I have started to measure my consumption using Shelly devices. I have installed two Pro 3EM in the electrical distribution board. This represents the complete power consumption. I have also installed 10 Shelly Plug S Plus. These are the main consumers.
So far, everything looks “plausible”. However, some characteristic curves of the current line show a strange course. Does this also occur with other loads? It seems to be particularly noticeable with low consumption, but also with consumers that draw significantly more power.
Power factor is a factor 
Your 3EM’s are for sure more accurate 
Accuracy class B (active energy)
Shelly Pro 3EM-3CT63 has a
measurement accuracy of 1%.
then your shelly plugs that only feature a HLW8012 for power measuring 
Thank you @orange-assistant,
I am aware of “Power factor”. I am talking about “active power” value.
If you seek more accuracy (or smoother graphs) I suggest installing esphome on your shelly’s and set the update_interval to 0.5s or less. That way more “real” values come in and less filtering (like average/throttle) happens which causes the graphs you see now 
Thx. I will check this out.
Any experience reports?
seems like the “flickering” of the values is more or less normal.
Over the time i learned to accept this. I see the values from the plug s plus more like a “nearby” value. Guess i wait for the next bill from my energy provider to check the real values against the meassured ones.
Also you should integrated the totals of power (AKA energy) directly on the device for most accuracy (never skipping a beat).
It is also possible with esphome to have a internal power sensor (not exposed to HA) with 0.1 seconds update frequency (for example) which is used to integrate (energy) and have a copy sensor with a throttle (like 1 second) to don’t spam HA while still have best accuracy regarding energy
Which load? With a resistive load (PF=1) and stable voltage I expected no “flickering” 
Hi @GKre , do you have Shelly Pro 3EM-3CT63 ?
thanks
Guess no. It’s a:
Shelly Pro 3EM (SPEM-003CEBEU)
von Shelly
Firmware: 20250924-062749/1.7.1-gd336f31
Hardware: gen2
hi @gkre
so are you fine with Shelly Pro 3EM (SPEM-003CEBEU)
ie all works as expected?
Can it sense based on the “behavior” which device is consuming what energy?
thanks
i have individual Shelly Plug S Plus connected with most of the suppliers. I am not aware that Pro 3 EM shall be able to estimate which device is consuming what energy.
Overall i am getting some inside view in the power consumption and generation. Guess not “perfect” values but the accuracy is in acceptable rang.
i saw that somehow wrote a script that can sense what device is on and what is it consuming.
i thought u have " I have installed two Pro 3EM " …
thx
i even have 3 Pro 3 EM installed. Two directly behind the “counters” as there’s two parties in the house and on in a Sub that is counting the energy for devices on all 3 phases.
@gkre do u use some script that can figure out what kind of devices are attached on wires?