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

[Computerizer]

I am the owner of a system in your spreadsheet labeled "Bellingham WA" under M215 and M250. My friend has been reporting the status (and he may continue to do so). I indeed have 24 M215s installed 10/4/2013 and 24 M250s installed 3/26/2014. None of them have had any failures of any sort. Just to confirm that my friend is telling the truth.

By the way, my ex-wife works for an installer who used to install several dozen Enphase inverters per week. She could probably get some stats from all of their systems if you want....

 

[RegGuheert]

No failures from either.

Thanks! Spreadsheet updated. Your friend in Redmond now has a demonstrated MTBF over 92 years.

Row 147 is the original non integrated ground design.

That's too bad. I simply don't have very many M215IGs in the spreadsheet. Right now, there are only my 28 and your 15 that I am sure about for a whopping total of 43. In 20 years, we will have only amassed a grand total of 840 device years. For now, I guess I'll just have to keep the M215s mixed in with the M215IGs.

I am the owner of a system in your spreadsheet labeled "Bellingham WA" under M215 and M250. My friend has been reporting the status (and he may continue to do so). I indeed have 24 M215s installed 10/4/2013 and 24 M250s installed 3/26/2014. None of them have had any failures of any sort. Just to confirm that my friend is telling the truth.

Thanks! I do wonder about QueenBee sometimes! :lol:

FWIW, your system now has a demonstrated MTBF above 133 years. Overall, the fourth-generation Enphase inverters have a demonstrated MTBF of around 475 years. That just means that in a system with the number of inverters you have, you can expect to have one inverter fail about every 10 years. Then they will fail more quickly toward the end of their lives, which hopefully will not come for another 25 years or so.

By the way, my ex-wife works for an installer who used to install several dozen Enphase inverters per week. She could probably get some stats from all of their systems if you want....

Thanks! Even though we are a bit shy on M215IGs and M250s, I think I'll stick with what we have here for now. It's easiest for me to get occasional updates from this forum.

Overall, here are my current impressions of the Enphase products out there:

M190: Enphase made the mistake of printing the words "- MTBF of 331 years" on the original M190 datasheet (since removed). Simply put, they have not lived up to that billing. The actual MTBF in the field seems to be more on the order of 44 years overall, with a few customers experiencing MTBFs as low as 5 years. Such a system with 50 M190s would experience about 10 failures EACH YEAR. Fortunately, Enphase has so-far been good about providing replacements, with the current replacement being a fourth-generation microinverter with better maximum voltage specifications. Enphase never made the mistake of quoting MTBF on any datasheet again.

D380: The D380 was basically two M190s in the same package. Unfortunately, that simply multiplied the failure rate. It seems Enphase recognized that product as a mistake pretty quickly and moved on. In fact, I believe Enphase has swapped out the entire set of microinverters on some (many?) systems containing D380s with M215s, including upgrading the cabling to Engage.

M215: I am convinced that the original M215s actually contained similar electronics (third-generation) to the M190s, but in the new Engage-compatible package and likely with known failure modes eliminated or reduced. To date, I have recorded five failures of these inverters. Unfortunately, three of those five failures are from a single system of 16 inverters belonging to GetOffYourGas up in NY state. That system currently has an MTBF for M215s of only 25 years. In contrast, the 58 original-style M215s in QueenBee's system have experienced no failures to date, demonstrating an MTBF of over 236 years (10X better). That seems to match the behavior of the M190s with some systems having much lower MTBFs than others. Had GetOffYourGas' system not been in my spreadsheet, the calculated MTBF of M215s would now be over 1000 years. But it IS in the spreadsheet and we are seeing and MTBF of around 500 years. That is still little consolation to GetOffYourGas, who can probably expect more than one M215 failure every two years.

M215IG and M250: So far I have not recorded a single failure of any of these fourth-generation inverters. That said, I have only recorded about 360 device-years for these inverters and the oldest ones have only been in the field about 2.5 years. In any case, I feel very good about the reliability of these units. Otherwise, I would not have purchased 41 of them! I also really like the Engage cabling system, price notwithstanding.

S230 and S280: I have no opinion about the reliability of these fifth-generation inverters as they are just now showing up in the field. Personally, I'll stick with the M-series inverters since my Envoy and the backup I purchased for when it fails are not compatible with the S-series microinverters.

Envoy: It seems that Enphase has greatly improved the MTBF of the Envoys from the very early units. The MTBF of the Envoys installed with M190 systems had an MTBF of 28 years, while the Envoys installed with M250s had an MTBF of double that at 56 years. While I do not have any reliability information on the Envoy-S, I will note that Enphase has increased their warranty to 5 years on those units.

 

[Computerizer]

My ex-wife doesn't want to go through the effort of collecting data from dozens of customers anyway. BUT, she did tell me that they have a customer with M190s in which almost every one has been replaced, and they have definitely had M215s and also M250s fail but they're very rare.

Unfortunately they haven't been installing very many Enphase systems here lately because they aren't Made-in-Washington, so they don't get as many incentives. Sadly the only Made-in-WA microinverter has a terrible MTBF, so they've been mostly using central inverters even in shady situations -- sometimes combined with DC optimizers.

 

[QueenBee]

I am the owner of a system in your spreadsheet labeled "Bellingham WA" under M215 and M250. My friend has been reporting the status (and he may continue to do so). I indeed have 24 M215s installed 10/4/2013 and 24 M250s installed 3/26/2014. None of them have had any failures of any sort. Just to confirm that my friend is telling the truth.

Thanks! I do wonder about QueenBee sometimes! :lol:

Hey, to be fair I did personally leave a lot of sweat helping install parts of these three systems

 

[DaveEV]

Your coworker's M215 system in Escondido has just past the 100-year mark for demonstrated MTBF. (BTW, do you know whether this system includes the original M215s or M215IGs? I would eventually like to break these two types out separately since their failure rates appear to be completely different. TIA!)

Those are the original M215s. If you you look at how old the inverters are and the M215IG release date that should help categorize the two, I believe that the M215-IG was announced in Jan 2014, though not sure exactly when they started shipping.

 

[Computerizer]

By the way, my M215s are the old ones, obviously, as they are made prior to 2014. However, my M250s have identical cases to those old M250s, not the newer style case of the IG ones, but Enphase's datasheet doesn't give any indication that M250s of this style might have existed. I assure you they did, as I have 24 of them.

 

[RegGuheert]

Those are the original M215s. If you you look at how old the inverters are and the M215IG release date that should help categorize the two, I believe that the M215-IG was announced in Jan 2014, though not sure exactly when they started shipping.

Thanks!

I knew the transition was sometime between when QueenBee installed his second and third sets of microinverters, but I wasn't sure exactly when. Interestingly, the 12 M215IGs I bought from QueenBee must have been some of the first units off the line since they have a date code of the second week of 2014. The serial numbers all start with "121402".

By the way, my M215s are the old ones, obviously, as they are made prior to 2014. However, my M250s have identical cases to those old M250s, not the newer style case of the IG ones, but Enphase's datasheet doesn't give any indication that M250s of this style might have existed. I assure you they did, as I have 24 of them.

There are actually nine of these M250s in the "Guheert Microinverter Menagerie," with serial numbers beginning "121348". These are the only used inverters (no warranty) I have in my system.

BTW, Enphase does acknowledge the existence of these oddball M250s in this document in which they compare the various fourth-generation offerings.

At this point, the "Guheert Microinverter Menagerie" has SEVEN different types of microinverters which can be differentiated by their packaging:

- 35 M190-72-240-S12 - Original M190 (of the 42 I purchased. 23 are currently cold spares)
- 1 M190-60-2LL-S22-IG - Replacement Fourth-Generation M190 designed for 60-cell PV modules
- 2 M190-72-2LL-S22-IG - Replacement Fourth-Generation M190 designed for 72-cell PV modules with a metal case
- 24 M215-60-2LL-S22-IG - M215IG
- 4 M215-60-2LL-S22-IG - Later M215IG with a metal case
- 9 M250-60-2LL-S22 - Early M250 with the groove in the lid
- 4 M250-60-2LL-S22 - M250

If I go by the "HW Part Num" reported by the microinverters to the Envoy, I can see that there are actually eight different types of inverters. The twelve M215IGs I bought from QueenBee have a different "HW Part Num" than twelve that I purchased later on eBay, even though the two sets were manufactured only six months apart in 2014. (I have M190s that we're manufactured FOUR YEARS apart that have the same "HW Part Num".)

Based on the date codes on my equipment, it seems that Enphase went back to metal cases sometime in the middle of 2015. Does anyone know why they did this? I doubt those cases are cheaper, so I guess it could be for one of two reasons: improved reliability or reduced EMI emissions. I'm hoping it is the latter, since I wouldn't want to have failures due to the plastic cracking or warping sometime down the road.

 

[jwarcd]

I'm a little late to this party but if you would like to add my system to the spreadsheet:

https://enlighten.enphaseenergy.com/pv/public_systems/3RST25147/overview

20 Enphase 215 Inverters with Sunpower 230W Panels (SPR-230-WHT)

Went live on 8/16/2011

Had 10 total failures out of 25 total inverters (some of the replacements ended up failing as well)

After many complaints to Enphase, In August, 2014, they ended up replacing all 20 inverters with new inverters with date codes: 1214020xxxxx. I assume those are the 215IG models.

I haven't had any issues or failures since the inverters were replaced.

 

[RegGuheert]

I'm a little late to this party but if you would like to add my system to the spreadsheet:

https://enlighten.enphaseenergy.com/pv/public_systems/3RST25147/overview

20 Enphase 215 Inverters with Sunpower 230W Panels (SPR-230-WHT)

Went live on 8/16/2011

Had 10 total failures out of 25 total inverters (some of the replacements ended up failing as well)

After many complaints to Enphase, In August, 2014, they ended up replacing all 20 inverters with new inverters with date codes: 1214020xxxxx. I assume those are the 215IG models.

I haven't had any issues or failures since the inverters were replaced.

Wow!

Thanks for sharing your information with me! That said, I have to say I'm a bit hesitant to put your data into my spreadsheet. Here's why:

Simply put, your installer NEVER should have installed the original M215s together with Sunpower SPR-230-WHT PV modules in MA. Why? Because the M215s are not capable to withstand the voltages which the PV modules are expected to produce EVEN AT ROOM TEMPERATURE.

I have tabulated all the specifications for the third- through fifth-generation inverters in this thread. As you can see in that table, the original M215s had the lowest Maximum Input DC Voltage rating of ALL Enphase inverters: 45V. The Open-Circuit Voltage (Voc) at room temperature of the Sunpower SPR-230-WHT PV modules is 48.7V. That is 3.7V HIGHER than the input rating of the inverter. When the temperature drops to 0F outside, that Voc coming out of the panels would rise to about 54V, NINE VOLTS higher than the rating of the inverter!

Frankly, I'm surprised that ANY of your M215 microinverters survived the first winter. And, frankly, I'm surprised any of your M215IGs are surviving the wintertime temperatures since they are only rated for 48V.

Given the PV modules your installer chose, you likely would have been better off with the original M190s than the M215s since they were rated for 56V DC at their inputs. And now Enphase has the 72-cell M190IGs (part number M190-72-2LL-S22-IG) which are rated for 60V DC at their inputs.

I hope I'm wrong about your M215IGs being at severe risk of damage, but I would encourage you to insist that Enphase ONLY use 72-cell-rated inverters if they ever need to make further replacements.

Can you tell me this: Did most or all of your inverters fail during the wintertime or soon thereafter?

 

[jwarcd]

You are correct..... M215s are definitely the wrong inverter for my panel.... Sorry, but my original post was wrong I have M210 inverters, not M215s.

I'm not sure why I was thinking of M215s... sorry for the confusion.

The part# for my new M210s is 800-00066-r03

 

[RegGuheert]

You are correct..... M215s are definitely the wrong inverter for my panel.... Sorry, but my original post was wrong I have M210 inverters, not M215s.

I'm not sure why I was thinking of M215s... sorry for the confusion.

The part# for my new M210s is 800-00066-r03

That makes a lot more sense! So I guess the part number printed on the label (which is different than the one in the Envoy would be something like M210-84-240-S12.

Those should work a lot better than the M215s or M215IGs, but they may have the kind of MTBF that is reported for the M190s in my spreadsheet. OTOH, with the most recent firmware, the failures seem to be few and far between for my system, even though it spent a few years with the old firmware. Time will tell.

Can you please tell me the date that the M210s were installed so that I can add your system to my spreadsheet as of that date? That will be the one and only M210 system I am tracking.

 

[jwarcd]

The new inverters were installed on August 15, 2014. I hope they perform better than the original inverters.

 

[RegGuheert]

The new inverters were installed on August 15, 2014. I hope they perform better than the original inverters.

Thanks! I have added your system as row 92. Please check that all information is correct.

I decided to group your system with the M190s. Your system currently has a demonstrated MTBF over 44 years.

 

[ltbighorn]

No changes on my M250 inverters installed a few months ago, row 162.

I've had some relative infrequent consumption metering errors on the Envoy-S, perhaps on 6-7 different occasions lasting 2-5 hours. Basically the real-time consumption metering values start fluctuating by +- a few hundred watts, sometimes leading to instantaneous negative consumption readings, before eventually going back to accurate readings. It seems to happen primarily on days with highly variable light output, i.e. bright days with small puffy clouds constantly passing.

Since consumption is a derived value from generation and grid export/import, I'm guessing it's some sort of software bug that causes the CT measurements to start being read at varying slightly offset times instead of simultaneously, resulting in miscalculations under the rapidly changing generation. It's hard to be sure, and I haven't been able to get my Enphase to look at it seriously (and my installer seems hesitant to even open tickets with them for anything not blatantly broken). For now I live with it as it is relatively infrequent.

 

[Computerizer]

By the way, my M215s are the old ones, obviously, as they are made prior to 2014. However, my M250s have identical cases to those old M250s, not the newer style case of the IG ones, but Enphase's datasheet doesn't give any indication that M250s of this style might have existed. I assure you they did, as I have 24 of them.

There are actually nine of these M250s in the "Guheert Microinverter Menagerie," with serial numbers beginning "121348". These are the only used inverters (no warranty) I have in my system.

BTW, Enphase does acknowledge the existence of these oddball M250s in this document in which they compare the various fourth-generation offerings.

For what it's worth, according to the Envoy, my M215s all have serials starting with 121312 or 121321, and HW Part Num 800-00103-r05 and Assembly Part Num 880-0008-r35 or -r36. The M250s, purchased a few months later, are 121342 or 121343 with HW Part Num 800-00179-r11 and Assembly Part Num 880-00046-r34. I could go out and get data off the labels if there's interest, too (it's ground-mounted, completely accessible).

BTW, my system is running with the "IEEE 1447 Mainland alternate" grid profile. Being a few hundred wire-feet from the transformer on the pole, they were going over-völtage (264 VAC) on the default profile when producing at peak (11.4 kW DC total). Despite having used extra-large wires the entire distance and been very careful with each connection, there's still a lot of resistance with that long of a wire!

And it's pretty complicated...

(The red arrows are pointing to circuits that I monitor with eGauge)

 

[RegGuheert]

No changes on my M250 inverters installed a few months ago, row 162.

Thanks! Updated. Your MTBF is now over 3.5 years!

I've had some relative infrequent consumption metering errors on the Envoy-S, perhaps on 6-7 different occasions lasting 2-5 hours. Basically the real-time consumption metering values start fluctuating by +- a few hundred watts, sometimes leading to instantaneous negative consumption readings, before eventually going back to accurate readings. It seems to happen primarily on days with highly variable light output, i.e. bright days with small puffy clouds constantly passing.

Since consumption is a derived value from generation and grid export/import, I'm guessing it's some sort of software bug that causes the CT measurements to start being read at varying slightly offset times instead of simultaneously, resulting in miscalculations under the rapidly changing generation. It's hard to be sure, and I haven't been able to get my Enphase to look at it seriously (and my installer seems hesitant to even open tickets with them for anything not blatantly broken). For now I live with it as it is relatively infrequent.

Interesting. I'm wondering if the Envoy-S reads BOTH the microinverters AND the current transformers. If so, then I wonder if there is some way to make a comparison between the two.

 

[ltbighorn]

Interesting. I'm wondering if the Envoy-S reads BOTH the microinverters AND the current transformers. If so, then I wonder if there is some way to make a comparison between the two.

Yes, it does read both values, using them in different contexts, using for example the inverter values for per-panel data on the website. The production CT has a higher rated metering accuracy than the microinverters. I tend not to see the couple % production over-reporting that most Enphase owners report, and my CT-based measurements take into account losses from the roof down to the electrical panel.

However the microinverters have no knowledge of the effectively export/import to/from grid, so it must rely on the consumption CT for that, and that's only valid for comparison with the production CT, which is why the production CT is mandatory for consumption metering. Which is why the CTs are used as the metering source for most overall-system measurements.

 

[RegGuheert]

For what it's worth, according to the Envoy, my M215s all have serials starting with 121312 or 121321, and HW Part Num 800-00103-r05 and Assembly Part Num 880-0008-r35 or -r36. The M250s, purchased a few months later, are 121342 or 121343 with HW Part Num 800-00179-r11 and Assembly Part Num 880-00046-r34. I could go out and get data off the labels if there's interest, too (it's ground-mounted, completely accessible).

Your M250s match mine exactly. I don't have any of the original M215s, so those numbers do not register.

BTW, my system is running with the "IEEE 1447 Mainland alternate" grid profile.

I don't know what that is. Is it a wider AC voltage range programmed into your inverters?

Being a few hundred wire-feet from the transformer on the pole, they were going over-völtage (264 VAC) on the default profile when producing at peak (11.4 kW DC total). Despite having used extra-large wires the entire distance and been very careful with each connection, there's still a lot of resistance with that long of a wire!

Thar be resistance in them thar wars! The highest I have seen is about 258VAC at the inverters with about 250 feet round trip, IIRC. (Nice picture, BTW!)

(The red arrows are pointing to circuits that I monitor with eGauge)

eGauge?

 

[philip]

However the microinverters have no knowledge of the effectively export/import to/from grid, so it must rely on the consumption CT for that, and that's only valid for comparison with the production CT, which is why the production CT is mandatory for consumption metering.

If the Envoy-S works anything like the old Envoy, it only receives data from the micros periodically (every 10 minutes??). So on a cloudy day when the sun comes through to the panels, the CT will see that immediately, but the micros will still be reporting the cloudy production, resulting in negative consumption in the reporting (Envoy Production + CT reading = consumption)

I see this in my own monitoring system where I read meter data from a Rainforest Eagle and get the enphase data from the envoy - on cloudy days the consumption graph becomes very "noisy" with the occasional negative consumption too.

 

[ltbighorn]

However the microinverters have no knowledge of the effectively export/import to/from grid, so it must rely on the consumption CT for that, and that's only valid for comparison with the production CT, which is why the production CT is mandatory for consumption metering.

If the Envoy-S works anything like the old Envoy, it only receives data from the micros periodically (every 10 minutes??). So on a cloudy day when the sun comes through to the panels, the CT will see that immediately, but the micros will still be reporting the cloudy production, resulting in negative consumption in the reporting (Envoy Production + CT reading = consumption)

I see this in my own monitoring system where I read meter data from a Rainforest Eagle and get the enphase data from the envoy - on cloudy days the consumption graph becomes very "noisy" with the occasional negative consumption too.

Philip,

You're right in that it does only get updates from the micro inverters every few minutes (about 5 with my M250s), so that would be the case if it didn't also have a production CT. With the two CTs it's able to read both values simultaneously and generate an accurate consumption reading even under varying light. When working properly, anyway, which is the majority of the time.