FERC on Friday rejected a rehearing request by a solar developer of the commission’s denial of its complaint and a tariff waiver over SPP’s interconnection studies for the planned facility (EL22-89).

The commission, citing Allegheny Defense Project v. FERC, denied the rehearing request by “operation of law.” FERC modified the discussion in its previous order but arrived at the same conclusion.

The D.C. Circuit Court of Appeals’ 2020 ruling in Allegheny found the commission no longer could grant rehearing requests “for the limited purpose of further consideration.”

The developer behind Cage Ranch Solar and Cage Ranch Solar II, a 900-MW project in West Texas, sought to reverse the commission’s May decision that found Cage Ranch had not met its burden to show that SPP violated its tariff or conducted its studies in an unjust and unreasonable manner. FERC said the solar facility did not demonstrate the study models underlying the cluster study were defective. (See FERC Sides with SPP Over Interconnection Study Complaint.)

Cage Ranch argued FERC erred by finding its interconnection was the “but for” cause of network upgrades, failing to address the developer’s cost-causation arguments; and that its waiver request did not address a concrete problem.

The commission said it was unpersuaded by the rehearing arguments and continued to find that Cage Ranch had not met its burden under the Federal Power Act to show SPP violated its tariff or that its allocation of costs was otherwise unjust and unreasonable.

“Nothing in the rehearing request demonstrates that the [SPP] study models underlying [SPP’s study] are defective,” FERC said. “Accordingly, we continue to find that Cage Ranch has failed to demonstrate that the network upgrades assigned to Cage Ranch … and the associated [study] payment amount that Cage Ranch was required to post, are unjust and unreasonable and unduly discriminatory or preferential. … None of the issues raised in the rehearing request persuade us that the commission’s conclusions were in error.”

Cage Ranch had said the SPP study in question should not have been used to determine interconnection costs for the solar farm and other customers in the study group because SPP failed to resolve alleged nonconvergence issues. FERC pointed out that the grid operator assigned Cage Ranch network upgrade costs using a modeling approach it applies to all interconnection customers.

Cage Ranch Solar also filed a challenge of FERC’s earlier ruling in August with the D.C. Circuit. It said the orders violate the Federal Power Act and the Administrative Procedure Act and are arbitrary, capricious and an abuse of discretion (23-01227).