Here in South Africa we are more often than not, required to prevent power being exported beyond the Meter (Grid).
We often encounter homeowners who have already invested in a solar power system, with some form of grid-tied inverter installed.
The typical upgrade involves installing MultiPlus or Quattro Inverter/Chargers with some form of lithium battery bank.
The question arises with regards to how we incorporate the existing grid-tied inverter?
If it is not a Fronius inverter, then we cannot use the "Fronius Zero Feed-In" functionality through using a single energy meter (Carlo Gavazzi ET112 or ET340).
If we retain the existing grid-tied inverter's export limiting device (current sensor or energy meter), and continue to implement an energy meter for the Victron system, then how should it be set up? Which device should be installed first in line? Should we set a buffer/threshold on one of the systems to ensure that they do not compete to achieve grid-power = 0 (or other set point)?
I foresee that the two different export limiting control systems will compete against each other and may result in instability and/or poor performance.
Any insights into this?