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  • Get Involved

    Get Involved

    Explore this website to understand how Ontario’s electricity market and system operate, as well as interact and participate in discussions about current topics affecting the industry. The IESO is available to answer your questions. Participate »

  • An Interdependent System

    An Interdependent System

    The IESO works at the heart of the electricity system, connecting the industry players who produce power, and then transport power on high voltage lines to the local utilities that distribute it to individual consumers. Ontario’s Power System »

  • Gateway to Ontario's Electricity Sector

    Gateway to Ontario's Electricity Sector

    Ontarians benefit from one of the most diverse and reliable electricity systems in the world. The IESO works at the heart of Ontario’s power system, balancing supply and demand through the electricity market. About the IESO »

Power System

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Learn how all the components of Ontario's power system work together. New ideas and technologies are changing the way the IESO operates the grid.

Ontario's Power System​​

Supply Mix​​​

Electricity Pricing​​​

Evolving the Markets​​​


Image of Physical Plant FloorInteract with Ontario's wholesale market as a generator, transmitter, large consumer, conveyer, or electricity service provider.

How to Register

Understanding your Market Obligations ​​

Market Rules and Manuals Library

Power Data


17,935 MW

Current Hour's Demand at 11:00 p.m. EST

  • 17,953 MW
    Projected Demand
    at 12:00 p.m. EST
  • 20,418 MW
    Today's Projected Peak
    at 6:00 p.m. EST
  • 27,005 MW
    Summer Record Peak
    Aug 1, 2006



Hourly Output by Fuel Type at 10:00 a.m. EST

  • 979 MW
    Hourly Imports
  • 3,000 MW
    Hourly Exports
  • 29,813 MW
    Generator Availability at Peak
    at 6:00 p.m. EST


3.38 ¢/kWh

Current Hourly Price at 11:00 p.m. EST

Hourly Ontario Energy Price ($/MWh)

  • 1.65¢/kWh
    Average Weighted Price
    for November
  • 8.23¢/kWh
    Global Adjustment
    for November

Stakeholder Engagement

The IESO and stakeholders work together to evolve and strengthen the market, enhance reliability, and implement market efficiencies. Learn about opportunities to contribute to the discussion.

Stakeholder Engagement

SAC and Technical Panel

Review of Ontario Interties

Image of employees in discussion 

About the IESO

The IESO manages the wholesale electricity market and oversees the reliable operation of the provincial electricity grid. Find out more about who we are and what we do.

What We Do

IESO Annual Report

Corporate Accountability

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