My system over all performs as well as to be expected.

I am however not certain that this amount of voltage drop from the PV Panels under increasing load is normal.
Here are the screenshots taken a few minutes ago. We have a glorious sunny day.
With a load around 3kW the PV voltage is around 240V at around 20A
If I now increase the load to around 4,8kW, the PV voltage drops to around 193V still at around 21A
Where would this, what I consider a large Voltage drop originate? The Solar cables (around 25 meters) or is it the Inverter MPPT that has such a large efficiency drop as it approaches it 5kW rating?
Anyone else that has monitored such large V drops? Maybe it is due to the winter sun just not having enough oomph at 10:30 to maintain the demand, which I suspect to be the case.
Just took another screenshot now, 30 minutes later and that drop has all but disappeared. Screenshots Load 5 and Load 6.


 

That is very normal, a function of the panels. I have similar voltage drops under load, and then voltage going up again when load ceases. The latter is useful in illustrating the importance of using Voc and not Vmp when sizing arrays 😎

Edited June 27, 20224 yr by YellowTapemeasure

20 minutes ago, YellowTapemeasure said:

That is very normal, a function of the panels. I have similar voltage drops under load, and then voltage going up again when load ceases. The latter is useful in illustrating the importance of using Voc and not Vmp when sizing arrays 😎

Thanks mate. As noted, about 30 mins to an hour later the voltage drop was basically gone and there was hardly a difference between a 3 and  5kW load.
Keep forgetting that now in the midst of our winter that I only have about a window of 2 to 3hours between about 10:30 to around 13:30 where I get the max solar power with my panel orientation.
Appreciate your data confirmation. 

The graph shows how the PV Voltage increased from about 10:45 with a fairly constant load

Edited June 27, 20224 yr by zsde

5 hours ago, zsde said:

Thanks mate. As noted, about 30 mins to an hour later the voltage drop was basically gone and there was hardly a difference between a 3 and  5kW load.
Keep forgetting that now in the midst of our winter that I only have about a window of 2 to 3hours between about 10:30 to around 13:30 where I get the max solar power with my panel orientation.
Appreciate your data confirmation. 

The graph shows how the PV Voltage increased from about 10:45 with a fairly constant load

Can you perhaps indicate how your wiring and what size is used from the panels to get to the inverter. At 21A do you have 2 or 3 strings and are they in parallel?

2 minutes ago, Scorp007 said:

Can you perhaps indicate how your wiring and what size is used from the panels to get to the inverter. At 21A do you have 2 or 3 strings and are they in parallel?

I have two strings of 6 panels each that are paralleled all connected on 6mm wire. 
The Inverter caps at 22A. The panels are rated at 12,9A, so I could potentially get just shy of 26 A.  Thus I will never see more than around 5500W from the potential 6400W. But it makes up for it on cloudy days.
When I noticed the voltage drop this morning I was alarmed at first but I was just expecting too much too early. Half an hour later and I had over 5kW solar whilst the load was at 4,8kW. 
One of those over analysed moments where one starts to imagine non existent problems
Blue is solar, red is load.

33 minutes ago, zsde said:

I have two strings of 6 panels each that are paralleled all connected on 6mm wire. 
The Inverter caps at 22A. The panels are rated at 12,9A, so I could potentially get just shy of 26 A.  Thus I will never see more than around 5500W from the potential 6400W. But it makes up for it on cloudy days.
When I noticed the voltage drop this morning I was alarmed at first but I was just expecting too much too early. Half an hour later and I had over 5kW solar whilst the load was at 4,8kW. 
One of those over analysed moments where one starts to imagine non existent problems
Blue is solar, red is load.

All seems to be fine looking at your load and PV produced vs the voltage.

I did ask about the strings as it appeared as if the current is capped once it reached the very steady state @ 10h30.

You are getting good current as early as 10h. Mine is only available after 11h15. My peak production is also very shorter.

When your load went down after 10h and PV remained high were you charging the battery?

30 minutes ago, Scorp007 said:

All seems to be fine looking at your load and PV produced vs the voltage.

I did ask about the strings as it appeared as if the current is capped once it reached the very steady state @ 10h30.

You are getting good current as early as 10h. Mine is only available after 11h15. My peak production is also very shorter.

When your load went down after 10h and PV remained high were you charging the battery?

Indeed, the battery was still taking the available Watts. I try to draw power during battery charge as I just don't feel comfortable when I suddenly see a 100Amp charge being pumped into the battery. Yes, thats what Hubble says is fine and the Li Protocol of the Inverter will push that much if it's available. Can't change the max charge rate unless I change to USE mode which defeats the purpose of having BMS comms.
But then there is me, I just apply a decent load and let the battery charge at a lower Amperage. Just my gut feel that I may prolong battery life by not pushing the charge rate to the limit.
As for earlier maximum solar, my panel orientation isn't true North, it is around 20° NE, thus earlier max and earlier deterioration.

Edited June 27, 20224 yr by zsde

3 hours ago, zsde said:

I try to draw power during battery charge as I just don't feel comfortable when I suddenly see a 100Amp charge being pumped into the battery.

Yep, I do the same. With my 3x Pylontech US3000Bs, I limit them to 75A charge (25A each) using the Sunsynk's limiter, even though the BMS is happy with 33A each. On my Hubble install, I allow 100A to the 3 of them, so that's 33A each. All in the name of longevity.