Integration for the IoTaWatt Open WiFi Electricity Monitor. It will collect data from the Current Transformer Clamps (Input CTs) and any Outputs that are defined on the IoTaWatt and create them as sensors in Home Assistant.


Adding IoTaWatt to your Home Assistant instance can be done via the user interface, by using this My button:

Manual configuration steps

Energy management

IoTaWatt does not provide the exact data that is needed for energy management. We’re working with the IotaWatt team on resolving this.

Until then, you can use these instructions to create the correct entities that work with energy management:

Configure IoTaWatt

You will need to configure two new IoTaWatt output sensors:

Name Unit Formula
MainsConsumption Watts (Main_In_Red + Main_In_White + Main_In_Blue) max 0
MainsExport Watts ((Main_In_Red + Main_In_White + Main_In_Blue) min 0) abs

Replace (Main_In_Red + Main_In_White + Main_In_Blue) with the correct formula for your main feed.

Configure Home Assistant

Add the following to your configuration.yaml file to convert the Watt measurements into kWh:

sensor iotawatt:
  - platform: integration
    source: sensor.mainsexport
    name: Total Grid Export
    unit_prefix: k
  - platform: integration
    source: sensor.mainsconsumption
    name: Total Grid Consumption
    unit_prefix: k