Needed a power monitor that can

- Monitor three phase power

- Monitor both directions, to measure sold solar energy

- Be easily integrable to open source home systems without needing to use propietary clouds

PC321-Z from OWON (sold also on other brands, don't know exactly which types tick these boxes).

Ordered two units directly from OWON. Unit price about doubled from ~50 € due to shipping and taxes but still not easy to beat the price.

Wired first to a simple AC cable, pressed the button for ~5 seconds and set Tasmota to discover Zigbee devices, was found and started to send MQTT messages with electricity stats. By default the data looks somewhat like this:

ZbZCLRawReceived: {"0xD149":{
  "0702/4002":"0x00000000F192",
  "0702/2002":197,
  "0702/3002":2400,
  "0702/3102":1224,
  "0702/4102":"0x00000000829F",
  "0702/2102":218,
  "0702/4106":67,
  "Endpoint":1,
  "LinkQuality":14}}

 Got the API specs from OWON against NDA but is also available in the internet.