Activity Maps is a heatmap of the energy use for a selected data point and helps you identify savings opportunities at a glance, providing you with an intuitive overview of how good (or bad) you are doing with your energy use.
Activity Maps immediately show you when someone has forgotten to switch off the equipment after hours (dark green peak consumption overnight) and when some machines are never switched off and run 24/7 (light green color overnight should be white to indicate no consumption).