I previously tracked specific item electricity usage using smart plugs but wanted a whole home solution. I bought a device from Frient which would be supported over Zigbee.

Installing it was easy and so was adding to the Zigbee network. It appeared in HA (Home Assistant) instantly.

My meter is a Kamstrup DK-8660 which has a diode which flashes 1,000 times per kWh which matches the default on the Frient reader so no configuration changes were needed.

Electricity Meter

Unfortunately now in HA while I can see my home homes power usage it is harder to see the device by device breakdown. This is because I cannot easily tell HA that the device energy usage is a subset of the whole home energy usage.

Electricity Graph

I was able to work around this somewhat for the current W usage but not for the kWh usage as it is an accumulating sensor the calculation will be more complicated.

My W method uses a template to subtract the individual devices from the whole home usage. I choose the max of 0 and the calulated value at the end to prevent negative readings when the smart plugs register usage before the Frient reads the usage.

  - sensor:
      - name: "Other Power"
        unit_of_measurement: "W"
        state: >
          {% set dishwasher = states('sensor.dishwasher_power') | float(default=0) %}
          {% set dehumidifier = states('sensor.dehumidifier_power') | float(default=0) %}
          {% set server = states('sensor.server_power') | float(default=0) %}
          {% set washing_machine = states('sensor.washing_machine_power') | float(default=0) %}
          {% set meter = states('sensor.electricity_meter_power') | float(default=0) %}
          {{ max(0,(meter - (dishwasher + server + washing_machine + dehumidifier))) }}