2025 Capacity Auction Timelines
June 12, 2025
The 2025 Capacity Auction will be held from Wednesday, November 26 to Thursday, November 27. The 2025 Capacity Auction Timelines document, which outlines key milestone dates and activities that must be completed by perspective Capacity Auction Participants to participate in the auction, has now been posted to the Capacity Auction webpage.
The IESO has also published its targets for the 2025 Capacity Auction in the 2025 Annual Planning Outlook report. The target capacities are 1,800 MW of capacity for the Summer 2026 obligation period and 1,200 MW of capacity for the Winter 2026/27 obligation period.
The annual Capacity Auction continues to be an important component of the IESO’s Resource Adequacy Framework, bringing value to Ontario ratepayers while serving as an additional revenue opportunity for existing, non-committed demand response, generation, energy storage and capacity import resources. 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.
For any questions related to participating in the upcoming 2025 Capacity Auction, please email capacity.auction@ieso.ca.