Skip Links
Corporate IESO > Media > News Releases > Continued Reliability for Ontario’s Electricity System, says Latest IESO 18-Month Outlook

News Releases

Continued Reliability for Ontario’s Electricity System, says Latest IESO 18-Month Outlook

December 15, 2015

New initiatives such as the first demand response (DR) auction will help Ontario's electricity system remain reliable over the next 18 months, according to the latest report from the Independent Electricity System Operator (IESO).

The latest 18-Month Outlook report, which covers the period from January 2016 to June 2017, also forecasts that there is adequate generation and transmission to supply Ontario's demand.

For the upcoming winter, peak demands will see downward pressure from conservation and lighting efficiency improvements in particular. Energy demand is expected to decline this year as conservation savings and distribution-connected generation will more than offset any growth from economic expansion or population growth.

The recently announced results from the DR auction will contribute DR capacity of 391.5 MW for 2016 summer season and 403.7 MW for 2016-17 winter season.

"Ontario continues to have adequate resources to meet consumers' needs over the next 18 months," says Kim Warren, IESO's Vice-President of Market and System Operations. "The combination of conservation and time-of-use rates will continue to have a role in reducing demand through the upcoming winter season."

About 1,850 megawatts (MW) of new supply – 1,300 MW of wind, 300 MW of gas and 240 MW of solar generation – will be added to the province's transmission grid over the outlook period.  By the end of the period, the amount of grid-connected wind and solar generation is expected to increase to about 4,550 MW and 380 MW, respectively. The distribution-connected wind generation over the same period is expected to increase to about 700 MW and distribution-connected solar generation is expected to increase to about 2,150 MW.

As part of the IESO-Hydro Quebec seasonal capacity sharing agreement, Ontario will make 500 MW available to Quebec in the winters of 2015-16 and 2016-17. The IESO has the option to call on up to 500 MW of capacity from Quebec for summer seasons; no request was made for the summer of 2016.

The IESO regularly assesses the adequacy and reliability of Ontario's power system. The 18-Month Outlook is issued on a quarterly basis, in conjunction with the Ontario Energy Report, which highlights key trends in the energy sector. The 18-month outlook can be found by visiting or 18-Month Outlooks.

About the IESO

The IESO manages the province's power system so that Ontarians receive power when and where they need it. It plans and prepares for future electricity needs and works with its partners to guide conservation efforts. For more information, please visit

IESO Media Contact: 
John Cannella

< Back to News Releases