High CPU usage by powerd process in macOS

A bug in the power management daemon powerd in macOS causes high CPU usage around 100-105%. On notebook Macs, this greatly impacts battery life and creates a lot of heat and fan noise.

Force-quitting the process in Activity Monitor is not affective. To kill the process, run the following command in Terminal:

pmset schedule cancelall

I recommend saving this command to a shell script and running it via bash when needed.

#!/bin/bash
pmset schedule cancelall