400 or 600 watts water pump 7a, refrigerator 57

moltensurfmoltensurf Registered Users Posts: 5 ✭✭
on the fence, but leaning towards a 24 volt system. I had a 12 volt system on my sailboat with 530 wats. Refrigerator maker claims a 220w panel will fun it. I live in the sothern United States, and travel to Mexico so plenty of sunshine most if the time.  
Water pump for ocasional use 7a
refrigerator 57ah 24 hours roughly 
maxfan deluxe 5a
tv 3.5 amos ocasional movie. 
Lights 5 a few hours a day. 
Charge phone 
drill batteries. 
So I am wondering would a 400 W system be sufficient? Or should I just throw two more panels up there to be sure. 

Comments

  • mcgivormcgivor Solar Expert Posts: 3,600 ✭✭✭✭✭✭
    Without knowing the voltage  current alone is meaningless, 7A at 12V is 84W,  at 24V is 168W, at 48V is 336W
    That aside 400W worth of PV is unlikely enough to support the refrigerator alone.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • moltensurfmoltensurf Registered Users Posts: 5 ✭✭
    edited October 18 #3
    @mcgivor so I am leaning towards 24 volts. The company claims one 220 panel will handle the load.  I ran a waco cold machine on my sailboat with 520 watts at 12 volts with all of my interior lights/running lights, water pump and tv. The only difference is my exhaust fans were solar power. So at max speed the maxfan pulls 5amps at 12volts
  • mcgivormcgivor Solar Expert Posts: 3,600 ✭✭✭✭✭✭
    Making claims based on panel wattage alone is far too simplistic, there are too many variables, such as days of cloud cover, seasonal changes in available solar isolation and geographic location that need to be considered. For this reason it's important to account for these variations in the design phase which invariably results in a system seemingly larger than initially perceived.

    Many people fall into the trap of underestimating their loads and overestimating the solar potential. This is by far the most common beginners mistake, usually rearing it's head a month or two later when the battery has failed, often at the onset of winter.
    Most who offer advice here have experienced this in one form or the other and are willing to assist others from making the same mistakes they made.

    Perhaps at the equator in a desert location with horizontal panels it would easier to predict, outside such ideal conditions things become somewhat more complicated. Don't fall into the trap.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • 706jim706jim Solar Expert Posts: 375 ✭✭✭✭
    More is better.

    Trust me.
    Island cottage solar system with 2400 watts of panels, 1kw facing southeast 1kw facing southwest 400watt ancient Arco's facing south.Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 27th year.
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