The California ISO, as a Transmission Service Provider and Transmission Operator registered with the North American Electric Reliability Corporation (NERC), must comply with NERC reliability standards applicable to those functions, including MOD-001-1a. Standard MOD-001-1a requires each Transmission Operator to select a methodology for calculating Available Transfer Capability (ATC) or Available Flowgate Capability (AFC) for ATC paths within their Transmission Operator area. The ISO has selected the methodology set forth in NERC standard MOD-029-2a “Rated System Path Methodology.”

Standard MOD-001-1a also requires each Transmission Service Provider to prepare and keep current an ATC Implementation Document (ATCID) that includes processes, procedures and assumptions used in the determination of ATC under the selected methodology. This document serves as the ISO’s ATCID and, therefore, documents the ISO’s compliance with the requirements of NERC standards MOD-001-1a and MOD-029-2a.

Additional information on the ISO NERC modeling, data and analysis (MOD) reliability standards is available on the Application Access webpage, under the Open Access Same-Time Information System (OASIS) heading.