Dear community,
I want to add four 590W panels to the roof. Before there were already 12 of them, 3s4p. Would you advice that I swap my MPPT150/100 for an MPPT250/100, to create a 4s4p, or instead get 2 additional MPPT100/20 with 2s1p each? All panels have the same orientation, but the shadow situation is complicated.
Pro buying two small MPPTs (instead of a Smart Solar MPPT250/100)
+ Having more MPPTs could be a benefit when there are difficult shadows
+ I understand that the maximum output of MPPT150/100 and MPPT250/100 are actually the same (5800W at 48V), so having three MPPTs would increase the theoretical maximum peak
+ Probably cheaper than selling the used MPPT150/100 and getting a new one
Against buying two small MPPTs (and for getting a MPPT250/100)
- adding one of the panel to each paralleled string would also help with the shadows, no big advantage of extra MPPTs
- having separate MPPTs means longer cables at lower voltages (2 more strings with 2 panels with Impp=17,25A open Voc=41,2V each) - thus, higher loss
- MPPTs might switch on a bit later, when only two panels in series
Any recommendations?
Thank you
