Additional information concerning the April 21st San Francisco outage

by Bill Fester on May 1, 2017

in Industries, Power

From Control Global

Submitted by Joe Weiss on Fri, 04/28/2017 – 16:14

Additional information concerning the April 21st San Francisco outage

The April 21, 2017, San Francisco outage should raise red flags at DOE, FERC and NERC about how they classify Critical Infrastructure and Key Resources (CIKR) and Bulk Electric System (BES) assets beyond voltage bright-lines and KVA classification. This outage emphatically points out that system reliability, the definition ofkey facilities, and economic impact should be considered during CIKR classification. The outage also demonstrates the limitations of several key NERC reliability and cyber security standards.

The first issue regards the NERC practice of providing exceptions for defining a transmission asset – Note that exceptions E1 and E3 can be used to exclude substations over 100KV from being defined as transmission thus relieving their owners from having to meet transmission-level requirements for these substations. Whether the Larkin Street substation has been defined as transmission or distribution should be of great interest to FERC and California PUC when they conduct their fact finding of the outage. But keep in mind that the Larkin Street substation is the largest load block in PG&E’s service territory.

Specifically, the CA ISO 2011-2012 Transmission Plan dated March 14, 2012, studied 68 contingencies in the bulk system for the Diablo Canyon Plant Interface Requirements. The study included an assessment of the consequences of the contingent loss of one load block at the Larkin Street Substation. There are several references to the CA ISO Transmission Plan that relate to PG&E, NERC, and this outage. The CA ISO Transmission Plan explicitly identifies the Larkin Street Substation as a bulk transmission asset. Therefore, the Larkin Street substation should be addressed by the NERC CIPs. The second reference is the statement that the Larkin Street Substation is the largest load block in PG&E’s service territory. Yet, by existing NERC CIP criteria, the Larkin Street Substation is only a “Low Impact” facility meaning that effectively no cyber security requirements, regardless of their importance to the national and international economy, are required. In fact, under some interpretations, the Larkin Street Substation may not even be considered a bulk transmission asset.


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