rotund chasm
So first we need to create a sensor that takes the product of the power and costs
template:
- sensor:
unique_id: ecc4d377-6e5e-4758-b570-549539525357
name: Device costs
state: >
{{ states('sensor.device_power')|float(0) * states('sensor.brabander_electricity_price')|float(0) / 1000}}
unit_of_measurement: "€/h"
state_class: measurement
It is dividend by a factor of 1000 because my power sensor reports in W and my price sensor in $/kWh
rotund chasm
This is a measurement in time and not a cumulative value.
Therefore we need a Integral helper.
hard tide
This is a measurement in time and not a cumulative value.
Therefore we need a In...
as type of "Riemann sum integral" right?
rotund chasm
Yep, put the newly created sensor into that helper and set it to hourly
hard tide
accuracy to 2 decimals
rotund chasm
If you have set the unit_of_measurement correctly in the created template sensor it will produce the right amount of costs
hard tide
sure!
What should be the intgration method of that riemann sum integrator? like "left Riemann sum"?
or "trapezoidal rule"?
rotund chasm
Yup left is the best
hard tide
ok
rotund chasm
Oh sorry reading the documentation the trapezoidal rule can be preferred depending on the power characteristics of the device. But I expect a charger to have a long continuous equal load so left will do the job
fresh bison
trapezoidal falls apart if the sensor is ever 0 for a long period of time
hard tide
the sensor will be like 7000 for hours 😄
rotund chasm
From there you can add utility meters to track the costs based on days/months/years etc
hard tide
So this integral helper counts the price during the charge
then I add a utility meter and reset it daily, weekly etc?
hard tide
From there you can add utility meters to track the costs based on days/months/ye...
ahh yeah.. you were faster
can this method also improve my "per charge" cost counter?
rotund chasm
Yes, what I do to calculate the costs for a run is create an input number and store the current value of the costs sensor into that input number at the start
At the end you can simply substract the state of the input number from the cost sensor
hard tide
do you do this with an automation? (like from the blueprint "Appliance has finished")
Or how do you track "the end"
rotund chasm
With an automation, but can also work with any blueprint that has options to add start and end actions
hard tide
ok, for one run you:
created 2 helpers of input number
#1 is for storing the current value of the riemann sum integrator
#2 is for storing the cost value of the last run
right?
rotund chasm
Yes, that would work. I personally dont store the cost value of a run, but send it in a notification to me
hard tide
when the charging starts, you store the value to #1 and reset #2
When the charging finishes you calculate the rieman helper value minus the #1 value to get #2 value?
ahh yeah.. also possible
rotund chasm
It will also work if you update #2 only at the end
hard tide
that makes it clear
yes you are right ^^
thanks a lot @rotund chasm 🙏 👍
well... wait^^
this calculates the cost of the run... but it doesnt take solar production into account 😄
rotund chasm
That's true
You can combat that by adding conditions in the first template sensor I guess
{#only solar is used so no costs#}
{% if sensor.grid_power | float(0) <= 0 %}
0
{%else%}
{{ states('sensor.device_power')|float(0) * states('sensor.brabander_electricity_price')|float(0) / 1000}}
{%endif%}
Not sure yet when you have both grid and solar usage at the same time how you can determine what goes to the charger, but if you do you can subtract the solar power first from the device_power.
hard tide
I thought about something like this:
- sensor:
unique_id: ecc4d377-6e5e-4758-b570-549539525357
name: Device costs
state: >
{{
states('sensor.device_power')|float(0) * states('sensor.brabander_electricity_price') / 100 *
(100 * states('sensor.grid_power') / ( states('sensor.grid_power') + states('sensor.solar_power') - states('sensor.grid_feed_power')))
/ 1000
}}
states('sensor.device_power')|float(0) * states('sensor.brabander_electricity_price')|float(0) / 1000}}
unit_of_measurement: "€/h"
state_class: measurement```that takes also parts of the produced energy into that calculation
yours assume, that all of the energy/power is 100% used by the car
I think this method should work there
rotund chasm
yours assume, that all of the energy/power is 100% used by the car
Not exactly, it assumes that if there is no power from the grid, all the power used by the device is coming from the solar production
hard tide
yeah, but I will never have this case ^^
My solar produces about 2000W peak
the char charges with something like 3000-7000W
so the "mixed power" is exactly the case I want to catch
but I think I can make it from here
rotund chasm
Yeah I think the calculation you mentioned above does a good estimate, you can use that in the template. The real problem is to allocate exactly how many of each power type is used by that circuit