131211
001224
Twelve kilowatts, drawn as a dramatic day.

Every chart of a unit uses one declared ceiling. A quiet day is a low trace with empty space above it, which looks worse on a screenshot and is the only way two days can be compared by eye.
Twelve kilowatts, drawn as a dramatic day.
The same twelve kilowatts. Nothing happened, and the chart says so.
A value above the ceiling clips there and the clipped run is drawn in violet. We would rather show you that a meter went off the top than quietly redraw the axis around it.
Comparison is two or four charts on one shared axis. Overlaying two meters on one chart makes both harder to read and neither easier.
There is no second series colour in this system. If you need to compare, put the charts next to each other.