Hello,
I am new to this communtyand like this forum: it’s full of great info 
I am planning on installing an ESS system at home with 28 solar panels (9kw total) 45 dégrées, south orientation and grid connected
My needs are basic and standard:
- 48v batteries (because it’s cheap)
- be able to backup when no grid is available (100% electric at home so I need to be able to drive at least 6 to 7 kw loads every day for an hour or two)
- reinject to grid all the over generated energy when batterie is full and hot water is done (solar production should always be at it’s maximum)
- Use energy from battery at night even when grid is present
- Produce solar energy even when grid is not présent
- Solar production will start even at low light (low production). WE have lots rain and low clouds in french bretagne
, but WE have very long day light duration here since theyre are no mountains and we are near the sea ==> low production X Long day Time Can make a big difference in winter ! - Good monitoring
After a lot of research with various inverter brands, I identfied the following config which seems to be the best for my case :
- Mppt RS 450/200 ( 3 strings of 6 panels)
- Multiplus II 10K
- Cerbo GX
- 2 x 16kwh 48v lfp batteries
Nothing fancy, quite standard config I think.
- Is this config compatible with my needs (I need to be sure there isn’t a twirk somehere) ?
- From the French certification point of view, I am not quite sure if the MP II needs adfitionnal HW to establish full backup/UPS ( full backup box for example) ?
Thank you