A MISO board committee advanced 432 projects from transmission owners at a cost of almost $12.3 billion under the RTO’s 2025 Transmission Expansion Plan.
The System Planning Committee voted unanimously to approve the MTEP 25 package at a Nov. 17 teleconference. The plan now moves to the full Board of Directors for consideration at its final meeting of the year on Dec. 11.
The projects, which total 1,901 miles, would support 11.6 GW of spot load additions. Louisiana contains the most investment at $3.4 billion. Wisconsin follows with $1.8 billion and Indiana with almost $1.7 billion. (See MISO 2025 Tx Expansion Estimate Drops Slightly to $12.4B.)
MISO Executive Director of Transmission Planning Laura Rauch said large loads seeking to reserve spots on the grid influenced the sizeable investment.
MTEP 25’s most expensive project — Entergy Louisiana’s $1.2 billion Cargas 500-kV and Smalling 500-230-kV stations in northeastern Louisiana — is planned to support a new $10 billion Meta data center.
Southern Louisiana’s Babel-to-Webre 500-kV line project is the second-most expensive MTEP 25 project at $1.066 billion. Entergy Louisiana said it’s needed to meet NERC reliability criteria.
The Missouri Multi-Entity New Transmission (MoMENT) project, a $604 million joint venture between Ameren, Evergy, MISO, SPP and Associated Electric Cooperative, is the third-most expensive. The 345-kV and 161-kV lines and substation in central Missouri are meant to improve reliability and be in service by December 2030.
Rauch told board members that MISO emphasized the collaboration behind the MoMENT project in its MTEP 25 report.
MISO’s Jeremiah Doner said load growth, AI data centers and economic development — all the “hot button issues” — influenced MTEP 25.
“The common theme this year is around those large load additions,” Doner said during a Nov. 3 gathering of the Planning Advisory Committee (PAC).
PAC’s 11 membership sectors voted in early November to approve MTEP 25. Six sectors voted in favor of the portfolio, two abstained from voting and three sectors didn’t respond to the emailed ballot.
MISO’s state regulatory sector typically abstains from voting on MTEP portfolios, reasoning that it’s improper for state commissioners to preemptively judge the projects that will come before them later for separate approvals.
MTEP 25 still contains a $92 million maintenance project for a 345-kV line that was part of MISO’s 2011 Multi-Value Project portfolio. Xcel Energy will replace cracking davit arms on a multi-value project in Minnesota. Any maintenance on multi-value projects must be classified under the multi-value category.
