Solar panel position

tonygcan
tonygcan Solar Expert Posts: 91 ✭✭✭✭
in General Solar Power Topics #1
Hi,

I have 12 185 watt sharp panels that I will be installing on the gable roof roof of my house as soon as I complete my renovation.

One side of my roof faces directly southwest.

I have researched that the panels normally should face south tilted to your location's latitude.

I would like to ask if it's okay to face my panels southwest at 15 degrees (Manila, Philippines)?

Thanks for any advise.
· Share on Twitter

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: Solar panel position

    You might try the International version of PV Watts: http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/International/inputv1_intl.cgi
    I'm not sure if there's a more recent edition of that, but it should give you some idea about solar South vs. magnetic South-West.
    Another thing to consider (and PV Watts doesn't cover this aspect) is heat. Your South-West exposure is bound to be hotter on the panels than South-East. Heat will drop panel output significantly. You may find it advantageous to put the panels on the opposite side and catch the cooler rays first thing in the morning (after the batteries have been used all night). Even better would be arrays in both directions on separate controllers; early recharging in the cooler temps plus "topping off" just before night.
    · Share on Twitter
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #3
    Re: Solar panel position

    Thank you for the quick reply and for the link.

    After reading your reply I re-checked my proposed roof's direction and I do have a south, south east orientation for my panels. I must have been groggy the first time I checked my iPhone's compass. :D

    I will use the PVWATTS site now and check it out.

    Thanks.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #4
    Re: Solar panel position

    Check your magnetic declination... In the Philippines, it can vary a lot depending on where you are at... Towards the southern end, it is not very much (a few degrees).

    The further north you are, the more it can vary from true south (by positive or negative values to over 20 degrees).

    http://www.magnetic-declination.com/

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #5
    Re: Solar panel position

    Thanks Bill,

    I'm located in Manila, a little bit north of center. I will check the link.
    · Share on Twitter
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #6
    Re: Solar panel position

    i would say you could go with 15 degrees and if you wanted to you could about get away with having them lay flat because of how close to the equator you are. that 15 degrees is about your latitude and it would be the the strongest at the equinoxes with it varying by +/-23.5 degrees from that for the winter and summer solstices. if you need more winter production then add a bit more to the angle, but my guess is it'll have a good compromise with the latitude in degrees of 15. go for it imho.
    · Share on Twitter

Categories