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RegGuheert
Posts: 6177
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

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

Tue Feb 27, 2018 2:02 pm

SurfHawk wrote:Row 221 still going strong with no failures on my 12x S280 inverters.
Thanks, SurfHawk! Updated.

That brings the total number of device-years for all S280s up to 86 with no known failures. So far so good!

The M250s are the current MTBF leaders. They are approaching 400 years with no known failures. The oldest units are nearly four years old. By that point, many M190s were already starting to fail.

pclifton has told me separately that he has a friend who owns many M215s as well as many M250s. He reports that quite a few M215s have failed, but only one M250. Unfortunately, I am unable to add that data into my database since I do not have any visibility of it. It's fine, since we are accumulating more and more data as time goes on.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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JeremyW
Posts: 1534
Joined: Sun Nov 13, 2011 12:53 am
Delivery Date: 23 Jun 2012
Leaf Number: 19136
Location: San Gabriel, CA

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

Tue Mar 20, 2018 8:50 pm

Has anyone noticed ENPH (the stock) has really rebounded in the last few days? :shock:
Former 2012 SL leasee 6/23/12 - 9/23/15
Now driving Honda Fit EV, License plate: CHADEMO
2000 Honda Insight for long trips

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RegGuheert
Posts: 6177
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

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

Wed Mar 21, 2018 7:40 am

JeremyW wrote:Has anyone noticed ENPH (the stock) has really rebounded in the last few days? :shock:
No, I hadn't. It looks like their latest investor report may be behind the stock move. It appears that they are moving into profitability and are about to offer off-grid-capable technology called Ensemble.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

GetOffYourGas
Posts: 1781
Joined: Tue Dec 20, 2011 6:56 pm
Delivery Date: 09 Mar 2012
Location: Syracuse, NY

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

Sat Mar 31, 2018 9:09 am

Now that the snow is melting, I have begun watching my panels again (it's really boring to see 0Wh produced every day). I noticed that another M215 inverter has bitten the dust. Looking through its history, it stopped reporting on December 19, 2017 at 10:20am, and has not produced anything since. I contacted my installer, and he says that they are in high demand because of the large number of failures (which of course doesn't match Reg's history). He expects my replacement to arrive in about 60 days. That means I'll miss out on some of the best production months of the year.

I also noticed another inverter which operates normally until it is in direct sunlight. On cloudy days, it will produce the same 50-60 W as the rest of the panels. On sunny days, it will be producing 2-5 W while all other panels are producing 180-200 W. I have never seen this failure mode. It clearly isn't meeting the spec, so I've reported it to my installer as well. I assume enphase will replace it.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
2017 Bolt Premier

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RegGuheert
Posts: 6177
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

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

Sun Apr 01, 2018 5:10 pm

GetOffYourGas wrote:Now that the snow is melting, I have begun watching my panels again (it's really boring to see 0Wh produced every day).
We've been in the "Nor'easter Hole" this year and only one of the four dumped on us. Our array had snow on it only for about two days in March and we beat our previous March production record by 61 kWh.
GetOffYourGas wrote:I noticed that another M215 inverter has bitten the dust. Looking through its history, it stopped reporting on December 19, 2017 at 10:20am, and has not produced anything since.
I recorded that as a failure of one of your original inverters on the date you gave.
GetOffYourGas wrote:I contacted my installer, and he says that they are in high demand because of the large number of failures (which of course doesn't match Reg's history). He expects my replacement to arrive in about 60 days. That means I'll miss out on some of the best production months of the year.
I think the real issue is that the M215s are no longer a standard product so they probably only produce a batch now and then.
GetOffYourGas wrote:I also noticed another inverter which operates normally until it is in direct sunlight. On cloudy days, it will produce the same 50-60 W as the rest of the panels. On sunny days, it will be producing 2-5 W while all other panels are producing 180-200 W. I have never seen this failure mode. It clearly isn't meeting the spec, so I've reported it to my installer as well. I assume enphase will replace it.
I'm sure they will replace it. The key is that it needs to produce less than 90% of its neighbors over a 7-day period. You didn't mention which type of inverter this was so I recorded it as a failure of one of the original M215s, just like the other one.

I will add two new M215IGs once those are installed.

Assuming these were both failures of the original M215s you had installed, you now have had 7 out of 16 fail after about 6.3 years of service. The spreadsheet is not overly friendly for calculating the MTBF of your system since each replacement is with a different type, but I did the calcs and I come up with 92.33 total device years and an MTBF of only 13.2 years after seven failures for the original M215s. You only have about 8.2 device-years on your M215IGs and no failures, so MTBF is really not established there.

By way of comparison, I have seen the following MTBFs in my system to date:

- M190s: 249 device-years - 6 failures - MTBF = 35.5 years (These are out of service now, but I intend to run 12 this summer.)
- M190IGs: 2.7 device-years - 0 failures - MTBF = ??
- M215IGs: 75 device-years - 1 failure - MTBF = 75 years (not well-established)
- M250s: 32 device-years - 0 failures - MTBF = ??
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

GetOffYourGas
Posts: 1781
Joined: Tue Dec 20, 2011 6:56 pm
Delivery Date: 09 Mar 2012
Location: Syracuse, NY

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

Mon Apr 02, 2018 4:35 am

RegGuheert wrote:We've been in the "Nor'easter Hole" this year and only one of the four dumped on us. Our array had snow on it only for about two days in March and we beat our previous March production record by 61 kWh.


Yeah, the back-to-back Nor'easters have been crazy. Although most of them haven't reached inland as far as Syracuse. It's mostly lake effect this year. We've had very few thaws through the winter and most were immediately followed by more lake effect snow.

RegGuheert wrote:I'm sure they will replace it. The key is that it needs to produce less than 90% of its neighbors over a 7-day period. You didn't mention which type of inverter this was so I recorded it as a failure of one of the original M215s, just like the other one.


In that case, it is definitely covered. The question is whether my contractor is paying enough attention to the details to realize that there are two in need of replacement.

Over the past 7 days, it has produced 1.47kWh. Its next lowest neighbor has produced 2.50kWh. That's 59%. It is an M215. I haven't had any issues with M215IGs yet.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
2017 Bolt Premier

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RegGuheert
Posts: 6177
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Re: Enphase field MTBF: M190: ~38 Years M215: ~460 Years M250: >300 Years

Wed Apr 04, 2018 5:44 am

RegGuheert on October 3, 2017 wrote:But I have now upgraded the wiring on the field array to allow for the transition from M190s to M250-72s. Once I started working on the wiring, I realized that I can easily accommodate BOTH M190-style wiring AND Enphase Engage wiring. This arrangement allows me to install any arbitrary combination of third- or fourth-generation Enphase inverters on that array.

Given this newfound flexibility, I am now in a bit of a quandary. The M250-72s have a peak production capability which is 612 W higher than that of the M190s (3000 W versus 2388 W). Since the array is ideally pointed during the coldest months, this will mean some additional production when it is lowest. OTOH, the M190s do not limit their output power during the other half of the year. Since my preference would be to keep the hours OFF the M250-72s as much as possible AND I would also prefer to put as many hours on the M190s as possible, I am thinking it may be best to operate the M190s during the summertime between the Spring and Autumn equinoxes when I adjust the array pointing and operate the M250-72s during the other half of the year. The goal is to try to encourage as many M190 failures as possible (to get fourth-generation replacements as spares) while limiting M250-72 failures as much as possible.

I'll probably give this a try during 2018 and see how much of a PITA it turns out to be.
Well, I made the swap today before the sun made it above the horizon. It only took about 15 minutes to do: I unconnected the DC from the 12 M250-72s, moved the weatherproof plugs from the M4 connectors on the M190s to the M4 connectors on the M250s and then connected the DC wires from the PV modules to the M190s. Done! Finally, I plugged in the original "pill" Envoy to talk to the old inverters and told the new one to ignore the 12 M250-72s for now.

It will be harder to swap them back in the Fall only because it is difficult to unmate the MC M4 connectors on the PV cables from the Amphenol H4 connectors which came on the M190s.

Let's see if I can get any M190s to fail during the summertime this year.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

wwhitney
Posts: 715
Joined: Sat Jul 17, 2010 10:10 am
Delivery Date: 01 Apr 2011
Location: Berkeley, CA

Re: Enphase field MTBF: M190: ~38 Years M215: ~460 Years M250: >300 Years

Wed Apr 04, 2018 7:17 am

RegGuheert wrote:The M250-72s have a peak production capability which is 612 W higher than that of the M190s (3000 W versus 2388 W). Since the array is ideally pointed during the coldest months, this will mean some additional production when it is lowest.

I take it you have actually observed clipping with the M190s? What is the economic value of the foregone energy if you left them in all year round?

Cheers, Wayne

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RegGuheert
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Location: Northern VA

Re: Enphase field MTBF: M190: ~38 Years M215: ~460 Years M250: >300 Years

Wed Apr 04, 2018 7:48 am

wwhitney wrote:I take it you have actually observed clipping with the M190s? What is the economic value of the foregone energy if you left them in all year round?
It's quite small. I've done the calcs once-upon-a-time for the 235 Wp PV modules on the roof which have an elevation angle of about 30 degrees. I believe I calculated that the lost production was less than about 300 kWh/year (out of about 14.5 MWh/year that array produces), which is around 2%.

But the field array gets an elevation angle of 60 degrees in wintertime, so it is well-pointed in the colder months. I have even seen all of the inverters in the field array producing 250 W each. I wouldn't be surprised if the field array might produce 5% or more additional electricity in the wintertime with the higher-power inverters. It's still not a huge amount of electricity.

Just to be clear, I did not purchase the M250s to harvest more electricity. I purchased them to extend the warranty by 17 years to cover the period from January 2026 to December 2042. But since I bought them, I realized that I can easily set them up to swap back and forth to take advantage of the higher output power capability. The main drawbacks are the effort to swap them back and forth and the risk to the not-active inverters by being connected to A/C even when they are not in use.
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
RegGuheert
Posts: 6177
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: Enphase field MTBF: M190: ~38 Years M215: ~460 Years M250: >300 Years

Wed Apr 04, 2018 9:34 am

RegGuheert wrote:Let's see if I can get any M190s to fail during the summertime this year.
Wow! That was fast! One of the M190s is now reporting a "Hardware Failure".

My evil plan is working! :twisted:
RegGuheert
2011 Leaf SL Demo vehicle
10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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