Found this great article.

http://blog.scosby.com/post/2012/12/13/Disabling-Windows-Server-2012-Lock-Screen-Timeout.aspx

Disabling the Windows Server 2012 Lock Screen Timeout

In Server 2012 by default, the lock screen will put the monitors to sleep after 1 minute. I found myself waking the monitors too frequently. An initial web search led me to a MSDN forum post for Windows 8 that unlocked a missing Power Settings feature in Server 2012.   1.       Open the following registry key     a.       HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\7516b95f-f776-4464-8c53-06167f40cc99\8EC4B3A5-6868-48c2-BE75-4F3044BE88A7   2.       Set the following value     a.       Attributes => 2
  3.       Now open Control Panel>Power Options>Change Plan Settings>Change Advanced Power Settings     a.       The new Display section “Console lock display off timeout” is now available.     b.      Configure your “Plugged in” value accordingly (0 to disable) – I haven’t tested to see if the monitor sleep setting still applies when the screen is locked.



Also, to set the timeout in a GPO:

Configuring a Power Plan with Group Policy Preferences (by Alan Burchill)

FellTheForce@8