Independent review of the IESO's Dispatch Scheduling and Optimization, and Day-Ahead Calculation Engine
August 25, 2022
A 2022 review of the IESO's Dispatch Scheduling and Optimization (DSO), and Day-Ahead Calculation Engine (DACE) processes and procedures has been completed. During the review, nothing material came to the attention of the audit firm, PricewaterhouseCoopers (PWC), which would indicate that the dispatch algorithms were not operating in accordance with the relevant market rules. The full reports are available at DACE Review and DSO Review.
The review included an examination of both the DACE and DSO tools. The DACE tool is the software program that runs the day-ahead dispatch algorithm and is used to optimize day-ahead schedules over a 24-hour period for energy and operating reserves. The DSO tool is the software program that implements the dispatch algorithms, calculates market clearing prices and formulates dispatch instructions for generators and loads. The DSO tool finds an optimal outcome every five minutes by integrating market and reliability priorities, which is crucial to serving all Ontario electricity consumers.
The PWC review approach was extensive and included, but was not limited to:
Testing of the applicable market rules, including:
- Automated testing using previously developed automated scripts
- Selected additional scenario testing for agreed upon market conditions and market rules not present in the day of test data
- Reconciliation of key data from DAOS and DSO to DSO/ DAOS displays
- Manual processes and Control Room testing
- Validation of input and output data from IESO website
This is the ninth independent review of the DSO since the market opened in Ontario and the fourth review of DACE.