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

Base Period (Peak-setting Period)	Adjustment Period (Billing Period)
May 1, 2020 to April 30, 2021	July 1, 2021 to June 30, 2022
May 1, 2019 to April 30, 2020	July 1, 2020 to June 30, 2021
May 1, 2018 to April 30, 2019	July 1, 2019 to June 30, 2020
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, 2019 to April 30, 2020

Original Rank	Date	Hour Ending	Allocated Quantity of Energy Withdrawn (MWh)	Embedded Generation (MWh)	Energy Storage Injections (MWh)	*Total (MWh)**
1	July 5, 2019	17	21,274.851	1,024.050	4.784	22,294.117
2	July 20, 2019	17	21,147.253	956.288	0.119	22,103.422
3	July 29, 2019	17	21,067.570	1,068.780	7.282	22,129.068
4	July 19, 2019	12	21,006.403	1,365.446	4.009	22,367.840
5	July 4, 2019	18	20,956.127	732.129	4.387	21,683.869

*The value in the Total (MWh) 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 (MWh)

110,578.32

Peak Demand Factor

0.00017906

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.