SageBrush
Posts: 741
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

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

Thu Jan 26, 2017 6:08 pm

pclifton wrote:
SageBrush wrote:I'm trying to settle on which micro-inverters to buy for my 340 watt panels.
I realize you Enphase folks have experience with what you own but if you could it again and wanted module level MPPT, what manufacturer would you choose ?


For me anyway, that is a real tough call. The things that worry me right now don't just relate to the reliability of the product. The warranty is only as good as the longevity of the company and it's financial condition. You might want to do some due diligence on Enphase's current financial situation.

I have been continuously looking at all the micro-inverter options. There are APS, Sunny, Chilicon Power and now Magnium Energy has a new storage-ready micro-inverter (Micro GT-500) too.

Like many folks here I went through the battery degradation with two 2012 LEAFs then the Enphase M190 failures. As RegGuheert will tell you the later series Enphase micros (so far) have been much better. There are more Enphase micros out in the wild than any of the rest... But, I can't say "yes" right now with the current financials... Hopefully a year from now things will be different. I really like the new Enphase design coming down the pike.

Ken Clifton

Thanks Ken.

Do you have an opinion about SolarEdge ?
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

ltbighorn
Posts: 70
Joined: Thu Nov 05, 2015 5:24 am
Delivery Date: 08 Nov 2015
Location: SF Bay Area

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

Fri Jan 27, 2017 12:18 am

SageBrush wrote:Please excuse the tangent...
I'm trying to settle on which micro-inverters to buy for my 340 watt panels.
I realize you Enphase folks have experience with what you own but if you could it again and wanted module level MPPT, what manufacturer would you choose ?


I have to agree with Ken, the main concern really comes down to their financial situation and their ability to support and warranty devices going forward. They have great products, but it's a significant downside if they're not in business anymore, and with their current financials it's hard to say what the outcome is going to be.

ltbighorn
Posts: 70
Joined: Thu Nov 05, 2015 5:24 am
Delivery Date: 08 Nov 2015
Location: SF Bay Area

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

Fri Jan 27, 2017 12:34 am

Anyone seeing strange data from Enlighten lately?

Two days in the last week there's been periods in the afternoon where pvoutput, pulling from the Enphase API, shows 0W for my array. On the 24rd from 3:35pm PST to 4:35pm PST, and on the 25th from 3:30pm-3:35pm PST. Readings outside these windows are normal.

Power produced as show in Enlighten Manager and MyEnlighten both show no such gaps. The pull to pvoutput isn't just one time either -- if I correct the values manually after the sun goes down, the next morning pvoutput pulls one more time and the gaps are repopulated.

Even more oddly...
In investigating, I find the "Site Energy Production" report on Enlighten Manager also shows very strange output. It purports to show me the values for the dates I've requested, off into future (2018!), but in reality it's really giving me the values from system install (July 2016) through yesterday. Anyone else seeing similar?

Site Energy Production
Generated on 1/26/2017
This report summarizes the daily energy production of the system from 1/20/2017 to 1/2/25/2017
Date/Time Energy Delivered (Wh)
01/20/2017 9,765
01/21/2017 10,219
01/22/2017 16,286
01/23/2017 15,897
01/24/2017 24,237
01/25/2017 23,913
01/26/2017 21,456
01/27/2017 23,644
01/28/2017 18,479
01/29/2017 14,637
01/30/2017 17,269
01/31/2017 9,814
02/01/2017 16,801
02/02/2017 19,216
02/03/2017 19,274
02/04/2017 20,782
02/05/2017 22,759
02/06/2017 24,085
02/07/2017 21,374
02/08/2017 19,059
....
08/11/2017 11,718
Total 2,706,326

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RegGuheert
Posts: 5421
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Location: Northern VA

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

Fri Jan 27, 2017 8:46 am

SageBrush wrote:
pclifton wrote:<snip>There are APS, Sunny, Chilicon Power and now Magnium Energy has a new storage-ready micro-inverter (Micro GT-500) too.<Snip>
Do you have an opinion about SolarEdge ?
I think SolarEdge is a very good option. We have a few threads on SolarEdge here that you can review:

Solar Edge Optimizers?
SolarEdge HD-Wave Inverter Technology
Failed SolarEdge optimizer causes entire string to fail

That last link recently had a drive-by posting which read:
12345678t wrote:I have a small commercial system that is about 4 months old. and have had 6 optmizers fail to date. System was working fine and just today tripped offline.
The bottom line is that we know that all of the options for module-based optimization will experience some failure rate. The question is this: Which ones are best? My spreadsheet attempts to quantify Enphase microinverter real-life MTBF numbers. It's not perfect, but I believe it is in the ballpark for the M190s. It should be closing in on the M215s and M250s. Additionally, it gives you an idea of the RANGE of experiences different users have. How much of that is related to the installer rather than the manufacturer is anyone's guess. (Don't discount the ability of a sufficiently-bad installer to ruin the reliability of your equipment! GetOffYourGas suspects that might account for his issues, at least partially.)

But there is NOTHING to compare against the Enphase results on my spreadsheet. While it's true that the M190 failure rates are way too high, it currently looks like the failure rates for the M215s and M250s are quite good. Unfortunately, we do not have nearly enough data for the S280s to form any opinion. We know that the architecture is completely different from the M215s and M250s, but we also can expect that Enphase has applied all of their experience to try to reduce field failures.

I suspect the same type of analysis I have done with Enphase could be done with SolarEdge, but I have not pursued it.

QueenBee has this little bit of information on APS.

Since you have not included your location in your signature, it is difficult to for us to say whether or not the S280 would be sufficient for 340W PV modules. My original installation employed PV modules rated for 20% more power than the microinverters were capable of producing and the production throughout the year was only reduced by a nominal amount (likely less than 1%). Your power ratio is only slightly higher, so your result should be similar or better if you live at a similar or lower latitude where temperatures are higher.

The bottom line is that if I were installing 340Wp PV modules, I might be inclined to go with 300W or 400W Optimizers from SolarEdge and purchase a central inverter that could take a battery from either Tesla or one of their competitors. (Just beware that adding the battery will both increase the initial cost AND the recurring cost, since it will likely be the least durable component.)
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 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

Fri Jan 27, 2017 8:54 am

ltbighorn wrote:Anyone seeing strange data from Enlighten lately?
Yes. That problem is still unresolved.
ltbighorn wrote:Two days in the last week there's been periods in the afternoon where pvoutput, pulling from the Enphase API, shows 0W for my array. On the 24rd from 3:35pm PST to 4:35pm PST, and on the 25th from 3:30pm-3:35pm PST. Readings outside these windows are normal.
I see those types of anomalies from time to time on Enlighten, not just for my data, but sometimes for others' data, as well. They typically get cleared up after a while.
ltbighorn wrote:Even more oddly...
In investigating, I find the "Site Energy Production" report on Enlighten Manager also shows very strange output. It purports to show me the values for the dates I've requested, off into future (2018!), but in reality it's really giving me the values from system install (July 2016) through yesterday. Anyone else seeing similar?
No, but I like the sound of that feature! What do I need to type into my browser to get the Envoy to tell me my future solar production? If I had that information, I'm pretty sure I could get rich very quickly! ;)
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

ltbighorn
Posts: 70
Joined: Thu Nov 05, 2015 5:24 am
Delivery Date: 08 Nov 2015
Location: SF Bay Area

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

Fri Jan 27, 2017 9:06 am

RegGuheert wrote:No, but I like the sound of that feature! What do I need to type into my browser to get the Envoy to tell me my future solar production? If I had that information, I'm pretty sure I could get rich very quickly! ;)

It's very user-friendly. Just follow these three steps: Click "Site Energy Report", click "Submit!", and you're done. There's is no step 3! The best part is that it also enables July-level production in January. :mrgreen:

SageBrush
Posts: 741
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Delivery Date: 13 Feb 2017
Location: Colorado

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

Fri Jan 27, 2017 9:22 am

Thanks very much everybody for the input and links.

One more question, if I may: The SE inverters vary little in price from 3.4 to 6.0 kW.
Any downsides to be aware of in oversizing the inverter for the expected production ?

If not I'd like to buy the bigger inverter for future proofing, a larger resale market if needed, and perhaps longer longevity ?
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

ltbighorn
Posts: 70
Joined: Thu Nov 05, 2015 5:24 am
Delivery Date: 08 Nov 2015
Location: SF Bay Area

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

Fri Jan 27, 2017 9:44 am

SageBrush wrote:Thanks very much everybody for the input and links.

One more question, if I may: The SE inverters vary little in price from 3.4 to 6.0 kW.
Any downsides to be aware of in oversizing the inverter for the expected production ?

If not I'd like to buy the bigger inverter for future proofing, a larger resale market if needed, and perhaps longer longevity ?


There may be other factors, but at least one is that an inverter is less efficient below certain output levels. For SolarEdge you can find some inverter efficiency charts here:

http://www.solaredge.com/sites/default/ ... ciency.pdf

The difference may not matter much in practice, especially when you consider that the worst efficiency comes when your power output levels are low. i.e. you're losing an extra percent or two of small amounts, rather than large amounts.

There could be other concerns like minimum startup levels but someone more familiar with SolarEdge would have to tell you. That may not be an issue with the optimizers.

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RegGuheert
Posts: 5421
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
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Location: Northern VA

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

Fri Jan 27, 2017 9:52 am

SageBrush wrote:One more question, if I may: The SE inverters vary little in price from 3.4 to 6.0 kW.
Any downsides to be aware of in oversizing the inverter for the expected production ?
Since SolarEdge Optimizers allow for constant-string voltage with a wide range of the number of modules in each string, I think that's a good idea.
SageBrush wrote:If not I'd like to buy the bigger inverter for future proofing, a larger resale market if needed, and perhaps longer longevity ?
Bigger power MOSFETs will run cooler because of their lower on resistance (assuming losses are not dominated by switching losses). However, the driver for the larger power MOSFETs will dissipate MORE power. If the different units employ the same gate drivers, then those components will run hotter in the higher-power units regardless of the power being processed. So I would expect the MOSFETs to be slightly more reliable and the gate drivers to be slightly less reliable. Neither of those two types of components should dominate the reliability calculations, however. Rather, it is likely to be dominated by the electrolytic capacitors (unless you get the HD Wave inverter, which has none). Those should operate at a lower RMS current and therefore should run cooler and experience less-severe thermal cycles every day. That could make a real difference in device reliability.

I'd be inclined to oversize the inverter, myself.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
RegGuheert
Posts: 5421
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

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

Fri Jan 27, 2017 9:59 am

ltbighorn wrote:
SageBrush wrote:There may be other factors, but at least one is that an inverter is less efficient below certain output levels. For SolarEdge you can find some inverter efficiency charts here:

http://www.solaredge.com/sites/default/ ... ciency.pdf
Wow! That's the first time I've seen the HD Wave efficiency curves. If those things are available today, note that you'll be throwing away a couple of percent of your energy at ALL power levels if you go with any of the other inverters. Since the HD Wave inverters are not yet available in the larger sizes, you'll have to trade that off against possible future expansion.

(Note that those efficiencies are for European & Asia Pacific units. U.S. units should be similar.)
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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