Ontario’s Electricity System

This map illustrates the many components that make up Ontario’s electricty system. Select a layer to reveal information on Ontario’s 21 energy planning regions, high-voltage transmission system, generators over 20 MW, 10 electrical zones, and the oil and gas pipeline network. Each layer of the map can be displayed independently or with some layers combined for comparison.

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Select a Layer

  • Generation
    • This layer displays in-service and in-development generation facilities with installed capacity of over 20 megawatts (MW) connected to the high-voltage transmission grid. Ontario’s more than 39,000 MW of installed generation capacity includes nuclear, hydro, gas, wind, biofuel, solar, and battery storage.
    Commercially operating
    Nuclear Hydro
    Natural Gas Wind
    Biofuel Solar
    Battery

    Under development
    Nuclear Hydro
    Natural Gas Wind
    Biofuel Solar
    Battery
  • Transmission
    • This layer shows the high-voltage IESO-Controlled Grid which includes 115 kilovolt (kV), 230 kV, and 500 kV transmission lines that span the province. There are over 30,000 kilometres of transmission lines in Ontario.
    500 kV
    230 kV
    115 kV
    Note: For areas where two transmission lines run parallel, the higher voltage line is shown.
  • Electrical Zones
    • This layer shows Ontario's transmission system is divided into ten electrical zones. Zonal boundaries chosen correspond with the major interfaces. Zonal boundaries are approximate.
    West Toronto
    Niagara Bruce
    Ottawa Southwest
    Northwest Northeast
    Essa East
     
  • Planning Regions
    • The IESO conducts regional planning in which local stakeholders contribute to the development of integrated solutions for reliable electricity service to Ontario communities. This map layer shows the 21 planning regions.
  • Oil & Gas Pipelines
    • Oil and gas pipelines deliver fuel from across North America to generation facilities in Ontario.
    Canadian Mainline
    Great Lakes Gas
    Enbridge Gas

Map combinations