FERC has given MISO an all-clear to cap project hopefuls lining up for its overflowing generator interconnection queue at 50% of the RTO’s peak load.

FERC said MISO’s plan to impose a yearly cap of 50% of the non-coincident peak per study region is fair considering the footprint’s 309-GW, backlogged interconnection queue (ER25-507). The commission said in the Jan. 30 order that the cap “will allow MISO to conduct its study cycles more effectively… which will ultimately benefit interconnection customers.”

The megawatt cap would take effect beginning with the grid operator’s 2025 cycle of queue submissions.

MISO late last year made a second attempt to instate a megawatt cap on its annual queue cycles after FERC rejected MISO’s first attempt based on concerns over too many cap exemptions, the formula to establish the cap being unrealistic and potential resource adequacy deficits from limiting new generation onto the grid. (See MISO Queue MW Cap to be Filed Sans Regulator Exemption for RA Generation Projects; MISO Stakeholders Debate Usefulness of MW Queue Cap Pending Before FERC.)

With the cap in place, MISO said it will reopen acceptance of a new queue cycle at the end of this year. MISO had paused processing new queue cycles for more than a year and skipped a 2024 cycle altogether. (See MISO Unveils Later Timeline for Queue Processing Restart.)

MISO said a jump in interconnection requests beginning in 2020 has made it nearly impossible to create accurate models to study the new interconnections.

It fielded 52.4 GW of requests in 2020, 76.8 GW in 2021, and 170.8 GW in 2022. The queue currently contains nearly 1,700 interconnection requests totaling about 309 GW. By comparison, MISO’s peak load holds at about 127 GW, and the footprint boasts a total 191 GW of functioning installed capacity.

FERC agreed with MISO that “the large number of interconnection requests submitted into MISO’s interconnection queue would cause MISO to make unrealistic modeling assumptions, producing study results with inaccurate network upgrade cost estimates.”

“Such inaccuracies, in turn, would drive withdrawals from the queue, further affecting study results and causing delays,” FERC wrote.

The commission said MISO’s 50% methodology is reasonable based on MISO’s explanation that it represents a cliff before studies begin showing that major transmission upgrades are necessary, which is “typically indicative of voltage collapse.” FERC also said MISO this time explained how the cap still would allow sufficient generation capacity to be developed to meet resource adequacy standards.

MISO has said that even with a cap in place, it could achieve a total 310-GW queue throughput through 2042.

“We agree with MISO that the proposed queue cap formula strikes a reasonable balance between limiting the volume of requests to a level that can be processed efficiently and avoiding unnecessary barriers to entry that will delay the development of the generation capacity needed to meet growing supply shortages within the MISO region,” FERC said.

FERC decided MISO’s thinning of cap exemptions was appropriate and took care of concerns that MISO would have “unbounded” exceptions to the cap. It disagreed with MISO South regulators that removal of an exemption for projects deemed necessities by state public service commissions treads on states’ authority. FERC said if a public utility wants to modify its generator interconnection procedures on file, it must file with FERC.

Exemptions to the cap now are limited to generators with provisional generator interconnection agreements; generators seeking to replace retiring counterparts and in need of extra interconnection service; and those generators wanting to convert their unguaranteed energy resource interconnection service with the higher-quality network resource interconnection service.

FERC dismissed clean energy groups’ concerns that the cap method doesn’t feature a “first-ready, first-served” approach for generation projects. The commission said projects entering the queue still must meet MISO’s commercial readiness requirements to advance into the queue. It also said MISO’s recently raised fees, automatic withdraw penalties and requirements that developers show proof they secured land should winnow out speculative projects. FERC declined to consider Shell Energy’s recommendation that MISO impose a per-developer limit on project submission based on similar reasoning.

FERC also rejected some stakeholders’ arguments that the cap isn’t reasonable because it didn’t resemble approved caps like CAISO’s and wasn’t limited to a specific amount of time like SPP’s. It said it wouldn’t go down the road of deciding whether the cap was “more or less reasonable” than other possible rate designs.

“MISO, CAISO, and SPP have chosen to address interconnection queue management problems caused by an overwhelming number of interconnection requests through different approaches based, in part, on regional needs and characteristics,” the commission said, while pointing out that MISO has committed to reviewing the effectiveness at the cap in about three years.

The commission refused utilities and MISO South regulators’ recommendation that FERC tie approval of the cap to a resource adequacy express lane MISO is working to build into the queue, saying the future filing is a separate issue and not yet up for consideration. (See Generation Developers Ask for Scoring System on MISO Queue Fast Track.)

However, Commissioner Mark Christie wrote separately to encourage MISO to try again at developing exceptions to the cap for generation facilities that are labelled indispensable to resource adequacy by public service commissions. He said FERC “wrongly” rejected exemptions for state-designated generators in MISO’s first filing.

Christie said he was “disappointed in MISO’s failure to include a state exemption in its second filing, as the membership of the commission has changed significantly since last January and already has shown much more acknowledgement of the critically important role played by state utility regulators in ensuring reliable power to their states’ consumers.”

“MISO should have stuck to its guns and vigorously restated its reasons for including a state exemption,” Christie wrote.

While FERC said it was in favor of MISO’s cap, it encouraged the RTO to “continue considering other avenues to manage its interconnection queue” and said MISO’s efforts to automate its studies appear promising.