FERC has denied rehearing requests regarding approved revisions to CAISO’s Open Access Transmission Tariff generator interconnection procedures, which contesting parties said rely partly on “subjective and discriminatory criteria.”

Calpine, Clean Energy Associations, Dynegy Marketing and Trade, and Vistra filed the rehearing requests in October 2024. On Nov. 7, FERC denied the requests and clarified the discussion in its queue reform order.

CAISO proposed the OATT interconnection revisions because of an “unprecedented numbers of interconnection requests” resulting from California state regulatory requirements and policies, the order said.

The revisions included a zonal approach that prioritizes interconnection projects in areas with existing or planned transmission capacity. The approach provided four cluster study criteria, including a “commercial interest” score, which is up to 30% of a project’s overall score.

The rehearing parties claimed that commercial interest points create opportunities for potential undue discrimination or preference, specifically by allowing load-serving entities (LSE) to allocate commercial interest points to affiliates. That allows for the disparate treatment of LSEs vs. non-LSEs and creates an impact on small LSEs, the parties argued.

The commission found these claims “unpersuasive” because CAISO’s revisions “balance LSEs’ role in resource procurement with appropriate tariff limitations on LSEs’ ability to award points, including limitations on points that may be awarded to affiliates,” the order says.

FERC disagreed with the rehearing parties’ claim that LSEs would be able to control access to the grid by using “subjective and discriminatory criteria to assign commercial interest points in an anticompetitive manner.”

The rehearing parties said allowing LSEs to award commercial interest points violates the Federal Power Act, which prohibits undue discrimination. The parties also said the commercial interest points process erodes “two longstanding commission policies that provide non-discriminatory and comparable access to all wholesale users and ensure interconnection rules are not unduly discriminatory or preferential.”

FERC pointed out the Federal Power Act does not prohibit all discrimination, only “undue discrimination.”

“Discrimination is undue when similarly situated customers are treated differently,” the commission said in the order. “Here, no party on rehearing has provided any persuasive explanation that similarly situated interconnection customers will be treated differently under the revised tariff.”

CAISO said rejecting commercial interest points would “significantly diminish the value of its proposal and result in more ties,” the order says.

The approved OATT revisions will allow CAISO to select and move forward with proposed generating facilities for reliability and public policy purposes, the order says.