Bulk Electric System (BES)

The Bulk Electric System is NERC’s formal, regulatory definition of the high-voltage backbone of the grid that its mandatory reliability and security standards (including NERC CIP) apply to. As a general rule, it covers transmission elements and generation resources operating at 100 kV or higher, and explicitly excludes local distribution facilities. NERC’s full definition includes additional formal inclusion and exclusion lists beyond that core statement.