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    Recalculated 2015 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 in 2015:

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

    The AESO must recalculate loss factors and losses charges in accordance with Decisions 790-D04-2016 and 790-D06-2017 of the Alberta Utilities Commission in Proceeding 790, Complaints Regarding the ISO Transmission Loss Factor Rule and Loss Factor Methodology. The recalculated 2015 loss factors are provided here:

    Notice to market participants: The AESO has identified an error in the implementation of the calculation of hourly raw loss factors for imports in the recalculated 2015 loss factors provided above. The error will be corrected and the recalculated 2015 loss factors will be republished in the future. The AESO anticipates the impact of the correction on non-import loss factors will be small and has posted the recalculated 2015 loss factors for the information of market participants. The data provided below and used in the recalculation of 2015 loss factors is not affected by the error in the implementation of the calculation. As well, the methodology used to recalculate 2015 loss factors is subject to the approval of the Commission in the Module C compliance filing process.

    The AESO must provide additional information related to the recalculated loss factors. This additional information is provided here:

    Actual losses on the transmission system were 2,355 GWh for 2015 and the average loss factor for the transmission system was 3.87% for 2015.