FERC issued another set of rulings on Order 881 compliance filings Thursday, ordering seven transmission providers to give more information on their timelines for calculating or submitting ambient-adjusted ratings (AARs). The commission accepted the other aspects of the transmission providers’ filings.
The affected transmission providers are GridLiance Heartland (ER22-2355), GridLiance High Plains (ER22-2354), Florida Power & Light (ER22-2353), Cube Yadkin Transmission (ER22-2466), Versant Power (ER22-2358), Nevada Power Co. (ER22-2304) and Cheyenne Light, Fuel and Power (ER22-2307).
The filing parties have until Nov. 12, 2024, to submit their timeline information, eight months before the July 2025 Order 881 implementation date. FERC said this extended due date accounts for the fact that it may be easier for transmission providers to submit AAR timelines closer to the 2025 implementation date.
This ruling is similar to previous FERC findings in April and June of this year. (See FERC Approves Batch of Line Ratings Compliance Filings and Order 881 Timelines Need Explaining, FERC Says.)
Order 881 requires transmission owners and operators to implement AARs — essentially real-time transmission line ratings — for short-term transmission requests on lines affected by air temperature, while requiring seasonal ratings for long-term service (RM20-16). FERC has said that existing static ratings based on worst-case weather assumptions limit the available transmission capacity and that the changes mandated by Order 881 will help free up a significant amount of capacity on the grid. (See FERC Orders End to Static Tx Line Ratings.)
