Extra PV Panels

Right now I have 1100 watts /24 volt of Pv Panels. They are fixed in one direction. My inverter allows 60 amps. I have room for one more panel or 14 amps.

Since panels don't put out 100% of wattage at once, is it possible to add 10-20% overage and then possibly add more in another direction for late evening sun?

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Extra PV Panels

    I think we need more details as there's a few things in your post that don't add up.
  • scheekscheek Registered Users Posts: 26 ✭✭
    Re: Extra PV Panels
    I think we need more details as there's a few things in your post that don't add up.

    Okay. Let me clarify. I have 8 solar panels adding to about 1100 watts. I have them pointed in one direction (noon). I have a 6000 watts Aims inverter with a built in charger. According to manufacturer I can have up to 60 amps of panels. As is, I am nearing that now. I have room for maybe one more.

    As I read most likely my panels will never be at 100% efficiency so could I have room for another panels to help offset that loss.

    Too, in late afternoon my main panel array will be doing little since they are fixed in one position. Again, my thought was could I add more panels in another direction to offset that loss.

    Hope this helps.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Extra PV Panels
    scheek wrote: »
    Okay. Let me clarify. I have 8 solar panels adding to about 1100 watts. I have them pointed in one direction (noon). I have a 6000 watts Aims inverter with a built in charger. According to manufacturer I can have up to 60 amps of panels. As is, I am nearing that now. I have room for maybe one more.

    As I read most likely my panels will never be at 100% efficiency so could I have room for another panels to help offset that loss.

    Too, in late afternoon my main panel array will be doing little since they are fixed in one position. Again, my thought was could I add more panels in another direction to offset that loss.

    Hope this helps.

    Okay a 24 Volt AIMS battery-based off-grid inverter, right? Because it can't possibly be a GT with those specs. Not a legal one, anyway.

    60 Amps @ 24 Volts is 1440 Watts, which makes sense.
    You have 8 panels totaling 1100 Watts? That would be 137.5 Watts each, which is a bit odd.
    So you have 'room' for 340 Watts more, or two more of the same panel.

    You are correct that panels rarely operate at 100% of their nameplate rating. 80% perhaps, and 77% is the standard derating used. As such you are also correct that you can "over-panel" a charge controller a bit without causing any harm. That is on a good controller. A cheap one, maybe not.

    At any rate it looks to me based on the info provided that you could add two more panels. Given the Watt rating on the panels they are probably "12 Volt" panels wired two in series to provide 24 Volts, and most likely have a Vmp of 17.5 and Imp of 7.8. Check to be sure of what the actual panel specifications are and that you can get an exact match for them.

    Now, can you add what amounts to a second array facing in a different direction to produce power once the sun comes off the first array? Usually yes. But it depends on a couple of things. A PWM type controller would have no issues with this. An MPPT type might. Good luck finding out what is inside that AIMS. It may even say "MPPT" but actually be PWM.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Extra PV Panels

    In general, you can overload an MPPT equipped inverter with as much PV in parallel that you want. The inverter will take as much current as it can handle and clip the rest. In series, however, it's a different story; never make a string so long that the total temperature corrected Voc will exceed the inverter's max input voltage at the record low temperature for where you are.
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