I am about to purchase one MPPT controller to operate two flexible panels each at 100W. I realize that one panel – one MPPT is optimum, but, in the meantime I wish to connect the two panels in parallel because of shading from my boom. Next year I get two more 100W panels and another MPPT – so that I will have two 100W panels in series per controller. Panels are rated at 5.68A. What size of controllers are best for this present plus future expansion? Is this scenario a good one? - David
With two 100W solar panels wired in series, one MPPT controller that can handle the combined series voltage and amperage is what you need. For instance the Victron MPPT 75/15 is well suited to handle two 100W panels wired in series.