Global Adjustment and Peak Demand Factor

Class A customers are assessed their portion of GA costs based on the percentage that their consumption contributes to the top five system coincident peaks during a predetermined base period, referred to as their Peak Demand Factor.

For example, if a Class A customer is assessed to be responsible for one per cent of Ontario's coincident peak demand for the five highest hours of a set base period, they will be charged for one per cent of total GA costs through the next adjustment, or billing period.

For more detailed information, see the Industrial Conservation Initiative Backgrounder.

Base period

Class A customers are assessed their portion of GA costs based on the percentage that their consumption contributes to the top five system coincident peaks during a predetermined base period (May 1-April 30) and will be charged their percentage of total GA costs through the next adjustment, or billing period (July 1-June 30).

Base Period (Peak-setting Period)

Adjustment Period (Billing Period)

 May 1, 2017 to April 30, 2018

 July 1, 2018 to June 30, 2019

May 1, 2016 to April 30, 2017

July 1, 2017 to June 30, 2018

May 1, 2015 to April 30, 2016

July 1, 2016 to June 30, 2017

May 1, (Year X) to April 30, (Year X+1)

July 1, (Year X+1) to June 30, (Year X+2)


Top 5 Peaks: Hours & System-Wide Consumption

The table below shows the final peak hours and the corresponding adjusted demand for the past base period. Embedded generation is included, as it represents Ontario demand that was met through local generation.

 

Base Period: May 1, 2017 to April 30, 2018

 Date

Hour Ending

Allocated Quantity of Energy Withdrawn (MW)

Embedded Generation
(MW)

Total
(MW)*

September 25, 2017

17

21,170.494

641.115

21,811.609

September 26, 2017

17

21,038.558

626.445

21,665.003

June 12, 2017

17

20,701.997

1,296.884

21,998.881

January 5, 2018

18

20,238.280

646.859

20,885.139

July 19, 2017

18

20,122.460

861.665

20,984.125

*The value in the Total (MW) column is the number used to calculate a customer’s Peak Demand Factor.

For historical peaks, download the Top 5 Peaks: Hours & System-Wide Consumption.

Calculating your Peak Demand Factor

After the IESO establishes the final top five Ontario demand peaks using adjusted AQEW for a base period, the IESO and LDCs then look at each Class A customer's consumption during those five hours (coincident peaks) to calculate their corresponding portion of peak demand. This portion is called a peak demand factor and is used to determine a customer's allocation of costs for the adjustment or billing period.

Example Calculation

A customer’s consumption during the
top 5 demand peak hours (MWh)
           

  3.1

   4.4

   3.9

   4.1

    4.3

   19.8

÷

 
Sum of Top 5 System-wide Consumption Peaks (MW)

107,344.757

 =        Peak Demand Factor

0.00018445


How Class A customers are charged GA

The Class A customer's Peak Demand Factor is used to calculate monthly GA charges during the adjustment or billing period. This is done by multiplying the monthly Ontario-wide total GA costs by the customer's Peak Demand Factor.

Example Calculation

System-wide GA costs for a given month 

$999.6 M

See Total GA costs ($M)

x

Your Peak Demand Factor from example above

0.00017204

=  

Your GA charge for the month

$171,971.18