The Independent Electricity System Operator (IESO) works at the heart of Ontario’s power system ensuring there is enough power to keep the lights on, today and into the future.
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
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
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.
