To tilt or not to tilt, that is the question.

Discussion in 'Solar Power' started by EA7VPG, Feb 3, 2012.

  1. EA7VPG

    EA7VPG

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    Hi..

    Just bought an 80w panel to charge the second leisure battery which is dedicated for the blueray player, satellite receiver, LED TV and led lights.
    I have noticed some panels on top of MH's tilted and angled towards the sun. Living on the Costa Del Sol where we have plenty of sun would there be any benefit tilting the panel or just fitting it flat to the roof which is my preferred option.
    Most of the commercial solar farms here in Spain have there panels tilted with some having azimuth rotatable bases to follow the sun across it's arc.

    I suppose having the panel perpendicular to the sun is ideal instead of the light hitting the panel at some incidence angle.... just wondering what the difference would be in charging times.

    atb
     
  2. hilldweller

    hilldweller Funster Life Member

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    It's simple trigonometry. sin(50) = 0.76. So 24% bonus if you track. But elegant though that is, on a bouncing van I think a pair of panels rigidly mounted is the better long term solution. KISS.
     
  3. vwalan

    vwalan Funster

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    hi ,i dont tilt mine .but friends tip theirs ,yes its better to tip and track.but you also have to work out do you want to be climbing up on the van. or paying for a tipping tracking gear. one mate can get out of a hatch enough to tip and turn his panel but its a bit dodgy in the windy days. he made his own gear.. personally more panels is easier. but see how you get on . i use 6x80wt . sees me through the winter in either maroc or spain. find portugal just doesnt quite seem to have enough sun. or the days seem shorter.
    more panels more batteries is the answer . in summer lots of sun but winter shorter days more leccy needed dont go together.
    have fun you can add as you go.
     
  4. scotjimland

    scotjimland Funster Life Member

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    On another thread...

    A reply from funster dave newell who has compared tilted and flat ...

    http://www.motorhomefun.co.uk/tech-mech-general/45339-10a-solar-controller-adequate.html#post543515

    which would indicate a gain of almost x 3 ...

    However, I'm with KISS.. unless you have a very small roof and can't add another panel.. then it MAY be worth considering ..

    Another point.. from a security point of view.. a tracking device also advertises them to all and sundry ... nice eye candy.
     
  5. hilldweller

    hilldweller Funster Life Member

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    OK, time to take this seriously !!

    Optimum angle for UK in Jun is 60 deg. sin(60) = 0.87 so you'll get 90% with the panel flat.

    But and what a BIG BUT, in Dec the optimum angle is 12 deg. sin(12) = 0.27 so mid winter when you need it most the flat panel is giving only 25%.

    So it's 4 panels needed if you don't tilt and track.

    And for winter this is best case, when the sun is so low there's a good chance it will be obstructed by buildings and trees. And clouds, don't forget the clouds.
     
  6. scotjimland

    scotjimland Funster Life Member

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    yes indeed.. lots of variables..

    Dave's test was this week.. .. so will obviously show a bigger gain than one done in mid summer... proves your point.. would it be worth it in southern Spain? probably not...

    I've never been a fan of tracking devices.. seems a lot of expense for what they do when another panel would be almost as good..

    I know snowbird was working on a DIY version as too was Olley.. ( saw his on the bench.. still there I think) .. but I think more a fun project than anything else.. summat to do
     
  7. hilldweller

    hilldweller Funster Life Member

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    Big difference, 30 deg is the winter angle so double what we get in the UK for a flat panel.
     
  8. eddievanbitz

    eddievanbitz Trader - Funster

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    And what about surface temperature?:Wink:

    Eddie
     
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