Recent hardware/drivers allow Windows to do that automatically. So this utility is kinda outdated but still can be used on old devices.
Application sets Power saver scheme when working on battery and High performance when power is plugged. A power scheme change produces a tray notification.
Compatibility
Application is tested on Windows 10 and expected to work properly on Windows 7 and higher.
Build
To build application run Build.bat.
Build requires .NET Framework 4.0.
Launch
Simply run Launch.bat.
Adding to Startup
Run Add to Startup folder.bat to put compiled exe file to your Startup folder.
Application doesn't use timers (at least explicitly) or any complexed logic that might slow down your performance.