Dispatch Scheduling Error Notifications

May 13, 2026 Update: See new charge types included for May 6, 2025 and May 31, 2025, these settlement adjustments will appear on market participants’ recalculated settlement statement (RCSS-5) on May 14, 2026.

Based on a review of day-ahead market (DAM) results, for all hours of trade date May 6, 2025, a dispatch scheduling error (DSE) has been declared due to an incorrect limit considered in the DAM for the ONT-PQAT interface. Settlement statements for affected market participants determined to be impacted by the DSE will include corrective amendments in accordance with the market rules.

The DSE during this period has resulted in settlement adjustment for the following charges:

• May 6, 2025: Charge Types 1100 (Day-Ahead Market Energy Settlement Amount for Generators), 1101 (Real-Time Energy Settlement Amount for Generators), 1102 (Day-Ahead Market Energy Settlement Amount for Dispatchable Loads), 1112 (Day-Ahead Market Energy Settlement Amount for Exports), 1113 (Real-Time Energy Settlement Amount for Exports) and 1115 (Non-Dispatchable Load Energy Settlement Amount), CT212 (Day-Ahead Market 10-Minute Spinning Reserve Settlement Credit), CT213 (Real-Time 10-Minute Spinning Reserve Settlement Credit), CT214 (Day-Ahead Market 10-Minute Non-Spinning Reserve Settlement Credit), CT250 (10-Minute Spinning Reserve Hourly Uplift), CT252 (10-Minute Non-Spinning Reserve Hourly Uplift)
• May 31, 2025: Charge Types CT 1116 (Internal Congestion and Loss Residual) and CT 1120 (Real-Time Net Interchange Scheduling Limit Residual Uplift)

These settlement adjustments will appear on market participants’ recalculated settlement statement (RCSS-2) on August 15, 2025.

For more information, please contact IESOCustomerRelations@ieso.ca.