Calculate power usage

Configuration
1

Have an electric heater controlled through MQTT in HA.
They are basic switches with reporting of 0 and 1 for on/off.
As i know their energy consumption (700w) i would like to calculate their hourly/daily usage. Seems it cannot be done with HA directly. Installed influxdb with grafana but seems i cannot do that either (if possible maybe a hint?)
So which history component i should use for that?

2

You should be able to do it with the History Statistics Sensor. https://home-assistant.io/components/sensor.history_stats/

Time on per day * power = energy per day.

1 Like
3

Two options:
A)
Start with this to calculate time on:

Then create a template sensor where you multiply the result(s) of the above mentioned component with your 0.74kW.
e.g. for yesterday

  - platform: history_stats
    name: Heater ON yesterday
    entity_id: sensor.heater
    state: '1'
    type: time
    end: '{{ now().replace(hour=0).replace(minute=0).replace(second=0) }}'
    duration:
      hours: 24

and the template sensor:

   energy_heater_yesterday:
      value_template: '{{ states.sensor.heater_on_yesterday.state | multiply(0.74) | round(2)}} kWh' 
      friendly_name: 'Heater yesterday kWh'

B)
You mentioned Grafana. I assume you also have InfluxDB.
Do your aggregations using a combination of template sensors (some math inside) and InfluxDB sensors:


However, since you are not reading kWh or kW directly I recommend option A.
3 Likes
4

For me the sensor returns a wrong value with your solution.

I used:

{{ (states.sensor.motor_on_today.state | float * 0.7 ) | round(2) }}

The value 0.7 means the 700W device.

Feel free to correct me if I’m wrong.

5

Any way to get this value into Energy Dashboard?