Is this configuration of panels the most optimal setup?

[solitarysecluded]

Hey guys. You probably heard it many times. Anyway appreciate your inputs.

I'm planning my initial setup and gradually add more panels later. I'll be using two inverters SPF 5000 ES in parallel and one 48V battery rack.
My panel specs : Qcell 410w

• Isc : 11.22A
• Voc : 45.13V
• Imp : 10.76A
• Vmp : 38.11V

My questions,

1. 4 panels enough to startup MPPT ? Weather range 18c - 28c yearly
2. 10 panels in series for each inverter is best configuration? as it less than 450V, 18A limit.
3. 10 panels each on two different roof facings. Should we mix 5 panels from 1st roof, another 5 panels from 2nd roof? Or retain 10.

My guess is 10 panels on same roof same inverter will give the whole system some slack instead of constant "heavy" work?

 

[sunshine_eggo]

1. not sure what you're asking.
2. No. You will exceed 450V. 9S max if your annual low is truly 18°C
3. All panels in a series string must be facing the same direction. You could have 9S one 1st roof in parallel with 9S on the second roof, but you couldn't split a string of 9S between the roofs.

You could probably exceed the 18A limit safely. IIRC some of these 18A limited units publish a higher Isc limit of 22.5A, but that's based on a vague memory. In other words, a 9S2P array may be okay. 450V will never be exceeded and the 18A limit is what the inverter will pull - it will ignore anything over that, but there may be an upper limit.

 

[solitarysecluded]

Thanks for the reply sunshine.

I meant minimum panels required to have the inverter start working.

I see. So if I go for 9S2P per inverter, I would have 21.52A which exceeds 18A but that would be fine ya?

So with 2 inverters, max I can have is 36 panels. Alright. Thanks!