Template sensor multiply with another sensor syntax

Configuration
1

Hello,

I have tried a few different ways and also had a google and cant find anything that helps, usually it’s easy to find someone else with the same problem but no luck.

Bit of background, so I have a load smart plugs which tell me power in watts, I then use the integration platform to turn that into kwh.

  - platform: integration
    source: sensor.living_room_devices
    name: energy_living_room_devices_kwh
    unit_prefix: k
    round: 2

I then do hourly, weekly, monthly, yearly using the utility_meter integration

#Utility Per Month
utility_meter:
  energy_living_room_devices_month_kwh:
    source: sensor.energy_living_room_devices_kwh
    cycle: montly

I then take the monthly sensor and created another template sensor to multiply by 0.15p to give me my £ per month cost.

#Living Room Power Usage
  - platform: template
    sensors:
      energy_living_room_devices_month_cost:
        value_template: '{{ states.sensor.energy_living_room_devices_month_kwh.state | multiply(0.15) | round(2)}}'
        unit_of_measurement: £
        friendly_name: 'Living Room Devices Month Cost'

This all works fine but I do wonder if there is a cleaner way of doing it.

But my main question is can I instead of multiply(0.15) can I multiply(another sensor) because I have changed to a different electricity tariff with 30min changes in the price.

I tried the below but with no luck.

- platform: template
    sensors:
      energy_living_room_devices_new_month_cost:
        value_template: '{{ states.sensor.energy_living_room_devices_month_kwh.state | multiply(states.sensor.octopus_current_price.state) | round(2)}}'
        unit_of_measurement: £
        friendly_name: 'Living Room Devices New Month Cost'

I would need to /100 afterwards as the price comes in as 12 for 12p instead of 0.12.

Any suggestions would be much appreciated.

Cheers

2

you have to convert the states to floats and multiply them together that way. YOu can use normal math.

"{{ (states('sensor.energy_living_room_devices_month_kwh') | float * states('sensor.octopus_current_price.state')) | round(2)}}"
3

Of course, I use float for my solar sensor, thank you.

I have just thought though my logic isn’t going to work anyway because it is just going to x the total monthly kwh by whatever the price is at the time.

I need to come up with a way of taking a snapshot of the usage per 30mins x by the cost at that time and then add them up for total month.

I wonder if I can just pull my monthly usage in via the octopus API, I will have a look.

Cheers