Array size for southern New Mexico

cptdondo Solar Expert Posts: 103 ✭✭✭
I'm trying to do a conceptual plan for an array in southern New Mexico. The biggest unknown is that I need to run a small AC during the hottest part of the day.

So assuming I need to run a small window shaker (1000W) for, say, 6 hours a day during the hottest, sunniest part of the day, any ballpark on the array and battery size?


  • MichaelK
    MichaelK Registered Users Posts: 234 ✭✭✭
    My rule of thumb is to have at least 2X the number of watts of panels, as is the load you are using.  So, for a 1000W load, I'd have 2000W of panels.  That's assuming you have adjustable mounts.  With fixed arrays, I'd recommend at least 3X.  You can look at one of my other posts on a hillbilly solar tracking array that I built.  Each array holds 1000W.  You'd need 2.

    In terms of the battery, I like to keep the battery drain at no more than 1/10 of the rated capacity.  Here's where you need to do a little math, because the capacity is dependent on both the amperage rating of the battery, and also the system voltage.  The math would be (load/system voltage X 10= battery capacity) 

    Let's say you have a 24V system.  1000W/24V=41.66A X 10 = 416.6AH of capacity.  A 400-420AH L-16 battery is the right size for this kind of draw.  You might get away with using components with somewhat lower values, but you'll need to monitor your inputs and outputs very closely.  I wouldn't be surprised that after you have it up and running, you'll decide you need 3 arrays.
    System 1) 15 Renogy 300w + 4 250W Astronergy panels,  Midnight 200 CC, 8 Trojan L16 bat., Schneider XW6848 NA inverter, AC-Delco 6000w gen.
    System 2) 8 YingLi 250W panels, Midnight 200CC, three 8V Rolls batteries, Schneider Conext 4024 inverter (workshop)
  • Wheelman55
    Wheelman55 Registered Users Posts: 232 ✭✭✭
    Consider a mini split for the AC. They use inverter technology giving the split a soft start, meaning no big surge. The splits likely will use far fewer watts than a shaker unit. 
    Off-Grid in Terlingua, TX
    5,000 watt array - 14 CS 370 watt modules. HZLA horizontal tracker. Schneider: XW6048NA+, Mini PDP, MPPT 80-600, SCP. 390ah LiFeP04 battery bank - 3 Discover AES 42-48-6650 48 volt 130ah LiFePO4 batteries
  • BB.
    BB. Super Moderators, Administrators Posts: 33,406 admin
    LG (and others?) have some Inverter-AC window units too.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset