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.


To add the IoTaWatt integration to your Home Assistant instance, use this My button:

Energy management

You can use the energy sensors directly with the Home Assistant energy dashboard.

If you have an energy production system such as solar panels, follow these instructions:

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.

Using a solar net system

The IoTaWatt team recommends that the inputs for solar reads positive which can be achieved by either changing the orientation of the CT sensor or in the IoTaWatt’s input settings, check Reverse.

Replace (Main_In_Red + Main_In_White + Main_In_Blue) with (Main_In_Red + Main_In_White + Main_In_Blue - Solar)

If you have two solar sensors named Solar1 and Solar2 you would use: (Main_In_Red + Main_In_White + Main_In_Blue - Solar1 - Solar2)

Configure Energy Management

In the Grid Consumption settings, select MainsConsumption.wh
In the Return to grid settings, select MainsExport.wh
In the Solar production settings, select Solar.wh