Thunder Bay Hydro Coporation

Serving the City of Thunder Bay with electricity.

Your Electricity System

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In order to answer many questions about what we do or what we can do, it is important to understand the role of Thunder Bay Hydro within the provincial power grid.

Thunder Bay Hydro is a Local Distribution Company.  We are owned by the City of Thunder Bay and overseen by a City-appointed board. 

Our role is to distribute power from the provincial grid to the residents and businesses within the City of Thunder Bay, build and maintain the lines and produce electricity bills and pass the money we collect on to the various provincial agencies involved in bringing electricity to our customers. We also distribute some locally generated power.

See our About Us page

Ontario’s Electricity Grid

The provincial electricity grid was once one entity that we remember as Ontario Hydro. On April 1, 1999 the former Ontario Hydro was restructured into five different companies.  Ontario's Electricity Act defines the entities and regulations which they operate under.

Ontario Power Generation (OPG) generates about 70% of the electricity for Ontario through fossil, nuclear and hydroelectric plants. To learn more, visit their website

Hydro One runs most of the high voltage transmission and some of the distribution systems for power in Ontario.

The Independent Electricity System Operator (IESO) administers the electricity grid and ensures there is adequate supply of electricity on a day to day basis.

 Electrical Safety Authority enforces electrical safety across Ontario.

 The Ontario Electricity Financial Corporation is responsible for servicing the debt and liabilities of the former Ontario Hydro that were not assigned to the successor companies.

These groups also play a role:

Ontario Energy Board Electricity prices are set twice a year by the Ontario Energy Board (OEB). Utilities do not make a profit on the sale of electricity to consumers.

Ontario Ministry of Energy has legislative responsibility for the provincial agencies.

Electricity Distributors Association is the voice of Ontario's local electricity distributors.

The Ontario Power Authority once coordinated province-wide conservation efforts, planned the electricity system for the long term, and issued contracts for clean electricity resources. The former Ontario Power Authority has merged with the Independent Electricity System Operator (see IESO above) creating a new organization at the hub of Ontario's diverse electricity system.

Learn more about the Ontario Electricity System at the Ministry of Energy's website.

Ontario System Wide Supply Mix Data

2015SupplyMix.pngElectricity Retailing – Disclosure to Consumers, O. Reg. 416/99, requires retailers to disclose to consumers the Ontario system-wide electricity supply mix in the manner established by the Ontario Energy Board. The Board’s Directive for the Disclosure of Information to Consumers by Electricity Retailers under Ontario Regulation 416/99 prescribes the manner and timing requirements for this disclosure. The Directive applies to all retailers, including distributors that provide standard supply service.
Under O. Reg. 416/99 the Ministry of Energy is responsible for providing Ontario’s electricity supply mix data for electricity suppliers. The following label discloses the system-wide electricity supply mix data for 2015. This data must be used by electricity suppliers for the purposes of complying with the disclosure obligations of O. Reg. 416/99 and the Directive. This data should be considered current until further notice.

Electricity Sources  Ontario's Electricity Mix*
Water Power  23.2% 
Alternative Power Sources  8.7%
Solar  1.9% 
Wind  6.4% 
 Biomass 0.4% 
Waste  0% 
Nuclear Energy 57.8% 
Natural Gas**   9.7%
Other   0.5%

* Includes both Tx (direct) and Dx (embedded) connected generation (Ontario Ministry of Energy)

**Includes generation from facilities that are predominantly natural gas (e.g., Lennox Generating Station)

Note: Figures may not add to 100% due to rounding