Figuring My Panel Wiring ?

[GregM]

I have 32 Solar Panels and I need help in figuring out how to plug them in to my Grid-Tie inverter.

The panels are 370 watts each.
Here is what their brochure says.





The inverter is a Growatt 11.4kw Grid-Tie unit.
Here is what it's brochure says.




I need to figure out the wiring of the panels so it does not exceed the inverter's input.
Is there a software program that can help in the figuring?
Or maybe someone who is a hobbyist that is good at figuring this type of thing out.

Thanks
Greg

 

[shvm]

Your Solar Panel (370Wp) stats are:

Voc = 41 V, Vmp = 33.92 V
You've got 32 of these.

Your Inverter Solar MPPT stats of concern are:
"No. of MPP Trackers" as 4
"No. of PV Strings per MPP Trackers" as 2
Operating Voltage range = 50 - 550 V, Nominal = 360 V
Max DC system voltage = 600 V

Calculations:​

16 panels in series would exceed your 'Max. DC system voltage' as 16 × 41 = 656 V.
The only next logical step would be to have 8 panels strings with Voc as 8 × 41 = 328 V which is well within the Operating voltage range of each MPPT.

You will get 4 individual strings of 8 panels in series which can be connected to each of the 4 MPP Trackers of your Inverter.

 

[pvgirl]

2 options:

• 8 in series connected to each MPPT tracker
• 2x 11 in series, and 1x 10 in series strings each connected a MPPT tracker, leaving one tracker available for future expansion.

 

[shvm]

2x 11 in series, and 1x 10 in series strings each connected a MPPT tracker, leaving one tracker available for future expansion.

I never thought it in a smarter way like this. This is the recommended way to go !!

 

[GregM]

2 options:

• 8 in series connected to each MPPT tracker
• 2x 11 in series, and 1x 10 in series strings each connected a MPPT tracker, leaving one tracker available for future expansion.

The array I planned (so far) to build is 8 columns and 4 rows.
So I would put each row in series and combine them at the inverter?
I'll have to look up what an MPPT tracker is.

Thanks for your brain time!
Greg

 

[pvgirl]

The array I planned (so far) to build is 8 columns and 4 rows.
So I would put each row in series and combine them at the inverter?
I'll have to look up what an MPPT tracker is.

Thanks for your brain time!
Greg

The MPPT tracker refers to the 4 separate inputs on the inverter. connect 8 panels in series either 1 row or 2 columns, and connect to one of the inputs on the inverter, repeat for each set of 8 panels. Dividing the array in to 2 column sections may reduce the impact of shading that effects one side of the array, during the beginning or end of the day. If one side of the array has some shading if divided up in to rows all 4 strings will be impacted by the shading, in groups of 2 columns only the strings at the end of the array will be impacted by shading.

 

[GregM]

PS
If it helps....
Since I have not built the array yet I can always reduce the number of columns to 7 etc

 

[GregM]

2 options:

• 8 in series connected to each MPPT tracker
• 2x 11 in series, and 1x 10 in series strings each connected a MPPT tracker, leaving one tracker available for future expansion.

Care to recommend a brand?

 

[pvgirl]

Care to recommend a brand?

Your growatt inverter has 4 mppt built in so no separate equipment is needed.

 

[GregM]

Huzzah!​