Good day
I have 2 x 48/5000/70 Multiplusses . I have 1 x 150/100 MPPT with 18 x 315W Canadian Solar's facing due East, connected to this giving a maximum of 5.6 kWp. I have also added recently a 250/100 MPPT with 12 x 355W Canadian Solar giving me about 4.22 kWp which is directly facing West.
The East facing MPPT and panels receives full sunshine very early in the morning (I am based in South Africa, Pretoria). I have noticed that it appears as if the system is throttling my MPPT to between 3200-3400 Watts. I sometimes see it spike up to 4kW but it never sustains it there. My curves are not bell shaped either and are more like chopped bell shapes with a level shape around these 3200-3400 values. I have no shading that blocks the light until about 1:30 pm in the afternoon. I thought that this might be an issue due to the installation but we have gone through it with a fine tooth comb and everything physically checks out. Which left me to believe it is probably ESS throttling my system. I have added load to the system and I have feedback to the grid enabled and no matter what I do I just can't get more out of the system.
I notice exactly the same behavior in the afternoon when maximum sun is available, it maxes it out at around 2700W and has almost identical curves to the issue described above, that it is flat lining it around this value.
My Multiplusses are both microprocessor 26 on version 430 connected in Master/Slave
I have feedback enabled to the grid
My CCGX is on ver 2.20
Both my MPPT's are on ver. 1.37
I have measured my results against 3 different design packages and even drawn in accurate shading etc. and the gap is substantial. I am "missing" at least 30%-40% of potential PV generated. Now I know one can't rely 100% on these values and if there was around a 15%-20% difference I might have accepted it, but 30%-40% is substantial.
I really would appreciate any thoughts that you might have on what could be the issue as I have seen somewhere else that ESS might be limiting the potential of inverting to 80% of the available power and if so that would explain it....but is there a way around it?
Below are the graphs