Inexpensive ground mounting

jmb
jmb Registered Users Posts: 42 ✭✭
Hi y'all!

At our cabin I currently have 8 Renogy 100 watt panels mounted onto wood frames and steel T-posts.  This is a temporary situation until I get the time and money to do something more permanent.  Next year money will be freed up and I intend to add another charge controller along with a few 290W panels.

I just had a flash of brilliance (or stupidity) and it occurred to me that setting (in concrete) some 2" schedule 40 into the ground and attaching a steel "pasture" gate panel to them would provide a good base to mount panels to.  A 4' x 14' gate panel can be had for about $100 and I could then attach mounting rails to them for the panels.  After pricing ground mount systems this looked like a pretty attractive way to get by for a lot less money.

Has anybody used something like this for a mounting platform?

Thanks...

Justin B.
Justin B.
Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter

Comments

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    One reason mounts tend to be expensive is they're usually made of aluminum, which being the same material as panel frames, minimizes potential for galvanic corrosion.

    I wouldn't try using steel in a coastal environment. It might be okay in other climates if conductive attachments were minimized (eg rubber gaskets where aluminum meets steel) though.
    Off-grid.  
    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
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Mono pole installation looks nice, it does however focus all stress on a single point, the base, an extremely ridged structure can be achieved using multiple legs along with triangulation utilizing thin gauge steel. The use of galvanized steel reduces corrosion to some degree, but after 5 years without  galvanized steel, in a high humidity, tropical non coastal environment there was minimal corrosion, galvanic or otherwise. The steel was however  painted with a zinc based primer and top coated with an enamel paint. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jmb
    jmb Registered Users Posts: 42 ✭✭
    The gate panels are painted and the cabin is in the mountains in SE OK.
    Justin B.
    Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

    Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter

  • myocardia
    myocardia Solar Expert Posts: 118 ✭✭✭
    @jmb how far are you from Idabel? I live not too awfully far south of Idabel myself. Anyway, the only really good, yet inexpensive, way to mount solar panels is by using treated 4x4s, or preferably what they call "corner posts" for fences. These corner posts are strong, treated lumber, that are 4" wide by 5.5 or so inches deep, and 8 feet long. Set them 36-42" inches deep in concrete, use 2x4s for the frame to hold the panels, and use 2x4s as bracing (the triangulation that mcgivor mentions above). Once you paint the 2x4s with a decent oil-based paint, they last about as long as the treated corner posts. I happen to have all of the needed tools, for what that's worth, if you are interested in some help. Oh, just make sure to use no nails. Screws cost a tiny bit more, but they are many times stronger.
    DoD= depth of discharge= amount removed from that battery   SoC= state of charge= amount remaining in that battery
    So, 0% DoD= 100% SoC, 25% DoD= 75% SoC, 50% DoD= 50% SoC, 75% DoD= 25% SoC, 100% DoD= 0% SoC
    A/C= air conditioning AC= alternating current (what comes from the outlets in your home) DC= direct current (what batteries & solar panels use)
  • jmb
    jmb Registered Users Posts: 42 ✭✭
    We're probably about 90 miles north of Idabel.

    I thought about all wood construction but want something more substantial.  OTOH all wood would be a lot easier.  Right now I'm just kicking around ideas.  Neighbor (about 2 miles away) has a Kubota with 12" auger that I can probably borrow to drill holes as being on a mountain manual post hole diggers work you to death!
    Justin B.
    Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

    Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I have a fair bit of ACQ treated construction around (non-coastal location). Galanized and coated fasteners are holding up quite well, but regular plated stuff not so much. A regular bright nail rusts out in a year or two, FWIW.
    Off-grid.  
    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
  • jmb
    jmb Registered Users Posts: 42 ✭✭
    Everything I've put together so far has been with coated deck screws and the hardware attaching the panels is stainless.
    Justin B.
    Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

    Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I've had pretty good luck with that combo so far in a temporary rack I made.
    Off-grid.  
    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
  • jmb
    jmb Registered Users Posts: 42 ✭✭
    edited August 2018 #10
    I'm hoping to build something pretty permanent as I'm getting old and if I build something that only lasts 5-10 years I'm liable to be too old and creaky to fix/replace.  Maybe cedar?
    Justin B.
    Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

    Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter

  • ColoradoSolar
    ColoradoSolar Registered Users Posts: 63 ✭✭
    I built my ground mount out of 4x4 and 2x6 pressure treated lumber mounted on concrete piers. I didn't want to embed the posts in the concrete just in case one needed to be replaced down the road. I used Iron Ridge XR1000 rails and put an isolation membrane between the rails and the pt lumber. I live in the mountains in Colorado so salt air and even moisture for that matter are not much of a concern. I went a bit overboard on the number of piers due to the high winds we get around here.
  • curiousnewby
    curiousnewby Registered Users Posts: 1
    JMB I just sent you a message .Looks like were neighbors
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    For 8 - 100 watt panels a simple ground mount made with pressure treated 2x4's, would be straight forward and lasting design. I built the ones behind the battery bank 13 years ago and only 1 2x4 has had to be replaced to date (badly warped when I sold the system to a friend.


    Note these are situated where the wind can not get behind them, they have  withstood 60 mph straight line winds in the face with no problems. You can see in the second picture the battery box sits on the frame work.  If I was doing this where the wind could get behind, I would likely do single panels vertically oriented, 2 feet high so I wouldn't have to worry about growth or thrown things when mowing. Vertically oriented so the whole thing wouldn't be above 6 feet tall. Drive some 'T' posts in the ground 2'  4 in front and 4 in the rear and secure to the frame work.

    I cut and drilled some aluminum angle to make the panel mounts.

    It's nicer to do them for both panels so the space is the same for each. Looks like Photobucket dumped my photos rather than switch my account to a free version so I don't have photos of those.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • geosierranevada
    geosierranevada Registered Users Posts: 57 ✭✭✭

    Off grid for 20 years. 5KW panels, Trace sw4024, Bergy XL1 wind generator, 3 EG4 Lifep04 200amphr batteries  3 SQF 2 well pump, 12kw back up gen.  Not easy living in the wilderness but it keeps you busy
  • geosierranevada
    geosierranevada Registered Users Posts: 57 ✭✭✭
    4" sch 80 3' in concrete 2 - 1.5 kw racks 1 -  2 kw rack. No problem with 60 mph winds.
    Off grid for 20 years. 5KW panels, Trace sw4024, Bergy XL1 wind generator, 3 EG4 Lifep04 200amphr batteries  3 SQF 2 well pump, 12kw back up gen.  Not easy living in the wilderness but it keeps you busy
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    I did my current system about 7 years ago now, and it's doing nicely 4x4's with 2x10 doubled supports between them top and bottom with pieces of 4x4 to screw in 1x5 decking boards (they were clearer of knots than the PT 2x6s I could find. and I didn't need more strength. I did finally add 4 panels across the top...lol. I had to buy 20' long boards since the mounted panels were just taller than 16'. I left the boards and asked some engineer friend about mounting panels and they thought it would be fine.



    Again, having no worries about wind catching it from behind is a real advantage. I used PT for ground contact and they are down well below the frost line in concrete.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • myocardia
    myocardia Solar Expert Posts: 118 ✭✭✭
    Well, @jmb sent me some photos via PM. Unfortunately for him, he is going to have to either buy or hire a chainsaw, since he has mounted his panels underneath trees, as you can see from the picturec below. Fortunately for him, the trees are tiny diameter, instead of huge diameter:


    DoD= depth of discharge= amount removed from that battery   SoC= state of charge= amount remaining in that battery
    So, 0% DoD= 100% SoC, 25% DoD= 75% SoC, 50% DoD= 50% SoC, 75% DoD= 25% SoC, 100% DoD= 0% SoC
    A/C= air conditioning AC= alternating current (what comes from the outlets in your home) DC= direct current (what batteries & solar panels use)
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Yup. Looks like there may be a bit of a downslope behind the truck though, so he may not have to clear too far back.
    Off-grid.  
    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
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    PM is private mail, not public as it now is, it's unfair to make something public which was intended as private, no matter what the opinion, keep the opinions between the two of you regarding a private message, private. Am I alone on this? 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    No, I think it's a valid point. Although seeing the pics may help others in planning, a PM isn't necessarily meant for publcation. Hopefully OP dosen't mind
    Off-grid.  
    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
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited September 2018 #21
    This was made for around  $75 US, 3 × 6m lengths of 2"×1" galvanized steel, 1×6m 3/4" tube, 6 bags of cement, 1/2 cubic meter each sand/stone and a jar of elbow grease. Despite its appearance it is very ridged, been typhoon tested twice last year, the legs have T feet embedded in the concrete pad.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,035 ✭✭✭✭✭
    Wow, that's a very clean looking home brew ground mount. 

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • BB.
    BB. Super Moderators, Administrators Posts: 33,422 admin
    You have diagonals that run left to right... Having some that run front to rear would not be a bad idea (that is the direction where you will get the most wind loading from the panels).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited September 2018 #24
    BB. said:
    You have diagonals that run left to right... Having some that run front to rear would not be a bad idea (that is the direction where you will get the most wind loading from the panels).

    -Bill
    That was something I had considered but the legs are wide side front to rear, 24" &  32"(60 & 80 cm) respectively, all welded construction, before mounting the panels I checked for any deflection, there was none. The wind can come from any direction, changing in minutes, the strongest typhoon winds  would come from the east, left on back view, the sail effect is minimal due to angle ~17°.  The picture below was the first I built  about 7 years ago,  picture just taken, slightly steeper for bett winter peformamce.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jmb
    jmb Registered Users Posts: 42 ✭✭
    edited September 2018 #25
    Estragon said:
    No, I think it's a valid point. Although seeing the pics may help others in planning, a PM isn't necessarily meant for publcation. Hopefully OP dosen't mind
    No, I don't mind - this time.  

    These pics were taken in the morning, IIRC, and there was a lot of shade on the panels and the front view of the panels is pointing North.  Cabin is toward the back and middle of a 'dozed clearing and these panels are slightly in front and to the East  and get full sun around 11:00 - 16:00.  I am going to put another set of panels (4 Mission Solar 360W) toward west of center in the clearing to get more morning sun.  We really don't want to cut down any trees  as this clearing sets closer to the road than I like but any further back and the slope would be to where I would have had to put the cabin on "stilts" and I didn't like that idea.  This is in the mountains so I don't really have much flat ground to work with.

    I am actually adding one more 100 watt panel so I can run a 3x3 array to keep my total Voc from being so close to the charge controller max input.  The additional array planned for next year will have it's own charge controller.  I will make another PVC three panel "rack" and then re-do the current configuration with a couple more T-posts and more lumber for a more sturdy arrangement.

    For the larger array for next year I am thinking of replicating something like the Orion Jupiter1 rack or purchase if not too expensive.
    Justin B.
    Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

    Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    You could always see how it goes over the winter. From the pic, it looks like the trees will be a problem in the lower fall/winter sun, but you could wait and see what if any clearing is needed/wanted then.

    Taking out bigger trees and letting smaller ones grow some might end up being a better screen from the road.
    Off-grid.  
    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
  • MrM1
    MrM1 Registered Users Posts: 487 ✭✭✭✭
    Cant Vouch for the Price or Quality,  but this system looks interesting if I was doing a ground mount.   Looks like it would be easy to tilt at different times of the year or allow you to tilt different panels in different orientations if the array was not facing South to maximize different panels potential at different times of the day.   Look to the bottom of this page to see the drawings for ground mount.  They also (appear) to sell the parts and brackets. 
    This Chap seems to like the setup.  (I follow his channel for the comedic value)

    REC TwinPeak 2 285W 3S-3P 2.6kW-STC / 1.9kW-NMOT Array / MN Solar Classic 150 / 2017 Conext SW 4024 Inverter latest firmware / OB PSX-240 Autotransfomer for load balancing / Trojan L16H-AC 435Ah bank 4S connected to Inverter with 7' of 4/0 cable / 24 volt system / Grid-Assist or Backup Solar Generator System Powering 3200Whs Daily / System went Online Oct 2017 / System, Pics and Discussion
  • jmb
    jmb Registered Users Posts: 42 ✭✭
    We'll see how it goes this winter.  Right now if it's not a cloudy day the batteries seem to stay well charged and we probably won't spend as much time up there in the wintertime as the wife hates the cold.
    Justin B.
    Cabin - 9 Mission Solar 310 watt panels, MidNite Solar Combiner, Iron Ridge mounting, 4 Speciaized Power 200 AH 24V LiFePO4 batteries, Samlex PST-1500-24 inverter, MidNite Solar Classic 200SL CC

    Barn - 9 Renogy 100W panels, Generic Chinese 40A MPPT CC, 6 Universal 12V 100 AH AGM batteries, Reliable 3KW 12V PSW inverter