Something limiting my PV production all of a sudden

[doronazl]

so i have this system for a couple of weeks now
its a 10k3ph deye inverter X2 connected in parrallel
15.3k solar panels - 32x480w
20kw tmda Li batteries

the first few days after it was installed i could see some moment of getting 12-13kw of PV from it, of course was around noon and when the sun was fully out.
today was a very sunny day, clear blue sky, for some reason it would not go over 10.3kw total(5.15kw on each inverter)
i dont know why its specifically on this number but that whats happened, for a few hours it was just capped at that number , would go unders sometimes but never over, im sending power back to the grid so nothing to do with load or batteries, if it can, it should go higher in these conditions.

what can cause this ?

 

[sunshine_eggo]

Most utilities have the ability to throttle output.

Does your grid tie agreement have a power limit?

 

[doronazl]

Most utilities have the ability to throttle output.

Does your grid tie agreement have a power limit?

No it doesn't, a week ago it reached 14kw
Been fiddling quite a lot with the settings since then but i can't figure out what could affect this

 

[sunshine_eggo]

No it doesn't, a week ago it reached 14kw
Been fiddling quite a lot with the settings since then but i can't figure out what could affect this

Can you plot your PV throughout the day? If so, does it show clipping, i.e., 10.3kW as a flat line that interrupts the normal power curve with a peak at high noon (on a true South array)?

Can you deliberately trigger a very high load or loads that exceeds your PV array's rated output? This might help to determine if it's throttling back to the grid.

 

[doronazl]

Can you plot your PV throughout the day? If so, does it show clipping, i.e., 10.3kW as a flat line that interrupts the normal power curve with a peak at high noon (on a true South array)?

Can you deliberately trigger a very high load or loads that exceeds your PV array's rated output? This might help to determine if it's throttling back to the grid.

I can try trigger the load but I'm curious, its supposed to send all excess energy back to the grid so there shouldn't be a cap right?
Here is the chart

 

[houseofancients]

so i have this system for a couple of weeks now
its a 10k3ph deye inverter X2 connected in parrallel
15.3k solar panels - 32x480w
20kw tmda Li batteries

the first few days after it was installed i could see some moment of getting 12-13kw of PV from it, of course was around noon and when the sun was fully out.
today was a very sunny day, clear blue sky, for some reason it would not go over 10.3kw total(5.15kw on each inverter)
i dont know why its specifically on this number but that whats happened, for a few hours it was just capped at that number , would go unders sometimes but never over, im sending power back to the grid so nothing to do with load or batteries, if it can, it should go higher in these conditions.

what can cause this ?

have you updated the firmware recently ?

 

[doronazl]

have you updated the firmware recently ?

I messaged Deye support about this issue today and their first move was updating the firmware. Didn't change anything

 

[sunshine_eggo]

This does not look like clipping at all:




That looks like the daily solar profile where you get peak sun in the middle of the day.

What is your actual array size?

 

[doronazl]

This does not look like clipping at all:

View attachment 122226


That looks like the daily solar profile where you get peak sun in the middle of the day.

What is your actual array size?

15.3kw
I noticed the curve looks natural, but i was observing it live during the couple of peak hours , it was stuck at 10.3kwh exactly, wouldn't cross it

 

[sunshine_eggo]

15.3kw
I noticed the curve looks natural, but i was observing it live during the couple of peak hours , it was stuck at 10.3kwh exactly, wouldn't cross it

can we see that too?

 

[doronazl]

can we see that too?

My point is it was not going over that number.
Whereas last week it did with no drama under same conditions.
Il try to take more photo tomorrow if same climate that is

 

[doronazl]

Recent findings, checking before the PV breaker? Getting 360v from each string, once i open the breaker that goes to the inverter, voltage drops to 280-300v

 

[brum]

That's normal. When you start drawing current from the panels the voltage will drop. Check the voltage/current curve for a PV panel and how MPPT works if you are curious why.

 

[doronazl]

That's normal. When you start drawing current from the panels the voltage will drop. Check the voltage/current curve for a PV panel and how MPPT works if you are curious why.

I see.
Ok good to know.
Really not sure whats the issue then.
Did Factory default too, didn't help

 

[LEDuser]

I don't think human eye can detect high humidity in the air. You can have blue sky and the power on the panels can be up to 30% lower due to lower visibility. You should use irradiance meter to get same conditions and compare power output.

 

[doronazl]

That's normal. When you start drawing current from the panels the voltage will drop. Check the voltage/current curve for a PV panel and how MPPT works if you are curious why.

I see.
Ok good to know.
Really not sure whats the issue then.
Did Factory default too, didnt hdlp

 

[doronazl]

Does this look more like clipping?

 

[sirslayer]

atmospheric conditions like high level clouds, fog and winter ( North America) dew have a major influence on your energy production

 

[doronazl]

atmospheric conditions like high level clouds, fog and winter ( North America) dew have a major influence on your energy production

Im sure they are but its reaching the EXACT same production 3 days in a row, 10.3kw maximum, not going higher.

This looks too consistent to me.

 

[sunshine_eggo]

Does this look more like clipping?

Not really. Clipping is a hard limit where you essentially show truly flat production. You have what seems to be a taper and a mid-day spike.

This seems more like a safety limiter. Maybe something is getting hot, and production is reduced.

Clipping looks more like this (top flat line repeatedly hit and never exceeded):



Are the charge controllers in a climate controlled area with adequate ventilation?