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Market Data

The IESO publishes detailed price and demand information for the IESO-administered markets. Descriptions of these reports are provided below.

IESO Public Reports
Security and Adequacy Assessment / System Status Reports Hourly Ontario Energy Price (HOEP)
Pre-dispatch Control Action in OR
Dispatch Generator Disclosure Reports
Transmission Rights Auction Ancillary Services Contracts
Transmission Outages Zonal Demands
IESO Reports Site

Download Historical Data Files (in XLS or CSV)
Last updated: October 21, 2019

The calculation used for the Hourly Uplift, Intertie Offer Guarantee, and Monthly Uplift download data files now incorporates a few additional charge types that were not previously included. This change took effect October 16, 2011.

Hourly Demands Hourly Ontario Energy Price (HOEP)
Hourly Demands 2002-2012 Daily Operating Reserve Prices
Hourly Demands 1994-2002* Generator Weighted Average Prices
HOEP Monthly Averages Hourly Nodal Prices for the 10 Zones
Hourly Import Export Schedules Hourly Wind Generator Output
Intertie Offer Guarantee Charges DACP Pre-dispatch of Record Prices
3-Hour Ahead Pre-dispatch Prices Uplift: Hourly | Daily | Monthly
Loss Penalty Factors  

*Ontario Demand prior to market opening was derived from operational meters and provides the best representation of the hourly load shape in Ontario. 

The CSV versions are available for some Public Reports and may be downloaded from the IESO Reports Site at For information on downloading these reports please read the Public Report Retrieval document.

The IESO is issuing some reports in XML format (see Quick Take 12: Accessing IESO Reports Formatted in XML PDF). These reports are available on the IESO Reports Site.

All price data is quoted in Canadian dollars and uses Eastern Standard Time. For the purposes of data reporting, the IESO does not adopt daylight saving time.
If you receive an error message on one of the Market Data pages, please close the browser and reopen the page.

Note: The IESO makes every reasonable effort to keep the prices appearing on this web page consistent and up to date with those prices used for settlement purposes. Should a discrepancy arise, the IESO will determine the appropriate price as quickly as possible and notify market participants of the change.

  • The Security and Adequacy Assessment (SAA) reports provide forecast demand and system status information for up to four weeks ahead.
  • The System Status Reports (SSR) provide forecast demand, system status information and any applicable advisory notices for today and tomorrow.
  • The pre-dispatch page contains information about the remaining hours of the current day and for the day ahead, based on the forecasted market demand and the bids and offers submitted to the IESO.
  • The dispatch page contains up to date market results for today and the past 30 days.
  • The Transmission Rights Auction (TRA) page contains market information pertaining to future auctions and results of past auctions.
  • The Planned Transmission Outages page contains public transmission system outages that are planned for the report period. Transmission system outages include non-transmitter owned facilities that form part of the transmission system.
  • The Control Action in Operating Reserve page contains resource price & quantity information associated with IESO's use of voltage reduction control actions in the Operating Reserve markets.
  • The Generator Disclosure Reports page provides daily and monthly generating unit/station capability and production information.
  • The Ancillary Services Contracts page contains annual costs and quantities of all contracted ancillary service and reliability must-run contracts entered into by the IESO.
  • The Loss Penalty Factors are used to account for the incremental change in system losses as a result of the change in resource output.
  • The Zonal Demands page contains the hourly demands of the 10 zones in the province.
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