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, 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.

2023 Capacity Auction

The 2023 Capacity Auction was held from Wednesday, November 29 to Thursday, November 30, 2023 for the summer 2024 and winter 2024/2025 obligation periods. Please subscribe to the IESO bulletin for future updates.

 

As part of the pre-auction capacity qualification process, the fleet-level availability de-rating factors (ADF) listed below were applied to the submitted installed capacity of any resource that did not receive its own availability de-rating factor.

Capacity Auction Resource Type

Zone

ADF - Summer Obligation 

ADF - Winter Obligation

Capacity Generation Resource (Thermal)

All zones 

0.94

0.94

Capacity Generation Resource (Hydro)

East

0.64

0.69

Capacity Generation Resource (Hydro)

Essa

0.48

0.73

Capacity Generation Resource (Hydro)

Niagara

0.67

0.64

Capacity Generation Resource (Hydro)

Northeast

0.51

0.63

Capacity Generation Resource (Hydro)

Northwest

0.45

0.60

Capacity Generation Resource (Hydro)

All other zones

0.58

0.64

Dispatchable Load Resource

All zones

0.99

1.00

Capacity Storage Resource

All zones

0.95

0.95


Please contact customer.relations@ieso.ca if you have any questions regarding the Capacity Auction.

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:

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.