EDIT: I'm sorry, you were asking for the default policies back. I proposed the solution I used for our custom policies. For the default simply execute:
:H:\>powercfg /LIST
Existing Power Schemes (* Active)
-----------------------------------
Power Scheme GUID: 381b4222-f694-41f0-9685-ff5bb260df2e (Balanced) *
Power Scheme GUID: 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c (High performance)
Power Scheme GUID: a1841308-3541-4fab-bc81-f71556f20b4a (Power saver)
I'll leave my original answer below to be complete.
They should be here: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
Controls Folder\PowerCfg\PowerPolicies
If they are missing and you have another machine you can list all GUIDs on the pc with the functioning policies:
powercfg /LIST
then export all GUIDs (this is an example, make sure to adjust to whatever GUID is shown and file you want):
powercfg -EXPORT C:\Temp\test.pow 381b4222-f694-41f0-9685-ff5bb260df2e
Then copy the .pow files and execute this on your machine with issues:
powercfg /IMPORT C:\test.pow