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DEMAND OVERVIEW

Electricity Demand Records

The winter peak for electricity demand set on December 20, 2004 was 24,979 MW.
The summer peak for electricity demand set on August 1, 2006 was 27,005 MW.

Forecasting Peak Electricity Demand

Electricity supply and demand must be in balance every minute of the day. The IESO must forecast peak demand to ensure that generation will be available to meet the peak.

Peak Demand Forecasts

Season Seasonal Normal
Weather Peak (MW)
Extreme Weather
Peak (MW)
Summer 2013 23,213 25,368
Winter 2013-2014 22,239 23,297
Summer 2014 22,937 24,954
18-Month Outlook, May 2013

Demand Patterns Throughout the Day

Electricity demand is primarily influenced by weather, hours of daylight, business hours, school holidays and consumption patterns as people arrive home from work. Typically, demand peaks between 4 p.m. and 7 p.m. every day. At certain times of the year, when neither heating nor air conditioning is required, demand in the middle of the night can be lower than 11,000 MW and can rise by more than 10,000 MW later the same day.

Total Annual Ontario Energy Demand

Year Total (TWh) Increase Over
Previous Year
2012 141.3 -0.14%
2011 141.5 -0.35%
2010 142 2.2%
2009 139 -6.1%
2008 148 -2.3%
2007 152 0.7%
2006 151 -3.8%
2005 157 2.3%
2004 153 1.1%
2003 152 -0.7%
2002 153 4.1%
2001 147 0%
2000 147 2.1%
1999 144 2.9%
1998 140 1.4%
1997 138 -

 

RELATED INFORMATION

Average Electricity Demand in Selected Ontario Communities

Toronto:                  3,900 MW
Mississauga: 1,240 MW
Brampton: 610 MW
Windsor: 430 MW
Guelph: 240 MW
Thunder Bay:125 MW
Stratford: 94 MW
Orillia: 49 MW
Kenora: 18 MW

Where to Find More Information About Ontario Demand

  • Up-to-date demand information is available on the Demand and Price page.
  • The Monthly Market Update provides demand information for the past month.
  • Detailed daily, weekly and monthly market summaries are available on the Market Summaries page of the "Inside the Market" section.
  • The seasonal Power Outlook provides a summary of demand forecasts and generation availability over the next three months.
  • More detailed 18-Month and Ontario Reliability Outlooks are available on the Forecasts page in the "Inside the Market" section.