Enphase field MTBF: M190: ~36 Years M215: ~316 Years M250: >357 Years

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I don't have solar or follow this thread, but thought this article might be applicable:

https://www.homepower.com/articles/...es/heliospiti-5-years-lessons-learned?v=print
Contrary to initial expectations, we have not been as lucky with the reliability of our PV system as we have with the SWH system. Our largest trouble spot was with our Enphase M190 microinverters. As of this writing, seven of 20 microinverters have failed, and others are showing intermittent output. While the Enphase warranty provides replacement microinverters, it does not cover the labor cost of hiring a solar contractor to replace the equipment, nor the expense of the boom lift necessary to service modules on a second-floor, 38° metal roof. Replacement of the failed units is averaging $180 per unit. The graph illustrates the decline of our PV production due to the periodic inverter failures, which began in 2012.
 
GetOffYourGas said:
Line 182 - no further failures. Still waiting for the weather to get hot (it was 40F yesterday morning - at least that's good for production!)
Thanks! Updated. The MTBF of the M215 microinverters in your system is approaching 30 years.

As you know, you have reported the majority of the M215 failures of which I am aware, so I am particularly interested to see if this trend continues or not.

Along the same lines, the one failure of an M215IG that I experienced in my system in January is ALL of the M215IG failures that I know about. The difference is that the 29 M215IGs and 13 M250s in my system come from six different batches (12 + 12 + 3 + 2 + 9 + 4 units) and have five different hardware versions, so I may be more immune to the possibility of having an entire batch of inverters which have a common manufacturing problem. Of course, if there is a common design problem, I'm not immune. In your case, the MTBF of the M215s is established by so many units for enough years that I seriously doubt that a design flaw is to blame. Of course we will learn more as time moves on.
 
Reddy said:
I don't have solar or follow this thread, but thought this article might be applicable:

https://www.homepower.com/articles/...es/heliospiti-5-years-lessons-learned?v=print
Contrary to initial expectations, we have not been as lucky with the reliability of our PV system as we have with the SWH system. Our largest trouble spot was with our Enphase M190 microinverters. As of this writing, seven of 20 microinverters have failed, and others are showing intermittent output. While the Enphase warranty provides replacement microinverters, it does not cover the labor cost of hiring a solar contractor to replace the equipment, nor the expense of the boom lift necessary to service modules on a second-floor, 38° metal roof. Replacement of the failed units is averaging $180 per unit. The graph illustrates the decline of our PV production due to the periodic inverter failures, which began in 2012.
Thanks for the link! Great article and a very interesting home design! It makes me wish I had chosen a drainback system for a solar thermal design which I did a few years ago. I'm not achieving the kind of thermal performance that I see reported there, even in a milder climate. Impressive!

The conclusions the author makes about what he should have done about the inverter failures warrant further discussion:
Jim Riggins in Home Power Magazine said:
Our takeaway? Scrutinize published reliability claims, and always plan maintenance and accessibility into the house design.
That's very good advice. But back in 2011 (or even 2012) when many of us were installing our M190-based systems, there was no indication of any reliability issues. Enphase had done fairly detailed analysis to try to predict the MTBF of these inverters and summarized their efforts in a couple of white papers on the subject. The 15-year warranty sealed the deal for many of us. Unfortunately, while the measured MTBF of the M190s achieved the promised 331 years that had been promised on the datasheet (at about two years' into my analysis), the failures quickly accumulated after that point. The overall M190 MTBF has settled in at around 40 years and it appears that my system is right about at that point. Unfortunately, some systems have experienced failures rates nearly 10X that average value (over 50X the datasheet value).

Enphase has since decided that printing an MTBF number on their datasheets was a dumb idea. But the good news is that their M215 microinverter currently has a measured MTBF of nearly 500 years in actual operation and the M250 may have a similar result given that no failures have been reported, yet.

But the simple fact is that there is STILL not much information available for new solar purchasers to go on regarding inverter reliability. Enphase certainly has this information, but they do not publish it. And neither do the other manufacturers. My data is the only data which I know of an it is only for the products from a single manufacturer. But even if you want to purchase an Enphase-based system, my spreadsheet does not contain a sufficient number of inverters nor time for the current-generation product to be of any use to anyone. (Although, it might help someone who is interested in purchasing new M215s from a warehouse which is selling them for $59 each right now!)

Ultimately, there is still a trade-off between heavily-shadowed performance (like when there is snow cover) and whether you have any electronics up on the roof.

Side Note: Unless he has experienced a failure and not reported it here (which I doubt), it appears that QueenBee has now operated his system containing 73 M215s for over 320 device-years without a single inverter failure. If his system can maintain that level of reliability, or higher, that should be quite acceptable for long-term operation.
 
Thanks again to RegGuheert for helping test out the Python for my Envoy (Pill-Style).

About two months ago I upgraded one of my Envoys to the Envoy-S . The Envoy-S provides more data in JSON format. That allowed me to create several Python scripts for the newer Envoy-S at: https://tinyurl.com/y83ma46a . I created repositories on GitHub for the code to display production, inventory and archive the eventlog. My favourite script displays per-inverter production locally with no Internet required.

Of course the Envoy-S can have it's internal AP enabled to get to things with the toolkit, but these scripts are really platform-independent. The inventory and per-panel production even work on my iPad and iPhone using the Pythonista app, and they are brutally fast.

Here is a screenshot of my per-panel production, each html table cell has the rgb value set to reflect the power production of that particular inverter:
production-screenshot.png


Ken Clifton
 
Today was a bit odd -- in the late afternoon I checked my system on pvoutput and saw that the power output had apparently dropped to zero at 3:30pm.

Checking with my Envoy-S's CTs, the system was actually still producing power the entire time, but from 3:30pm-6:30pm it thought all the microinverters were failing to report. Eventually they all started reporting again, one by one, over a 20 minute window.

Enlighten has since updated to show some flat-line power graph than approximates the average output during the outage time, presumably based on the increased energy total, and this is the data that gets shared with pvoutput via the API. Viewing the full system specifically under "graphs" though and a real power curve is visible -- it must be getting those values from the CTs.

Have others run into this before? I was wondering if maybe the devices were non-responsive while getting a firmware update, but an inventory.json pulled during the period when a couple had started reporting again and the rest were still non-responsive showed no difference in version between the two sets. I hadn't been previously archiving inventory.json (I am now), so I'm not 100% sure. Either way, the system

pvoutput tends to pull from the Enphase API in the morning one final time for the previous day, so tomorrow I'll correct the pvoutput data with my measured values from the Envoy-S CTs. (I have some cron scripts which save and archive the json output every few minutes, just in case.)
 
ltbighorn said:
Have others run into this before?

I have seen this many times over the past 5.5 years. It seems to me that the communications between the microinverters and the Envoy get cut off, but the microinverters continue to monitor themselves. When they do finally report, it is the right number of kWh (or it seems to be, AFAICT), but spread over a longer interval. Therefore the Envoy reports just an average value. The integrated power (area under the curve) is correct.
 
I've had one or two micros fail to report for a few minutes over the last year, but only 1-3 times max. This is also the first time that all of them have gone offline. Sounds like from your experience that's a normal occurrence though and doesn't indicate anything special is going on. Good to know. :) Thanks!
 
This probably isn’t your case, but I routinely lose communication between my Envoy and my microinverters. After a while, I determined that it was because I had a treadmill on the same branch circuit as the Envoy. Everytime I’d turn it on (even not in active use), I’d lose comms. Which just goes to say that powerline communication is subject to noise.

On the reliability side, I just had another failure of the D380’s That is now 10 out of 60 inverters that have failed in 6 years :( I had failures in June 2017, Aug 2016, Jan 2016, Aug 2015, April 2015. I am on line 28.
 
FairwoodRed said:
This probably isn’t your case, but I routinely lose communication between my Envoy and my microinverters. After a while, I determined that it was because I had a treadmill on the same branch circuit as the Envoy. Everytime I’d turn it on (even not in active use), I’d lose comms. Which just goes to say that powerline communication is subject to noise.
Absolutely! So far, I've had two loads in my house which have majorly disrupted commonications between my Envoy and the microinverters:

1) The LEAF's OBC: Our LEAF disrupts our PV system while charging at L2
2) I had a wall-wart for our SlingBox Pro HD fail in a way which seriously disrupted communications with the Envoy
FairwoodRed said:
On the reliability side, I just had another failure of the D380’s That is now 10 out of 60 inverters that have failed in 6 years :( I had failures in June 2017, Aug 2016, Jan 2016, Aug 2015, April 2015. I am on line 28.
Thanks for the update! I have updated the spreadsheet to reflect these failures. Since each failure of a D380 counts as two, your MTBF now stands at 35 years. That is close to the average I see for the overall population of M190s and D380s.

It's interesting that you have had one of every six D380s fail in six years while I have had one of every seven M190s fail in about six-and-a-half years. (And I likely would have experienced more failures if I had not placed most of my M190s into storage as cold spares about a year ago.)

BTW, what does Enphase send you as replacements for the failed D380s? If they are M190IGs, I'm interested in knowing about them since I now also track their failure rate in my spreadsheet. (Unfortunately, those appear to have the highest failure rate of all Enphase microinverters.)
 
Reg,

Line 183 update.

Prior reported existing system with 28 Suntech 245 Pluto with 28 M215 Enphase microinverters: still no inverter failures.

System upgraded with additional installation 4/5/17 with 15 LG305 Neon X with 15 M250 Enphase microinverters. No inverter failures. Using same Envoy.
 
iPlug said:
Line 183 update.

Prior reported existing system with 28 Suntech 245 Pluto with 28 M215 Enphase microinverters: still no inverter failures.
Thanks, iPlug!

That brings the MTBF of your M215s up to over 136 years and still you have no failures. That's a very good result for a five-year-old system. My M190-based system (with 42 inverters) had four failures by the time it was that age.
iPlug said:
System upgraded with additional installation 4/5/17 with 15 LG305 Neon X with 15 M250 Enphase microinverters. No inverter failures. Using same Envoy.
Thanks! Added. Currently, these new M250s reside in row 198. Those M250s are attached to the highest-power PV modules I am tracking. Hopefully they will fair as well as all of the other M250s have.

BTW, any chance those M250s are the 72-cell versions? I've noticed quite a few of those kicking around on eBay, so I thought I would ask.
iPlug said:
Using same Envoy.
Just so everyone knows, I do not have a great idea of what to do with the Envoy MTBF columns when new inverters have been added to the system. As such, the overall MTBFs calculated for the Envoys are certainly not correct. The good new here is that many of us have had our Envoys operating for over 6 years without any failures. While that tells us nothing about MTBF, it provides a bit of comfort regarding the life of a component which used to come with only a one-year warranty (now five).
 
RegGuheert said:
...Those M250s are attached to the highest-power PV modules I am tracking. Hopefully they will fair as well as all of the other M250s have.

BTW, any chance those M250s are the 72-cell versions?...
Understandably the M250 have peak output of 250W and continuous at 240W. So the 305W panels seem like a poor match. But I added all 15 of these panels to a northwest facing roof slope, so probably little lost.

For example, today the highest output panel maxed at 216W (almost summer solstice but 111F today). A week ago, on an unseasonably cool day, the system had the best production to date and one panel hit a record 239W at peak exposure. On most prime days, the panels max 10-20W lower than this.

The M250s are 60-cell versions.

Thanks for your work on the spreadsheet!
 
I may be looking at my 4th M215 failure. The inverter flickered on and off for the past two weeks, and has not produced anything at all since Saturday afternoon (6/17 at 1:30). I got the automated email this morning. I'll probably call my installer later today.

This is the typical behavior that I've noticed for other inverters in the last week or two of their lives.
 
GetOffYourGas said:
I may be looking at my 4th M215 failure. The inverter flickered on and off for the past two weeks, and has not produced anything at all since Saturday afternoon (6/17 at 1:30). I got the automated email this morning. I'll probably call my installer later today.

This is the typical behavior that I've noticed for other inverters in the last week or two of their lives.
I know you are aware of this but, unfortunately, your system is a strong outlier in the field when compared with all other M215-based systems. This failure (reported on the anniversary of when you reported your second failure) means that 25% of your inverters have already failed and your MTBF has dropped to only 22 years. The overall MTBF of the M215s I am tracking is now around 400 years, or about 20X what you are experiencing. In fact, my slightly-older M190s now have a demonstrated MTBF which is approximately twice what you are seeing. In fact, it has been about 10 months since my last M190 failure (though I only have 12 operating right now).

BTW, is Enphase sending you M215IGs as replacements? (I think you said they were previously, but I wanted to confirm that.)
 
RegGuheert said:
GetOffYourGas said:
I may be looking at my 4th M215 failure. The inverter flickered on and off for the past two weeks, and has not produced anything at all since Saturday afternoon (6/17 at 1:30). I got the automated email this morning. I'll probably call my installer later today.

This is the typical behavior that I've noticed for other inverters in the last week or two of their lives.
I know you are aware of this but, unfortunately, your system is a strong outlier in the field when compared with all other M215-based systems. This failure (reported on the anniversary of when you reported your second failure) means that 25% of your inverters have already failed and your MTBF has dropped to only 22 years. The overall MTBF of the M215s I am tracking is now around 400 years, or about 20X what you are experiencing. In fact, my slightly-older M190s now have a demonstrated MTBF which is approximately twice what you are seeing. In fact, it has been about 10 months since my last M190 failure (though I only have 12 operating right now).

BTW, is Enphase sending you M215IGs as replacements? (I think you said they were previously, but I wanted to confirm that.)

Yes, sadly my system is quite the outlier. I couldn't tell you why, exactly, although I do wonder if my installer did something wrong or cheaped out somewhere he shouldn't have. I now have 4 of the 6 known M215 failures in your spreadsheet. Lucky me.

I double-checked my enlighten page. All three M215s that have been replaced so far have had M215IGs as their replacement. This failure is one of the original M215s, and not an M215IG. I will report back when this fourth inverter gets replaced.

Do you want me to dig into when each of the M215IGs were installed? Maybe you should add them as a separate line in your spreadsheet, so they don't get counted with the M215s.
 
GetOffYourGas said:
Do you want me to dig into when each of the M215IGs were installed? Maybe you should add them as a separate line in your spreadsheet, so they don't get counted with the M215s.
I have the information in the spreadsheet in the notes for your system. (Approximate dates are fine for this purpose, but if you'd like to provide accurate dates, that's great!) If you would like me to break them out like I have done with the M190IGs, I certainly can. Unfortunately, the M190IGs look particularly unreliable thus far. As far as M215IGs go, I'm in your boat: I have 100% of the known-to-me failures!
 
I was chatting with my friend (not a member of MNL) about your spreadsheet, and how I have 4 of 6 known M215 failures. He was intrigued, and gave me permission to give you info to add to your spreadsheet.

His public envoy site: https://enlighten.enphaseenergy.com/pv/public_systems/hNDa25959/overview
Located in Clay, NY
In service since 8/9/2011
Consists of 24x Suntech STP225-20/Wd modules mated with 24 M215 inverters

No failures to date.
 
Hi RegGuheert,

Update for lines 204-206 - no issues with any of the 3 systems (all S280s)

I have a friend who just had a system installed with the new IQ6+. I dont have his public Enphase URL yet (it doesnt seem to be enabled, but his system ID is 1267857).

But if you want to add him now, he has 20x320W LG panels using IQ6+ and the compatible Envoy S. He's in Irvine, CA. His system was turned on 6/21/2017 at 2PM.


Thanks!
 
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