Energy Dashboard: when to use a energy-sensor vs. using a utility meter?

Hi dear community,

I am playing around with the Energy Dashboard. I can add some energy sensors in (kWh) to the dashboard or I could create a utility meter sensor and add this to the Energy Dashboard. What’s the difference? What are the use cases to use one or the other?

Background:
I have 2 sonoff pow2 and a shelly 3 EM. Sonoff only provides Power (Watts), so I am using the riemann integral function to create a energy sensor (kWh). I then created a utility meter sensor, both sensors are showing the same values.

I’m curious about this too.
I have an integration, configured in YAML which has a sensor for “electricity power” in Watts.
I’ve tried a few Riemann integrations and a Utility Sensor but have failed to generate an accurate daily consumption in (k)Wh using either approach.