Ontario’s Electricity System

This interactive map illustrates the many components that make up Ontario’s energy system. Click on each layer to reveal information on Ontario’s 21 energy planning regions, local distribution company service areas, transmission, generation, and the oil and gas pipeline network. Each layer of the map can be displayed independently with some combined for comparison.


Select a Layer

  • Generation
    • This layer displays generation facilities with installed capacity of over 20 megawatts(MW) connected to the high voltage transmission grid. Ontario’s 35,591 MW of installed generation capacity includes nuclear, hydro, gas, wind, and soon solar.
    Nuclear Hydroelectric
    Gas-fired Wind-powered
    Biofuel Solar
  • 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.
  • Local Distribution Companies (LDC)
    • Select this layer to reveal service boundaries of all local distribution companies (LDCs) in the province. Local distribution companies operate the low-voltage grid to deliver power to 4.9 million consumers. Zoom in to see additional LDC names. For more information on each LDC, see ieso.ca/findutility.
  • 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
    Union Gas

Map combinations