Close collaboration with Ontario

On May 8, 2015, Hydro-Québec and the Ontario Independent Electricity System Operator (IESO) signed a 500-MW seasonal capacity sharing agreement.

Québec has excess capacity during summer and increased capacity needs in winter, whereas Ontario’s pattern is generally opposite, with increased capacity needs in summer and excess capacity in winter. Taking advantage of this complementarity in peaking periods, the agreement supports the reliability of both electricity systems in a cost-effective manner.

In October 2016, IESO and Hydro-Québec concluded a long-term agreement (2017–2023), under which:

  • Ontario will receive 2 TWh per year from Hydro-Québec to limit its GHG emissions from natural gas generation;
  • Hydro-Québec will receive capacity from Ontario to help meet its winter peak needs;
  • Energy exchanges will assist Ontario in maximizing its generation of renewable energy.

History of energy trading with Ontario


Signing of a six-year contract between Hydro-Québec and the Hydro-Electric Power Commission of Ontario for deliveries totaling 28 TWh.


Hydro-Québec commissioned a new 1,250-MW interconnection with Ontario, significantly increasing the interchange capacity between the two provinces.


Signing of a seasonal capacity sharing agreement between Hydro-Québec and IESO.

Interchange capacity between Ontario and Québec: 2,700 MW

Volume that can be delivered to Ontario through existing interconnections: 14 TWh

Long-term contracts with Cornwall

Hydro-Québec and Cornwall Electric have signed two long-term wholesale electricity contracts to supply the municipality of Cornwall, Ontario, through the Cedars Rapids transmission system. The first, signed in 2000, is for 45 MW, and the second, signed in 2008, is for 100 MW. Together, the two contracts provide for annual purchases of at least 600 GWh.

These contracts ensure a reliable supply of electricity and stable rates for the city of Cornwall.