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The International Energy Agency Photovoltaic Power Systems Program has for decades produced wonderful, high quality research.

Australian’s are historically, very strongly  represented amongst the committed individuals who have contributed invaluably to their research and its worth browsing their web site for all manner of fascinating information.

Recently I stumbled across a report produced late last year which analysed the issues associated with cracked cells in modules.

Having worked for a PV manufacturer and with a number of clients who manufacturer, I know a little about the reality of cell cracks. Its not a  huge issue but it is an issue and it is one of the tiny details that can differentiate a really great product that will last a lifetime with minimal degradation, from one that has been handled poorly, will degrade quickly and unfortunately, may not be immediately obvious.

In summary the report found that through real world sampling of 103 “as delivered modules”  cell cracking was evident in 6% of cells, in the modules delivered.

However, it is important to note that the type of crack really matters – in terms of an impact on power output and or long term degradation rate. They noted that “The predominant crack classes are “cells with more than one crack direction” and “cracks parallel to the busbar” and that “cracks parallel to the busbar may degrade the module power most”.

The report notes that they found this rate “a bit surprising” and came to the conclusion that a “a special but common event, for example high mechanical loading during transport” may have occurred.

Quality manufacturers use electroluminescent imaging to check for cracking during production these days, but the report does not describe the manufacturers sampled or whether they use this technique. It does say “We explicitly accept that there are additional cracks which are not initiated by transport” however, suggesting they had some insight into the issue.

For my money, that would be the “golden nugget” in the report; differentiating the results between those who have made the investment in electroluminescent imaging and those who have not.

This issue aside, it does highlight that transit damage is real, as tough as these things are. Investing in expensive equipment for precise handling of cells, test equipment, packaging and transport costs might seem like minor details when price is all so important,  but in the long term these things can really count.

Its proven.

Image Credit: Olegusk/Shutterstock