Use Power Save Settings

[Power Save Settings] is an option under Settings.

To save power, the PS3 system and Wireless controllers can be set to turn off automatically after a certain period of inactivity.

System Auto-Off

After 1 / 2 / 3 / 5 Hours: The system turns off after the specified period of inactivity.
Off: The system is not set to turn off automatically.

Hint
The system will not turn off automatically under special conditions such as during gameplay, video playback or slideshow playback. If you want the system to turn off automatically even under these special conditions, select [Turn Off System Automatically Even Under Special Conditions] in the screen that is displayed after enabling the System Auto-Off option.

Controller Auto-Off

Off: The controller is not set to turn off automatically.
On: The controller turns off automatically.

Hint
When [Controller Auto-Off] is set to [On], the controller will turn off after 10 minutes of inactivity. If you want to use a controller that is turned off, press the PS button on the controller.