sleep mode 
noun Electronics
A power-saving mode of operation in which devices or parts of devices are switched off until needed.Office equipment must automatically switch to a low-power sleep mode after a certain period of inactivity....
- Since they're always in sunlight, they never have to go into a sleep mode and there's a greater science return for the dollar.
- Activating the built-in sleep mode on your PC's display will help conserve electricity and save more money than you might think.