Tlp is a command line utility we can use to optimize power consumption on Linux. It provides reasonable defaults, and, at the same time, an easy to understand text-based configuration file we can use to create our own setup. An external project provides a user-friendly GTK frontend to Tlp written in Python: Tlpui.
power
How to check and tune power consumption with Powertop on Linux
Powertop is a free and open source utility developed by Intel to monitor power consumption on Linux. The tool is able to display and export reports about the estimated discharge rate, and statics about processors and devices behavior. It also lets us easily tune some kernel parameters on the fly in order maximize battery life.
How to handle ACPI events on Linux
ACPI is the acronym for Advanced Configuration and Power Interface; as a standard, it was first implemented in the year 1996, as a successor to APM (Advanced Power Management). As a main feature, it brought the ability to handle power management at the operating system level, whereas before it was handled in BIOS. Some ACPI events on Linux are, by default, handled via systemd-logind, but more complex configurations can be achieved by installing and running the acpid service.