Hey everyone! I'm currently working on completing my 25 kW off-grid solar installation, but I'm short six 400 watt panels. I'm considering using four 600 watt panels instead of the six 400 watt ones. My plan is to wire them in series on the same string. I am aware that there might be some efficiency loss, but this would just be a temporary solution while I wait a couple of months for the arrival of the 400 watt panels. Any insights or experiences with this setup? Thanks in advance for your advice!
3 Answers
Wiring mismatched panels can be tricky. If the 600W panels have similar voltage to your 400W ones, then they’ll likely end up producing around 400W too, because the 400W panels will limit the overall output. Since this is just a temporary fix until the new panels arrive, I’d say go for it! Just don’t expect to get the full capacity out of those 600W panels during this time.
It's best if the panels in series have roughly matching amperage, though voltage can vary a bit. You could place the 600W panels at the end of the string with the 400W panels, which might help maintain a more balanced output. But honestly, if you’re replacing them later, it might not be a huge concern.
If it's just a temporary setup, you could even just leave the wires in place of the six missing panels. That way you won’t have to worry about mismatching at all!