1. Terry Baker Peak Reliability
September 20th, 2015
San Diego Load Shed Event
Terry Baker Peak Reliability

2. Brief Summary of Event
Otay Mesa Energy Center (OMEC) was forced out of service due to emission issue in the plant.
Based on values produced by Peak’s VSA Real Time tool, Peak determined that imports in the SDG&E area were approaching the real-time IROL. As a result, the Peak RC issued a Reliability Directive to the CAISO to shed 150 MW of load in the SDG&E area to maintain a sufficient margin away from the San Diego Import IROL as calculated by Peak’s real time VSA tool.
In response, CAISO issued a Directive to SDG&E to shed interruptible load and subsequently to shed 150 MW of firm load.

3. A
A – Otay Mesa Generation Offline

4. B
B – Peak VSA calculates 0 MW limit when tool does not converge for critical contingency

5. C
C – load shed

6. Lessons Learned Lessons learned for Real Time Tool:
Modeling accuracy and data inputs are critical for our tools
Assumptions need to be consistent (load modeling, RAS, capacitor switching, etc)
Load shedding philosophy has been improved
Coordination and Communication amongst the impacted entities

7. Moving Forward
New standards approved which require outage coordination, Operational Planning Analyses and Real-time Assessments
Path Operator Implementation Task Force and SOL Methodology revision
Peak working with Idaho Power, SCE, and SDG&E to advance real-time VSA
Focus continues to be on improving reliability through improved tools and processes

8. Questions?