Hello, I was also dismayed yesterday, after redoing my entire energy monitoring setup to use HA’s energy dashboard, that it does not expose a per-device energy cost, like it does for the grid connection.
This feels to me like a very solid use case, since the very reason why many of us go through the trouble of measuring device energy usage is to try and understand how much these devices are costing us in actual currency. If you are on a fixed rate, this is very straight forward to do. But for folks that are on dynamic energy rates, this gets very very complicated very quickly.
You have two options:
Add in each device as a separate grid connection. I don’t have a grid connection sensor, so that used to work fine for me. But I moved away from this because I’m looking to get a grid connection monitor.
You give it a sensor that tracks the energy usage of your device, and a sensor that tracks your energy rates, and it takes care of the rest, exposing entities that tracks hourly, daily, weekly, monthly etc costs. So far it’s been working quite nicely for me.
I will see if I can maybe contribute some changes to the energy dashboard to include an optional per-device energy cost output, imo this is a really critical requirement to make the dashboard truly usable.