installing different voltage panels

[rdg469]

I currently have two Siemens model SP130-24P panels hooked up in parallel. I would like to add two UniSolar US-64 panels in series to this system. Will this work?

This is an off-grid application in Mexico.

Thanks for any help you can provide.

[sensij]

Depending on the compatibility with the rest of your gear, you have two reasonable options:

1) Put each of the UniSolar panels in series with each of Siemen's panels, giving you two strings at 49.5 Vmp and 3.9 Imp, giving 49.5 V and 7.8 A combined.
2) Put the UniSolar panels in series with each other, created a 3rd string in parallel to your other two. Each of those strings would be 33 Vmp and 3.9-3.95 Imp, giving 33 V and 11.8 A combined.