Use the Energy pane of the Activity Monitor window to see the energy use of your Mac. You can monitor overall energy use, and see details about the energy use of each app.
Click Energy in the Activity Monitor window.
To make more columns visible, choose View > Columns.
The energy use of individual apps and their processes are displayed in the upper part of Activity Monitor’s window.
Energy Impact: A relative measure of the current energy consumption of the app (lower is better).
Average Energy Impact: The average Energy Impact score for the past 8 hours (lower is better).
App Nap: Whether App Nap is active for this application.
Preventing Sleep: Whether this application is preventing your Mac from going to sleep.
The lower part of the window shows information on your overall energy use. If you have a portable Mac, you see additional information related to its battery.
All Mac computers
Energy Impact: Combined energy impact over time.
Graphics Card (Multiple graphics cards): The type of graphics card being used, if there are multiple graphic cards installed. Higher–performance cards require more energy.
Mac Portable Computers
Remaining charge: The percentage of charge remaining on the battery.
Time Until Full (plugged in): The amount of time your Mac must be plugged into an AC power outlet until the battery is fully charged.
Time on AC (plugged in): Time elapsed since your Mac was plugged into an AC power outlet.
Time Remaining (unplugged): The estimated amount of battery time remaining.
Time on Battery (unplugged): The amount of time that’s elapsed since your Mac was plugged into an AC outlet.
Battery (last 12 hours): The battery charge level over the last 12 hours.