On May 26, 2023, the Commission accepted Southwest Power Pool, Inc.’s (“SPP”) proposed revisions to its Tariff to establish the “framework under which an electric storage resource may be considered a transmission asset.” 

On July 12, 2022, as amended on December 2, 2022, SPP proposed revisions to its Tariff to include Storage as a Transmission-Only Asset (“SATOA”) and related provisions, including cost allocation and recovery, transmission planning, interconnection, market participation, and market monitoring for SATOAs.  

The Commission found that SPP’s proposed revisions ensure that a SATOA will serve a transmission function.  First, under SPP’s proposed revisions, a SATOA “must be connected to the transmission system as a transmission facility solely to support SPP’s transmission system.” The proposed SATOA must also be identified as the preferred solution to resolve a transmission issue in SPP’s transmission planning processes. In addition, FERC provided that the transmission issue to be resolved by the SATOA cannot be addressed by a market solution; that SATOA’s market participation is limited to charging from and discharging to SPP’s transmission system as needed to provide the service it was approved to deliver; and that the SATOA will be subject to SPP’s operational control.

With regard to cost recovery, the Commission approved SPP’s proposal to use the appropriate existing transmission cost allocation and recovery methods that apply to the relevant type of transmission project for which the SATOA qualifies under SPP’s Tariff.  The Commission reasoned that given that the scope of a SATOA is restricted to performing transmission functions, it is appropriate for the SATOA to recover costs in a manner consistent with the existing transmission facilities within the same category of the transmission project.

FERC’s order, issued in Docket No. ER22-2344, can be found here.