Does this mounting idea make sense? And a couple related questions...

RandomJoe
RandomJoe Solar Expert Posts: 472 ✭✭✭
in Caravan, Recreational Vehicle, and Marine Power Systems #1
Back again after quite a while - the home system has been working great for a few years so now it's time to see if I can have the same luck in a mobile setting...!

I just bought a Ford Transit (the big one) for a camper / toy-hauler and am going to put a small house power system in it.  I've been measuring and checking dimensions for panels today and think I have the setup I want.  My concern is with the mounting of the panels.

Don't have a picture, hopefully this makes sense...!

I'm using Ford's rack kit, they have threaded holes in the roof for four crossbars.  The rear one can't be used due to the MaxxAir vent fan.  The front three are unevenly spaced, one is just a couple inches in front of the vent fan, the middle one 39" farther forward, the front bar another 29" forward.  (Total span 68".)  

I'm planning to use two Kyocera KD140GX panels (each 60" long, 26" wide) mounted side by side.  I can't center them over the rear two crossbars because of the vent fan and don't want to use just the two front ones (figure 29" spacing is too narrow, and that'd have the front of the panels over the downslope portion of the roof).  If I have the tail end of the panels over / very near the rear crossbar, that leaves quite a bit (21") of overhang forward of the middle bar.

My idea is to get three lengths of aluminum angle, U-bolt those to all three of the crossbars, then bolt the panels to the three angle pieces.  That would let me support the leading edge of the panels well, and puts that leading edge about 8" back from the front bar.  Is that sensible?  Overkill? :smile:  What thickness of angle should I use?  Just a quick look at Home Depot's website shows they have 1/16" and 1/8", I'm thinking 1/16" would be too thin but then I'm known for massively overengineering things...


Related to this...  I'm planning to use an MPPT controller, so could wire the panels in parallel or series.  There are pros and cons to each method, of course.  I'm wondering if anyone has had experience with a situation like this,  I'd normally just series them but wonder whether there'd be enough of an advantage to paralleling them - not sure how often I might find myself with one side of the van shaded and the other in sun.  With them side by side in the center of the van they may effectively work as one...

Also, the controller I have on hand is a Morningstar SunSaver MPPT.  Of course it's rated for a max of 200W, but I seriously doubt my 280W of panels will regularly exceed that since they'll be mounted flat.  Any real benefit to upsizing?  I've been drooling over a Midnite Kid but haven't been able to convince myself it's "necessary"... :smiley:  (I already have the SunSaver.)

Thanks!

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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
    parallel the panels for redundancy if there is shade where you park
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • Iceni John
    Iceni John Solar Expert Posts: 103 ✭✭
    #3

    If in doubt, always use thicker/heavier/stronger when making anything for a vehicle!   I suggest using 1/8" 6061-T6 structural angle if it's available, but Home Despot may perhaps only have 6063 "architectural" aluminum which will also be OK.   Use stainless bolts, Nylok nuts and washers, but use anti-seize or lube on the threads or they will gall.   Just remember that driving down the road at 70 MPH will put the same load on the panels as an entry-level hurricane!

    Parallel the panels to reduce the effects of partial shading, and use heavy cables to minimize voltage drop.

    Have fun, John

    40' Crown bus with 2kW of tiltable panels on the roof:

    Eight Sharp 255W, two Morningstar TS-MPPT-60, Magnum MS2000, Champion C46540 generator converted to propane, eight golfcart batteries, and maybe a small Exeltech inverter for the fridger.

    Southern California

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  • RandomJoe
    RandomJoe Solar Expert Posts: 472 ✭✭✭
    #4
    I'm sure I can get the angle from a better supplier.  One of my coworkers does a lot of welding, I'll find out where he buys his stock.  HD doesn't mention the metal number in the details.  A customer comment also says their price is outrageous (about 4x "normal") so better to look around anyway.


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