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Learn about the IESO, Ontario's power system, how the electricity market works and what consumers can do to use electricity more efficiently.

About the IESO

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.


Ontario's Power System

Electricity service enables Ontarians to live, work and play. It is an inseparable and indispensable part of our modern society. Learn about how the Ontario power system delivers reliable, safe and sustainable electricity.

Electricity Pricing

How much electricity you use determines the rate you pay. Residential consumers and small businesses, for the most part, pay time-of-use rates, while mid and large businesses pay hourly wholesale prices. Learn about the different rates and charges, including global adjustment.

Ontario's Supply Mix

Ontario has a diverse energy supply mix. Its generation fleet continues to evolve, using greener forms of supply to safely and reliably meet the province’s changing electricity needs.

Conservation and Energy Efficiency

Investments in conservation and energy efficiency help meet Ontario’s energy needs today and for the future at a lower cost than building new infrastructure.