Updates to the Path Rating Process for Approval by the PCC Chifong Thomas October 14-15, 2015

Western Electricity Coordinating Council In PCC meeting in July 2015 Peak RC with change its SOL methodology to be implemented, only Paths that are stability limited with have “Path SOL” Path that are thermal limited will have Path TTC SOL Exceedance is not allowed; TCC will respect the SOLs Action Item: Review and identify language updates needed for path rating process to replace references to System Operating Limits (SOL) and bring back to PCC for review in October. Western Electricity Coordinating Council

Western Electricity Coordinating Council Review Results There were 4 instances where the word “System Operating Limit” or “SOL” appear in the “Project Coordination, Path Rating and Progress Report Processes” Page 29 – on Criteria for Paths subject to the Path rating Process Page 97 – no change needed because the reference is on “WECC SOL Methodology” in general Western Electricity Coordinating Council

Changes Proposed on Page 29 Transmission paths shall complete the Path Rating Process specified in this document and obtain an Accepted Rating if any of the following criteria apply: The limiting condition (e.g., thermal limit, stability, or voltage) in determining the Total Transfer Capability of the path or the Ssystem Ooperating Llimit for transmission facilities that impact the path is on another system and the affected member system requests the path be rated. The path must be operated within the constraints of a nomogram to meet NERC Reliability Standards and WECC Criteria, the elements of the nomogram (e.g., path flows or generation levels) are in different systems, and one of those systems or a neighboring member system requests the path be rated. The path owners or operators have requested a seasonal or operational Total Transfer Capability System Operating Limit for a new path or the path owners or operators have requested a seasonal System Operating or operational LimitTotal Transfer Capability that is in excess of an existing path’s rating (Accepted, Existing, or Other). A facility (generator, series, or shunt reactive equipment; Remedial Action Scheme; etc.) that an Existing or Accepted Rating depends on is modified9 or retired from service, without regard to whether the facility is owned by the same system as the rated path. Western Electricity Coordinating Council

Western Electricity Coordinating Council Proposed Motion PCC approves the proposed changes to be implemented after WECC approves the elimination of the Path SOL for non-stability limited Paths. Western Electricity Coordinating Council