Ontario’s electricity system has many moving parts, all working together to ensure electricity supply remains reliable, affordable and sustainable. Here are some quick facts, videos and online tools to help boost your energy IQ.
Key statistics about Ontario’s electricity system, electricity marketplace and programs and initiatives delivered by the IESO. All values have been rounded.
Save on Energy
Through Save on Energy, the IESO offers programs and incentives to help individuals and businesses use energy more wisely. Discover your energy-saving potential by visiting the Save on Energy website.
Capacity is a measure of how much electricity Ontario's system can produce at any given time. As of September 2022, Ontario's transmission-connected capacity was over 38,000 MW.
Transmission-Connected Capacity as of September 2023 (Source: Reliability Outlook)
Electricity System Output
Output is the actual amount of electricity that is produced and delivered to customers. In 2021, Ontario's electricity system produced more than 142 TWh of electricity.
Electricity Output by Fuel Type (2021)
Community and Stakeholder Engagement
Helpful Tools | Electricity Facts and Tools
This collection of maps and online tools can help you understand and navigate Ontario’s electricity system.