What is my best array set-up for 20 405w panels

[AlbaCORPS]

I'm looking to do my best set-up for (20) Q-cell 405w panels to a Growatt 12kW inverter. Being a newb to all this & still learning, I'd sooner swallow pride than make any grave mistakes.
So my question..... Whats my way to hook all this together? How many in series/parallel for how many strings? I'll attach pics of specs if that helps



Any & input is appreciated & TIA

 

[Hedges]

Panel Voc 48.1V, Charge controller 150V max. MPP operation 60V to 145V.

The only safe, working configuration is 2 panels in series. So 2s10p.
3 in series would only be within voltage limits at nominal temperature, voltage too high on a cold day.

That is 8100W (STC) of panels, slightly over maximum 7000W indicated for charge controller. Probably not a problem, but it does give charge controller an opportunity to hurt itself if it wants to.
What I would like to do is 2s5p of one orientation, another 2s5p of a different orientation. That will reduce peak power and extend hours of PV production.

 

[AlbaCORPS]

Thanks Hedges, a lot
Due to the suns path & roof orientation, they would be in sun from 9am-5pm. I hadn't thought about doing a different orientation for a string (duh)?....love it tho.
So with your advise & getting me rethinking, 2 strings of 2s4p, then a 2s2p in a different orientation (space available). Sound about right? At least until I can add another inverter to go bigger.

 

[Hedges]

Consider your battery's preferred charge current and program the system accordingly. My PV could charge my AGM batteries at over 0.5C, but I've set them for 0.2C. The additional power is available for AC load or backfeeding the grid.

If you have lithium, it can take a higher "C" rate, but only around nominal temperature. You can select a max charge current and a minimum temperature for charge-disconnect by the BMS such that batteries aren't degraded. I've seen lower temperature charge specs for some, down around 0.15C or 0.07C for temperatures around 5 or 10 degrees C. I figure charge rate of 0.15C is enough to fully recharge a battery during one full sunny day, so most off-grid use I think can get by with such reduced charge rates, to tolerate cooler temperatures. If running a generator, would want high charge rate but also ensure warm battery.

Multiple PV angles extends the hours available for charging.

 

[AlbaCORPS]

Understood, I'll find that info in inverter manual & set accordingly. Currently the battery bank is 48V FLA (-4°F to 113°F)/ (-20°C to +45°C). The plan is upgrading to 48V LFP in the future.

 

[MrM1]

Did you purchase the inverter yet? If not, why not purchase the 250vdc model and then you could run panels in a 4s config.

If you did buy it already, how have you see it up?

Has anyone figured out the 2 PV inputs? Are there actually 2 60 amp MPPT controllers inside? Do you have to have 2 arrays?

 

[AlbaCORPS]

Did you purchase the inverter yet? If not, why not purchase the 250vdc model and then you could run panels in a 4s config.

If you did buy it already, how have you see it up?

Has anyone figured out the 2 PV inputs? Are there actually 2 60 amp MPPT controllers inside? Do you have to have 2 arrays?

Yes I pre ordered it, yet still not here. The plan was/is 2 arrays

 

[ghostwriter66]

Panel Voc 48.1V, Charge controller 150V max. MPP operation 60V to 145V.

The only safe, working configuration is 2 panels in series. So 2s10p.
3 in series would only be within voltage limits at nominal temperature, voltage too high on a cold day.

That is 8100W (STC) of panels, slightly over maximum 7000W indicated for charge controller. Probably not a problem, but it does give charge controller an opportunity to hurt itself if it wants to.
What I would like to do is 2s5p of one orientation, another 2s5p of a different orientation. That will reduce peak power and extend hours of PV production.

I know that typically the better SCC's are "underrated" BUT 8100 being pushed continuously through a 7000 - even if its only for a few days a year -- is going REALLY push the limits of this SCC .... YES i know that the panels really only ever get about 85% of their rated output BUT there has been times that I have hit literally 98% and my equipment was glowing - to the point where we were knocking panels offline ...

Just food for thought ... my gut says - screw it - go for it ... BUT YOUR wallet may disagree after having to buy another SCC ... you could always add a small SCC and take 4 of the panels off that string and connect it to another SCC