DCPP Curtailment Guidelines Ken Johnston Director, Operations Services PG&E October 20, 2016 I

2016 Summer Loads and Resources Subhead title to go here and here. Subhead to go here and here and here. • Lorum ipsum dias en sanctus en monterium et tus monte rium. • Lori ipsum dias en sanctus en monterium et tus monterium. • Dias en sanctus en monterium et tus monterium en sanctus monterium. • Dias en sanctus en monterium tus monterium en sanctus. Subhead to go here and here and here. • Lorum ipsum dias en sanctus enmonterium et tus monte interiumonterium en sanctus. 2

Role of Cal ISO The California Independent System Operator (CAISO) provides open and non-discriminatory access to the bulk of the state’s wholesale transmission grid, supported by a competitive energy market and comprehensive infrastructure planning efforts. 3

Emergency Curtailment Emergency curtailment orders may be issued due to grid stability concerns Can be required to curtail by ISO Specific criteria for requesting emergency curtailments and for DCPP’s response to such a request are included in confidential sections of DCPP Operation Policy Confidentiality is due to market sensitive nature of information. 4

Non - Emergency Curtailment PG&E’s Short Term Electric Supply’s (STES) mission is to procure and schedule electricity to meet PG&E retail load in a least cost fashion STES forecasts PG&E retail load and schedules generation and load to CAISO in the day ahead and hour ahead markets. STES monitors system load and generation continuously, and acts as PG&E’s single point contact for generation related coordination. STES bids DCPP as base load (i.e. both units operating at full capacity) unless there is a scheduled outage or curtailment. 5

Over - Generation Curtailment Over - Generation Curtailment Agreement Although DCPP has an over generation curtailment agreement with STES, neither the ISO or STES has ever requested that it be exercised. Limitations of the Curtailment Agreement Curtailment would be for a limited amount of MWe. Curtailment duration would be limited to small fraction of the year. Sufficient notice would be provided to allow for safe execution of a normal power ramp. 6

Thank you Ken Johnston KEJ5@pge.com 7