Where to put an PV inverter in an ESS system to make sure all its production goes to the grid?

Hi all,

I am in Martinique (French West Indies) and for now I have a SMA inverter (SB 2.5) with 2200Wc PV. It is a "sale everything to the grid" contract, all the production is to be sent on the grid.

I also have a backup system: a charger/inverter with batteries for backup (it is important for the hurricanes season).

I would like to add more PV for my consumption this time (I can't change my first contract so that part will stay).

So my question is: how to build the ESS so that my old inverter still sends everything to the grid, my new PV plugged into a bluesolar MPPT into a multiplus II enables me to consume as much of its production as possible (using the batteries I already have, lead gel, around 12kWh) and everything produces for my consumption in case of a blackout (both inverters and batteries then).

Thanks for any hint towards a solution!

Manu