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.
Electricity Use
5.3 million electricity customers in Ontario – including 4.8 million residential customers - in 2020
128.2 million MWh of electricity delivered to customers in 2020
22,428 MW highest summer peak demand in 2021 (set on August 24)
27,005 MW all-time highest summer peak demand (set on August 1, 2006)
20,455 MW highest winter peak demand in 2021 (set on December 7)
24,979 MW all-time highest winter peak demand – set on December 20, 2004
250,000 homes and businesses have benefitted from Save on Energy programs since 2011 (Source: Save on Energy)
16 TWh reduction in electricity use as a result of energy efficiency and conservation initiatives since 2011 – enough to power 1.7 million homes for one year
220,000 energy efficiency projects undertaken by business customers to lower their costs and improve their operations
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.
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.
