November 2, 20232 yr I have 14 x 425 w Canadian solar panels which is 5.95 kw in total. After all the rain here in Hillcrest , KZN the skies finally cleared and panels are nice and clean. My output got up to 7.1 kw yesterday from my 5.95kw array. Clearly the Canadian panels are under spec as that is a massive output.
November 2, 20232 yr That is a tad worrying though, if I spec Canadian panels for my system and it's on the verge of what the MPPT can handle, I risk blowing it if they put our more than what their spec sheets state...
November 2, 20232 yr Author 2 minutes ago, jbroo said: That is a tad worrying though, if I spec Canadian panels for my system and it's on the verge of what the MPPT can handle, I risk blowing it if they put our more than what their spec sheets state... I agree but fortunately I have an 8kw Sunsynk which can handle it fine.
November 2, 20232 yr The cooler temps and cloud edge when the sun comes out does wonders. Have had a record 7,4kW from my 6,4kW JA Panel array before. Yesterday it peaked at 6,8kW.
November 2, 20232 yr 13 minutes ago, Nicholas Strachan said: I agree but fortunately I have an 8kw Sunsynk which can handle it fine. Yeah, us 24v Axpert commoners have to worry 😄 I was told elsewhere on this forum to overspec the system - my MPPT can handle 1kw (I know, I know), but it was suggested I could spec up to 10-20% higher, so was planning 2 x 600W panels. Now this has me worried... That one day in the year when it's extra clear and your panels overproduce, and *poof* 🫣
November 2, 20232 yr If well within the voltage specs it shouldn't go "poof". Curious to know though, when folks are seeing way higher than rated output are they seeing voltages going past the advertised Voc or just amps climbing?
November 2, 20232 yr 11 minutes ago, LumexClipsal said: If well within the voltage specs it shouldn't go "poof". Curious to know though, when folks are seeing way higher than rated output are they seeing voltages going past the advertised Voc or just amps climbing? So I checked my PV string voltage and over the past 2 days it has been rather stable with the highest voltages in the early hours of the morning (6/7am) and then during the day it does not get close to that so don't know if the cloud edge effect did not last long enough for it to be logged or if the voltage does not increase much and its more the current which might increase. There were periods where I saw my PV production increase significantly for a short period of time, but whether the clouds just cleared up or whether it was cloud edge effect I cannot say for certain either.
November 2, 20232 yr 26 minutes ago, LumexClipsal said: are they seeing voltages going past the advertised Voc or just amps climbing My panels are rated just short of 13A. When these high peaks occur I have seen the Amps between 15 and 16A. The voltage doesn't change much. This is yesterday's peak at 6,85kW at 09:42. One string each feeding each Inverter. The Amps went to 15 and 15,7 respectively Voltage stays normal, in fact because of the load it actually drops slightly. Edited November 2, 20232 yr by zsde
November 2, 20232 yr All solar panel suffer from the cloud edge effect . Solar panels perform best when cold but on our roofs they run at roof temp so never get close to there rated amps wats and volts . On a hot sunny clear day as an big cloud makes shadows for a few minutes the roof and panels cool and as the cloud moves the sun strikes the cool panels and so they generates more than they rated . So best is not to run strings close to controller volts and if your are to remove one panels .
November 2, 20232 yr 3 hours ago, LumexClipsal said: If well within the voltage specs it shouldn't go "poof". Curious to know though, when folks are seeing way higher than rated output are they seeing voltages going past the advertised Voc or just amps climbing? As indicated you can never get a voltage higher than Voc when the panels are not open circuit. That is the reason they give this voltage. As you draw more power the voltage will sag a bit. The higher the load at the same other factors the lower this voltage will be. Cloud edge will affect the voltage as the panels cooled down a bit while the sun was behind the cloud. For sure no need to worry even if you did over spec. This high output is only for a few minutes while the panel temp increases and the output drops. High output always goes with high amps and a bit lower volts. Edited November 2, 20232 yr by Scorp007
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