How to get power usage on a Mac

Question

I'm trying to get the power usage (in watts) but I can't figure out how. I looked at pmset and IOKit but couldn't find anything about it. coconutBattery can calculate it for laptops using the MacOS internal power information.

Answer 1

/usr/sbin/system_profiler SPPowerDataType | grep Wattage

The utility also accepts an -xml flag; the specific key in the XML is sppower_ac_charger_watts.

Answer 2

If you only need this information for a laptop, call IOPMCopyBatteryInfo and look at the values for the kIOBatteryVoltageKey and kIOBatteryAmperageKey keys to compute the power usage.