Utility meter not accurate

typekcz · May 4, 2022, 4:21pm

I have noticed that my utility meter is always showing less that when I manually calculate energy by day.
I have Shelly 1PM and I’am using it’s energy sensor.

utility_meter:
  ev_nabijeni_denne:
    name: "EV nabíjení denně"
    source: sensor.shelly1pm_48551903116e_energy
    cycle: daily
    offset: "08:00"

This is the history of the Shelly energy sensor (top) and history of the utility meter (bottom):

You can see that Shelly energy has gaps and that is probably what is causing the lower readings on the utility meter. Gaps are caused by low WiFi signal strength, but that shouldn’t cause any inaccuracy. The value is 10% off!

Does anyone have some experience with it or some advice how to fix this?
Thanks

tom_l · May 5, 2022, 2:02am

My Shelly PM and Utility meter are within 0.5% of each other.

typekcz · May 5, 2022, 1:29pm

I think that the issue I have is with utility meter when there are missing data rather than Shelly.

tom_l · May 5, 2022, 1:43pm

Must be. At the end of the day I have a 0.3% difference (basically the least significant digit). I have no missing data though.

typekcz · May 5, 2022, 1:56pm

It must be something with missing data.
Here are the graphs overlayed with same scale:
obrazek
It should go up straight (constant derivation) but on the red (utility meter) there are some flats and it’s not a straight line like on the blue Shelly graph.

tom_l · May 5, 2022, 2:11pm

Here’s the issue and explanation:

github.com/home-assistant/core

utility_meter shouldn't care that the old state was "unknown" when using "delta_values"

opened 02:18AM - 21 Jan 22 UTC

closed 09:08AM - 01 Apr 22 UTC

melyux

integration: utility_meter

### The problem The code for Utility Meter shows that it disregards the sourc…e sensor value change if its "from" state or its "to" state is "unknown/unavailable". When you're using `delta_values` as `true` as an option for Utility Meter, it shouldn't care what the "from" state is; instead, Utility Meter ignores this first non-unknown value and only starts incrementing after it. This doesn't make sense. The sensor is telling you that there was a delta change to the sensor value; this shouldn't be ignored and leads to wrong cumulative data from Utility Meter. Addendum A: The "from"/old state shouldn't matter even if `delta_values` is `false`. Utility Meter is supposed to persist sensor data across HA restarts. It has access to the "old" value. It should use that for the old value instead of the source sensor's old value (which could be unknown after an HA restart, since for some reason HA still doesn't persist any other sensor data across restarts except for Utility Meter sensors). Because right now, Utility Meter misses the first data that's reported after a HA restart in every case. Addendum B: There should be better support for rollovers for when `delta_values` is `false`; right now, Utility Meter ignores the first data reported it when the sensor's data rolls over to 0 from its max value. Same kind of situation. This can be done by using a `max_value` attribute to let the integration know when rollovers will occur, and how to handle it. ### What version of Home Assistant Core has the issue? core-2021.12.7 ### What was the last working version of Home Assistant Core? _No response_ ### What type of installation are you running? Home Assistant Container ### Integration causing the issue utility_meter ### Link to integration documentation on our website https://www.home-assistant.io/integrations/utility_meter ### Example YAML snippet ```yaml utility_meter: rain_daily: name: "Rain Daily" source: sensor.rainfall_total cycle: daily delta_values: true ``` ### Anything in the logs that might be useful for us? _No response_ ### Additional information _No response_

But that was specifically for using the delta option. I’m assuming you aren’t. So you would need to open a new issue.

typekcz · May 5, 2022, 3:59pm

Thank you, for finding that issue.
The merged code indeed covers just delta values option and I am not using that option.

typekcz · May 12, 2022, 2:05pm

So I solved it on my own.

I have input number and automation:

automation ev_zasuvka_energie:
  - alias: "EV záskuvka energie - poslední validní hodnota"
    trigger:
      platform: state
      entity_id: sensor.shelly1pm_48551903116e_energy
    condition:
      condition: template
      value_template: >
        {{ trigger.to_state.state not in [trigger.from_state.state, 'unavailabl$
    action:
      service: input_number.set_value
      entity_id: input_number.ev_zasuvka_energy
      data_template:
        value: "{{ trigger.to_state.state }}"

And utility meters are set to use this new input number instead.
But still I think that this should be handled some way in utility meter. What the difference between delta values and difference between last known values? It should behave the same.

MiguelAngelLV · June 13, 2022, 7:30am

Any other solution for no need use input_number?

I think that we need a alternative mode for utility meter that use always the last valid value