If you extract the date from the date/time column into a new column, you can use a pivot table to get the daily totals for all the devices. Once the data is in that layout you should be able to easily create the graph you’re looking for.
Make a copy of the sheet because if it’s updating while you’re messing with it you may experience problems.
Add a new column and use “Date” for the header. Enter the formula below into the first cell and then copy that cell and paste it to the rest of the cells in that column.
=int(a2)
Then click the column header so that the whole date column is selected and change the number format to date.
The next version of the SmartApp will have an option for automatically including the date column so that you don’t have to manually perform those steps.
Then create a pivot table using the date column for the row and the device for the column… The Values would be Event Value using SUM and then filter the event name by “energy”.
Edit: To create the graph, open the “Explore” popup by clicking the little plus in the bottom right corner of the screen.
I only have 1 energy device so the chart below uses the average temperature.
