write "consumption (kWh per day)" to permanence

[jochen-schuettler]

As you can see in the pictures, the "consumption (kWh per day)"-curve starts at zero the day the data starts. Our stateful-set is keeping a backlog of 10 days. So, every day a day of data older than 10 days ago is lost.
Now - as "consumption (kWh per day)" is calculated anew, it starts at zero again on 02/07, instead of the value it had earlier on 02/07.
I would like the past values to be permanent, and the current values to be appended to these values.