This page contains information related to the NERC Bulk Electric System (BES) definition and the Notification and Exception Processes. The materials linked to this page are the current compilation of materials that support the application of the BES definition and detailed materials designed to provide entities with the information needed to make uniform determinations of BES elements. This page will be continuously updated as additional materials become available.
On March 20, 2014, FERC approved the revised definition of BES, as envisioned in Order Nos. 743, 773, and 773-A. The definition includes bright-line core criteria with various enumerated inclusions and exclusions. As a result of the application of these BES definition provisions, all Elements and Facilities necessary for the reliable operation and planning of the interconnected bulk power system will be included as BES elements. FERC also approved the process for review of Elements on a case-by-case basis to allow for exceptions from the definition, where appropriate, as well as a process for entities to self-notify Regions of their respective determinations of BES elements. Entities should apply the definition of BES, including the respective inclusions and exclusions, to their asset inventory effective July 1, 2014.
An ERO enterprise-wide software application, the BES Notification and Exceptions Tool or BESnet, has been developed to support implementation of the definition. Entities should use the BESnet application to submit to their respective Regional Entity notifications of changes to BES assets that affect the registered entity’s responsibilities for compliance with the Reliability Standards. The BESnet application is the official means of notifications to Regional Entities of newly identified inclusions and exclusions as a result of application of the definition. Entities are encouraged to have preliminary discussions with their Regional Entities prior submitting notifications for the record. Entities also should use the BESnet application to request to include or exclude an Element from the BES on a case-by-case basis.