Edit a file with pico editor using this command: 

sudo pico /var/lib/polkit-1/localauthority/50-local.d/hibernate.pkla


In the hibernate.pkla file, you should put in these lines:

[Enable Hibernate]

Identity=unix-user:*

Action=org.freedesktop.upower.hibernate

ResultActive=yes

After putting in the above lines, save the configuration, then reboot.  

Click the power symbol upper right, choose system settings, and then adjust your power settings -
Most notably what to do when the laptop lid is closed.