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  • #91
    Originally posted by ButchDeal View Post
    You set up alerts such that individual module data issues trip an alert. We have this and we monitor all our installs. We have been told that we have had the most module replacements by far over any other company, and all of them warranty issues. This is because of the module level monitoring. That said it is a small percentage but I have to imagine that since we are the only ones monitoring actively like this and we have the highest number of modules warranty replacements that other installers and even the big guys like SolarCity, SunEd, etc would benefit from monitoring at the module level.
    Sounds like your company is doing a very conscientious job of maintaining somewhat failure prone equipment. You could
    probably detect a failure as well by monitoring peak current on a sunny day, or matching outputs of 2 string inverters, like me.
    Service might be more complex in finding the exact fault, but it wouldn't happen as often.

    A clamp on ammeter and a voltmeter could locate 24 bypassed cells in a string of 720 here; a non contact thermal gauge
    also might locate the fault. I suppose the micro readouts look more attractive when working on a roof. The ammeter does
    check for best performance here several times a year. But I've run 5 million panel hours and 100,000 inverter hours with
    zero failures so far. Bruce Roe

    Comment


    • #92
      Originally posted by J.P.M. View Post
      If so, why would I or any potential customer want to use a product or rely on a vendor who would sell such a product that might fail at a higher rate per install than a string inverter (if for no other reason than their being more of them per install), and have such failures slip under the radar, or, as an alternative, require a customer to perhaps be more diligent in their own monitoring. Seems to me a string inverter failure ...
      I don't think your statements track logically.
      If the modules fail at about the same rate they will fail about the same rate whether it's a string inverter or solaredge.
      From my install I have *fewer* panels because I have solaredge than I would if I had gone with a string inverter. Because I can get more kwh out of the same panels because partial shading is handled better.
      But even if we ignore that, I don't see a reason you would have MORE modules than a string inverter. Only reasoning I can see is if it were less efficient. And I haven't seen evidence that a Solaredge system has a lower efficiency than a string inverter system. (If there were, I'd think that'd be a marketting point that would be played up by SMA and others.)

      The other thing is you seem to think that it'd be more noticeable on a string inverter. I would think the opposite.
      If I have a set of 12 modules and one of them is providing 10% less power IMO you will *only* see that when looking at per-module monitoring data. If I can only look at string-level data I won't be able to tell the difference between 10% lower on one module and all modules being less than 1% lower.

      If it's an [I][B]inverter [/B][/I]failure for string vs. micro-inverter, then I would agree that the string is more likely to be noticed quickly.
      But we are talking about module replacements under the module's warranty.

      Comment


      • #93
        Originally posted by ButchDeal View Post

        JPM and others have pointed out that to a homeowner that monitors system level closely, a bad or partially failed module would often show up. Possibly but harder to automate an alert on that.
        Out of curiosity, when you use the word "module", is it safe to assume that you are referring to the PV panel, not the optimizer or inverter? If so, I think it is bad logic to infer that the panels you are installing are of inferior quality, when your ability to detect bad modules is superior to those who are using the typical monitoring system provided with string inverters. I respect Bruce's point that string inverters *could* be effectively monitored, but in practice, they aren't. Most monitoring systems are looking only at output power, and not individual string voltage and current. This is a benefit of SolarEdge (and microinverters) that is probably not going to be appreciated by most owners (since the module failure rate is low), but in aggregate, and the volumes you work with, it seems like a actual source of value.
        CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

        Comment


        • #94
          FWIW, it seems to me that the chief point of failure in these micro-inverters is due to roof mounting; they receive far less cooling. i live in the country and whenever i visit an urban area with few trees and much asphalt (roads and roofs), the difference in temperature is dramatic! it takes all evening for a hot asphalt roof to cool down. imagine how much heat radiation hits one of these inverters.

          Comment


          • #95
            Originally posted by sensij View Post

            Out of curiosity, when you use the word "module", is it safe to assume that you are referring to the PV panel, not the optimizer or inverter? If so, I think it is bad logic to infer that the panels you are installing are of inferior quality, when your ability to detect bad modules is superior to those who are using the typical monitoring system provided with string inverters. I respect Bruce's point that string inverters *could* be effectively monitored, but in practice, they aren't. Most monitoring systems are looking only at output power, and not individual string voltage and current. This is a benefit of SolarEdge (and microinverters) that is probably not going to be appreciated by most owners (since the module failure rate is low), but in aggregate, and the volumes you work with, it seems like a actual source of value.
            A module is made up of solar cells, what many call a panel, but....
            Panel is a group of modules, an array is a group of arrays ( for example two faces on a roof would be an array of two panels)

            this is my assessment as well. Modules fail, squarely chew threw wires, **** generally happens, good monitoring helps find these issues AND diagnose them. On top of that we use revenue grade meters built into the inverters which simplifies install and SREC monitoring.
            OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

            Comment


            • #96
              Originally posted by bcroe View Post

              Sounds like your company is doing a very conscientious job of maintaining somewhat failure prone equipment. You could
              probably detect a failure as well by monitoring peak current on a sunny day, or matching outputs of 2 string inverters, like me.
              Service might be more complex in finding the exact fault, but it wouldn't happen as often.

              A clamp on ammeter and a voltmeter could locate 24 bypassed cells in a string of 720 here; a non contact thermal gauge
              also might locate the fault. I suppose the micro readouts look more attractive when working on a roof. The ammeter does
              check for best performance here several times a year. But I've run 5 million panel hours and 100,000 inverter hours with
              zero failures so far. Bruce Roe
              Really you think we should install two inverters at every site across the US and compare them constantly. Got any software to do all that?

              Of course we would have to balance them all with equal parts on each face so they are identical and compensate for shade etc. yeah that will work and not cost too much either.

              OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

              Comment


              • #97
                Originally posted by J.P.M. View Post

                I appreciate and respect the difference of opinion.

                But - there's always a but I suppose - you post raises some questions in my mind:

                1.) If you've been told that you have "the most module replacements by far...", how would you answer those who suggest (and accepting for the time being the idea that all such modules are ostensibly created approx. equal) that rather than blaming the product, the higher replacement rate is due to the quality of the install ? Seems by your own admission, you have more replacements. Are your modules of inferior quality to those from the same source, or inferior to those used by other vendors ?
                We sell many different brands as stated, multiple distributors, and many different installers (national remember). We drop ship the equipment from the distributors to the installers or sites.
                Why are you assuming that we are having a higher failure rate than others who do not monitor. Most would assume the failures are fairly evenly distributed, but only a few are found (by those looking). I am not talking about workmanship issues, but PV module failures. They are really easy to see on SolarEdge. Optimizers we have had very few failures on, and most were with two installers who we have stopped using after sending different installers out to investigate.

                Originally posted by J.P.M. View Post
                2.) How "small" (a failure/service call rate) as compared to string inverters ? Small seems a relative thing.
                not sure what you mean here.

                Originally posted by J.P.M. View Post
                3.) If the modules are indeed created about equal, which seems at least plausible, and your failure rate is indeed due to better monitoring, could that mean the other such modules may be failing at something like an approx. equal but unreported or unknown rate? If so, that would seem to give at least some credence to my opinion and conjecture that small(er) failures of, say, one panel, would have a higher probability of going unnoticed by users. If so, why would I or any potential customer want to use a product or rely on a vendor who would sell such a product that might fail at a higher rate per install than a string inverter (if for no other reason than their being more of them per install), and have such failures slip under the radar, or, as an alternative, require a customer to perhaps be more diligent in their own monitoring. Seems to me a string inverter failure, being something like an order of magnitude larger and thus more prominent and more quickly noticeable, might be easier for an owner to catch rather than waiting/hoping/relying on monitoring from some company not as diligent as yours.
                The failure rate is not due to the increased monitoring. Knowing about the failure rate is due to the increased monitoring.
                Again we have had very very few optimizer failures. We have actually had more string inverters fail than optimizers. Which is incredibly surprising since we have installed very few string inverters.

                Most installers do not like to give module level access to homeowners either. We set up all our monitoring (because they do such a poor job of it) and always give module level.
                We also set them all up in PVOutput and give them a managed account. Even with all this very few of our homeowners notice the issues, when they come up. We call them and let them know we are sending out a tech to look at it and they are surprised. We let them know that they are only loosing a small amount (in the case of just a module failure).
                I am not trying to toot our horn here just saying what can be done.
                A diligent homeowner that is familiar with electronics could maintain a string inverter well as you have and that is clearly the best choice for such a person (I have a string bimodal system myself), but for the homeowner that doesn't want to play with the thing all the time or really wants an appliance, SolarEdge makes a strong argument.
                Still waiting to see if SMA can get as integrated with their optimizer solution after a few generations.
                OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                Comment


                • #98
                  Originally posted by ButchDeal View Post

                  Really you think we should install two inverters at every site across the US and compare them constantly. Got any software to do all that?

                  Of course we would have to balance them all with equal parts on each face so they are identical and compensate for shade etc. yeah that will work and not cost too much either.
                  Naw, only if its already there. That's why I offered peak current on a sunny day. Software, its supposed to
                  be available for the job requirements, though that may be far from reality. How frequent are your present
                  checks? Bruce Roe

                  Comment


                  • #99
                    Originally posted by bcroe View Post

                    Naw, only if its already there. That's why I offered peak current on a sunny day. Software, its supposed to
                    be available for the job requirements, though that may be far from reality. How frequent are your present
                    checks? Bruce Roe
                    The default alletrs check daily for issues and send emails. I usually change some of them though. Like connectivity to two days, as homeowners sometimes have internet outages etc that can set it off. Two days rarely gives alerts that way.
                    OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                    Comment


                    • Originally posted by foo1bar View Post

                      I don't think your statements track logically.
                      If the modules fail at about the same rate they will fail about the same rate whether it's a string inverter or solaredge.
                      From my install I have *fewer* panels because I have solaredge than I would if I had gone with a string inverter. Because I can get more kwh out of the same panels because partial shading is handled better.
                      But even if we ignore that, I don't see a reason you would have MORE modules than a string inverter. Only reasoning I can see is if it were less efficient. And I haven't seen evidence that a Solaredge system has a lower efficiency than a string inverter system. (If there were, I'd think that'd be a marketting point that would be played up by SMA and others.)

                      The other thing is you seem to think that it'd be more noticeable on a string inverter. I would think the opposite.
                      If I have a set of 12 modules and one of them is providing 10% less power IMO you will *only* see that when looking at per-module monitoring data. If I can only look at string-level data I won't be able to tell the difference between 10% lower on one module and all modules being less than 1% lower.

                      If it's an [I][B]inverter [/B][/I]failure for string vs. micro-inverter, then I would agree that the string is more likely to be noticed quickly.
                      But we are talking about module replacements under the module's warranty.
                      I was referring to Micros as modules as I perhaps incorrectly assumed Butch was doing I was actually referring to micro inverter failures. I'll admit to bad and confusing wording with apologies. My thinking is that 250 Watt failure on a 6 kW array may go unnoticed but a string inverter failure is likely to be noticed much more quickly.

                      I'm also not including discussions about partial shading and the partial advantage that micros and other systems such as SolarEdge can bring to the table, although I think that advantage may be a bit overstated in the hype. A 50% shaded array will not have 50 % of it's unshaded instantaneous output restored by use of micros or a SolarEdge system.

                      I also never wrote that a sting inverter will allow a smaller array than a micro inverter equipped system.

                      One of my points might be better explained this way: With a micro inverter system equipped array of 16, ea. 300 Watt modules, one micro inverter failure may well not be noticed as quickly, or at all maybe as if the inverter dies on a similar paneled but equipped with a string inverter.

                      See further posting. I bet there's a difference of opinion, but maybe some terms need to be cleared up before things get more out of hand and confused.,
                      Last edited by J.P.M.; 04-27-2017, 11:28 PM.

                      Comment


                      • Butch: Further to my prior posts on this thread, and others from other posters, there looks to me like a lot of confusion about what I wrote in my 04/27/17, 2:02 P.M. response to your 1:12 P.M. post of the same date. Maybe the following will help clear up what I wrote and what I was trying to get at.

                        1.) I believe some of that confusion centers around the use of the word "module". I'll need to own that your use of the word "module" was perhaps incorrectly assumed and interpreted by me to refer to either micro inverters or optimizers as in a SolarEdge system. If I misinterpreted your meaning, I apologize.

                        But I'd be less than candid if I didn't say that IMO, you could have been a bit more on topic or a bit more specific when referring to equipment other than the subject of the post which I feel was clearly confined to roof top inverter components.

                        2.) The crux of my original point(s) was about micro inverters, and to a large extent, optimizers as well, in that a single device failure of a micro or optimizer on an array that would cause one panel's output to get knocked out, and such a relatively small reduction is likely to be less catastrophic in terms of array output than if an if a string inverter on a similar size and paneled system fails, knocking out the entire array's output. And so, because of that reduced noticeability, may well, without monitoring by either the user or the vendor, also stay unnoticed for some time, and with a higher probability of going unnoticed for longer than if a string inverter died. Such long times of unnoticed reduced output can thus have an effect on annual production. Right now, vendor monitoring may be good from decent vendors, but as (and if) things head south, vendor monitoring quality may suffer. I have little confidence in user monitoring unless a whole system stops. That's why I think individual panel monitoring capability is mostly a red herring.

                        I'll stick with the other points I made about rooftops being a harsh and unnecessary environment for electronics making them more failure prone; more of them, and so having a higher probability of failure due to more failure points; and lesser accessibility of rooftop equipment vs. ground accessible string inverters as points against micros and other electronic equipment on a roof.

                        3.) When you responded to my 1:02 P. M. Re: "adding to the chorus" post, it kind of read to me that you were disagreeing with my statement that the novelty of individual panel monitoring wears off quickly, and in doing so, implying that your were agreeing with the rest of the portions of my 1:02 P.M. post.

                        4.) When you stated you have been told you have "the most module replacements by far...", that is where I (looks like now, in hindsight) erred, in the sense that I assumed you were referring to micro inverters or optimizers replacement as I was, [U]not[/U] entire panel/optimizer or panel micro combinations, or individual solar panels.

                        5.) However, the rest of my point 1 of my 2:02 P.M. post is essentially unchanged in that if one vendor has more replacements than other vendors of similar or even identical equipment, why would someone not logically come to at least one conclusion of several, that differences in failure rates of different vendors may lie in places other than the equipment ? An example: If vendor A and vendor B both install 1,000 M250 micro inverters over the same time period and calendar dates, and vendor A reports ten M250's need replacing, while vendor B reports two M 250's need replacing/ What's one possible conclusion ? Valid, correct, fair or not, one conclusion that's easier to say and spread than disprove is that, given that same equipment, the vendor with the higher replacement rate doesn't do as good an installation. I'm not calling you a bad vendor - FWIW, I believe you are ethical, honest and knowledgeable. I've seen the dirt vendors and damn them, and I believe I know the difference. I'm only asking what one semi logical conclusion to such a statement as you made about your seeming agreement with someone who said your outfit has the highest replacement rate by far. Why is that?

                        6.) Point 3 of my 2:02 post was almost a rhetorical question: If [U]you[/U] have higher replacement rates of equipment, and it's assumed those higher rates are from problems discovered from monitoring, and, assuming replacement rates among (quality) vendors to be approx. the same by virtue of similar equipment and decent installation quality, would that not mean that there may well be a lot of equipment out there that is operating less than optimally but not monitored ? To the extent that may have some validity, see my point 2 of this post.

                        7.) I don't know where or how I gave Foo1bar the impression - except perhaps in the confusion of the terminology discussed above - that I stated or implied that string inverters would allow smaller arrays for the same output as micro or optimizer equipped arrays. Most of us, including me, understand there is good design logic that leads to smaller arrays being possible with micro or optimizer equipped systems over sting inverter systems in applications where system shading is moderate to substantial.

                        I would argue however, and as a bit of an aside, that, because a micro or optimizer equipped system cannot create sunlight, it's not possible, for example, to have the instantaneous output of a 50 % shaded array to be restored to that of an identically oriented and sized unshaded array simply by using micros or optimizers. Seems to me that's somehow left unsaid and untouched for the solar ignorant to infer on their own.

                        8.) Nor did I ever state or mean to imply that the type of inverter method employed will have any effect (that I'm aware of anyway) on solar panel longevity or performance.

                        Maybe it's time for a sticky on micro inverter pros and cons.

                        Comment


                        • Originally posted by J.P.M. View Post
                          7.) I don't know where or how I gave Foo1bar the impression - except perhaps in the confusion of the terminology discussed above - that I stated or implied that string inverters would allow smaller arrays for the same output as micro or optimizer equipped arrays.
                          You said "if for no other reason than their being more of them per install"

                          Since you were talking about "modules", I assumed you were using the usual definition of that term. A module is what is sometimes called a "panel" - a collection of PV cells, usually 60 or 72 of them in an aluminum frame. A "module" is a good term for them as it is short and descriptive of it yet is a distinct term from the thing you put circuit breakers into.

                          My best guess is that for a situation with some shade the micro-inverter or optimizer setup gets you a few percent benefit vs. a string inverter.
                          Obviously it's going to change based on what kind of shading, etc.
                          I don't think I've seen "hype" that a 50% shaded array you'll get 50% of the unshaded output.
                          My guess is that you'd see less than 25% of the output with a string inverter (depending heavily on the type of shading)
                          And you'd see a significant increase in production with microinverters or optimizers.
                          BUT it'd really really really depend on the type of shading and the topology of the system.

                          Comment


                          • Originally posted by J.P.M. View Post
                            One of my points might be better explained this way: With a micro inverter system equipped array of 16, ea. 300 Watt modules, one micro inverter failure may well not be noticed as quickly, or at all maybe as if the inverter dies on a similar paneled but equipped with a string inverter.
                            With no monitoring or alerting I agree. The string inverter system will have more lose in production likely noticed on the next bill. With automated alerts though the micro/optimized system would alert at most 48 hours though. Enphase does not make this alerting easy though and few people take the time to add an email address to solaredge to get the preconfigured alerts or adjust them ( they are highly configurable)
                            OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                            Comment


                            • Originally posted by J.P.M. View Post
                              1.) I believe some of that confusion centers around the use of the word "module". I'll need to own that your use of the word "module" was perhaps incorrectly assumed and interpreted by me to refer to either micro inverters or optimizers as in a SolarEdge system. If I misinterpreted your meaning, I apologize.

                              But I'd be less than candid if I didn't say that IMO, you could have been a bit more on topic or a bit more specific when referring to equipment other than the subject of the post which I feel was clearly confined to roof top inverter components.
                              Possibly. I and a few others stick to the nomenclature that modules are devices made of PV cells usually in groups 60 or 72, panel is a contiguous group of modules in a plane, array is a group of panels at a single site with one interconnect or controlling mechanism.

                              Originally posted by J.P.M. View Post
                              2.) The crux of my original point(s) was about micro inverters, and to a large extent, optimizers as well, in that a single device failure of a micro or optimizer on an array that would cause one panel's output to get knocked out, and such a relatively small reduction is likely to be less catastrophic in terms of array output than if an if a string inverter on a similar size and paneled system fails, knocking out the entire array's output. And so, because of that reduced noticeability, may well, without monitoring by either the user or the vendor, also stay unnoticed for some time, and with a higher probability of going unnoticed for longer than if a string inverter died. Such long times of unnoticed reduced output can thus have an effect on annual production. Right now, vendor monitoring may be good from decent vendors, but as (and if) things head south, vendor monitoring quality may suffer. I have little confidence in user monitoring unless a whole system stops. That's why I think individual panel monitoring capability is mostly a red herring.

                              I'll stick with the other points I made about rooftops being a harsh and unnecessary environment for electronics making them more failure prone; more of them, and so having a higher probability of failure due to more failure points; and lesser accessibility of rooftop equipment vs. ground accessible string inverters as points against micros and other electronic equipment on a roof.
                              I tend to agree here IF no one has taken the simple step to set up automated monitoring. It is relativly simply for an automated system with PV module level monitoring, to tell if there is a failure on a single micro inverter or optimizer and send an alert via text, email, or smart phone alert. Without taking the step to enable this the lose of a single PV module would be hard to notice on a non-string system. On a string system, it would be noticed at the next utility bill most likely for a diligent homeowner (not many are even this diligent).

                              Originally posted by J.P.M. View Post
                              3.) When you responded to my 1:02 P. M. Re: "adding to the chorus" post, it kind of read to me that you were disagreeing with my statement that the novelty of individual panel monitoring wears off quickly, and in doing so, implying that your were agreeing with the rest of the portions of my 1:02 P.M. post.
                              I was stating that looking at the module level output gets old but that having a system that knows about the module level output allows simple automated alerts such that the system can easily tell the homeowner (or installer, or broker etc) that there may be a problem. I get a few false alerts each day particularly in winter due to snow fall but SolarEdge makes it easy to clear those out in a few minutes. I have talked to them about adding some snow "smarts" to the alerts, they are working on it.

                              Originally posted by J.P.M. View Post
                              4.) When you stated you have been told you have "the most module replacements by far...", that is where I (looks like now, in hindsight) erred, in the sense that I assumed you were referring to micro inverters or optimizers replacement as I was, [U]not[/U] entire panel/optimizer or panel micro combinations, or individual solar panels.


                              Originally posted by J.P.M. View Post
                              5.) However, the rest of my point 1 of my 2:02 P.M. post is essentially unchanged in that if one vendor has more replacements than other vendors of similar or even identical equipment, why would someone not logically come to at least one conclusion of several, that differences in failure rates of different vendors may lie in places other than the equipment ? An example: If vendor A and vendor B both install 1,000 M250 micro inverters over the same time period and calendar dates, and vendor A reports ten M250's need replacing, while vendor B reports two M 250's need replacing/ What's one possible conclusion ? Valid, correct, fair or not, one conclusion that's easier to say and spread than disprove is that, given that same equipment, the vendor with the higher replacement rate doesn't do as good an installation. I'm not calling you a bad vendor - FWIW, I believe you are ethical, honest and knowledgeable. I've seen the dirt vendors and damn them, and I believe I know the difference. I'm only asking what one semi logical conclusion to such a statement as you made about your seeming agreement with someone who said your outfit has the highest replacement rate by far. Why is that?
                              SImple, we are national. We use MANY installers and multiple distributors of the equipment. We have had a very few set of isolated failure clusters and they turned out to be installers with poor practices, which we have discontinued using those installers. We have no problem sending a different installer out to check an installers work when something like this is suspected, particularly on newer installers. In your example If Vendor A is checking the monitoring and Vendor B is not (like many installers tend to do) would this change your evaluation.
                              Note that with SolarEdge they have recently (about 2 years ago) added a feature of association such that individual site monitoring can be shared fully between two companies such are ours and our installers. Before that we had to set up SUB accounts for installers. With this older sub system, it lets us see EVERY site the installer has ever set up so I know that they do not monitor them as most of them are not fully set up, don't have customer access, have no alerts configured, and even some failures for months/ years (but no one is looking).


                              Originally posted by J.P.M. View Post
                              6.) Point 3 of my 2:02 post was almost a rhetorical question: If [U]you[/U] have higher replacement rates of equipment, and it's assumed those higher rates are from problems discovered from monitoring, and, assuming replacement rates among (quality) vendors to be approx. the same by virtue of similar equipment and decent installation quality, would that not mean that there may well be a lot of equipment out there that is operating less than optimally but not monitored ? To the extent that may have some validity, see my point 2 of this post.
                              This is my point, there is a lot of equipment out there that is not operating optimally due to diode failures, wire failures, etc. Hard to tell. From the full access we have with some of our installers, I have access to several community scale projects that a few have worked on that have whole arrays down. Yes these are being "monitored" in the sense that they are sending data to the cloud but not in the since that anyone is looking at it or automated alerts are going out. One has had an entire inverter offline for months, another an entire string (half of one inverter), several have a smattering of failed pv modules. These are all large jobs using 3 phase 33kw inverters.
                              BTW when I say failed PV modules I am guessing but it is a fairly educated guess. The optimizer is working still so the PV module is putting out some power, but at a level below the neighboring modules by a factor of 1/3 or 1/4, which tends to indicate failed wiring or diodes. There are some that the optimizer is not reporting and these could be either the optimizer or PV module, but in our experience, is more likely to be (in order of probability): wiring, PV module, optimizer.

                              Other failures we see occasionally are Arc Fault which the inverters will shut down and stay down for arc faults till physically reset. These have so far always been wiring issues, one case was a poor connection in the inverter, and all the rest have been rodent damage to wires. We had a similar arc fault on a fronius, turned out to be improperly torqued wiring, but that was the day after turn on where often wire damage shows up months or years latter. (Yes we monitor Fronius systems as well, in fact we monitor nearly all the systems including OutBack, SMA, Enphase, Fronius, and SolarEdge).

                              Originally posted by J.P.M. View Post
                              7.) I don't know where or how I gave Foo1bar the impression - except perhaps in the confusion of the terminology discussed above - that I stated or implied that string inverters would allow smaller arrays for the same output as micro or optimizer equipped arrays. Most of us, including me, understand there is good design logic that leads to smaller arrays being possible with micro or optimizer equipped systems over sting inverter systems in applications where system shading is moderate to substantial.

                              I would argue however, and as a bit of an aside, that, because a micro or optimizer equipped system cannot create sunlight, it's not possible, for example, to have the instantaneous output of a 50 % shaded array to be restored to that of an identically oriented and sized unshaded array simply by using micros or optimizers. Seems to me that's somehow left unsaid and untouched for the solar ignorant to infer on their own.
                              I didn't get that impression.

                              Originally posted by J.P.M. View Post
                              8.) Nor did I ever state or mean to imply that the type of inverter method employed will have any effect (that I'm aware of anyway) on solar panel longevity or performance.
                              Maybe it's time for a sticky on micro inverter pros and cons.
                              I agree on the longevity but
                              I would say that optimizers can improve unshaded performance over time.
                              In the simplest account this comes into play with the fact that PV modules have a rating of X watts -0,+y , That difference will be better taken advantage of with optimizers (the +y part). Further they will not soil or degrade at a constant rate over time so the optimizers will continue to pull the max power from each PV module as the differences between them increases over the years.
                              This improved performance is not great but measurable. In my personal self install we spent a bit of time balancing the 4 strings of 3 modules such that each string would be as close as possible to each other in performance, few installers do that on string installs, and to be fair the gain is small. Now that my system is 3 years old, it is unlikely to be still as balanced since the modules likely degraded slightly differently.

                              I don't like tigo systems currently (maybe SMA can improve them). The communications are problematic and they complicate the installer rather then simplify it (like solaredge does). Our CEO and co founder put in a schneider bimodal system with Tigo optimizers (his is heavily shaded) at the same time as my Outback. Keeping those tigos reporting is a pain in the a$$, it is the main reason we do not install them and settled on Outback (outback does not have module level optimization but has better monitoring than schneider and simpler installs for us).
                              OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

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                              • not to rain on anyone's parade, but this thread seems to have been hijacked. not that it is irrelevant to PV systems, but perhaps this 'departure' might be moved to the new topic?

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