What is the first issue likely to occur in your solar panels? Micro cracks. Chances are you may even have such nasty defects from day one without even knowing. Virtually unrecognisable to the human eye, solar panel micro cracks often evolve to greater issues.

Firstly, what causes solar panel micro cracks must be understood as the source will often vary initially. Cell fractures are a common issue faced by solar panel manufacturers and system owners alike, before and after installation. Understanding prevention on all levels is the best means towards avoiding a cure.

Micro Cracks - Solar Review

Note:

As a more accurate description, solar panel micro cracks should be referred to as solar cell micro cracks or cell fractures. However more general search terms refer to solar cell fractures as solar panel micro cracks.

Causes.

Micro Cracks - Solar Review

Solar panel micro cracks can occur within 3 stages. During manufacture, during transport/ installation and when the solar panel is subject to it’s installed environment. Occurrence within either stage is quite simply due to stress. 

Manufacturing.

Manufacturing will subject selected cells to fracturing. There are several quality testing methods one can employ to identify micro cracks. Notable of them is electroluminescence (EL) or electroluminescence crack detection (ELCD) testing.

EL testing is a process that makes use of image analysis and measurement which enables it to see directly into the solar cells to locate potential defects inherent. EL testing can discover hidden defects that were not detected by other testing methods, such as infrared imaging with thermal cameras, flash testing, and V-A characteristic.

Ideally, EL testing is carried out once before lamination to identify and replace the defect solar cells, and it is also repeated after (careful) lamination.

This could be a time-consuming procedure and requires extensive resources which some PV manufacturers are not willing to undertake, but it is necessary to produce quality solar panels.

Transport/ Installation.

Often the cheaper you go, the higher your susceptibility to solar panel micro cracks. Low cost Tier-1 manufactured solar panel brands poses minimal protection toward the prevention of stress fractures. In turn, the lower the purchase price, the cheaper the warehousing transportation and installation channels.

There is virtually no way of identifying solar panel micro cracks when a solar panel arrives on site initially. This is a crucial stage where selecting a reputable installation company is the key.

Environment.

Natural factors (mechanical and chemical) which stress the panel operating in areas such as snow, hail, severe cold, wind, and sun will cause micro cracks in selected panels. Other stress factors can be attributed to the cells thermal cycle which involves expanding, contracting, stretching metal contacts, and wire interconnects.

Advanced construction techniques implemented by selected manufacturers can assist in the prevention of solar panel micro cracks occurring from environmental factors. 

Side Effects.

Micro Cracks - Solar Review

Although it’s almost impossible to avoid micro cracks in the long-run, their potential side effects could lead to a serious issue if not addressed as early as possible.

Soft Outcomes.

Soft outcomes mean a defect that affects the reduction of yield, efficiency, and short circuit cell efficiency. Soft outcomes occur due to mechanical forces or thermal stress. In the process of production, micro cracks do occur mostly while laminating the panel, especially when certain EVA films are used with weak moisture impermeability.

In scenarios like this, even slight moisture cannot evaporate easily which poses a challenge in hot areas and environments. In such cases, the moisture passes through the micro cracks on the front of the laminate, and then oxidization of the contact fingers follows.

High Resistance.

Solar panel micro crack will lead to higher cell resistance. Just like water, electricity follows the path of least resistance. Fractured cell sections ensure electrons are forced to use alternative (congested) paths, just like a busy freeway/ highway. Consider when the sun is shining at the optimum time of day it’s basically peak hour for electrons. You need your solar panels to be built like a city with an efficient transportation system for maximum energy production. 

Lifespan Reduction.

Left undetected, solar panel micro cracks will lead to a less than expected lifespan. A reduced lifespan will affect return on investment calculations, overall performance and the proposition of premature replacement arrays. Replacing affected singular panels is often not an option due to electrical characteristic changes over time.

Snail Trails

Micro-cracks may appear visible on the panel in the form of so-called snail trails. However, one needs to note that snail trails are a sign of a long-term impact which is being caused by a chemical process leading to changes at the cell surface.

Prevention.

Micro Cracks - Solar Review

To effectively prevent solar panel micro cracks the 3 key areas must be addressed; manufacturing, transportation/ installation and environment (Manufacturing construction). Selecting a solar panel manufacturer which acknowledges the prevention of microcracks in it’s build quality is 2/3 of the solution.

A reputable manufacturer certified installer is the final part of the prevention toward solar panel micro cracks. Certified installers must purchase solar panels through the authorised distribution channels. Such channels are often in place to uphold the integrity of the solar module from manufacture through to installation. If your preferred solar module lacks certified installers, then maybe that particular solar panel all it’s cracked up to be.

Got insight?

Don’t forget to share your insight or questions below in the comments section!

2 COMMENTS

  1. Hi there, I have JINKO solar panels that are around 4years old. In the prevention photos just above I have exactly the same as the bottom left picture. Out of our 22 panels we have, at least half of the panels have them and there’s 45-50 of them scattered around, some panels with 10 on them, others with none. WIERD!! So I sent photos of them to the installer, they were curious, so they thought they should come and have a look and them, then proceed to tell me they are snail trails and there is nothing to WORRY about and then wanted to charge me $120 for a so-called system check without any consent. So I’m basically concerned about going forward and if I am getting full capacity out of my panels and if it is a warranty issue.

    • The best thing you can do is consistently log system performance over time. Also, keep a photo log of your solar array at regular intervals if possible overtime. The difficult scenario your in though is neither the manufacturer or the installer will want to take responsibility should the scenario worsen.

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