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 in the energy market. 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 in the energy market 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 was 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.
Links and documents pertaining to Capacity Auction participation can be found below.
- Market Rules and Manuals Library
- Capacity Auction Rules Library
- Capacity Auction Reports: Pre-Auction and Post-Auction Reports via the IESO Public Reports site
- Capacity Auction: Online IESO Step-by-Step Guide
- Capacity Auction Form – Notice of Force Majeure Event
- Capacity Auction: Market Renewal Program Alignment Document
- Capacity Auction Zone Table
In preparation for the capacity auction capacity test, please refer to the following links and documents:
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 the annual Capacity Auction. The IESO will automatically register existing Capacity Auction Contacts for the eLearning modules as they become available. 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
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.