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    Previous loss factors and calibration factors

    2017 loss factors

    Loss factors are used to determine the transmission losses charges that apply to system access service under the following rates of the ISO tariff:

    • Rate STS, Supply Transmission Service
    • Rate XOS, Export Opportunity Service
    • Rate IOS, Import Opportunity Service
    • Rate DOS, Demand Opportunity Service

    The AESO must establish and maintain loss factors in accordance with section 501.10 of the ISO rules, Transmission Loss Factors (the “Loss Factor Rule”). The 2017 loss factors are provided here:

    2017 loss factors effective 1 Jan 2017 [Posted: Oct 31, 2017]

    In accordance with subsection 3(2) of the Loss Factor Rule, the AESO must provide additional information used to establish loss factors. This additional information is provided here:

    Hourly merit order data for 2017 loss factors (ZIP file,  15 MB)

    Sample of hourly load data for 2017 loss factors (ZIP file, 2 MB)

    Process for requesting access to system topologies

    Procedure to determine transmission system losses for loss factor calculations

    Software and scripts used to calculate hourly raw loss factors(ZIP file,  97 MB)

    Workbook showing calculations for 2017 loss factors (Microsoft Excel, 87 MB)

    Anticipated losses on the transmission system are 2,230 GWh for 2017 and the average loss factor for the transmission system is 3.60% for 2017.

    2016 loss factors

    Loss factors are used to determine the transmission losses charges that apply to system access service under the following rates of the ISO tariff:

    • Rate STS, Supply Transmission Service
    • Rate XOS, Export Opportunity Service
    • Rate IOS, Import Opportunity Service
    • Rate DOS, Demand Opportunity Service

    The Alberta Utilities Commission (the “Commission”) found the methodology currently used to calculate loss factors to be non-compliant with the Transmission Regulation. A new loss factor methodology is being determined through Commission Proceeding 790. The AESO will continue 2015 loss factors into 2016 on an interim basis, until loss factors based on a new approved methodology are implemented. The 2015 loss factors are provided here:

    2015 loss factors

    In accordance with section 32 of the Transmission Regulation, the AESO must make loss factors available to the public for a generating unit proposed to be constructed in Alberta. Updated information relating to the loss factors for some existing services may become available from time to time. The loss factors for the new services, as well as the updated information for existing services, are provided here:

    Loss factors for new services and updated loss factors for existing services

    For additional context, System Average Losses for 2016 have been estimated at 3.84%, compared to System Average Losses for 2015 of 3.66%.

    Note that the AESO has requested and received forbearance from the Market Surveillance Administrator (MSA) in respect of any related non-compliance with Section 501.10 of the ISO rules, Transmission Loss Factor Methodology and Requirements. Please refer to the November 6, 2015 letter posted on the MSA website.

    2017 calibration factors

    2016 calibration factors

    2015 loss factors

    2015 calibration factors