Guys, I have 6 strings on my system in Australia due to roof orientations.
I have 1/2 cut 370w panels - Canadian Solar that go to two Solis inverters.
The string giving me problems has 13 panels on it - 6 of them with optimisers.
The 6 panels with optimisers are laid in a horizontal plain - whilst the other 7 are a mixture of Horizontal and Vertical.
The sun creeps across (due to being on the low side of the street) until mid morning - it is shading the whole length of the horizontal panels and slowly works its way down throughout the morning.
We installed the TIGOs on these panels with advise from the sellers in the belief that the TIGOs would essentially isolate the panels from the string - allowing the 7 unshaded panels to produce at full capacity and to gradually add the capacity of the shaded panels and the sun progressed - this is not happening
The whole string is bought down with extremely low current until all of the panels are free of shade.
What we have done so far to try and resolve this
1) Remove the optimized panels from the string - i.e bypass them entirely - result was that the 7 remaining panels operated as expected as they were in full sunlight - so we feel that proves that these panels are working fine and working with the inverter (we have 50 of these panels) - this also proves that electrically that string is fine
2) Removed all optimizers from the 6 panels and added them back into the string - we found that when this was done and the 6 panels were shaded - the Bypass Diodes worked as expected and the string continued to output as per 1) above. As the sun moved and exposed a whole set of 3 panels (they are laid as two rows of 3 panels) then they "joined the string" and added their power to it
3) Added optimizers to the top 3 panels (the ones that come of out the shade last) and the string was dragged back down in production until all panels were in the sun again.
We initially thought we had a faulty optimizer so we used two spare that were for another part of the system - (yet to be installed) and swapped these in with no change in result - we moved them around until all 3 of the units had been replaced and still the same result
We were at a loss until we found this article
We then posted on a local forum and have had a number of people come out saying that they believe they are seeing less than optimal performance from the TIGOs
Essentially it appears (from the article) that until the firmware is updated and the correct panel/inverter combination is chosen through the CCA software that less than optimal results could be experienced with non monitored TS4-AOs
Can anyone add anything or comment further ?
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