Chargers
Kevin, I am curious about what you are seeing on the Outbacks as well. Have dozens of these out in the field. They have been pretty reliable for me. The biggest issue that I have had with them is when the inverters are transferring from generator charging back to inversion. If you leave this at the factory default, 1 s, you will see light flicker, and sensitive electronics will go into error. This transfer rate can be adjusted down and has cured most of the power quality issues with the battery charging. A different issue than harmonics under load, but it might help. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & 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
Re: [RE-wrenches] DC Fusing/Breakers for Battery Circuits
Dan, Wanted to respond to your comment about wooden battery boxes. I have many of them in the field and have never had an issue. Interestingly, I alway had the perspective, why put something with huge current capabilities in a conductive box? But, I will certainly second the need for series fusing. Seems like cheap insurance and I put it in all battery systems both on and off grid. On the fire hazard, I am not so sure. Hydrogen won't combust until a concentration of greater than 4%. Per NEC, I try to keep hydrogen level below this point. In recent years I have begun installing 2 active vents in all system, in case of failure. Again... cheap insurance. This is even on battery banks as small as 700AH. So, I hear your concern and maybe some kind of firewall would be wise. But, I don't see wood boxes as any great threat if done well. Maybe I am slightly numbed after witnessing all of the crazy home brew battery set ups in the back woods here. Have seen some very sketchy off grid battery installations. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & 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
Re: [RE-wrenches] Watsun problem
Jesse, Have had this happen. Can be a couple things. There are little plastic pieces inside the control box that have contacts. These can be adjusted. You will need to get at the control box and open it. Wattsun can walk you through it. If not they will send you a new controller. Same thing can happen in the N-S place, but it is usually a sign of wear on the plastic nut, yes plastic, in the actuator arm. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com On Sep 22, 2014, at 12:30 PM, Solar wrote: Hello, I am having an issue with a Watsun dual axis tracker. It is a 24VDC model, run of a battery bank that is charged through an outback inverters connection to the grid. So the battery voltage is always at 24V. The tracker will run fine for a couple days then it will get stuck in the east facing direction. I can make it track by switching the control box to "Manual Control Mode" and then moving the array in any direction for a second or two and then switching it back to "Automatic Control Mode". It will then track for a couple days and get stuck in the east direction again. Everything is greased regularly, and the voltage at the motors is always where it needs to be. I haven't noticed anything binding the tracker in the east direction and it seems like to sensor is fine because it tracks after I use the steps I described above to move it. Any thoughts? Thanks as always, Jesse Sent from my iPhone ___ 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
[RE-wrenches] 3" Pipe Fittings/Pinning
Adam, We have never pinned the pipe directly. But we have pinned into ledge with a short but wide sono tube. Cold Rolled steel rods through the 3" pipes to lock into the pour. In this case we let pipe condensate drain into small sand bed under the concrete pour. Extremely solid install in windy location on ledge. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.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
[RE-wrenches] Interstate L-16 vs Trojan L-16REB
Maverick, "But you would think after 20 years, inverter manufacturers would make some software similar to generator cycling to handle this cycling issue. " I believe that the XW Inverters have this ability in sell mode. There is traditional sell voltage. And then there is a setting that puts the batteries through a traditional bulk cycle while still "selling" back any excess energy. The next question would be, is this better for battery longevity. Seems like a hybrid of the two would be ideal. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
[RE-wrenches] Smart grid grid-connected compatibility
Kent, I went through a similar situation with an Enphase system. With a little discussion we decided that the easiest change is on the Utility side. We encouraged the utility to put all solar systems with Smart metering on a different schedule. Now the solar residence is only pinged at night when the frequency shift wont cause the inverters to drop out. I wonder how many string inverters are doing the same thing but go unnoticed. The Enlighten graphs make detection of this event very evident as it looks like a huge crash every day at the exact same time. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] bubbling Sanyo modules
Randy, We installed Sanyo's for a couple seasons and I have one job with similar bubbling. The bubbles have grown pretty large, but Sanyo feels that it is not a warranty claim until the module fails. I think that one module with this issue along the frame will eventually fail. But we are past the 2 year warranty of defects at this point. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com On Dec 4, 2012, at 3:07 PM, Randy wrote: Hi Wrenches, I have some Sanyo HIT modules in operation since 2006, that are bubbling in the back. The bubbles are small perfectly rectangular shapes, smaller than the cell, a few per module. I put an IR camera on it and didn't see any additional heat. I also did an IV test and got good results. Anyone seen something like this that led to a problem. (question mark) My keyboard question mark doesn't work after I spilled tea on my keyboard. Thanks Randy Randy Sadewic Positive Energy Office: 505 424-1112 Cell:505 570-0137 ___ 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
Re: [RE-wrenches] CIS mods
Ok so its a reading night. There are a bunch of very good papers about this effect on all the different types of modules. www1.eere.energy.gov/…dfs/pvmrw2011_p25_tf_dunn.pdf Best summary of Soaking would be : controlled exposure to light under controlled environmental conditions. The "soaking" seems to come from exposing the panel to light for --extended-- periods. Thus finding the effects on the panel after it has reached a critical point of light exposure. Like a sponge, the panel has been fully soaked with light. Then they observe effects. Some pretty interesting effects in some panels. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] CIS mods
Carl, Everything you said is true, but it does not answer the original question fully. It is more about the variation in electrical output than long term degradation. If I had to summarize it a different way it would be this. Flash testing a CIGS module to STC will give you certain voltages and ISC results. However, CIGS take longer to stabilize electrically. So exposing them to light for minutes or hours effects the voltages and current results. The CIGS don't reach peak levels until the modules have been fully "soaked" in light. The time it takes to soak the modules and the intensity of the effects depends not only on the different module types, but specific manufacturing approaches. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
[RE-wrenches] crystalline VS uni-solar and beyond
How about the longevity? This is the one area that has not been tested. Crystalline cells have proven their longevity for the most part. Their weakness seems to be sealants and gaskets more than cell longevity. How will the amorphous panels be producing in 20 years? Is this why Sanyo has kept its warranty at 20 years for its cell design?(and I like their panels) Thoughts? Doug Wells The Solar Specialists Worcester, VT 05682 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] Back feeding battery inverter with grid-tie inverter
I was excited about using a new Apollo controller. Did they ever come up with a listed GFI/breaker setup for that high of a voltage? Doug Wells The Solar Specialists Worcester, VT 05682 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
Re: [RE-wrenches] Sanyo Bi-facial
Bill, I am not going to go off about Sanyo modules, especially the bifacial brand. However I will say this. I have installed a lot of residential systems with their panels. I installed a system at a retired engineers home last summer and he is keeping very close records of production. We are commonly seeing production which is at or above nameplate rating ON THE AC SIDE. A 3.6 kW array is producing 3400 to 4,000 watts AC on cold sunny days. This is not the norm in PV production in my opinion. This brings up 2 questions for me 1. Why the hell are very intelligent engineers overloading inverters with DC production. I know the easy answer is Nameplate DC rating for incentive programs. 2. Is the multi-junction Amorphous approach all pumped up the first 5 years and then going to let go in year 18? Thoughts experience? Can't deny the early production in VT. Doug Wells The Solar Specialists Morrisville, VT 05661 (p) 802-223-7014 (c) 802-498-5856 www.thesolarspecialists.com ___ 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
