The description below is from the book DOS the Easy Way by Everett Murdock Ph.D.
CLICK HERE for information about downloading the book.
Type: External (6.0 and later)
Purpose: Used to turn power management on and off, report the
power management, and set levels of power conservation.
Before you can use the POWER command you must use the DEVICE command in
CONFIG.SYS file to install the POWER.EXE device driver. If you enter the
command by itself on the command line, a status report will be displayed.
adv[:max|reg|min] - Use this option if you want to conserve power when
applications and hardware devices are idle. Use MAX for maximum power
conservation. Use REG, to balance power conservation with application
device performance. Use MIN if the performance of an application or
not satisfactory when you specify MAX or REG. The default is REG.
std - If your computer supports the Advanced Power Management (APM)
specification, STD conserves power by using only the power-management
of your computer`s hardware. If your computer does not support the APM
specification, STD turns off power.