Market Renewal - Day-Ahead Market

The IESO is working with stakeholders to design and develop a financially-binding Day-Ahead Market. A Day-Ahead Market will provide market participants with price certainty ahead of real-time, increase operational certainty for both market participants and the IESO, and reduce out of market payments.


Soon after the market opened in 2002, the IESO began discussions with stakeholders on the development of a financially-binding day-ahead market. The Day-Ahead Market project did not proceed for a number of reasons but a key challenge was the complexities of settlement and operation under the existing two-schedule system for pricing and dispatch.

The IESO launched a day-ahead commitment process (DACP) in 2006, which commits certain dispatchable generators and the economic scheduling of imports in the day‐ahead time frame, in return for a financial guarantee.  A number of further enhancements were made to the day-ahead commitment process in 2011, including improved optimization and allowing committable generators to submit their start-up and operations costs along with their energy offers.

While many improvements have been made to the commitment process, the absence of a day ahead financial commitment for all resources limits the extent to which participants will fully and efficiently participate.

The replacement of the existing Enhanced Day-Ahead Commitment Process with a financially-binding Day-Ahead Market (DAM) can provide significant improvements and benefits:

  • dispatchable resources have improved production certainty
  • the system operator has improved operational certainty as real-time approaches, and
  • consumers benefit from more efficient and cost-effective decisions overall. 

The transition to a DAM is enabled significantly by the move to a single schedule electricity market under Market Renewal. 

Get involved

This initiative will reenvision how stakeholders participate and are committed in the day-ahead timeframe and will therefore be of interest to all IESO market participants.

Interested parties are invited to participate in, and provide feedback on, any of the Market Renewal initiatives.

For more information about how to become involved or to provide comments on this initiative, please contact

Stakeholder Engagement Plan (Draft)

Schedule of Activities



Expected Actions

Q3 –Q4

Phase III – Final Decisions and High Level Design

March 27, 2018

Stakeholder Meeting

February 28, 2018

Stakeholder Feedback

IESO Response to Stakeholder Feedback


January 31, 2018



Stakeholder Meeting

November 27, 2017


Stakeholder Meeting – Design Elements Fundamentals: Market Power Mitigation, Price Formation, Settlements

Materials posted one week in advance of meeting                       

Recorded Presentation

November 10, 2017

Stakeholder Feedback

IESO Response to Stakeholder Feedback


October 30, 2017


Stakeholder Meeting 

Recorded Presentation

October 11, 2017


Stakeholder Meeting - Introduction to Engagement, High Level Overview of Design Elements and Scope

Recorded Presentation


September 28, 2017

Announce Engagement and Post Draft Stakeholder Engagement Plan