EPA has strengthened the requirements for earning the ENERGY STAR to meet energy use guidelines in three distinct operating modes: standby, active, and sleep modes. This ensures energy savings when computers are being used and performing a range of tasks, as well as when they are in standby. ENERGY STAR qualified computers must also have a more efficient internal power supply.
Since computers are in use more hours per day than they used to be, power management is important to saving energy. ENERGY STAR power management features place computers (CPU, hard drive, etc.) into a low-power “sleep mode” after a designated period of inactivity. Low-power modes for computers reduce the spinning of the hard disk, which decreases power consumption. Simply hitting a key on the keyboard or moving the mouse awakens the computer in a matter of seconds.