Hi, I have a house with a 4kW GT system on FIT on phase A
I have added a 12kW array which I am planning to split over phase B and C.
I want to use a multiplus II as a smart inverter/charger from a lithium battery to store excess energy from any phase.
My supplier meter is net metering (non smart). So what I (think I) need is my own net metering meter which talks to the Multiplus and tells it to charge or discharge the battery to keep the import/export at zero. However this will only be pulling off one phase. This is why I need the external meter. If I am exporting 1kW on phase B and C (for example), with no import, but the Multiplus is on phase A, it can still import 2kW on phase A with no supplier charges.
I have researched Modbus meters but I just wondered if anyone had done anything similar - presumably I need an interface between the Modbus and the Multiplus to convert Net Export Power into Victron charge now Power.
I will have a zappi car charger and a DHW store system to soak up the excess energy. Ideally this would be priority order
1. Car (if present)
2. House batt
3. DHW cylinder
4. Export.
Although I would be willing to always do House first if that is less complicated (the zappi and DHW system will communicate internally but I don't know if they would communicate with the Victron).
I believe delays can be programmed such that the Victron could have a shorter delay on start up than the Zappi which would ensure the house batt gets priority over the car.
Of course as the car isn't always there I thought that would be best if the car got first dibs as hopefully if its a sunny day the house would get a chance later after the car leaves.
I should be good for producing approaching 16000kWh per year with this system (the 1year old original 4kW array made close to 4000 in a year and the 12kW array is less shaded)
My background is Marine - off grid so use a lot of Victron products. I have used R pi a bit so I guess this or Arduino could maybe be a useful interface if there isn't a premade solution available.
Thanks in advance
Olly