Issue: The power management policy created calls for hibernation after a specified time but the machines are never going into hibernation. The issue is not insomnia. Further investigation reveals that hibernation is not available in the control panel even though it should be.
Cause: The wrong powermanagement driver is installed for the machine chipset rendering hibernation unavailable.
Resolution: Obtain the chipset driver from the Manufacturer of the machines in question and install it to obtain hibernation settings for machines.