The restructuring of Ontario’s electricity sector in the mid-to-late 1990s saw the elimination of the integrated power system planning function that had played a central role in the development and management of Ontario’s power system from 1906 to 1998.

Shortly after Ontario Hydro’s monopoly was eliminated and Ontario’s competitive electricity market was opened, it was apparent that Ontario faced a looming electricity supply shortfall.

It was concluded that this shortfall would require a more coordinated and integrated approach to establishing electricity sector targets and guiding investment than had been provided for by earlier restructuring reforms. The Ontario Power Authority fulfils these roles.

Other players in Ontario’s energy landscape include:

Ministry of Energy
Its responsibility is to ensure that Ontario’s electricity system functions at the highest level of reliability and productivity. It is also focused on promoting ingenuity and innovation in the energy sector. By encouraging the development of new ideas and technologies, it is helping to make Ontario a world leader in the global energy market. Developing renewable sources of energy, cleaner forms of fuel, as well as fostering a conservation culture, are all cornerstones of the ministry’s vision for Ontario’s electricity future.
Contact: www.mei.gov.on.ca

Ontario Energy Board
This is an independent adjudicative tribunal responsible for regulating Ontario's natural gas and electricity sectors. Part of its mandate is to protect the interests of consumers with respect to prices and the reliability and quality of electricity service.
Contact: www.oeb.gov.on.ca

Ontario Power Authority
"The OPA is responsible for ensuring an adequate, long-term supply of electricity in Ontario, which is critical to the province's continued growth and prosperity," - Dwight Duncan, then Minister of Energy

Independent Electricity System Operator
This organization manages the reliable operation of Ontario's power system and forecasts the short-term demand and supply of electricity. The IESO also operates the real-time spot market electricity market and represents Ontario in international electricity reliability issues.
Contact: www.ieso.ca

Ontario Power Generation
This is a provincially owned electricity generation company -- its hydroelectric, nuclear and fossil fuel stations generate approximately 70 percent of Ontario's electricity.
Contact: www.opg.com

The balance of Ontario’s electricity is generated by private companies. Among these are Bruce Power, which operates a nuclear generating station in Bruce County, as well as other, smaller operations that use a variety of technologies to generate electricity.

Hydro One
A provincially owned company that operates the majority of Ontario's transmission lines, Hydro One also serves as an electricity local distribution company in some areas of the province.
Contact: www.hydroone.com

There are many local distribution companies that also deliver electrical service to homes and businesses – about 90 in total. Hydro One typically services rural areas, while electric utility companies, such as Toronto Hydro, service urban areas.