Capacity Auction
The annual Capacity Auction is the competitive procurement mechanism in the IESO’s Resource Adequacy Framework that secures the capacity needed to meet the balance of Ontario’s resource adequacy needs on a short-term basis. The Capacity Auction enables participation from existing and non-committed demand response, generation, energy storage and import resources that compete to make their capacity available. Capacity suppliers who secure an obligation in one or both of two, six-month obligation periods (summer and winter) can receive a payment, based on the auction clearing price, for making their capacity available during a window of hours on each business day.
The IESO continues to develop enhancements to the Capacity Auction, in consultation with stakeholders, to ensure the auction continues to procure sufficient capacity to meet incremental resource adequacy needs, provide a stable and transparent investment signal to market participants, drive competition and promote ratepayer value.
Parties interested in participating in an upcoming Capacity Auction are encouraged to review the associated Market Rules, Market Manuals, and information on this webpage.
2024 Capacity Auction
The 2024 Capacity Auction will be held from Wednesday, November 27 to Thursday, November 28, 2024, for the summer 2025 and winter 2025/26 obligation periods. Please subscribe to the IESO bulletin for future updates related to the Capacity Auction.
- Market Rules and Manuals Library
- 2024 Capacity Auction Pre-Auction Report via the IESO Public Reports site
- 2024 Capacity Auction Timelines
- 2024 Capacity Auction Fleet-Level Availability De-Rating Factors
- 2025 Demand Response Contributor Management and Measurement Data Submission Timelines
- Capacity Auction: Online IESO Step-by-Step Guide
- Capacity Auction Zone Table
- Capacity Auction Form – Notice of Force Majeure Event
- Capacity Auction Capacity Test FAQ
Please contact customer.relations@ieso.ca if you have any questions regarding the Capacity Auction.
eLearning Modules
The IESO has a suite of training offerings available to prepare potential participants who may be looking to participate in this year’s Auction. The IESO will automatically register existing Capacity Auction Contacts for the eLearning modules. If you just recently registered, are not yet a Capacity Auction Contact in the IESO’s online registration system (Online IESO) and/or would like to register for the Capacity Auction eLearning modules, please email IESO Customer Relations at customer.relations@ieso.ca and include the following:
- Organization name (name registered with IESO)
- First and Last name
- eLearning Module(s) you would like to be enrolled in
- Email that you would like us to use for your eLearning account registration (preferably your organization email address)
See archive section below for past Capacity Auction results and supporting materials.
Past Capacity Auctions
Historic rules, pre- and post-auction reports and demand response resource-related timelines are found below:
- Capacity Auction Rules Library
- Auction Reports: Pre-Auction and Post-Auction Reports via the IESO Public Reports site
- Demand Response Contributor Management and Measurement Data Submission Timelines
Further auction specific information by auction year is found below:
Demand Response Auction
For information relating to the former Demand Response Auction, including Pre-Auction Reports, Post-Auction Reports and other related documents visit the Demand Response Auction webpage.