Market Renewal - Enhanced Real-Time Unit Commitment

The IESO is working with stakeholders to design and develop an Enhanced Real-Time Unit Commitment (ERUC) program. An Enhanced Real-Time Unit Commitment Program will improve the efficiency of unit commitments in the intra-day timeframe by taking into account all resource costs in commitment decisions. An ERUC will also improve commitment decisions overall by optimizing over multiple hours rather than solving for each hour independently.


The Real-Time Generator Cost Guarantee (RT-GCG) program ensures that generators with long start-up times are available to meet reliability, if needed, in real-time. It has evolved over the years in terms of its eligibility criteria and the cost recovery framework and methodology.  However, there remain a number of systemic issues with the design of the current program.

  • Inefficiency: Resources under the program are committed solely on the basis of their energy offers; start-up, speed no load and other costs are not included in this calculation and are recovered under the pre-approved cost recovery framework. 
  • Lack of Competition: The lack of consideration of start-up costs means generators in the program do not have to compete on those costs to get a commitment.
  • Misalignment with Day-Ahead: The day-ahead and intra-day commitment programs use different optimization both in terms of the inputs considered and the optimization timeframe (day-ahead commitments are based on three-part offers and 24 hour optimization where RT-GCG commitments are based on energy offers only and each hour is optimized independently). 
  • Administration and Oversight: Historically, cost submissions have been subject to review and audit creating a high administrative burden for both the IESO and market participants. 

The design of the RT-GCG program has also been criticized in several Market Surveillance Panel reports due to its inefficiency, cost and lack of transparency.

Under Market Renewal the current commitment program will be enhanced to one that facilitates greater competition and more efficiently commits resources anticipated to be needed for reliability in real-time.  This will be achieved by:

  • Allowing participants to competitively submit offers reflecting incremental energy, start-up and speed-no-load costs respectively
  • Including all costs associated with offers in the IESO’s optimization tools
  • Making commitment decisions based on the total efficiency of all hours across the commitment period

Enhanced Real-Time Unit Commitment, together with a Day-Ahead Market and a Single Schedule Market collectively will improve the dispatch, commitment and pricing of resources in the energy market.

Get involved

This initiative will re-envision how stakeholders participate and are committed in the intra-day 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 28, 2018

Stakeholder Meeting


February 15, 2018

Deadline for stakeholders to submit feedback on materials and issues discussed at January 31st meeting


January 31, 2018


Stakeholder Meeting

December 7, 2017

Stakeholder Feedback

IESO Response to Stakeholder Feedback


November 27, 2017


Stakeholder Meeting – Design Elements Fundamentals

Materials posted one week in advance of meeting

Recorded Presentation

October 30, 2017


Stakeholder Meeting – Design Elements Fundamentals

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