In 2009, the U.S. Air Force put 525,000 computers under ENERGY STAR power controls, replacing wasteful always-on use with sleep settings and targeting $15 million in annual savings

Air Force's approach focused on putting computers into lower-power states when they were not being actively used. Under the settings being implemented at the time, monitors could enter sleep mode after 10 minutes of inactivity, while computers could enter a low-power state after 30 minutes.

Raccontata daeconomictimes.indiatimes.com