FERC on Wednesday denied a rehearing request over its February decision approving SPP’s tariff revisions that add an annual transmission revenue requirement (ATRR), a formula rate template and implementation protocols for GridLiance High Plains-owned facilities in Nixa, Mo. (ER18-99).

The commission said that according to precedent set by the D.C. Circuit Court of Appeals’ Allegheny Defense Project v. FERC decision, the rehearing request is denied by operation of law. The 2020 order found FERC no longer could grant rehearing requests “for the limited purpose of further consideration.”

FERC did modify the discussion in the February order but continued to reach the same result.

The commission’s order affirmed an administrative law judge’s 2021 decision finding SPP’s proposal to incorporate the Nixa assets into one of its transmission pricing zones was consistent with cost-causation principles and was just and reasonable. (See “Order on GridLiance ATRR,” FERC Grants Rehearing of SPP Capacity Accreditation Proposal.)

Several cities in Arkansas and Missouri and a group of SPP transmission owners (Evergy, American Electric Power and Xcel Energy subsidiaries and Western Farmers Electric Cooperative) filed a joint rehearing request in March. They argued that a cost shift associated with a zonal placement decision under SPP’s tariff cannot be just and reasonable unless each customer or group of customers that will bear some portion of the assets’ costs is deriving a benefit from those specific assets that is “roughly proportionate” to those costs.

The commission said it disagreed that rough proportionality is the only appropriate way to approach cost causation under SPP’s zonal placement process. It sustained its decision not to adopt the requirement, saying the intervenors’ approach “does not square with the existing zonal rate construct under the SPP tariff.”

“SPP’s zonal rate construct does not attempt to measure each transmission customer’s benefit from each transmission asset included in the zonal ATRR. Nor does it charge each customer transmission costs on an asset-by-asset basis,” FERC wrote. “Instead, under that zonal construct, the costs and benefits associated with network service in a zone are assessed on an aggregate level, with each customer paying for transmission service based on its load ratio share, which reflects its total use of the aggregate assets in the zone.”