Evergreen solar panel failure

Dapdan

All,

There is a company located in Florida that was very popular in mid 2000s and 2010s and alot of sales were typical made with Latina America and the Caribbean. I was one of those that both alot of equipment from them, 100s of panels. The panels were attractively priced and were the off-grid type having 18, 36 or 72 cells. The very popular one was the evergreen panels that soon became a store brand without the evergreen branding but had the trademark rectangular cells. I can tell you I am very disappointed in their long term performance and would say that they have failed miserably. 

I am now noticing a 50%, yes you read correctly, a 50% reduction in power output. I installed and sold many of these panels and at least two other persons with the exact same panels have reported the similar observation. As a comparison I both some Kyocera (130 and 140 with MC3 and junction boxes) that are performing nearly as new and they are at least 3-4years older. I started buying these panels from this company around 2009/2010 between $2 and $2.5 per watt back in the day and they purported 20-25year performance to 80 or 90% rated output. They have failed miserably. 

I can tell you the reason is probably failure of the eva encapsulant as I was noticing a rust brown cast over all cells on the panels for a few years now but didn't pay much attention or wasn't really concerned until I was doing some mainteance on my classic CC when I saw the dramatic reduction in output. I checked all the wiring and even repaired some area where it was breaking down. I checked back a midday and it was same diminished output.

I am now not so sure if I should pursue a claim on warranty with said company. I know that evergreen label has all but disappeared as I have not seen them on the market for a while. Are there any members on the forum that have had this experience first or second hand. Please give me your thoughts, opinions or even recommendations.

thanks much.

D

littleharbor2

I have had some experience with Evergreen panels. While any real Evergreen branded panels have been out of production for probably 20 years the ones I have dealt with are still looking great. I bought a couple pallets of used 205 watt 12 volt panels from Santan Solar a couple years ago. They looked nearly new. My next door neighbor has 4 of the 205 watt 12 volt panels on his roof and they are looking and performing great. Keep in mind, the extreme heat we're experiencing right now will really take it's toll on panel output, also panel tilt has a lot to do with current production. Mine are at my 31 degree latitude so summer output suffers. I'm lucky to get 1300 watts from my 2100 watt array at this time of year.

As to the off branded, string ribbon celled panels out there they may have cut some corners in an attempt to stay competitive in the rapidly evolving PV tech of the time.

Dapdan

It is hard to say what is truely a "true" brand. I can tell you from my research the degradation of the eva encapsulant is real and it is quite obvious on my panels. Right now I am at 13 deg north and we just past the summer solstice so the sun is nearly overhead head towards 13deg to south for the winter solstice. My panels ar around 5-7deg facing the south so I would be getting nearly maximum irradiation at this time of the year. I use to religiously check on their performance when they were younger and would get around  3200w max for a 3600w array at this time I am barely scraping 1600w max when I checked a few weeks ago. Yes we are having high highs around this time but it cant explain a 50% drop in output. The highest ambient we have been getting in Barbados is around 31/32C (90F) so it isn't as bad as in the States. Yes, string ribbon was the term I was trying to recall.

Do the ones you are dealing with have the brownish or yellowish cast over all the cells. Mine have also developed "snail trails". Interestingly, directly over the snail trails the brownish cast does not occur. Mine are between 190w and 210w depending on the specific model, at 18V mpp. So disappointed.

littleharbor2

All the Evergreen panels I handled didn't have any bronzing of the encapsulant. nor snail trails. I know exactly what you are describing as to the bronzing. I have multiple panels with plenty of it. It looks to be heat related because it is only where there is energy flowing. Are you sure the snail trails aren't microcracks? that would sort of explain the lack of bronzing along them.

Dapdan

I am sure the trails are micro cracks. The panels were constructed using "non perfect" cells that had some cracks and chipped ends and the finished produce was not perfect (i.e. cells didn't line up exactly) but they output the exact power or more when "new". In fact that was part of their marketing saying that it was just "a sheet of glass and didn't have to be perfect..." guess some of us are paying the price now  , can find a angry emoji.

littleharbor2

Dapdan

  

Dapdan

I am humbled by your expertise in emoji

Photowhit

Well I'll call BS across the board! I bought Evergreen panels in 2004 which I sold to a friend and are still producing nicely. 

2011, I bought some of the last batch that were as I recall from my feeble mind, were produced in Tawain from US or German Cells (the string ribbon tech was pretty neat!) In an odd deal they were shipped to Europe and the company went from Chapter 11 to dissolving (Chapter 7?) Without apparent warranty Sun Electronics bought the remaining shipment which didn't qualify for lucrative Tax incentives in Europe, some 110 containers worth. 

My pallet load from that period always produced around the normal NOCT value of 75-80%, we had a late cloud escape a couple months ago and they were producing around 2500 watts from the 4000 watt array, while in bulk ('around' because I have added 500 watts of other panels and was close to 2900 watts production) About what I would expect from a 10 year old array.

I believe a China company bought up the remains of the company for the string ribbon technology, I think Sun electronics was warrantying them.

If you were getting 3200 watts from a 3600 watt array during noonday sun in the tropics, Don't "Bogart" that joint my friend!

Dapdan

Sir,

Unlike you I respectfully object. You calling BS is meanless catch phrasing. I monitored these panels nearly every day when they were new and they are all the 200w type. Right now I can't even get more than 100w per panel going through a classic 150 and I have been looking at the CC data every week for pass 6 weeks when I noticed the output power from the CC. Please see attached " real " evidence of the failure and continue your assault on something that I have more evidence on.

The panel out in the sun for the past12-13 years have the brownish cast. The panel below it is the same panel except never used as I had it in storage for the past decade or so. I had all panels from new, direct from US supplier at a not significant cost as they had to ship twice by ground to freight forwarder and then by ocean and truck to me. So panel work out to be more expensive to those who can not necessarily afford it.

D

Dapdan

having some issue attaching pic. 

BB.

I have had failed solar panels that had that "browning" over an overheating J-Box (eventually, panels were replaced under warranty).

But I also had "brown staining" from leaves/water "tea" drying on panels that looked very similar to overheating/browning. Soap and water did remove the staining (typically also saw this staining near frame edges where water "tea" would collect and dry).... I don't think this was the issue with your panels.

-Bill

Dapdan

Thank you BB. I thought the picture would silence the nay sayers. I don't come on this forum to BS anyone. I seek to share my experiences and observations with the forum with the hope it could assist someone. I also seek assistance and recommendations at time from a group of wonderful, experience, generous and open people. I did contact the owner of the company and took many photo and vides for him as he requested (did it last week friday) and I am waiting to hear how he would respond. I made no demands or gave him any ultimatums just want to see how it will pan out organically. It is really disappointing tho as i consider my roof spaced very valuable real estate. The idea of panels up there getting worst and working inefficiently could get distressing especially when you think if this would happen to another set of new panels as you really could never know and have to let time tell. My confidence has diminished especially when China and India has flooded the market with low priced panels and you really wont know what you may get. I just thought the person on this forum should  be aware of poor quality eva encapsulants and by extension pv modules that maybe circulating as PV manufactures cut corners in a bit to be price competitive. 

Thanks again BB. 

Dapdan

Gentlemen,

I reached out to the owner and engaged him via WhatsApp giving video, photo and power harvest data on the performance of his house branded product. It started out well and ended badly with him accusing me of all manner of things. I really wasn't expecting much in terms of warranty but I wasn't expecting abuse. I would just advise installers, DIYs to be cautious of what they buy and who they purchase from in terms of "claimed performance" and warranty promises. This is why I love dealing with companies like Midnite Solar who are accessible and manufacture their equipment. I am sure there others like them out there but they are at the top of my list. You live and you learn.

OutsourcedGuru

Honestly, it looks like water vapor got inside the panel itself and began a slow process of corrosion.

DanS26

Before damning the panels......have you checked every connection for corrosion or high resistance?  While you are doing that test each panel individually to maybe find one or more poor performers in each string.

When you reconnect use "silver conductive grease" sparingly on each connection.  Not to be confused with dielectric grease which will have the opposite effect.

chugachrich

Hi folks,

PhD student researcher who has inspected more than 10,000 PV modules over the past 20 months. It is highly unlikely that the encapsulant browning is causing this kind of degradation - more like just a few percent. I find it interesting that this is an off brand rather than Evergreen. The Evergreen modules I have inspected have mostly performed very well with the exception of one that had two hot cells.

You will see photobleaching (reversing of the EVA browning) where microcracks allow oxygen to seep through the backsheet (which i not a hermetic seal). Over time, these cracks can propogate and expand. Depending on where they occur in a cell, it can isolate portions of that cell from producing power. 

If you wish to identify more of a root cause, you can ship some modules to me at the Solar Reuse Test Lab for more detailed analysis including electrical characterization, UV fluroescence and electroluminescence imaging. https://www.equitablesolarsolutions.org/research

My gut feel is that the cells might have been left over from Evergreen and picked up by another manufacturer. I suspect poor ribbon solder connections or even failed bypass diodes for this level of performance fallout.  

Happy to do some analysis at no cost since this supports my PhD research.

Regards,
Rich

littleharbor2

chugachrich said:

Hi folks,

PhD student researcher who has inspected more than 10,000 PV modules over the past 20 months. It is highly unlikely that the encapsulant browning is causing this kind of degradation - more like just a few percent. I find it interesting that this is an off brand rather than Evergreen. The Evergreen modules I have inspected have mostly performed very well with the exception of one that had two hot cells.

You will see photobleaching (reversing of the EVA browning) where microcracks allow oxygen to seep through the backsheet (which i not a hermetic seal). Over time, these cracks can propogate and expand. Depending on where they occur in a cell, it can isolate portions of that cell from producing power. 

If you wish to identify more of a root cause, you can ship some modules to me at the Solar Reuse Test Lab for more detailed analysis including electrical characterization, UV fluroescence and electroluminescence imaging. https://www.equitablesolarsolutions.org/research

My gut feel is that the cells might have been left over from Evergreen and picked up by another manufacturer. I suspect poor ribbon solder connections or even failed bypass diodes for this level of performance fallout.  

Happy to do some analysis at no cost since this supports my PhD research.

Regards,
Rich

Has your research covered "Snailtrails" and if so, what can you tell us about them that we may not already know?

JRHill

My 15yo strings of Suntech 195 are suffering a bit more each year. They don't have any discoloration but at least 1/3 of them have a crack or two in the glass. But on a cool day with bright sun and a little air movement they will come close to full output. But in hot weather is when they suffer more for output.

After installation I was so happy with them I bought a few shares of Suntech. That was a major failure.

littleharbor2

Are they putting out anything near 70% in the heat of the summer?

JRHill

littleharbor2 said:

Are they putting out anything near 70% in the heat of the summer?

Not quite that. S'ok though. It's enough to have filled the batteries by 3 or 4:00.

Monstervi

I had a similar experience with some older panels I bought back in the day. They seemed great at first, but after several years, I noticed the performance wasn’t holding up as expected. It can be really frustrating when you’ve trusted a brand that doesn’t live up to its promises, especially when it’s such a big investment.

JRHill

Just a thought, but another thing is data. Consider the green bar:



The annual dropping in solar harvest is expected but also the most recent 'bomb cyclone' in the last week. These things happen. Right now we are on a continuous low fog which obliterates what little solar we might have harvested. There is no cloud edge right now. Even in a normal year that disappears before the solstice. I mean, dang, 3.3kWh is the high for the week before Thanksgiving? These things are usually explainable and, no, it's not just the panels getting old.

BTW, our consumption is through the roof because I have family here doing a project and using larger power tools and late into the night shop stuff. Even still we'd be on generator this time of season but not near so much. If I have any immediate evidence its the increase in oil change intervals for the genset. Oh, and fuel.

Bottom line is if there's no solar to harvest its not the panels' problem. But in the heat of the summer it's a different thing.