Install ARGOS Gnome Extension: https://extensions.gnome.org/extension/1176/argos/

Enable ARGOS Gnome Extension

Download SimpleWattage-Argos and put it in ~/.config/argos folder

Screenshots:

Enjoy

Tags: Wattage; Watt; Show Watt; Watt usage; Watt usage Ubuntu; Watch usage Gnome Shell Extension; Powerusage Gnome; Powerusage Ubuntu; Show PowerUsuage Ubuntu; Gnome Battery Info; Gnome Shell Extension