solar panel voltage

robocop
robocop Registered Users Posts: 118 ✭✭
Hi
It is a long time

Would like to know a friend of mine has a system running on 24volts

Now he is going to add more panels and I am trying to io order  for him.

A company green solar offer a 72 pcs solar panel . and say it is for 24volt use.

plse help me out , He also said  a 96 pcs is for 48 volt

My friends plse explain


Regards
Robert

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Robert,

    I am not sure I understand your question... 72 pcs -- Is that a 72 cell panel? Or you want to purchase 72 panels?

    Anyway, details matter here. Size/type of batteries (AH, AGM, Flooded cell, etc.), Brand/model of solar charge controller(s).

    Vmp&Imp of the existing panels (brand/model), configuration of existing array (number of panels, series / parallel configuration).

    Vmp&Imp of new panels, and suggested configuration, etc...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    Robert,
    I understand your question, 72 cell panels are the best panels for a 24 volt system,  when using a PWM type controller. 96. cell panels are about 53.5volts at maximum power so a bit too low a voltage for a 48 volt system, you will need two in each series string for a 48 volt system.  In my opinion , stick with the 72 cell panels, they are far more common and easier to match if you want to upgrade. 96 cell panels are more suited for grid tie are far rarer.
    That said I have 26 72 cell Sharp NE-170 panels and 20 Sanyo HIT 200 watt 96 cell panels on my dual 24 volt systems. The 72 cell panels are easier to configure for 24 volt. I use 2 Sharp 72 cell panels in each string for about 72 volts into a MidNite Classic 150 controller but the 96 cell panels are all in parallel to another Classic 150 due to the too high voltage in series of 116 volts, so on that system I have twice as many breakers and combiners to keep the voltage in the "cofrortable range" for the controller.
    please post what type controller you want to use.....with PWM type controller a 72 cell panel is a perfect match to a 24 volt system.  If you plan a MPPT type controller use 2 panels in series for each string. 
    Please tell all of what you have now in service.......it will be far easier to recommend with all the details
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
  • robocop
    robocop Registered Users Posts: 118 ✭✭
    sorry people  I meant 72 cell panels