4 series 2 parallel ocv difference

[Scot-Cameron]

Hello fellow solar people, i have just finished fitting my solar panels, all the same brand new, east west facing, 4 series each side, the ocv on the east side is 141v and the new west side just fitted is 128 ocv, about 13 volts of difference, my question is should i chase the voltage difference or just carry on with it, I expected a few volts of difference but not that much. Was going to test each panel today to see if one is low today but not sure if im just wasting my time chasing it.
Thank you
Scot

 

[littleharbor2]

The difference is not surprising. The cell temperature of the panels on different sides of the roof is likely the reason for the difference. Do you have dual MPPT inputs on wherever you are connecting to?

 

[Scot-Cameron]

Hi
I only have a single input hybrid inverter to use just now, been reading up on the best way to connect, will try both so ive arranged it so i can change from 8 in series to 4 series 2 parallel without much hassle. Its on my garage roof and the apex / pitch is very low, not like a house, If no good will look at dual input, Its all new to me so treading carefully. Will get on with the rest of my wiring if it seems ok. will check again when the sun is shining equally on both sides as the day proceeds along with a temperature read of each side.
Thank you
Scot

 

[littleharbor2]

Better to put the two 4s strings into parallel. The small voltage difference won't hurt. In series your current will be whatever the lowest panel's current is, Not good.

 

[Scot-Cameron]

Okay, I understand, will do, Been about 6 months reading up, getting close to that solar cup of coffee, exciting stuff.
Thank you