I have an ESS installation with two parallel connected Quattros 48/15000, two MPPT RS 450/200 solar chargers and one MPPT 150/45 solar charger. The system is controlled by a Cerbo GX, and I use MG batteries.
I had a burglary where one of the builders who built the shed in which the system is housed stole my batteries, so the system was offline for a few months while I replaced the stolen and damaged components. After I reconnected the system, I noticed that the system was now constantly drawing power from the grid, even when there was plenty of solar power available. This draw was between 600W and 1kW (averaging 700W) - even when there was 18kW worth of solar power available, of which 12kW was being fed into charging my batteries. I asked my dealer to look into it and he did something and now the draw is more in the 300W-800W (averaging 400W) range. The system is never feeding any power back to the grid, not even a few Watts. My dealer says that this is normal and that the draw cannot ever be exactly zero, and I understand from the posts on this forum that this is indeed the case.
However, what is strange is that last summer, before I had the burglary, the system was fluctuating between -150W and 300W when there was plenty of solar power - according to VRM. According to my Carlo Gavazzi meter, the meter was, however, stopped. The "meter stopped" LED was on. And my utility meter was not advancing at all - during the sunny months, it would not advance even by 0.1kWh over the course of a week. So even though the Quattroes were sometimes drawing 300W, sometimes feeding back 150W, it seems that the fluctuations were taking place with high enough frequency that the utility meter registered no net energy consumption.
Now, however, my Carlo Gavazzi meter confirms a constant draw of 300W-800W from the grid, and my utility meter is constantly advancing - even when there is enough solar power to supply all my energy needs twice over. My pre-Victron installation average consumption was about 1.5kW, so this 300W-800W is not a small amount of power draw - when taking into account the overheads of the Quattros and other Victron components and the UPS and the ventilation fans and the fact that I get no solar power on dark winter days, I'm not sure if on an annual average basis, my average utility power consumption is higher or lower now that I've installed all those solar panels than it was before I installed the Victron system.
I've asked my dealer and he says it is what it is, this is the best we can do. But this can't be the case, as last summer, on sunny days, there was no net draw from the grid.
In ESS settings, my Grid setpoint was set to 70W last summer and I had reduced it to 50W more recently. I have now reduced it still further to 0W, but there is still net draw from the grid when it isn't needed.
However, in the meantime, we have upgraded the firmware of all my devices a few times. For example, my Cerbo GX is now running firmware version 3.30, whereas before it was running an earlier version (unfortunately, I do not know which version).
What could have resulted in this change of behaviour? And how can I get the old behaviour back?
Thank you.
