Mis matched panels

mountainmanmountainman Registered Users Posts: 439 ✭✭
If I were to combine a panel of 8.53 imp and 30.5 wmp with a panel of 8.64 and 30.7 in series would the voltage combine 61.2 and the imp would be  of the lowest panel 8.53. 522 watts? And in parallel the imp would combine 17.17 and the lowest voltage 30.5. Is this how it works? And wouldn't these to panels be close enough to use together?
2kw array 6 345 q cells  make sky blue 60 cc
 6 230ah GC @36 volts 
18 amp accusense charger. 3650 champion 


  • BB.BB. Super Moderators, Administrators Posts: 32,008 admin
    Those panels are close enough for you to treat them like they are identical.

    More or less, panels match their ratings within 5% (Vmp and Imp).

    And the curves have "flat enough peaks), that you can match panels that are within 10% of each {i.e., 30.5v + 10% = 33.55 volts for "high Vmp match").

    They will probably hit a middle point where in-between the high and low.

    Remember Vmp falls by almost 20% between a cool morning vs hot noontime operation. 5% is within the margin of error.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    IMHO, they're close enough that you could see bigger differences in identical panels from measurement error, manufacturing tolerances, temperature difference from differing airflow, etc.

    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mountainmanmountainman Registered Users Posts: 439 ✭✭
    Great a 260 and a 265 mono panel new. Left overs  for .48 cents a watt. Local pick up And I only have to buy 2. Thought I'd never find 60 cell panels to series on a 100 voc cc. Without having to buy a pallet and pay a crazy shipping fee. Thanks @ bill and @ estragon
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
  • PhotowhitPhotowhit Solar Expert Posts: 5,655 ✭✭✭✭✭
    I bought six panels from a commercial install, they told me they were 320 watt panels and I saw one that was 320 watt, but when I was putting them in storage I noticed they were 320 - 335 watt panels... 
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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