HomeAssistant + Sigenstor + Fronius + BYD
I've been experimenting with a fairly niche setup and thought it might be useful to someone else.
I recently added a Sigenergy SigenStor (20 kW / 32 kWh) alongside an existing Fronius GEN24 (5 kW) + BYD (13.8 kWh) system.
One thing I wasn't happy with was that the GEN24 couldn't "see" the real site load once the Sigenergy battery was managing import/export. As a result, the Fronius would often start charging the BYD even though I'd rather use the available PV to charge the Sigenergy battery first.
To solve this, I built a small Home Assistant add-on that emulates a Fronius Smart Meter over Modbus TCP. It reads the Sigenergy Modbus registers and presents the GEN24 with a virtualised grid import/export value (with optional virtual load compensation), allowing the Fronius to prioritise supplying site demand before charging the BYD.
It won't suit every installation, but if anyone else is running a mixed Sigenergy + Fronius system, it might be useful.
I'd be interested to hear if anyone else has tried something similar or has ideas for improving it.
GitHub:
https://github.com/systemx-xx/ha-energy-addons/tree/main/fronius_sigenergy_direct