October 7, 2026 - The Midcontinent Independent System Operator (MISO) is seeking federal approval to accelerate an interconnection study covering approximately 71 gigawatts of proposed generation, drawing broad support from utilities, renewable energy developers and state regulators.

MISO warned that its 2022 Definitive Planning Phase study could face at least another 18 months of delays without changes. Those delays could also slow subsequent groups of projects awaiting interconnection reviews.

In its September 21 filing with the Federal Energy Regulatory Commission, MISO proposed changing withdrawal rules and limiting repeated studies that have prolonged the approval process.

Under existing rules, developers may keep projects that are unlikely to proceed in the queue to avoid withdrawal penalties, MISO said. When those projects eventually exit, their departures can require additional studies and revised upgrade costs for remaining participants.

For the 2022 study cycle, MISO would allow developers to withdraw without penalties before the October 20 second decision point. The grid operator requested a FERC decision by October 19.

The proposal would also tighten eligibility for subsequent penalty-free withdrawals. The network upgrade cost increase needed to qualify would rise from 35% to 50%.

A separate change applying to all study cycles would limit MISO to one final restudy during the last phase of its interconnection review.

MISO said the revisions would help clear older applications, improve cost predictability and shorten the time needed to connect generation to the transmission system.

Advanced Energy United supported the proposal, saying substantial changes are necessary to address the backlog and move toward MISO’s goal of completing interconnection reviews within one year.

The Organization of MISO States, representing state utility regulators, offered tentative support. It said the changes could accelerate older studies while maintaining necessary reliability reviews.

Utilities Ameren and Alliant Energy also urged approval. Alliant said the proposal reflected cooperation among stakeholders to improve queue management while supporting reliability and adequate generation supplies.

RWE Americas backed the changes but called for further reforms to address unpredictable cost reallocations. The company said projects with signed interconnection agreements can still face additional expenses when other developments withdraw.

Independent power producer Pathway Power opposed the proposed increase in the cost threshold for penalty-free withdrawals. It argued that the change would place more financial risk on developers remaining in the queue.

Pathway also questioned the proposal’s development process, saying MISO worked with a limited group of companies—Clearway Energy Group, NextEra Energy Resources and EDP Renewables—and allowed only 10 days for comments.

The company warned that restricting withdrawal options could weaken MISO’s incentive to provide accurate upgrade cost estimates.