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 Annual Planning Outlook Data Tables (Excel)
Demand Forecast
- Demand Forecast Module (PDF)
- Demand Forecast Module Data (Excel)
- Demand Forecast Methodology (PDF)
- Hourly Demand Forecast – Zonal, Net (Excel)
- Hourly Demand Forecast – Zonal, Grid (Excel)
Resource Adequacy
- Supply, Adequacy and Energy Outlook Module (PDF)
- Supply, Adequacy and Energy Outlook Module Data (Excel)
- Resource Adequacy and Energy Assessment Methodology (PDF)
- Ontario Generation Resources Database (Excel)
- Operability Module (PDF)
Transmission Security
Other/Miscellaneous
- Fuel Cost (Excel)
- Capacity Expansion Scenario, Costs, and Emissions Module Data (Excel)1
- Capacity Expansion Scenario, Costs, and Emissions Module (PDF)1
- Marginal Energy Costs and Capacity Costs (Excel)
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.
2024 Annual Planning Outlook
Modules, Methodology and Supplemental Data
Demand Forecast
- Demand Forecast Module (PDF)
- Demand Forecast Module Data (Excel)
- Demand Forecast Methodology (PDF)
- Hourly Demand Forecast – Zonal, Net (Excel)
- Hourly Demand Forecast – Zonal, Grid (Excel)
Resource Adequacy
- Supply, Adequacy and Energy Outlook Module (PDF)
- Supply, Adequacy and Energy Outlook Module Data (Excel)
- Resource Adequacy and Energy Assessment Methodology (PDF)
- Ontario Generation Resources Database (Excel)
- Operability Module (PDF)
- Resource Costs and Trends (PDF)
Transmission Security
Other/Miscellaneous
- Fuel Cost (Excel)
- Avoided Cost (Excel)
- Avoided Cost - Marginal Resource Data (Excel)
- Carbon Pricing Module (PDF)
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.
- 2022 Annual Planning Outlook Report (PDF)
- 2022 Data Tables (Excel)
Modules, Methodology and Supplemental Data
Demand Forecast
- Demand Forecast Module (PDF)
- Demand Forecast Module Data (Excel)
- Demand Forecast Methodology (PDF)
- Hourly Demand Forecast – Zonal, Net (Excel)
- Hourly Demand Forecast – Zonal, Grid (Excel)
Resource Adequacy
- Supply, Adequacy and Energy Outlook Module (PDF)
- Supply, Adequacy and Energy Outlook Module Data (Excel)
- Resource Adequacy and Energy Assessment Methodology (PDF)
- Ontario Generation Resources Database (Excel)
Transmission Security
Other/Miscellaneous
- Fuel Cost (Excel)
- Carbon Pricing Module (PDF)
The 2022 Annual Planning Outlook was used to inform the Pathways to Decarbonization report and the Conservation and Demand Management Framework Mid-Term Review.
2021 Annual Planning Outlook
- 2021 Annual Planning Outlook Report (PDF)
- 2021 Data tables (Excel)
- Annual Planning Outlook in 7 graphs
- Supply Scenarios: Planning Information Session
Modules, Methodology and Supplemental Data
Demand Forecast
- Demand Forecast Module (PDF)
- Demand Forecast Module Data (Excel)
- Demand Forecast Methodology (PDF)
- Hourly Demand Forecast – Reference Case – Zonal, Net (Excel)
- Hourly Demand Forecast – Reference Case – Zonal, Grid (Excel)
- Hourly Demand Forecast – High Demand Case – Zonal, Net (Excel)
Resource Adequacy
- Supply, Adequacy and Energy Outlook Module (PDF)
- Supply, Adequacy and Energy Outlook Module Data (Excel)
- Resource Adequacy and Energy Assessment Methodology (PDF)
- Ontario Generation Resources Database (Excel)
Transmission Security
- Transmission Security Methodology (PDF)
- Transmission Data (Excel)
- Ontario Transmission Interfaces and Interties Overview (PDF)
Other/Miscellaneous
- Fuel Cost (Excel)
- Ancillary Services Module (PDF)
- Carbon Pricing Module (PDF)
- 2019 to 2021 Annual Planning Outlooks Comparisons (PDF)
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.
- 2020 Annual Planning Outlook Report (PDF)
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Updated on February 9, 2021. A previous version of this report misstated the values of GHG emissions in 2030 on p67; the values in the data tables are correct and remain unchanged.
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- 2020 Annual Planning Outlook Data Tables (Excel)
- Executive Summary
- The APO in 5 Graphs
- Video: APO Highlights with Chuck Farmer, IESO Senior Director of Power System Planning (courtesy of the Association of Power Producers of Ontario)
Modules, Methodology and Supplemental Data
Demand Forecast
- Demand Forecast Module (PDF)
- Demand Forecast Module Data (Excel)
- Demand Forecast Methodology (PDF)
- Hourly Demand Forecast - Scenario 1 (Excel)
- Hourly Demand Forecast - Scenario 2 (Excel)
Resource Adequacy
- Supply, Adequacy and Energy Outlook Module (PDF)
- Supply, Adequacy and Energy Outlook Module Data (Excel)
- Resource Adequacy and Energy Assessment Methodology (PDF)
- Ontario Generation Resources Database (Excel)
Transmission Security
- Transmission Security Methodology (PDF)
- Transmission Data (Excel) | Updated on June 11, 2021 to correct Limiting Contingency and Limiting Element data in Table 1
Fuel Cost, Avoided Costs, Avoided Emissions
- Fuel Cost (Excel)
- Avoided Cost (Excel)
- Avoided Emissions (Excel)
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
- Highlights
- Annual Planning Outlook (PDF)
- Data Table (Excel)
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.