April Peak Week Operations Review

1. April Peak Week Operations Review Presentation to ISO Business Issues Committee May 22, 2002

2. ISO Load Forecast Issues • NYISO - PJM Interface DAM Scheduling • Transmission Constrained Operation • #91 Leeds-Pleasant Valley maintenance outage • Significant generating unit maintenanceoutage • Generator Operating Capability • ISO Operations Actions • Follow-up New York Independent System Operator

3. Load Forecast Issues • No prior historical basis for April 16-19 weather/loads • Weather forecast error (5.8%) • Statewide load forecast model error (5.2%) • Average peak forecast error (2500MW) • Forecast model updated based on April 2002 loads New York Independent System Operator

4. NYISO - PJM DAM Scheduling • SCUC modeling normally forces all NYISO-PJM transactions to flow across NY- PJM interconnections • High exports from IMO and NYISO to PJM resulted in a portion of transaction (loop) flow around Lake Erie • SCUC exceeded normal NYISO-PJM scheduling capability (2500MW) New York Independent System Operator

5. Transmission Constrained Operation • # 91 Leeds-Pleasant Valley 345kV line scheduled out for Athens substation work • #92 Leeds-Pleasant Valley 345kV line de-rated from seasonal winter capability to account for high 90+ degree temperatures • Declared Emergency Transfer Criteria operation for #92 Leeds-Pleasant Valley 345kV line • SCD/BME indicated the ability to secure the # 91 line constraint based on as-bid generator capabilities New York Independent System Operator

6. Unavailable Generator Capability • BME/SCD considered as-bid unit capability that apparently could not be achieved in-day • Significant difference in on-dispatch generator bids vs. actual unit output (400 - 800 MW) • Some generator capabilities reflected Winter seasonal ICAP values and not in-day operating capabilities • Generators expected to de-rate or adjust bids to reflect actual operating capability New York Independent System Operator

7. Operator Actions to Maintain Reliability • Used SRE to commit additional units in response to forecast error • Declared Emergency Transfer Criteria for #92 Leeds-Pleasant Valley constraint • Units required OOM since actual operating capabilities were insufficient to secure #92 Leeds-Pleasant Valley constraint and were not reflected in BME/SCD schedules • Units required OOM since actual operating capabilities were insufficient to meet reserve requirements and were not reflected in BME/SCD schedules • Export transactions curtailed to maintain reserves • Maintained high levels of import transactions from ISO-NE New York Independent System Operator

8. Follow-up issues • Address generator owner bidding concerns of ICAP requirements vs. actual in-day operating capability (Reliability and Pricing Impacts) • Propose GT Resources taken OOM for ISO Reserves be eligible to participate in price setting pass of hybrid dispatch • Enhance Control Room GT management tools New York Independent System Operator

9. Follow-up issues continued: • Review SCUC and BME Load Forecast Procedures • Discuss potential solutions with ISO Business Issues and Operating Committees New York Independent System Operator