Poor Module Performance

**arborlinden** · 07-19-2015, 04:55 PM

Originally posted by ecoalex

40 - 275 SW Mono modules with Solaredge optimisers 2 6000w string inverters.Install 7.30.14

Why would one, or two modules be reporting such low generation? No shading of the module.This is new for this install.

Update- I have a 31% variance in one module,22% in another at 10:30 Am. The modules are in the bank, not on the edge, their neighbors show much better generation.At the end of the day however, the poor reporting module out performed many others.Is this a monitoring glitch with the optimisers?

Thanks

[ATTACH=CONFIG]7282[/ATTACH] [ATTACH=CONFIG]7287[/ATTACH]

I too would like to hear how this can happen. As I new solar system owner my knowledge is almost zero. I am told that the inverter maintains the string voltage (determined by the sumation of all the panel voltages) by setting the string current (up or down) and then each individual intelligent optimiser has to adjust the its panel voltage to get the most power off of that panel it can produce for the illuminence available to that panel at that current. Words of wisdom from the experts needed here!
If that is the case could it not be that the panel in question is just not happy that at specific panel current but when the other string panels added voltages allow the inverter to maintain the correct string DC voltage with a different string current that particular panel efficiency is restored?

**Mike90250** · 07-19-2015, 06:43 PM

I would look over the affected panels carefully and see if there are any spots showing irregularities or heating. Low power mid day and batter power AM and PM seems to indicate a thermal problem, probably a poor solder contact in the panel, or a hairline crack in a cell that opens when really hot.

**ecoalex** · 07-19-2015, 08:23 PM

End Of Day All OK

As you can see, later in the day, the generation appears to catch up, even exceed it's neighbors.

The temperature of the modules is lower when the few are reporting lower production,(morning) which rules out heat, or conversely, when they do heat up later in the day , something changes.
The idea of temperature and soldering makes sense, however at the end of the day, the performance of the questioned modules is equal, or better than the others.
I'm leaning towards the problem being the Solaredge optimisers on the 2 modules reporting to the #2 inverter.

Module #17 had an equal or better total at the end of the day yesterday.

A view at 5;15pm :

Improved performance.5pm4.png

Attached Files

**Ben25** · 07-19-2015, 08:44 PM

Some optimizers will take a little bit longer to power up than others. If you look at the details you can see panel voltages which tell you if your panel is ok. I have 2 optimizers on my roof that don't pair intermittently when it's cloudy, but outperform others when it's sunny.

Ben

**sensij** · 07-20-2015, 12:05 AM

Originally posted by ecoalex

As you can see, later in the day, the generation appears to catch up, even exceed it's neighbors.

I would like to point out that the difference between the best and weakest panel in the first picture is only 60 Wh, which is 0.06 kWh. At the end of the day, you still have that much difference between panels, although maybe not the same ones. That is a very, very small amount of energy. I see no problem here at all, and most likely, the differences are due to the random timing the panels have in communicating their status. Since they can't communicate simultaneously, in the morning, when the Poa irradiance is increasing, the first panel reporting may be as much as 20 min ahead of the last, and would appear to be underperforming if you thought all panels were reporting at the same time. Later in the day, the opposite it true... the first panel reporting each cycle will appear to be outperforming the others.

**ecoalex** · 07-20-2015, 11:32 AM

2 Kw Difference

At the end of the day, there was a 2+ Kw difference. This is substantial- 2000 + watts.

End of day total 7.19.png

**SunEagle** · 07-20-2015, 11:34 AM

Originally posted by ecoalex

As you can see, later in the day, the generation appears to catch up, even exceed it's neighbors.

The temperature of the modules is lower when the few are reporting lower production,(morning) which rules out heat, or conversely, when they do heat up later in the day , something changes.
The idea of temperature and soldering makes sense, however at the end of the day, the performance of the questioned modules is equal, or better than the others.
I'm leaning towards the problem being the Solaredge optimisers on the 2 modules reporting to the #2 inverter.

Module #17 had an equal or better total at the end of the day yesterday.

A view at 5;15pm :

Sounds more like a timing issue on how each unit is reporting. If there was a production or wiring issue IMO the low producing one would still be lower then the rest at the end of the day.

Couldn't hurt to check the wiring and panel surface to see if there is anything obstructing the sunlight or reducing output.

**sensij** · 07-20-2015, 12:11 PM

Originally posted by ecoalex

[ATTACH=CONFIG]7301[/ATTACH]

In this image, the difference between the inverters is 1.31 kWh, about a 4% difference between them, and about 2% "loss" relative to what you would produce if both inverters were at the higher number. That may be enough to indicate a difference between the strings, but it is not necessarily indicating a problem, either.

Did your installer set up a public SolarEdge portal page? Would they do that if you ask (it is easy, and free)? Without a more consistent description of the symptoms, it is hard to help.

**posplayr** · 07-20-2015, 12:46 PM

Originally posted by ecoalex

As you can see, later in the day, the generation appears to catch up, even exceed it's neighbors.

The temperature of the modules is lower when the few are reporting lower production,(morning) which rules out heat, or conversely, when they do heat up later in the day , something changes.
The idea of temperature and soldering makes sense, however at the end of the day, the performance of the questioned modules is equal, or better than the others.
I'm leaning towards the problem being the Solaredge optimisers on the 2 modules reporting to the #2 inverter.

Module #17 had an equal or better total at the end of the day yesterday.

A view at 5;15pm :

[ATTACH=CONFIG]7294[/ATTACH]

Is it possible to either repost the figure showing the end of day Kw-hr for the 6 strings or just list the numbers. The figure you posted is illegible.

**ecoalex** · 07-20-2015, 12:53 PM

I Am Installer

Originally posted by sensij

In this image, the difference between the inverters is 1.31 kWh, about a 4% difference between them, and about 2% "loss" relative to what you would produce if both inverters were at the higher number. That may be enough to indicate a difference between the strings, but it is not necessarily indicating a problem, either.

Did your installer set up a public SolarEdge portal page? Would they do that if you ask (it is easy, and free)? Without a more consistent description of the symptoms, it is hard to help.

I am the owner/Installer.

The graphics you see are from the Solaredge monitoring portal.

The symptoms are diminished total for the day on String #2 compared to String #1. 2 Kws - 2000 watts, this is significant.

There is no obstruction, dirty modules. The connections on String #2 modules #4 and #17 are good.

**sensij** · 07-20-2015, 01:06 PM

Originally posted by ecoalex

I am the owner/Installer.

Great, then you can post a link to the public page! The troubleshooting discussion will go much smoother with access to the data and not just screenshots. It will also help if you can avoid conflating kWh (energy) with kW (power).

If the public page data isn't enough, I can provide a personal email address and you could add me as an owner (with report access). It wouldn't give me anything more than read access, but would make available some of the panel level data that would help clarify what is going on, including timestamps for individual data points. You could remove my access at any time if you felt like my observations were not helping you understand your system better.

Edit, if you are unsure of the data contained in the public link, here is a link to mine. Make sure to also include the "layout" for access to panel level data.

**ecoalex** · 07-20-2015, 01:36 PM

Thanks

Originally posted by sensij

Great, then you can post a link to the public page! The troubleshooting discussion will go much smoother with access to the data and not just screenshots. It will also help if you can avoid conflating kWh (energy) with kW (power).

If the public page data isn't enough, I can provide a personal email address and you could add me as an owner (with report access). It wouldn't give me anything more than read access, but would make available some of the panel level data that would help clarify what is going on, including timestamps for individual data points. You could remove my access at any time if you felt like my observations were not helping you understand your system better.

Edit, if you are unsure of the data contained in the public link, here is a link to mine. Make sure to also include the "layout" for access to panel level data.

I'm in contact with Solaredge, I believe they are my best avenue to find out if there is a problem, they can access my inverter thru the web, and make any adjustments to the inverter settings, also view the operation of the system.

I appreciate your offer,I was hoping someone could give me some insights as to why my production between the 2 strings has changed from a few months ago. The simple reasons; obstructed modules is moot, as I have been washing them, and there is no shading of the array.

Thanks again.

**sensij** · 07-20-2015, 01:39 PM

Originally posted by ecoalex

I appreciate your offer,I was hoping someone could give me some insights as to why my production between the 2 strings has changed from a few months ago.

Yeah, sorry. If you are unwilling to share the data, I have no insight to offer. If only SolarEdge has access to it, and you will have to rely on them. Good luck.

**J.P.M.** · 07-20-2015, 02:46 PM

Originally posted by ecoalex

I'm in contact with Solaredge, I believe they are my best avenue to find out if there is a problem, they can access my inverter thru the web, and make any adjustments to the inverter settings, also view the operation of the system.

I appreciate your offer,I was hoping someone could give me some insights as to why my production between the 2 strings has changed from a few months ago. The simple reasons; obstructed modules is moot, as I have been washing them, and there is no shading of the array.

Thanks again.

Seriously, maybe the washing knocked something loose/changed something.

Poor Module Performance

Poor Module Performance

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment