1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

apexcarl
apexcarl Registered Users Posts: 7 ✭
in Solar Beginners Corner #1
Hi guys ! (and gals)..so here's the scoop, i have 1.4 kw array on the roof, a bank of 6 6volt l16's 420 amph each..i think thats 1260 amphours @ 12 volts...charge controller is a outback flex80.. a 4500 watt puresine inverter..off grid my elec use is about 6 kwh per day...i get tons of sun everyday...and have several honda 3000 & 2000 watt generators on hand if needed for backup...so...do you brainiacs see any issues? by the way, i stopped by naws last week..nice guys...i will be back..:roll:
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #2
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    I think you are going to be short on Pv

    MY rule of thumb is the 50% rule,,, take the name plate rating of your PV ~1400 in this case divide that in half to account for all system losses and then multiply that number by 4 to represent the average number of hours of good sun.

    1400/2=700*4=2800 wh out the inverter. You might get more than 4 hours, but most places you can't count on much more over an average year. Do a PV watts calc.

    Tony
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  • chevenstein
    chevenstein Solar Expert Posts: 100 ✭✭
    #3
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    Agreed on the PV assessment. It sounds like you're in AZ, which means you get lots of good sun most of the time but 1.4KW is still small for that bank and load. My 1.6KW array is a little small for us and we use 2-3KW per day with the system in my signature.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    i agree with the guys as all looks good except the loads may exceed what you bring in. monitor the battery condition and watts in vs watts out to see what you may need to add in the way of more pv or you can just kick on a generator every day to take up the slack.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #5
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    Fyi for comparison, We live off grid, use ~.6 kwh/day generate from ~400 watts of panels, into 450 ah of battery.

    Tony
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  • apexcarl
    apexcarl Registered Users Posts: 7 ✭
    #6
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    thanks for the input guys, i think i will add just 2 more panels for summer, as i'm collecting 7.5~8.5 kwh per day, and the batteries seem pretty happy. and then late fall i will see if i can add another 4 panels, the only problem im seeing right now is that we use 75% of our power at night....do you guys know how many kwh's i get from 1260 amphours? and how many should i use to keep my bank @ 75% reserve?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,641 admin
    #7
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    Is this what you are asking for?
    • 1,260 AH * 12 volts * 0.25 use from battery = 3,780 WH = 3.78 kWH
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • apexcarl
    apexcarl Registered Users Posts: 7 ✭
    #8
    Re: 1.4 kw array, 1260 ah bank, 6 kwh per day use..does this add up?

    yes yes ! thank you bill, i think i'm on the right track, just some fine tuning, and help from you guys and i'm looking good! thanks again!
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