Ontario's Energy Capacity

Over the past decade, wind, solar, bioenergy, hydro, refurbished nuclear and natural gas-fired resources have replaced Ontario’s coal fleet. These resources, together with investments in conservation, demand response and transmission have reduced greenhouse gas emissions in Ontario’s electricity sector by more than 80 percent.

The current installed capacity on Ontario’s transmission grid is 36,130 MW. In addition to transmission-connected generation, there is currently about 3,138 MW of generation capacity within Ontario’s local distribution systems. The largest percentage of distributed generation, also known as embedded generation, is from solar facilities.

Current installed capacity - transmission system

This chart shows Ontario’s current installed energy capacity by fuel type on Ontario's transmission system, as of March 2017. These figures do not include the capacity of embedded generators that operate within local distribution systems, except those that are registered to participate in Ontario’s wholesale electricity market.

Current Ontario Supply Mix Transmission Connected

Source: 18-Month Outlook, released March 21, 2017, updated quarterly.

See Document Library for previous 18-Month Outlooks.

Current installed capacity - distribution system

This chart shows the amount of energy by fuel type that is in commercial operation on Ontario's distribution systems, as of December 2016. This is also referred to as current installed embedded generation.

Current Ontario Supply Mix Distribution Connected

Source: Progress Report on Contracted Electricity Supply, Fourth Quarter 2016.

See Document Library for previous reports.


Interested in how much energy is currently being produced by Ontario’s energy resources? The IESO publishes hourly generation output by fuel type. See Power Data for real-time data.

Contracting for cleaner energy

The IESO has ensured that Ontario’s electricity needs can be met now and into the future by contracting for energy from diverse resources such as wind, solar, hydro, bioenergy, nuclear and natural gas. The procurement targets for each fuel type are set out in the government’s 2013 Long-Term Energy Plan.

The IESO has signed contracts with a wide variety of energy suppliers including private sector businesses, cooperatives, public sector organizations, Indigenous communities, community groups, school boards, farmers and homeowners.

While Ontario is experiencing a strong supply situation, now is a good time to consider changes to Ontario’s energy markets that will allow for more market-based opportunities for investment and participation.

Read how the IESO is working with stakeholders to provide evolve the electricity market, enhance its electricity market design to improve market efficiency and unlock future opportunities.