By Amanda Durish Cook

CARMEL, Ind. — MISO last week committed to adopting its Independent Market Monitor’s recommendation to implement market mitigation for a new category of narrowly constrained areas (NCAs) identified by momentary congestion and associated market power.

‎Within a month, the RTO will file Tariff revisions on a proposal to create dynamic NCAs after staff spoke extensively with the Monitor on the issue, according to MISO Director of Market Evaluation and Design Dhiman Chatterjee.

“Conceptually, we are in alignment that the broadly constrained areas leave open some needs,” Chatterjee said at a June 8 Market Subcommittee meeting.

But while MISO is adopting the Monitor’s proposal without changes, there are still some minor details to be worked out, and the RTO is accepting stakeholder feedback, Chatterjee said. The RTO and Monitor will both need to make software changes before the definition is introduced into the market in late fall after FERC approval, he said, adding that stakeholders have generally supported the idea.

“We don’t believe at this point there are any broad, outstanding questions that are in the way,” Chatterjee said.

Monitor David Patton recommended in April that the RTO expand mitigation measures on NCAs by creating a new definition aimed at short-lived congestion and applying mitigation if the constraint has bound in 15% or more hours over at least five consecutive days. The new category would set a conduct threshold at $25/MWh. The definition would differ from FERC-defined NCAs, which must bind for more than 500 hours annually. (See MISO IMM Recommends Tighter Rules for Constrained Areas.)

Patton said FERC’s definition of NCAs is inadequate because it only measures binding constraints annually and does not tackle intense but temporary congestion. Only about 10 to 15% of MISO’s footprint is subject to traditional NCA mitigation, in Patton’s estimation.

Patton said dynamic NCAs would only be declared in situational congestion where normal market participants have more market power than usual. Mitigation measures would be lifted once the binding congestion dissipates.

“It won’t be defined on a more permanent basis like the NCAs are,” Patton said.