The derivative integration measures the rate of change of a sensor.
The derivative of energy with respect to time is power. This will be measured in W, not Wh as per your second graph.
I find it hard to believe that the device that is supplying your energy sensor does not have a power sensor. Maybe check the entities in the device page. Settings → Devices & Services.
Woops, for some reason I tested that and was not successfull. But it’s indeed the right way to do it…
Unit is kind of weird though, Wh/h .
The device does not have a powersensor, it’s a french utility meter, I have some kind a serial adapter connected to it and push data into hass via mqtt.