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Peak Demand Factor and the Global Adjustment (GA)

Each Class A customer’s portion of the province-wide total GA cost is calculated using their Peak Demand Factor.

After the IESO establishes the top five demand peaks 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. 

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 peak demand contributes to the top five system coincident peaks during a predetermined​ base period. 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.

Base Period (Peak-setting Period)

Adjustment Period (Billing Period)

May 1, 2014 to April 30, 2015

July 1, 2015 to June 30, 2016

​May 1, 2015 to April 30, 2016

July 1, 2016 to June 30, 2017​

​May 1, 2016 to April 30, 2017

​July 1, 2017 to June 30, 2018

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

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

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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.​

 

Date

Hour Ending

Allocated Quantity of Energy Withdrawn (MW)

Embedded Generation (MW)

Total (MW)*

July 28, 2015

17

22,015.634

1,008.076

23,023.710

July 29, 2015

17

21,899.846

935.595

22,835.441

August 17, 2015

17

21,882.182

1,010.057

22,892.239

July 27, 2015

18

21,561.628

761.649

22,323.277

September 3, 2015

14

21,428.697

1,431.536

22,860.233

 *The value in the Total (MW) column is the number used to calculate a customer's Peak De​​mand Factor.


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 demand 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

A customer's consumption during the top 5 demand peak hours (MWh/h)
3.1
​4.4
​3.9
​4.1
​4.3
19.8


÷


Sum of Top 5 System-Wide Consumption Peaks
(MW)
113,934.90




=


Peak Demand Factor
0.00017378




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



System-wide GA costs for
December 2015
$999.6 M
See Total GA ($M)




x


Your Peak Demand Factor from
example above
0.00017378





=


Your GA charge for
December 2015
$173,710.49