Active Power Management is implemented through software that allows an enterprise to control energy consumption of its desktop and/or data center equipment.  Typically, this is done through a central administrative function that can tune the power consumption of all computers on an enterprise network.

Compare with Behavioral Power Management.

More about Active Power Management at Vertatique's Computer Power Management Resources.

Verdiem, for example, claims it's software can cut "100 to 300 kilowatt-hours (kWh) of annual energy use from every PC . . . an average $20 cost savings for each one, every year . . . a 5% to 15% organization-wide reduction in electricity consumption"  (Verdiem is funded through KPBC's Greentech investment initiative.)