Annual Planning Outlook

A long-term view of Ontario's electricity system, the IESO’s Annual Planning Outlook (APO) forecasts electricity demand, assesses the reliability of the electricity system, identifies capacity and energy needs, and explores the province’s ability to meet them. In providing comprehensive information and insights about future electricity needs, and other considerations, including system performance, the outlook helps inform the decisions that will lay the foundation for a reliable and affordable electricity future.

2025 Modules, Methodology, and Supplementary Data

2025 Annual Planning Outlook Data Tables (Excel)

Demand Forecast

Resource Adequacy

Transmission Security

Other/Miscellaneous

1 Updated on May 13, 2025: A previous version of the Capacity Expansion Scenario, Costs, and Emissions Module showed provincial energy production that considered imports and exports. The Module and corresponding figures and data tables have been updated to indicate Ontario-only generation results.

2 Updated on May 22, 2025 to correct an error in the installed cumulative CapEx installed capacity of DR and Hydro in Table 2: Cumulative CapEx Installed Capacity (MW).


2022 Annual Planning Outlook

2022 Annual Planning Outlook

The IESO presented key findings of the 2022 APO at the January engagement days. A recording of the session is available.

Modules, Methodology and Supplemental Data

Demand Forecast

Resource Adequacy

Transmission Security

Other/Miscellaneous

The 2022 Annual Planning Outlook was used to inform the Pathways to Decarbonization report and the Conservation and Demand Management Framework Mid-Term Review.

2020 Annual Planning Outlook

2020 Annual Planning Outlook

The IESO presented key findings of the 2020 APO at the January engagement days. A recording of the session is available.

Modules, Methodology and Supplemental Data

Demand Forecast

Resource Adequacy

Transmission Security

Fuel Cost, Avoided Costs, Avoided Emissions

2019 Annual Planning Outlook

Documents referenced on this page, but not posted, can be obtained by contacting customer.relations@ieso.ca with a link to the web page that lists the document and advise whether it needs to be provided in an accessible format. Please allow a minimum of one business day for a response.


2019 Annual Planning Outlook

Modules, Supplemental Data and Methodology

Demand Forecast

  • Demand Forecast Module
  • Demand Forecast Module Data
  • Demand Forecast Methodology
  • Hourly Demand Forecast - Reference Case
  • Hourly Demand Forecast - Energy Efficiency

Resource Adequacy

  • Resource Adequacy Module
  • Resource Adequacy Module Data
  • Ontario Generation Resource Database
  • Resource Adequacy Methodology

Costs, Avoided Costs, Avoided Emissions

  • Fuel Cost Assumptions
  • Marginal Costs
  • Avoided Costs
  • Avoided Emissions

Annual Acquisition Report

The IESO’s Annual Acquisition Report (AAR) was designed to translate planning and operational information into a series of acquisition requirements, as well as signal anticipated targets and acquisition mechanisms that could secure services to supply the province’s needs over a variety of time frames.

The AAR was published in 2021 and 2022. To reflect policy announcements made in 2023, and to provide a more complete picture of future reliability needs and planned actions to meet those needs, the AAR was integrated into the Annual Planning Outlook in 2024. The published AARs and related information are archived below.