Ontario’s electrical power system is one of the largest in North America, serving the power needs of more than 12 million people in a market that is 1.1 million square miles in size.

• Transmission - Electric power is transmitted across the province on 29,000 kilometres of high-voltage transmission lines, most of which are owned by Hydro One. Ontario's high-voltage lines interconnect with lines from Manitoba, Quebec, New York, Michigan and Minnesota, allowing up to 4000 MW of electricity to be imported into and exported out of Ontario.
  
  
• Distribution - Transformers are used to link electric power from the high-voltage lines to low-voltage lines. Hydro One, municipally owned utilities and private companies then distribute the electric power at low voltage to end-use customers.
  
  
• Generation - Ontario currently has the capacity to generate 30,000 megawatts of electric power from 94 generating stations across the province. These include hydroelectric, fossil-fuel and nuclear generating plants. OPG currently provides about 70 per cent of the electricity produced in the province.