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Peak Tracker

Class A Global Adjustment

Customers who participate in the Industrial Conservation Initiative (ICI) pay Global Adjustment (GA) based on their contribution to the top five peak hours of energy use in Ontario over a 12-month base period (May 1 to April 30). Customers participating in this initiative are referred to as Class A.

In previous base periods, the top five peak hours were determined using Final adjusted AQEW values. Starting with the May 1, 2022 base period, peak hours (as defined in O. Reg. 429/04) will be determined based on real-time ICI Ontario demand values. At the end of the 12-month base period (April 30, 2023) a customer's consumption during the top five peak hours will be used to determine their GA allocation (peak demand factor) for the next 12-month adjustment period (July 1, 2023 to June 30, 2024).

Class A customers that track and reduce their consumption during the top five peak hours will reduce their overall electricity charges. Read more about Class A Eligibility and the Industrial Conservation Initiative.

The IESO publishes tools and information below to help track ICI Ontario demand values and identify the top peak hours of the current base period.

Today’s Ontario Demand Forecast

The graph below identifies the forecasted Ontario demand for the next 24 hours and whether it could be a top 10 ICI Ontario demand peak during the current base period.

Hour Ending (EST) Forecast Ontario Demand (MW)
Hour Ending (EST) Forecast Ontario Demand (MW)
Hour Ending (EST) Forecast Ontario Demand (MW)
Hour Ending (EST) Forecast Ontario Demand (MW)

Forecasted Ontario Demand Daily Peak for the Next Six Days

The table below is the forecasted Ontario demand daily peak and hour looking out over the next six days.

As of April 2025

Date Hour Ending (EST) Maximum Forecasted Ontario Demand (MW) Link

Additional Adequacy Reports can be accessed from the IESO Reports Site.


ICI Ontario Demand Peak Tracker

Top 10 peak hours and ICI Ontario demand values with coincident adjusted AQEW values to date

The table below provides a real-time snapshot of the top 10 peak hours and ICI Ontario demand values with coincident adjusted AQEW values for the current base period. This information can be used by ICI customers to track ICI Ontario demand peaks and estimate their GA allocation for the peak hour.

Last updated June 20, 2025

Rank Date Hour Ending (EST) ICI Ontario Demand* (MW) Coincident Adjusted AQEW (MWh) Status* (Initial, Prelim, Final)

Ontario Demand values, ICI Ontario Demand values and adjusted AQEW values are available on the IESO Reports site.

*Status

ICI Ontario Demand Status: Initial peak values are published in orange approximately 1 hour following the end of the trade hour. Final peak values are published in black by the end of 3 business days following the initial publication.

Coincident Adjusted AQEW Status: Initial data is published 7 calendar days after the trade date. Preliminary data is published 10 business days after the trade date. Final data is published 20 business days after the trade date. A blank column indicates adjusted AQEW values are not yet available.

The coincident adjusted AQEW value is the metered consumption value associated with the peak hour and represents the volume of electricity withdrawn from the IESO-controlled grid. This value is the main contributor in establishing the Total System Consumption Value that is used as the denominator in determining an ICI customer's peak demand factor. ICI customers can use this value to estimate their global adjustment costs for the upcoming adjustment period.

Additional Peak Tracker Data

Additional tools and information to help anticipate when peak hours are more likely to occur
  1. Time of year: Electricity demand is largely driven by the weather. Ontario is a summer peaking province, meaning the highest times of peak demand tend to be during hot, humid days and/or during a heatwave. Demand can also be high during the winter when the weather is very cold.
  2. Time of day and days of the week: Demand peaks always occur on weekdays when businesses are in operation. The highest times of demand in a day vary between seasons. For example, winter tends to be in the early evening when electricity consumers across the province are turning lights on and making dinner. In the summer, demand tends to be higher in the early to mid-afternoon when air conditioners are turned up during the hottest time of the day.
  3. Class A-specific tools on the IESO’s website: See the top ten real-time demand peaks, and forecast data for the hours and days ahead to track peaks in the charts above.
  4. Adequacy Reports: These reports provide Ontario's hourly electricity requirements for today, as well as the next 34 days and are updated to reflect changing conditions throughout the day.
  5. Power Data: Follow current and projected demand in real-time at Power Data.

Energy management

Learn about reducing your peak demand through IESO's brochure, The Bottom Line on Energy Management: Making Ontario's Electricity Market Work for Your Business or by contacting your distributor. By reducing their energy use during system peaks, businesses will pay lower global adjustment costs next year.