Solar Panel Positioning

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Shasta1
Shasta1 Registered Users Posts: 15
I'm considering mounting my solar panels so that they face towards the front of the RV instead of the side.

Can any of you more experienced people think of any reasons why this may not be a good idea?

I've considered the shading of the panels by any roof structures, wire runs, mounting surfaces, etc. My thought is that if I aim the front of the RV towards the south sun, I'll be exposing less of the RV to the sun's heat, as opposed to the side of the RV. We'll be traveling the S.W. and in the hot desert frequently.

Any feedback on this?

Thanks

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Solar Panel Positioning

    Flat mounted to the roof it won't make any difference. But if you intend to tilt them up once you reach your destination (properly angle for maximum insolation) the ones in front may cast shadows on the ones behind.

    Mobile applications are always a compromise. And a pain. :cool:
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
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    Re: Solar Panel Positioning

    the sun will still heat your rv as it'll pore into the front windshield. you can't always face the best direction so mount them flat as a compromise. the only other alternative is to remote mount the pvs and you can keep the rv out of the sun.
  • Shasta1
    Shasta1 Registered Users Posts: 15
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    Re: Solar Panel Positioning

    Boy, aren't you two a couple of rain clouds on an otherwise sunny day......

    There will be no shading;
    I've considered the shading of the panels by any roof structures, wire runs, mounting surfaces, etc.

    Perhaps I should've been more explicit :roll: The panels will not be mounted anywhere subject to shading by any other structures of any type on the roof of the RV regardless of flat or tilted positioning.

    the sun will still heat your rv as it'll pore into the front windshield

    The sun won't "pore" in through the reflective white windshield cover that I have, similar to the thousands of other RV's. And, we've even devised a curtain system on the inside that can be closed for privacy and shading. ;)

    My initial thought was that I would be exposing 3/4 less side surface area of the RV to the direct sunlight, including the door and four windows.....possibly reducing the heat transfer in to the full length of the RV.
    Mobile applications are always a compromise. And a pain.

    I did find a very innovative and simple solar panel mounting technique on another forum that negates any concerns I might have had.

    Sorry.....I'm probably asking you fellows the wrong questions. :p
  • BB.
    BB. Super Moderators, Administrators Posts: 33,478 admin
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    Re: Solar Panel Positioning

    No--It is just not always clear what variables "we" have to play with...

    People point things "sidways" to south so they can mount as many panels, shade free (remember, many of us also include low sun angles of winter when we attempt to answer questions). Also, there is a resistance to placing living quarters facing west--afternoon sun + heat seem to be worse for heat gain.

    Another question I would have is--I was unclear if the panels were to be mounted flat vs on the face of the overhang--where you can get rocks and stuff blown off trucks hitting the panels directly. The "good panels" are generally single weight (~1/8" thick) tempered glass... You get any torque, hard objects, scratches--the whole panel will shatter--and pretty much be useless.

    However, there are other options and things to look at. If you do not need a lot of panels and/or do mostly non-winter camping--then you may be able to place panels on the narrow end of the vehicle. And if you have a nice shade for the "west side" of the RV, then afternoon sun will be less of an issue...

    I have also seen RV's that mount panels on hinges on the side of the RV and point the side to the south--and tilt up the panels for shade--a Two For.

    People here try to ask questions and put up straw-men (and straw-women) for comments... We try to be very flexible and adjust our suggestions based on the needs of the original poster.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Solar Panel Positioning
    Shasta1 wrote: »
    Can any of you more experienced people think of any reasons why this may not be a good idea?

    Maybe I misunderstood that question.
    I was wondering if you'd considered the possibility of angled panels in front causing shadows on the panels at the rear, depending on the angle vis-a-vis the time of year and latitude. I don't know if it will happen on your particular RV install, but it sure is a potential problem on all other flat roof installs.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
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    Re: Solar Panel Positioning
    Shasta1 wrote: »
    I'm considering mounting my solar panels so that they face towards the front of the RV instead of the side.

    Can any of you more experienced people think of any reasons why this may not be a good idea?

    I've considered the shading of the panels by any roof structures, wire runs, mounting surfaces, etc. My thought is that if I aim the front of the RV towards the south sun, I'll be exposing less of the RV to the sun's heat, as opposed to the side of the RV. We'll be traveling the S.W. and in the hot desert frequently.

    Any feedback on this?

    Thanks
    I don't think it will make much difference. The sun moves through 180 degrees (+ or -) of azimuth every day, and at noon when the sun is due south, especially in the summer when heat is more of an issue, it will be more overhead and impacting the roof more than the sides of the RV. I'll bet that it's pretty much a wash.
  • bluewickedburner
    bluewickedburner Solar Expert Posts: 78 ✭✭✭✭
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    Re: Solar Panel Positioning

    Had to chime in on this one. People mount panels in virtually all directions with a variety of tilts without too many difficulties.

    If you mount the panels width wise (across rather than along the length of the roof) you have the advantage of being able to run down the road without lowering them so long as the tilt isn't very high. People do this all the time.

    Rocks and things from trucks do not impact the roof. On the roof many have sat dishes, air con units and other things and they aren't usually rock chipped. Imagine debris from a truck tire and you going down the road at say 50 mph. That rock or debris not only has to jump 14 feet in the air but then has to drop on your roof. Things don't work that way. They might hit your windshield and often do but they aren't landing on your roof.

    Yes, panels on the roof reduce the amount of heat hitting the roof. There simply isn't enough heat transferred by the mounts to the roof to mean anything at all but the shade afforded to the roof sure does. Heat rises. Just make sure your panels aren't being bonded to the roof is all.

    RV systems aren't any harder to do than any other except for pulling the wire. Sometimes the wire routes are difficult but not usually. In fact, many modern RV have all the electrical systems in place and are easy to use with solar. No messing with AC connections, where to place the inverter, batteries - all that is taken care of for you.

    The one thing you have is pre-defined space for panels and batteries. You have what you got so many times all the calculations don;t come into play, you might wear about batteries faster but that is the price to pay when using an RV.

    Most of the time, anyone going solar in an RV isn't trying to save money, that is rare unless you sit in one place and are a minimalist.
  • Shasta1
    Shasta1 Registered Users Posts: 15
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    Re: Solar Panel Positioning

    bluewickedburner,

    Thanks for your response. And for restoring a little of my faith in common sense and reading comprehension.