Note: Operational and settlement data will be available on the 20th calendar day of each month, for the previous month. Global Adjustment by component and transmission rights clearing account data will be available on the 28th day of each month, for the previous month.
Select a Year and Month, and then click on the Generate button to create the monthly report.
Feedback on the revised Monthly Market Report is welcome - please contact customer.relations@ieso.ca.
Are you looking for a report prior to May 2025?
On May 1, 2025, the IESO launched a new single schedule, day-ahead market structure for Ontario.
Monthly Market Reports for April 2025 (and prior) can be found on the pre-MRP Monthly Market Report Archive page.
Market Prices
This section provides information on several key prices in the Ontario wholesale electricity market. A brief description of each reported price item is included. For more information on any of the price items, please refer to appropriate market rules, market manuals and training materials, or contact IESO Customer Relations.
Day-ahead Ontario Zonal Price (DA-OZP)
The Day-ahead Ontario Zonal Price is one of the components of the Ontario Price (the other being the Load Forecast Deviation Adjustment). The Ontario Price is applicable to non-dispatchable loads. Because the DA-OZP comprises such a large portion of the Ontario Price, it is a good predictor of the final Ontario Price.
The actual supply/demand balance can vary from these projections for a number of reasons:
- The actual demand for electricity can fluctuate as factors such as weather, temperature, amount of cloud cover, and wind etc., affect the amount of electricity used by consumers.
- At the same time, operational difficulties, unexpected generation losses or delays in a generation unit returning from an outage can result in higher priced generation being called on to fill the gap.
- Changes in interjurisdictional trade.
This graph shows daily average Day-ahead Ontario Zonal price for energy, as well as daily maximum and minimum prices.
Source: IESO Public Reports Site - Day-ahead Ontario Zonal Energy Price Report
Source: IESO Public Reports Site - Day-ahead Hourly Energy LMP Report
Monthly Weighted Average based on Ontario Demand = $ XX.XX/MWh or X.XX¢/kWh. This weighted average is provided as information.
Note: On-peak average price is the straight arithmetic average of DA-OZP in hours 8 to 23 (EST), Monday to Friday (5 x 16). Off-peak average price is the straight arithmetic average of DA-OZP for all remaining hours in the week. The wholesale market does not use a formal definition of on-peak and off-peak hours. The IESO is providing this calculation purely for information purposes, and uses this definition throughout the year.
Source: IESO Public Reports Site - Day-ahead Ontario Zonal Energy Price Report and Day-ahead Hourly Energy LMP Report
Real-time Market Price
This graph shows Real-time Ontario Zonal Prices (RT-OZPs). RT-OZPs are for information purposes only unless the DAM is declared by the IESO to have failed. If this occurs, and if RT-OZPs are available, they are used for settlement purposes.
Source: IESO Public Reports Site - Real-time Ontario Zonal Energy Price Report
Source: IESO Public Reports Site - Real-time Hourly Energy LMP Report
Source: IESO Public Reports Site - Real-time Ontario Zonal Energy Price Report
Day-ahead and Real-time Operating Reserve Price at Reference Bus
Operating Reserve (OR) is stand-by power or demand reduction that can be called on with short notice to deal with an unexpected mismatch between generation and load. Operating Reserve is purchased by the IESO in amounts needed to meet the reliability rules established by the North American Electricity Reliability Corporation (NERC), and the Northeast Power Coordinating Council (NPCC). The IESO recovers the required funds to pay for the purchased operating reserve from all customers in the wholesale market, via hourly uplift settlement charges.
The IESO purchases defined amounts of Operating Reserve from participants via three real-time markets: a 10-minute synchronized (10S) reserve market, a 10-minute non-synchronized (10NS) reserve market, and a 30-minute reserve (30OR) market.
The graph below shows the Operating Reserve prices at the reference bus from the day-ahead market for the three operating reserve products (10-minute Synchronized Reserve, 10-minute Non-Synchronized Reserve, and 30-minute Operating Reserve).
The graph below shows the Operating Reserve prices at the reference bus from the real-time market for the three operating reserve products (10-minute Synchronized Reserve, 10-minute Non-Synchronized Reserve, and 30-minute Operating Reserve).
Source: IESO Public Reports Site - Day-ahead Hourly OR LMP Report
Source: IESO Public Reports Site - Real-time Hourly OR LMP Report
Transmission Rights Market
The Transmission Rights Market is a financial market that is based on the import and export of electricity on the interconnection lines between Ontario and its surrounding markets in Manitoba, Quebec, New York, Michigan and Minnesota. When the interconnection lines reach their limits, energy prices can differ between Ontario and its surrounding markets. The Transmission Rights Market allows participants to buy financial protection ahead of time, to hedge against the possible price differences in the day-ahead market. These transmission rights are financial only. They do not give the holder of these rights any scheduling priority and do not limit other participants’ access to physical transmission across the interconnection lines.
The Transmission Rights contracts are auctioned off by the IESO. Successful bidders pay the market clearing price for the particular Transmission Right, in return for the right to receive revenues from the IESO in amounts proportional to the financial congestion that may in the day-ahead market occur over that interface for the duration of the contract.
Results from this month’s Transmission Rights Market are below. Specific information on auctions is available on the Market Calendars page. All figures are $/MW and are rounded to the nearest dollar.
Source: IESO Public Reports Site - TRA LT Post Auction Sales and Price Report (Auction Round 1) and TRA ST Post Auction Sales and Price Report and TRA LT Post Auction Sales and Price Report (Auction Round 2)
Transmission Rights Payments
The holders of Transmission Rights Contracts own the right to receive payments from the IESO if there is a non-zero congestion cost component in a Day-Ahead Market intertie locational marginal price on the path and in the direction (import or export) which they purchased.
Transmission Rights Clearing Account
The table below provides the activity of the Transmission Rights Clearing Account on a monthly basis for the past 6 months. It shows the revenues from the Transmission Rights Market, congestion rents from the market, interest earned on the balance and the Transmission Rights payments to Transmission Rights holders in millions of dollars. Long-term auction revenues are allocated evenly over the applicable 12-month term and the table below does not include revenues from future months. As per Chapter 8, section 4.18 of the market rules the reserve threshold as set by the IESO Board is equal to $20 million.
Allocation of Transmission Costs paid over TRCA balance period (%)
The Transmission Rights Clearing Account (TRCA) disbursement amount is split between the load and exporter classes based on the proportion of transmission costs paid by each class over the TRCA balance period.
Market Demand
Market Demand Definitions and Graphs
The graph below plots values for both Total Market Demand and Ontario Demand.
Total Market Demand represents the total energy that was supplied from the IESO-Administered Market.
The IESO calculates Total Market Demand by summing all output from generators registered in the Market plus all scheduled imports to the province. It is also equal to the sum of all load supplied from the Market plus exports from the province, plus all line losses incurred on the IESO-controlled grid.
Ontario Demand represents the total energy that was supplied from the IESO-Administered Market for the purpose of supplying load within Ontario.
It is also equal to the sum of all loads within Ontario which is supplied from the Market, plus all line losses incurred on the IESO-controlled grid.
Source: IESO Public Reports Site - Hourly Demand Report
Imports & Exports
The graph below plots both daily average imports to Ontario and daily average exports from Ontario during the month. Economic imports and exports are scheduled into/out of Ontario on an hourly basis, up to the physical capabilities of the IESO-controlled grid and the interconnections between the systems.
Source: IESO Public Reports Site - Yearly Intertie Actual Schedule and Flow Report
Unavailable Capacity
Demand for electricity varies greatly; from hour to hour, from day to day, and from season to season. The amount of generation available for operation also varies greatly over these same timeframes. This graph shows the total capability of generation within Ontario that is unavailable for operation. These quantities are published by the IESO several times per day in the Adequacy Report. The daily values in this graph are calculated by summing the average hourly MW quantities of the following:
- capacity of generators on planned and forced outages
- capacity of planned and forced deratings
- bottled capacity
- 2% of generator outages, derates and bottled capacity
- unscheduled capacity from Intermittent, Self-Scheduling, and Transitional Scheduling Generators
The values are taken from the most up-to-date Adequacy Report at any point in time.
Source: IESO Public Reports Site - Adequacy Report
Longer-Term Trends
This section provides graphs that display average quantities over longer periods of time. This longer-term perspective shows seasonal variations. Additional background information on some of these graphs is available on related graphs in previous sections.
Day-ahead Market Ontario Zonal Price Trends
Source: IESO Public Reports Site - Day-ahead Hourly Ontario Zonal Price Report
Day-ahead Market Ontario Zonal Prices
Source: IESO Public Reports Site - Day-ahead Hourly Ontario Zonal Price Report
Operating Reserve Prices
Source: IESO Public Reports Site - Day-ahead Hourly OR LMP Report
Source: IESO Public Reports Site - Real-time Operating Reserve LMP Report
Comparison to Neighbouring Control Area Prices
Source: PJM, NYISO, MISO, NEISO and IESO Public Reports Site - Hourly Day-ahead Ontario Zonal Price Report
Average Differences between Day-ahead Market Ontario Zonal Price and Pre-dispatch Ontario Zonal Price
Source: IESO Public Reports Site - Hourly LFDA Report and Pre-dispatch Hourly Ontario Zonal Price Report
Henry-Hub Natural Gas Closing Price
Source: Independent Statistics & Analysis - U.S. Energy Information Administration
Daily Market Demand Trends
Source: IESO Public Reports Site - Hourly Demand Report
Monthly Energy Totals
Source: IESO Public Reports Site - Hourly Demand Report
Monthly Energy by Fuel Type
Note: The current month is based on preliminary data and is subject to change.
Source: IESO Public Reports Site - Generator Output by Fuel Type Monthly Report
Imports/Exports per Intertie Zone (Monthly Total)
Note: Imports are depicted as above zero and exports are depicted as below zero.
Source: IESO Public Reports Site - Yearly Intertie Schedule and Flow Report
Daily Maximum Unavailable Capacity Trends
Source: IESO Public Reports Site - Adequacy Report
Global Adjustment
The Global Adjustment (GA) is the difference between the total payments made to certain contracted or regulated generators, and conservation programs, and any offsetting market revenues. The GA charge is applied to all consumers in Ontario, including those who pay the Ontario Price (Day-Ahead Ontario Zonal Price plus the Load Forecast Deviation Adjustment) and those who have signed a contract with a licensed electricity retailer. For customers on the Regulated Price Plan (RPP), it is factored into the rate set by the Ontario Energy Board.
The global adjustment is calculated as a total dollar amount for each month based on the difference between market revenues and the following components, broken down by fuel types and programs. These are the current components:
Wind
- Includes projects under Renewable Energy Supply, Renewable Energy Standard Offer Program, and the Feed-in-Tariff program
Biomass, Landfill and Byproduct
- Includes projects under Renewable Energy Supply, Renewable Energy Standard Offer Program, Feed-in-Tariff, converted OPG Atikokan facility, and NUG contracts with the IESO
Hydro
- Facilities with agreements through Renewable Energy Supply Program, Renewable Energy Standard Offer Program, Hydroelectric Contract Initiative, Hydroelectric Standard Offer Program, and the Feed-in-Tariff programs, as well as OPG's facilities that fall under the Hydroelectric Energy Supply Agreement
Nuclear
- Bruce Power nuclear
Natural Gas
- Natural gas facilities including OPG’s Lennox (dual fuel)
Solar
- Includes projects under Renewable Energy Supply, Renewable Energy Standard Offer Program, and Feed-in-Tariff program.
Other Programs - IEI and Storage
- Industrial Electricity Incentive (IEI) Program: An incentive for eligible consumers in Ontario to increase industrial production. Eligible activities include building a new, or expanding, a facility that falls within a specific NAICS Canada 2012 sector
- Storage: Includes facilities operating under the Phase II energy storage program
Funds and Financing
- Includes programs supporting community groups in the design and delivery of renewable energy initiatives and also includes contract penalties received from generators
Conservation
- Conservation programs including Save on Energy and Grid Innovation Fund (formerly Conservation Fund)
Ontario Power Generation – Regulated Nuclear and Hydro
- Regulated rates for OPG’s nuclear and remaining hydro generation as set by Ontario Energy Board
Ontario Electricity Financial Corporation – Non-Utility Generation
- Contracts administered by Ontario Electricity Financial Corporation with existing generation facilities
Customers with an average peak demand over one megawatt and some customers with an average peak demand of between 500 kilowatts and one megawatt are eligible to pay for GA based on a coincident peak calculation (i.e. Class A customers). All other customers pay GA based on the total amount of electricity they used for the month (i.e. Class B customers). Learn more on how Class A and B customers pay the GA. The total GA amount and the actual Class B rate are depicted below.
Source: Class B Global Adjustment
The table below highlights the components of the GA charge for the current month. The GA charge increase or decrease in response to changes in Day-ahead Ontario Zonal price (DA-OZP). When the DA-OZP is lower, the GA will be higher to cover the additional payments for energy contracts, and regulated generation.