Can a solar panel deliver over and above its rated output?





Results 1 to 10 of 10
  1. #1
    Join Date
    Sep 2006
    Location
    Randburg
    Age
    48
    Posts
    170
    Thanked: 26

    Default Can a solar panel deliver over and above its rated output?

    I have seen a couple of mentions made where panels exceed their stated specks and my question mostly revolves around the camping style/size setups.
    I have a 150W solar panel setup with a Steca PR 1515 (PWM) controller

    This is connected to an Engel 56A battery pack and NL 40L fridge and it serves my purposes fine for the odd one or two day stop over during holidays where there is no AC available. I donít mind drawing the battery down by 80% as I might only use it 5 days a year and it would probably outlast the battery life expectancy. I do however try and keep the battery charged when not in use.

    Panels are rated at
    ē Voltage - maximum power - 18 v
    ē Current (Amp) - maximum power - 8.34 A
    ē Voltage - open circuit - 22.1 v

    Question:

    During my last trip, I used the setup for four days in the Karoo over December and the Charge controller displayed an Amperage as high as 10.8A delivered by the panels. The battery was 100% charged, indicating 13.8V with a minimal 0.2A draw from panels ). The fridge was running concurrently with a draw of 3.8A

    With a rated max 8.3A on the panels is this 10.8A panel display possible with a PWM controller or even MPPT? Or does the controller perhaps reflect the Amps interpreted @ 12V?

    Am I missing something here?

  2. #2
    Join Date
    Jan 2013
    Location
    Friemersheim, Southern Cape
    Age
    57
    Posts
    3,699
    Thanked: 2046

    Default Re: Can a solar panel deliver over and above its rated output?

    Solar irradiation ....
    1998 Daihatsu Rocky 'The Kitty'
    2002 Daihatsu Rocky 'The Bully'

  3. #3
    Join Date
    Sep 2006
    Location
    Randburg
    Age
    48
    Posts
    170
    Thanked: 26

    Default Re: Can a solar panel deliver over and above its rated output?

    Quote Originally Posted by Prof View Post
    Solar irradiation ....
    Really, that much more than claimed on the panels?

  4. #4
    Join Date
    Aug 2017
    Location
    Centurion
    Posts
    973
    Thanked: 848

    Default Re: Can a solar panel deliver over and above its rated output?

    I canít report on amps, but I frequently see up to 370w on a 320w panel

  5. #5
    Join Date
    Jan 2013
    Location
    Friemersheim, Southern Cape
    Age
    57
    Posts
    3,699
    Thanked: 2046

    Default Re: Can a solar panel deliver over and above its rated output?

    On my best day I got 1275W from a nominal 960W installed.
    Attached Images Attached Images  
    1998 Daihatsu Rocky 'The Kitty'
    2002 Daihatsu Rocky 'The Bully'

  6. The Following User Says Thank You to Prof For This Useful Post:


  7. #6
    Join Date
    Sep 2006
    Location
    Randburg
    Age
    48
    Posts
    170
    Thanked: 26

    Default Re: Can a solar panel deliver over and above its rated output?

    Quote Originally Posted by Prof View Post
    On my best day I got 1275W from a nominal 960W installed.
    Thanks. I would never have thought it possible, as the norm seems to be an expect 75% deliver on average.

    I imagine that my readings would fall above ideal tested conditions then.

  8. #7
    Join Date
    Aug 2017
    Location
    Centurion
    Posts
    973
    Thanked: 848

    Default Re: Can a solar panel deliver over and above its rated output?

    Standard testing is done at 1000w/m2 of irradiation.

    As shown in the map posted by Prof, one can get much higher levels of irradiation in ZA.

    Quote Originally Posted by bloudraad View Post
    Thanks. I would never have thought it possible, as the norm seems to be an expect 75% deliver on average.

    I imagine that my readings would fall above ideal tested conditions then.

  9. #8
    Join Date
    Sep 2009
    Location
    Paradise Beach
    Age
    66
    Posts
    62
    Thanked: 43

    Default Re: Can a solar panel deliver over and above its rated output?

    Thereís nothing strange with this particular scenario. The controller is showing the actual current at that instant with respect to the voltage at that instant
    18 volt & 8,34 amps = 150 watt
    13.8 volt & 10.8 amps= 150 watt

  10. The Following 2 Users Say Thank You to fredwb For This Useful Post:


  11. #9
    Join Date
    Sep 2006
    Location
    Randburg
    Age
    48
    Posts
    170
    Thanked: 26

    Default Re: Can a solar panel deliver over and above its rated output?

    Quote Originally Posted by fredwb View Post
    Thereís nothing strange with this particular scenario. The controller is showing the actual current at that instant with respect to the voltage at that instant
    18 volt & 8,34 amps = 150 watt
    13.8 volt & 10.8 amps= 150 watt
    Thanks.


    I made those exact sums and the first made total sense.

    The second however I was skeptical of as it felt too easy in getting to the exact same result.

    Somehow my little brain wanted to bring something more into the calculation like the battery being under charge albeit minimal, and the fridge drawing current although seemingly direct from panel.

    I guess I didnít want to settle for the simple answer that it in fact really was.

  12. The Following User Says Thank You to bloudraad For This Useful Post:


  13. #10
    Join Date
    Oct 2013
    Location
    Centurion
    Age
    62
    Posts
    681
    Thanked: 281

    Default Re: Can a solar panel deliver over and above its rated output?

    Depending on the amps reading device as some cheaper PWM units can report 15% higher reading than the true amps.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •