Historical Demand

 

Summer Peak

The summer (and all-time) peak for electricity demand set on August 1, 2006 was 27,005 MW.

Winter Peak

The winter peak for electricity demand set on December 20, 2004 was 24,979 MW.

Electricity Demand Records

Below are the top twenty record demand days for the province of Ontario since the market opened on May 1, 2002.

Rank Date Ontario Demand (MW)
1 Tuesday, August 01, 2006 27,005
2 Wednesday, July 13, 2005 26,160
3 Monday, June 27, 2005 26,157
4 Monday, July 31, 2006 26,092
5  Monday, July 17, 2006 25,898
6 Tuesday, June 28, 2005 25,861
7 Monday, July 18, 2005 25,857
8  Wednesday, August 02, 2006 25,816
9 Tuesday, August 9, 2005 25,816
10 Tuesday, July 12, 2005 25,808
11 Tuesday, June 26, 2007 25,737
12 Thursday, August 02, 2007 25,584
13 Monday, July 11, 2005 25,506
14 Wednesday, June 27, 2007 25,467
15 Thursday, July 21, 2011 25,450
16 Tuesday, August 13, 2002 25,414
17 Wednesday, August 01, 2007 25,402
18 Thursday, July 21, 2005 25,383
19 Thursday, July 14, 2005 25,362
20 Monday, August 12, 2002 25,349

Total Annual Ontario Energy Demand

Year Total (TWh) Increase Over Previous Year
2022 137.6 2.8%
2021 133.8 1.2%
2020 132.2 -2.2%
2019 135.1 -1.7% 
2018 137.4
 4.0%
Total Annual Ontario Energy Demand (in TWh) prior to 2017
Year Total (TWh) Increase Over Previous Year
2017 132.1 -3.6%
2016 137.0 0%
2015 137.0 -2.0%
2014 139.8 -0.64%
2013 140.7 -0.42%
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  -

Total Annual Ontario Energy Demand Data is taken from IESO's Hourly Demand Report

Peak demand across the province of Ontario

For some communities, peak demand occurs in the winter, while others are in the summer. Peak demands for 2018 for select communities across the province are shown below.

Ontario Map showing Peak Demand by City, Source: Ontario Energy Board Yearbook

Local data is taken from the Ontario Energy Board's 2020 Yearbook of Electricity Distributors.