Run the Enable Hibernate application from Software Center: First check to see if this option is available on your PC and if it is, turn it on.
Use hibernation when you know that you won't use your laptop or tablet for an extended period and won't have an opportunity to charge the battery during that time.
Hibernate uses less power than sleep and when you start up the PC again, you’re back to where you left off (though not as fast as sleep). It is not available for Desktop computers. This option was designed for laptops and tablets.
