A few newbie Q's

garynappigarynappi Registered Users Posts: 99 ✭✭
My system is going to be used EXCLUSIVELY for home perimeter (Malibu type) lighting, 12 volt fountain pumps (2) and for emergency purposes a USB port with a single 95Ah deep cycle battery. I am NOT using an inverter for A/C purposes or tying to the local grid in south Florida. My controller is a Morningstar Sunsaver 20

My questions are:

My single 100w [fixed typo--Bill] panel (Mightymax solar) is going to be mounted on a directly south facing wall ~12 feet from the ground but it only gets direct sunlight (due to trees in the east) from about 10am till about 6:30 (summer) Near Fort Lauderdale Florida) a bit less sun exposure in winter.  

Q1. Should the panel be oriented vertically or horizontally? My brackets are tilt adjustable to take advantage of high summer sun and low horizon winter sun. 

Q2. Regarding actually mounting the panel. The back of the solar panel bracket thin so I'm hesitant to mount my brackets to it, but the sides are thicker and more robust. Are mounting brackets that attach to the panels customarily mounted to the sides? 




  • EstragonEstragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I assume the panel size (1000w) is a typo (s/b 100w)?

    Near Ft.Lauderdale, I'd set the panel at a ~30-40° angle from horizontal.  If you want to change seasonally, spring/summer would be flatter, ~15°, fall/winter would be steeper ~40°.  If loads are about equal year-round (maybe more lighting in winter?), I'd leave it set for a winter angle.

    If by "vertically or horizontally" you mean portrait (long edge vertical) or landscape (long edge horizontal), I'd mount landscape.

    Don't do anything to the back of the panel.  They should be mounted using perimeter framing, either with frame holes in the panel  designed for that purpose, or with frame clamps to rails, also designed for this purpose.  I'd use stainless fasteners, and aluminum mount. 
    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
  • BB.BB. Super Moderators, Administrators Posts: 32,924 admin
    I guess a typo? 1,000 Watt vs 100 Watt panel?

    Is your system using more energy in the winter (longer nights)--Or are the lights on a timer (4 hours per night...)?

    A good place to start is with:


    For your area, vertical mounting, is very poor performance. Horizontal is not bad (closer to equator, closer to flat is ok).

    You can look up and figure out if you want to favor summer (flatter), or winter (more vertical). Or just split the difference and choose the middle setting. Fixed array, facing south, Hialeah:

    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 64° angle from vertical:
    (For best year-round performance)


    Losing sunlight before 10am is not great... You can use PV Watts or other solar prediction program to estimate how much sun you lose:


    If you have a standard 100 Watt panel:
    • 100 Watts / 17.5 volts Vmp = 5.71 Amps Imp
    • 5.71 Amps * 4.44 hours of sun (December no shade) = 25 Amp*Hours per average December day harvest
    Not a bad match for a 95 AH battery... You probably don't want to use more than ~1/2 that amount of charging Amp*Hours (~12.5 AH per day) on average (carry your system through in bad weather).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • garynappigarynappi Registered Users Posts: 99 ✭✭
    edited July 2019 #4
    Thx all.

    Yeah, it's 100w (darn phone mini keys) I figured "landscape" would be best but it's better to ask than re-do :--)

    The lights will be on the controller timer for ~4-6 hours, right now 7 lights with 1 watt LED's not much power but I plan on doubling that to cover the rear of the house soon. 

    I'm fabricating the  mounts from 1" square aluminum tubing and now that I know there are clamps for that purpose, I'll look at them.
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