Slightly different panel wattage in one string.

[Jemplayer]

Quick question. Can two 290 watt panels be mixed with 10 300watt panels in the same string of 12, for grid tied inverter?

[sensij]

Are they all 72 cell panels? If so, it isn't ideal, but the penalty for mismatch in that arrangement will be small. Just make sure your string voltage doesn't exceed the allowed value... 12 x 72 cells might be trouble.

[J.P.M.]

Maybe. Best chance for pulling it off is to have panels from the same mfg. 12 LG 300's for example, can probably be replaced by 10 LG 300's and 2 LG 290's with not much noticeable loss in array output. Mixing mfg. might be more of a challenge.

[NEOH]

Please post the following PV Panel NOCT data ...


290 Watt Panel
============
Vmp =
Imp =


300 Watt Panel
============
Vmp =
Imp =


How well the Imp values match, will determine how many Watts you will lose from the mismatch.