This policy setting specifies the active power plan from a specified power plan's GUID. The GUID for a custom power plan ...

This policy setting specifies the active power plan from a specified power plan's GUID. The GUID for a custom power plan GUID can be retrieved by using powercfg, the power configuration command line tool.  

If you enable this policy setting, you must specify a power plan, specified as a GUID using the following format: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX (For example, 103eea6e-9fcd-4544-a713-c282d8e50083), indicating the power plan to be active.

If you disable or do not configure this policy setting, users can see and change this setting.