Hi, I have seen on some days that my solar production ramps up in the morning and then stops at around 2.8kW where it stays for a few hours before it goes down during evening.

I have a 5kW Deye, 5kW Volta battery and 6 x 545W = 3270W solar panels. I have seen the panels produce near that maximum during cooler lightly cloudy days where the clouds scatter the sunlight.

Is there any reason why this might be happening? My settings seem to allow the higher wattage, but on warm sunny days it seems to be limited. See below graph as example:

Edited November 23, 20232 yr by ZippyZappy
Better pictures

6 hours ago, ZippyZappy said:

Hi, I have seen on some days that my solar production ramps up in the morning and then stops at around 2.8kW where it stays for a few hours before it goes down during evening.

I have a 5kW Deye, 5kW Volta battery and 6 x 545W = 3270W solar panels. I have seen the panels produce near that maximum during cooler lightly cloudy days where the clouds scatter the sunlight.

Is there any reason why this might be happening? My settings seem to allow the higher wattage, but on warm sunny days it seems to be limited. See below graph as example:

The reason this is happening is due to cell tempreature that degrade the cell output. At lower temps the cells are more effiecient the same applies for higher temps each degree above 25°C degrades the cell degrade by the same margin than below 25°C tested at STC. Yesterday in Mpumalanga i recorded solar panel surface temps of 61°C.that is 36°C above STC.

Edited November 23, 20232 yr by TaliaB

6 hours ago, ZippyZappy said:

Hi, I have seen on some days that my solar production ramps up in the morning and then stops at around 2.8kW where it stays for a few hours before it goes down during evening.

I have a 5kW Deye, 5kW Volta battery and 6 x 545W = 3270W solar panels. I have seen the panels produce near that maximum during cooler lightly cloudy days where the clouds scatter the sunlight.

Is there any reason why this might be happening? My settings seem to allow the higher wattage, but on warm sunny days it seems to be limited. See below graph as example:

 

Perhaps heat, but looking at the production curve, it does seem a bit flat, perhaps your amps are being throttled? What is the max amps of the MPPT compared to the string? (assume all panels are on one string). Suspect those panels are rated at 13A while the MPPT can only handel 11A

Edited November 23, 20232 yr by I84RiS

2 minutes ago, TaliaB said:

The reason this is happening is due to cell tempreature that degrade the cell output. At lower temps the cells are more effiecient the same applies for higher temps each degree above 25°C degrades the cell by the same margin than below 25°C tested at STC. Yesterday in Mpumalanga i recorded solar panel surface temps of 61°C.that is 36°C above STC.

I also first suspected this, but the curve will still have a roundish shape, is it not to flat for it to be only heat related?

5 minutes ago, I84RiS said:

I also first suspected this, but the curve will still have a roundish shape, is it not to flat for it to be only heat related?

Yeah you are correct normally the 545w panels Imp is around 13.25 amps while the Deye max current input is 11 amps. It would have been interesting to see the result on 15 amp Mppt.

1 hour ago, I84RiS said:

 

Perhaps heat, but looking at the production curve, it does seem a bit flat, perhaps your amps are being throttled? What is the max amps of the MPPT compared to the string? (assume all panels are on one string). Suspect those panels are rated at 13A while the MPPT can only handel 11A

The MPPT max A is 13A so does not seem like that is the issue

1 hour ago, TaliaB said:

The reason this is happening is due to cell tempreature that degrade the cell output. At lower temps the cells are more effiecient the same applies for higher temps each degree above 25°C degrades the cell degrade by the same margin than below 25°C tested at STC. Yesterday in Mpumalanga i recorded solar panel surface temps of 61°C.that is 36°C above STC.

I am leaning to this as you can see the voltage drop as the temps get hotter during the day while the current is steady at 12.7-ish