Overseeing the Electricity Market

Electricity, just like other commodities, is produced by suppliers and sold and transported to customers. At the centre of this cycle is Ontario’s wholesale electricity market. Through the electricity market, generators and facilities capable of reducing their energy use on short notice, (such as factories and processing plants), bid to provide Ontario’s energy needs.

The IESO's Role in Ontario's Electricity Markets

The IESO oversees and evolves Ontario's electricity markets, driving competition to maintain affordability. The IESO:

  • Reviews and accepts bids from electricity suppliers, starting with the lowest-cost options, until Ontario's energy needs are met
  • Sets and enforces rules that govern participation in Ontario's electricity markets
  • Fosters an open, dynamic and sustainable marketplace that encourages new opportunities for emerging resources
market renewal icon - line arrow graph going steady

The Value of Electricity Markets

In Ontario, electricity is produced by suppliers and sold to distributors (local hydro companies) through the wholesale electricity market. This competitive process:

  • Improves the reliability and operability of Ontario's electricity system
  • Signals economic opportunities for electricity suppliers
  • Helps keep electricity prices affordable

Visit The Value of Electricity Markets web page to learn more.

What is an Electricity Market?

Market Renewal

The Market Renewal Program will result in a fundamental redesign of Ontario’s electricity markets. When fully implemented, it will result in a more efficient, stable marketplace with competitive and transparent tools that meet system and stakeholder needs at the lowest cost. It will also help prepare Ontario for the future by laying the groundwork to incorporate new and emerging technologies.

Specifically, market renewal is focused on improving how:

  • Electricity is scheduled and dispatched to help reduce overall system costs.
  • The system can reliably and efficiently respond to unexpected, short-term changes in supply and demand.

Visit the Market Renewal webpage to learn more about the changes the IESO is making to Ontario’s electricity markets.

20th Anniversary of Ontario's Wholesale Electricity Market

Since the market opened in 2002, Ontario’s electricity sector has experienced major changes and it continues to evolve as new technologies transform the way electricity is produced and used. Discover the milestones that have shaped Ontario’s electricity markets by visiting the Market Anniversary web page.

Planning for the Future | About the IESO

The IESO forecasts electricity demand, plans electricity system infrastructure and secures new supply to ensure Ontario's energy needs are met.