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    GUOC Estimate Calculator & Yearly Updates

    The owner of a proposed generating unit or aggregated generating facility with a maximum capability of greater than 1 MW is required by the ISO tariff to make a Generating Unit Owner’s Contribution (GUOC). To estimate the amount of GUOC that will be required, please enter the planning region and maximum capability in the estimation calculator below.

    Rates listed for each planning region are based on the ISO tariff currently in effect. For more information about GUOC and the ISO tariff, please see the following links:


    Contribution Estimate: $2300.01
    Download region map

    This online calculator is designed for convenience and should be used for informational purposes only. The accuracy of the calculator and its applicability to particular cases is not guaranteed. The AESO will issue a GUOC assessment and final invoice which may differ from the estimate generated by this online calculator. The AESO makes no claims, promises, or guarantees regarding the accuracy or completeness of the information provided by this online calculator, and expressly disclaims liability for errors or omissions. Consequently, any reliance placed on the information provided herein is at the user’s sole risk.

    GUOC Rates and Yearly Update Process

    The AESO has published a process document that provides stakeholders details on the new GUOC Rate update process, which it plans to implement in conjunction with the 2023 ISO tariff rates update application expected to be filed for approval by the Alberta Utilities Commission (“AUC”) in late 2022.