The Multiplus II and GX devices are increasingly used in ESS (home applications). However, Victron currently lacks a proper system for measuring incoming power.
When the Multiplus is installed in the Fuse box, this generally poses no issues, especially when combined with a current clamp sensor and PV generation on AC-Out1. But if the Multiplus is located far from the grid connection, challenges arise, especially with devices like the ET340 meter. RS-485 USB connected to a GX Device and then converting the signal via a cable to the meter Fuse box / Grid connection can be complex.
I believe this can be simplified with the following solutions (some of which already exist in the community):
- P1 Port support (Smart meter support) DSMR support V2 to V5 via RS-232
- Wifi-based GX measurement (not the DIY Zigbee construction that is recommended)
- Software-based measurement (e.g., MQTT, coming from an ESP32 from the P1 meter or current sensor)
Another argument is that solar panels connected to the grid (AC-IN) also need to report their power, as an ET340 cannot distinguish the flow direction compared to the smart DSMR meter commonly used in the Netherlands. ESS then becomes confused because the system doesn't know whether to charge or discharge.
In summary, P1 support in the GX landscape, is that coming? Due to the issues mentioned above, it appears that competition from hybrid inverters is gaining an edge in terms of cost and functionality. This is happening despite the rich capabilities of the Victron GX System.
