MISO defends limited exemptions on proposed gigawatt cap for interconnection queue

The Midcontinent Independent System Operator has defended its interconnection queue cap proposal against publicly filed protests, saying in a response Dec. 31 to the Federal Energy Regulatory Commission that it had provided substantial evidence to support its exclusion of a key exemption to the cap.

MISO's interconnection queue cap proposal (ER25-507) seeks to implement a limit on the total gigawatt value of interconnection requests entering a given study cluster, and it was filed Nov. 21 at FERC, along with a related proposal calling for limited exemptions to the cap related to existing generators. This is MISO's latest attempt at implementing a queue cap after FERC rejected a previous proposal included in a package of interconnection queue reforms last January.

The new proposal, however, has since elicited protests from MISO stakeholders, including Mississippi and Louisiana utility regulators who have urged FERC to reject the proposal because it does not include exemptions to the cap for projects that state regulators consider necessary to maintain resource adequacy.

MISO's response took specific aim at the criticism over the lack of exemptions for a relevant electric retail regulatory authority, or RERRA. Previous versions of the cap proposal introduced during the stakeholder process had included anywhere from one to three exemptions per RERRA entity before MISO ultimately omitted them from the plan submitted to FERC.

The grid operator said in its response that it had determined that "the RERRA exemption was not in and of itself a complete solution to the needs of RERRAs."

"RERRAs need a separate process that will ensure projects needed to meet specific resource adequacy goals are processed in sufficient time to meet the RERRA's needs," MISO added. "In addition to priority and streamlined access to the queue, ensuring that time-sensitive resource adequacy needs are met also necessitates expediting the study of the projects once submitted. ... This does not mean that the needs of RERRAs are not important. To the contrary, MISO believes they are important enough to merit specialized procedures and their own filing."

The protests had also taken issue with MISO's still-developing Expedited Resource Adequacy Study proposal to address RERRA needs by helping speed up the queue process for generation projects deemed urgent. The grid operator plans to file the ERAS proposal to FERC in February.

The Mississippi and Louisiana regulators in their Dec. 16 joint protest said MISO had committed a "classic bait and switch" by failing to include a RERRA exemption while offering the promise of an undeveloped ERAS proposal. The regulators also said MISO decided unilaterally to remove the RERRA exemption at the last minute despite months of stakeholder discussions over its design and that its filing "offers no explanation for MISO's failure to include it."

MISO called the "bait and switch" assertion a "mischaracterization" in its Dec. 31 response and said arguments regarding the ERAS proposal are out of scope for the queue cap filing as it has not been submitted to FERC and remains under development by MISO and stakeholders.

MISO, which manages the electric grid across 15 Midwestern and Southern US states and Canadian province Manitoba, also indicated in its response that it does not see the removal of the RERRA exemption from the current queue cap proposal as a threat to resource adequacy.

"MISO's decision to remove the RERRA exemption from this current proposal will not cause or exacerbate resource adequacy problems within the MISO region," the grid operator said. "The capacity available in the MISO, even with a cap, will exceed the capacity needs for the MISO region."

Under terms outlined in the filing, MISO's cap formula will be 50% of non-coincident peakload per planning region (five regions total) for each cycle. Based on MISO's 2023 non-coincident peakload data per planning region, the estimated cap for the next queue cycle would total around 68 GW. For comparison, earlier this year MISO reported that in its most recent cycle it had received 600 interconnection requests comprising around 123 GW new generation across its footprint.