wwhitney
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Fri Jan 27, 2017 10:52 pm

RegGuheert wrote:As the power factor is reduced, does the reactive power simply increase without any loss of what is delivered to the grid, or does the amount of power exported decrease as the power factor is reduced? Or perhaps it does the prior below max inverter output power and the latter once the limit is reached?

I'm pretty sure this last idea is correct, but I'm not 100% sure.

Cheers, Wayne

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RegGuheert
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Mon Jan 30, 2017 2:28 pm

RegGuheert wrote:I may have just experienced the first failure of a four-generation inverter including an integrated ground. (To my knowledge, all failures of M215s that I have recorded to date were the early ones without the "IG" suffix.) I currently have four of the latest-style fourth-generation M215IGs on my roof that include the metal case. They were built in week 45 of 2015. One of those four inverters malfunctioned yesterday. It had a dropout at about 12:30 PM with no event recorded in the log. Then at about 2:00 PM it stopped producing power. About an hour later it reported "DC Power Too Low" in the event log and did not produce any power for the rest of the day. This was true even though yesterday was the only fully-sunny day we have had so far this month. Very strange behavior.

This inverter did wake up this morning and start producing the same power as its neighbors. If this unit is failed, that will be a rather disappointing development. If so, hopefully it is just a random failure quite early in life (this unit was installed almost exactly six months ago). Six months is about how long it was before my first M190 failure.

I'll update on this microinverter if there are any further malfunctions.
This inverter limped along over the past few days when it was cloudy, but today it was sunny and it only functioned properly for a short while. I called Enphase to report it and the support representative was quite surprised to see a failure of such a new inverter. He said he doesn't see many of these like he does with the M190s and M380s. That's good to hear and it agrees with what we are seeing (so far). Anyway, because of it's non-functional condition and the fact that they likely don't have many failed M215IGs, he authorized an RMA immediately without the 7-day watch period that they normally schedule for the M190s. I suppose it's time to climb up there and install one of my fourth-generation spares.

Interestingly, this puts the MTBF of the various units in my system at the following values:
M190s: 40 years (with 6 failures)
M215IGs: 41 years (with 1 failure)
M250s: >12 years (no failures)

If I lump all of my fourth-generation inverters together, then the MTBF for the M215IGs and M250s together is 53 years (1 failure).

It has become interesting calling Enphase: I tend to get questions about my "odd" system:
"How many Envoys do you have?"
"Did you know one of them is not communicating?"
"What are those four inverters on the display which haven't reported in a long while?"
"Did you realize you have a bunch of inverters which are not reporting?"

I guess there aren't many out there with spare Envoys and inverters kicking around... :)
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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RegGuheert
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Tue Jan 31, 2017 2:08 am

It's nice having spares. I called Enphase at 3:30PM yesterday. They authorized the RMA. I was up on the roof with a spare by 5:00PM. The spare is installed and will wake up with the morning light today. The new unit will go into the box of spares when it arrives and the old one will get shipped back to Enphase.
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

ltbighorn
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Tue Jan 31, 2017 2:14 am

Glad to hear it was easy this time, though too bad on the gen 4 numbers.

That said, with your new spare, do you ever consider testing/burning them in for a few months to make sure they won't suffer from early failure? Somewhat presumes the concern that they might not be around to service the warranty forever. Also I'm assuming as a replacement, your warranty continues from the date of the originally purchased inverter, not the replacement.

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RegGuheert
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Tue Jan 31, 2017 5:21 am

ltbighorn wrote:Glad to hear it was easy this time, though too bad on the gen 4 numbers.
I'm hoping that number doesn't stick!
ltbighorn wrote:That said, with your new spare, do you ever consider testing/burning them in for a few months to make sure they won't suffer from early failure?
Not really. Enphase does that when they manufacture them. That said, this failure DOES indicate that one slipped through undetected.
ltbighorn wrote:Somewhat presumes the concern that they might not be around to service the warranty forever.
That is my presumption. But that brings up the real question: Is there something about the new metal cases that caused this failure? If there is, then I should be running the four M215IGs with cans that I bought AND the two 60V M190IGs that I received as spares in 2016. IF I have another failure of a fourth-generation inverter with a metal can, those things will definitely go right up onto the roof!
ltbighorn wrote:Also I'm assuming as a replacement, your warranty continues from the date of the originally purchased inverter, not the replacement.
That's right. And for the unit just being replaced, it was manufactured toward the end of 2015. The replacement will be a little bit newer, but not that much, so it doesn't make much difference. However, with the M190 replacements, the story is very different. The M190s that I purchased new only have 9 years left on their warranties, but the replacements are built the same way as new inverters with 25-year warranties, so I'm basically hoping that the old M190s last as long as possible and that I can get more than two 15-year lifetimes out of the M190 plus its spare.

One final point is that the old M190s have electrolytic capacitors in them that fail FASTER if not energized than if they were used every day. OTOH, when they are used, they run hotter, which also tends to reduce their life. While I think they are good for a couple of decades of storage, if any of those old inverters stay in the boxes for more than about 5 years, I will likely swap them out into the field to get their capacitors annealed. In any case, it is probably better to be storing the inverters with no electrolytic capacitors since those should not have similar storage failure modes. My decision to put the M190s into storage had more to do with the fact that the replacements I was getting were not rated for the voltage of the PV modules in the field array. But that reasoning all changed with the shipment of 60V replacements which Enphase started in 2016. Still, if they go out of business, I'm back to where I was wanting spares for my field array.

It will be several more years before we know if this failure was an isolated incident or not. The M190s are the only inverters where I think we have a ballpark number on failure rates (and it seems to be different for different systems).
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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RegGuheert
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Mon Feb 06, 2017 11:31 am

RegGuheert wrote:It's nice having spares. I called Enphase at 3:30PM yesterday. They authorized the RMA. I was up on the roof with a spare by 5:00PM. The spare is installed and will wake up with the morning light today. The new unit will go into the box of spares when it arrives and the old one will get shipped back to Enphase.
Enphase shipped the replacement very early on Friday morning. FedEx says it will arrive on Thursday. That's nine calendar days from when I called to report the problem until the replacement unit arrives. Considering I'm on the opposite side of the country, I guess that's about as good a job as they can do. Kudos to Enphase support on this one!
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

SageBrush
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Mon Feb 06, 2017 12:07 pm

Re: FedEx,

I have seen shipments take a lot of time when FedEx hands off to the USPS for the last leg to my home. I've learned to avoid that choice since the retail shipping cost is not much more.
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

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drees
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Mon Feb 06, 2017 10:33 pm

RegGuheert wrote:Wow! That's the first time I've seen the HD Wave efficiency curves.

Yeah, 99%+ efficiency is pretty amazing. I wonder if that includes the optimizer efficiency as well?

This type of inverter tech would be very useful in the opposite direction for battery storage, too.
'11 LEAF SL Powered By 3.24 kW Enphase Solar PV

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RegGuheert
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Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Tue Feb 07, 2017 9:44 am

SageBrush wrote:Re: FedEx,

I have seen shipments take a lot of time when FedEx hands off to the USPS for the last leg to my home. I've learned to avoid that choice since the retail shipping cost is not much more.
Yeah, it looks like it may have been shipped using FedEx "SmartPost". FedEx always pads their estimate by a day to cover for the U.S. Postal Service. Since the package is now in the local area, I expect it will be delivered tomorrow instead of Thursday. We'll see.
drees wrote:
RegGuheert wrote:Wow! That's the first time I've seen the HD Wave efficiency curves.

Yeah, 99%+ efficiency is pretty amazing. I wonder if that includes the optimizer efficiency as well?
No, I think that excludes the optimizers. But the datasheet I have for the optimizers shows a CEC-weighted efficiency of 98.8% and a peak efficiency of 99.5%! If you are operating at a point where the optimizers have an efficiency of 99.5% and the inverter is operating at 99.5%, then you still end up with 99.0% overall efficiency. That is better than the efficiency of the WIRES in most PV installations.
drees wrote:This type of inverter tech would be very useful in the opposite direction for battery storage, too.
Agreed. But I don't think they offer a battery-capable version of the HD Wave inverters, yet.
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

SageBrush
Posts: 1496
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Delivery Date: 13 Feb 2017
Location: Colorado

Re: Enphase field MTBF: M190: ~44 Years M215: ~470 Years M250: >275 Years

Tue Feb 07, 2017 9:49 am

Reg,
Do you know details about the 1500 watt supply from the PV when the grid-tie is down ?

I'm wondering what extra needs to be bought/installed to have the feature,
and whether the power can be sent into the home automagically.

Addendum:
One SE csr told me this feature is unheard of;
The second one said it has been delayed.
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California with 63.9 Ahr after 22k miles
Car is now enjoying an easy life in Colorado

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