String of multiple panels wired into one optimizer?

[Hendo1337]

Hi solar crowd,

I have a question regarding a planned setup of panels that would require the use of optimizers but given their price tag, I am wondering if I could do wire mutiple panels on a string into a single optimizer?

The reason for this is:

I have a south facing roof space and an east facing roof space. The big south facing roof has a top row of 5x 465W Panels and a bottom row of 5x 545W, the east facing roof has a another 4x 465W panels which are currently wired into one string going into MPPT1 of my Solis Hybrid Inverter (6kW).

The 5x 545W panels are wired into a flat roof system located on my garage, which are positioned towards due south at the same angle as the roof mounted panels.


If you haven't guessed it already, as soon as the sun moves towards south west, and then west, 4 out of the 9x 465W panels are sitting in the shade and my overall string performance ein MPPT1 drops significantly as I did not use any optimisers.

Now to my question: Would I need to add optimisers in between each of those panels on that string, or could I simply put one optimizer in between the south facing (5 panels)
and east facing (4 panels) facing array?

Thanks a million in advance,

Hendrik

 

[MisterSandals]

panels which are currently wired into one string going into MPPT

panels are wired into a flat roof system located

So what exactly is "wired into"?
Is this a series connection, a parallel connection, dead short or ??

 

[GregTR]

What optimizer are you considering? Tigo's spec sheet limits to 80V Voc and 15A continuous current with a max power of 700W. This essentially limits its abilities to a single 465W panel.

Optimizers are meant to fix current imbalance within a single string of panels in series by lowering panel voltage and boosting panel current to the highest current within the string. Additionally it will match string voltages of parallel strings by lowering voltage and increasing string current to match the voltage of the lowest producing serial string in a series/parallel combined configuration.

Using them selectively will only work if the panels you put the optimizers on are the problem in your string, meaning reducing their voltage and boosting their current helps in the aggregate. Adding optimizers to a single panel in a series string will help that string. Adding a single optimizer to a string that is wired in parallel to another string and it goes to the MPPT as a XsYp configuration will not help with optimizing voltages between the two parallel strings. You would need optimizer on every single panel in the string which's voltage needs to be lowered to match that of the other string.

Sounds like you have a setup where strings are facing different directions with possibly different slopes and likely with different number of panels in strings in parallel you would definitely benefit from optimization or a revisit of your setup for a better placement or combining of the panels.

There was very limited information provided in the original post so the advice is limited in completeness or value.