1. Enhanced Curtailment Calculator (ECC) Jeremy West Sr. Operations Engineer

2. 2 Learning Objectives History behind need for ECC Review ECC proposed functionality ECC interactions with scheduling

3. 3 Prior to 2011: No IROLs identified in the West RC and TOPs primarily focused on Major WECC Transfer Paths Equipment/Facility ratings not considered SOLs April 2012 – RC SOL Methodology revised SOLs – facility ratings, bus voltage and stability limits IROLs – process for identification August 2013 – RC SOL Methodology second revision Improve processes for determining IROLs Greater emphasis on determining acceptable pre- and post- Contingency operating conditions The Evolution of SOLs/IROLs in the West

4. 4 A reliability tool that Peak RC can use in conjunction with its other tools to ensure acceptable system performance What is the ECC? Phase I – Situational awareness Phase II – Enhanced curtailment / redispatch How will the ECC be implemented? Enhanced Curtailment Calculator (ECC)

5. 5 webSAS Limitations UFMP restricted to 6 Qualified Paths TDFs based on seasonal models Increased system awareness Visibility of untagged flows Incorporation of outage info (gen and trans) Compliance Address IRO and TOP standards Address September 8 event recommendations What issues does ECC address?

6. 6 ECC Phase I e-Tags Dynamic Transfers Network & Native Load Market Flows ACE / RBC Flows RSG Flows Provides situational awareness to RC Current hour – uses SE for topology Look ahead hours – starts with SE topology but adds generator and transmission outage data Visualizes “layers” of impacts

7. 7 Implementation of FERC-approved curtailment methodology Transition from webSAS to ECC for support of UFMP on 6 Qualified Paths Redispatch and curtailment to manage congestion on defined elements as needed to support reliability o Collaborative effort with entities when implemented ECC Phase II

8. 8 e-Tagging Source/Sink Granularity ECC Interactions with Scheduling BA A BA B = Contract (On) Path= Off Path BA A BA B

9. 9 Dynamic Transfers Catalog Effort for Peak Telemetry Forecast Data Dynamic Schedules – energy profile accuracy? Pseudo-Ties – options e-Tag Build in ECC EIR Registration ECC Interactions with Scheduling

10. 10 Task Force advising Peak on ECC Reorganized under Peak MAC Chair → Raj Hundal Meetings open to public ECCTF

11. 11 https://www.peakrc.com/whatwedo/ECC/Pages/default.aspx ECC Information