2026 Annual Planning Outlook in 5 Graphs and a Map
Every year, the IESO releases a long-term forecast of Ontario’s electricity needs that reflect plans to support economic and population growth, and the progress Ontario is making to procure new resources and build a reliable, affordable and sustainable electricity system.
The IESO’s 2026 Annual Planning Outlook uses market intelligence, forecast data, models and studies to identify system needs over the years 2027–2050 and outlines planned actions to meet those needs.
Here are some of the key takeaways from this year’s outlook:
Energy demand is still rising significantly over the long term
Ontario electricity demand is forecast to grow 65 per cent, in line with recent forecasts, driven by economic development, population growth and electrification. Strong growth potential persists despite geopolitical disruption. High- and low-growth scenarios have been modelled to provide greater insight into how key variables, like electric vehicle adoption, could alter the trajectory.
Key fact: In the Reference Scenario, data centres are expected to make up 8.6 per cent of Ontario demand in 2050, about 60 per cent more than what was previously forecast.
There are more uncertainties than ever, and the IESO is evolving its forecasting in response
In addition to adding high- and low-demand scenarios, the IESO is introducing a new growth margin that groups together areas of demand growth that are particularly variable, like electric vehicles and data centres. Separating these variables from more stable factors influencing demand growth, like population growth, allows for improved tracking and monitoring of key drivers that impact year-over-year planning.
Key fact: Despite shifting electric vehicle policies and adoption rates, they remain the largest driver of demand growth, accounting for more than half of the growth margin and 15 per cent of total Ontario energy consumption by 2050.
Energy efficiency is having a bigger impact
New and expanded energy efficiency programs are reflected in this year’s forecast and will contribute to an overall demand reduction of 8 per cent by 2050, the equivalent to the annual power needs of Toronto today. One of our lowest-cost resources, energy efficiency benefits the grid while helping families and businesses reduce costs.
Key fact: Energy efficiency programs will save $12.2 billion in system costs by 2050.
Most of Ontario's capacity can be met with existing and recently procured resources until the mid-2030s
Thousands of megawatts of battery storage and natural gas-fired generation have been competitively procured in recent years, meaning Ontario will not have significant incremental capacity needs until the mid-2030s. Most capacity needs that emerge earlier will be met by reacquiring existing supply at lower prices, leveraging energy efficiency programs and the annual Capacity Auction. While Ontario’s current position is strong, continued investment is needed, with several procurements planned for the coming years.
Key fact: The Long Lead-Time Request for Proposals (RFP) is one of several planned actions that will help meet capacity and energy needs from 2035 and on. Launching this spring, it allows resources with longer development timeframes to compete, such as hydroelectric and long-duration storage, which has never been built before in Ontario.
Energy needs emerge earlier than capacity needs
There are a variety of options to help meet energy needs, with an 8 TWh need emerging in 2032. On-time delivery of new and refurbished nuclear can address a significant portion of energy needs in the early-2030s, while resources like wind and solar are expected to be procured for the first time in 10 years through the second Long-Term RFP. Gas generation is modelled to operate at levels far below its capability and can provide more energy as necessary.
Key fact: The Local Generation Program offers an opportunity to re-acquire about 2,000 MW of existing small-scale solar and wind within local distribution networks at lower cost, extending their operations.
New transmission is being built in every corner of the province
More than 1,800 kilometres of transmission projects are planned or under development across the province, and several new transmission lines are expected to be announced this year. Competitive transmission selection is being introduced in Ontario for the first time to drive down costs, beginning with the first-in-Ontario underwater line that will support Toronto’s growing electricity needs.
(Note: Dotted lines indicate conceptual locations for anticipated transmission projects and not final routes.)
Key fact: The IESO currently has 5 bulk plans and 9 regional plans underway. Transmission is often recommended as one of the most cost-effective solutions to meet growing demand, allowing a greater amount of power to flow from where it’s generated to where it’s needed.