It is defined in winnt.h as GUID_MIN_POWER_SAVINGS.
Unfortunately, if I put those DEFINE_GUID statements into winnt.h, it breaks compilation of other modules.
```
//
// =========================================
// Define GUIDs which represent well-known power schemes
// =========================================
//
//
// Maximum Power Savings - indicates that very aggressive power savings measures will be used to help
// stretch battery life.
//
// {a1841308-3541-4fab-bc81-f71556f20b4a}
//
DEFINE_GUID( GUID_MAX_POWER_SAVINGS, 0xA1841308, 0x3541, 0x4FAB, 0xBC, 0x81, 0xF7, 0x15, 0x56, 0xF2, 0x0B, 0x4A );
//
// No Power Savings - indicates that almost no power savings measures will be used.
//
// {8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c}
//
DEFINE_GUID( GUID_MIN_POWER_SAVINGS, 0x8C5E7FDA, 0xE8BF, 0x4A96, 0x9A, 0x85, 0xA6, 0xE2, 0x3A, 0x8C, 0x63, 0x5C );
//
// Typical Power Savings - indicates that fairly aggressive power savings measures will be used.
//
// {381b4222-f694-41f0-9685-ff5bb260df2e}
//
DEFINE_GUID( GUID_TYPICAL_POWER_SAVINGS, 0x381B4222, 0xF694, 0x41F0, 0x96, 0x85, 0xFF, 0x5B, 0xB2, 0x60, 0xDF, 0x2E );
```
--
https://gitlab.winehq.org/wine/wine/-/merge_requests/7706#note_100980