Just days into 2026, MISO already has approved or recommended dozens of expedited transmission projects for the 2026 cycle, including a substation project in Indiana that spawned several hundred million dollars in corrective action upgrades.
The price tag of the five added reliability projects to support the single expedited transmission project left stakeholders with questions over who would pay for them.
Most of MISO’s Jan. 6 Expedited Project Review Technical Study Task Force teleconference focused on expedited projects in Indiana. MISO recently completed analysis and mitigation plans for 22 transmission projects to either support a cumulative 3.7 GW in load additions or bolster reliability. The RTO recommends those projects advance to its 2026 MISO Transmission Expansion Plan (MTEP 26) after the Planning Advisory Committee has a chance to review them.
MISO already approved another 26 expedited transmission project requests for its MTEP 26 cycle as of Dec. 31, 2025. The projects represent about 5 GW of spot load additions.
MISO reviews transmission projects on an expedited basis when it cannot wait until the usual, end-of-year MTEP approval. With expected load growth, expedited requests have trended upward. MISO has received 50 submissions under its expedited process since June 2025.
This crop’s project with the highest total is a new Antioch 345-kV substation which, combined with the handful of reliability projects it requires, would cost around $378 million.
The $68.8 million project from AES Indiana involves construction of a new 345-kV breaker-and-a-half substation in the greater Indianapolis area to serve 1.2 GW of new data center load.
MISO’s Dave Seelye said the new substation project requires five corrective action plans to maintain reliability: a $2 million uprate of a nearby autotransformer, nearly $12 million to restore a neglected autotransformer to service, a $30 million switchyard expansion and connection to the local 138-kV transmission system, a $15 million equipment replacement on the nearby Guion-Whitestown 345-kV line to increase winter ratings, and finally, a $250 million investment in 55 miles of new, double-circuited 345-kV line.
MISO said the $250 million baseline reliability project supplants several rebuilds in the area that otherwise would be required.
Senior Expansion Planning Engineer Amanda Schiro said MISO conducted several rounds of study to capture all the mitigations the Antioch project would require.
Stakeholders in attendance questioned MISO’s classification of the corrective action plans for load growth projects as necessary reliability projects.
Sustainable FERC Project’s Natalie McIntire asked whether MISO would allocate the costs of the corrective action plans according to its baseline reliability project cost allocation.
Costs of baseline reliability projects in MISO are allocated to the transmission pricing zone where they’re located and spread out according to a load distribution factor. Costs are recovered by the transmission owners developing the projects.
Schiro said MISO merely analyzed “the reliability needs based on the changes to the system” and discovered NERC transmission planning violations based on the expedited projects. She said MISO categorized the projects as baseline reliability projects based on their purpose and did not consider cost allocation in its review of expedited projects. Schiro said cost sharing of the corrective action plans likely would align with their project classification.
WEC Energy Group’s Chris Plante said if stakeholders have concerns about the cost allocation of corrective action plans, they should raise them at the Planning Advisory Committee, not at expedited review task force meetings.
“This is probably not the right forum to address those,” Plante said.
MISO’s next Planning Advisory Committee meeting is Jan. 21.
Beyond the Antioch project, Hoosier Energy plans a $75.3 million, 345-kV substation expansion and line project to serve nearly 1 GW in data center load expansion in southwest Indiana. Hoosier Energy’s project also requires a $2 million corrective action plan, with construction of an additional 345-kV circuit planned between substations to reliably accommodate the load.
Finally, MISO vouched for ITC Midwest’s plans for an $11.3 million transmission project relying on Duane Arnold Energy Center, the Iowa nuclear plant NextEra Energy hopes to restart in late 2028 or early 2029. Duane Arnold’s reconnection is included in MISO’s expedited queue lane.
ITC plans to expand a 161-kV bus to support four new radial 161-kV lines that would be owned and operated by Central Iowa Power Cooperative to serve a 620-MW load addition.
The Iowa load addition project also requires a $1.2 million corrective action plan to replace transmission structures to increase line ratings.
