Mixed solar panels?

[KMAG YOYO]

Hi, I have a big 190w panel that was designed for grid tie so it's high voltage, 32v I think. I'd like to add more solar, but chances are I won't find a match to this panel. Is it okay to mix and match? Is it better to run parallel or series?

The panels run into an MPPT charge controller so higher voltage isn't an issue.

 

[29chico]

Hi, I have a big 190w panel that was designed for grid tie so it's high voltage, 32v I think. I'd like to add more solar, but chances are I won't find a match to this panel. Is it okay to mix and match? Is it better to run parallel or series?

The panels run into an MPPT charge controller so higher voltage isn't an issue.

Providing you don't exceed the input limit on your MPPT controller I would buy another grid tie panel or two and wire in parallel with your existing panel.  Parallel wiring will perform better in partial shade.

Right now the best cost to watt values in grid tie panels seems to be in the 250-290w or so range.

I have mixed mono and poly panels before in parallel and had very good results.  That was with a very old tech PWM controller, I'm pretty sure a MPPT controller would do even better in similar conditions.

 

[blars]

If your parallel panels don't have the same Vmp, you won't get the rated power from them. Try to get them as close to the same as practical.

 

[jimindenver]

I did a bit of mixed panel test both in parallel and in series. Match them up in both type and spec as well as possible. Running them in parallel will give the best result if miss matched, in series the weaker panel will limit any others to what it can do.

Another thing is miss matched voltages will confuse a MPPT controller. In the test the voltage was constantly going up and down as the controller was trying to find a sweet spot that wasn't there. With a single or matched panels it locks on to a set point and stays there as long as the conditions remain.