MISO said its first crack at long-range transmission planning in the South region likely would take about three years to culminate in potential project recommendations.
Director of Expansion Planning Jeanna Furnish said MISO would form the scope of transmission and build system models over 2026. From there, an assessment of need could continue into 2027, Furnish told the Entergy Regional State Committee Working Group on Oct. 7.
The RTO expects to wrap the study with project recommendations in 2028.
Furnish reiterated MISO’s stance that the first long-range transmission study in MISO South would begin with the Amite South and Downstream of Gypsy load pockets in southeastern Louisiana. She said the study would result in “options that can inform our next steps” and that new generation as well as new transmission would be on the table to solve constraints. (See MISO Kicks off South’s Long-range Tx Plan with More Restrained Approach.)
Given the amount of time, Yvonne Cappel-Vickery, of the Louisiana-based Alliance for Affordable Energy, asked whether MISO would explore other load pockets in MISO South.
Furnish said the study would be limited to Louisiana.
Southern Renewable Energy Association Transmission Director Andy Kowalczyk asked if scoping would be flexible enough to include more of MISO South. The RTO is conducting an assessment to measure reliability risks in the southeastern Louisiana load pockets, along with the West of the Atchafalaya Basin pocket, which extends from southwestern Louisiana into East Texas, and the Western pocket, which is entirely in Texas.
Furnish said MISO hasn’t identified all elements of the study scope yet but said the focus would be the state of Louisiana and would not extend to Texas. It will examine Louisiana’s transfer patterns alongside the state’s “unique weather conditions.”
Windy Beck, of the Deep South Center for Environmental Justice, asked why the study would be limited to a particular geographic area when long-range planning works best at a regional level. She also pointed out the South system mainly comprises Entergy’s assets.
Furnish responded that Louisiana has seen the most load growth and generation retirements when compared to other MISO South states. She promised more to come on the long-range analysis and that her update is merely a “teaser.”
MISO South has accounted for billions of dollars in transmission investment in recent years, mostly classified under reliability needs. In MTEP 23 alone, Louisiana and MISO’s relatively small portion of southeast Texas comprised $3.9 billion of the $9 billion 2023 MISO Transmission Expansion Plan (MTEP).
The South took an almost $2 billion share of the $6.7 billion MTEP 24. For MTEP 25, Louisiana is to receive the most investment of all MISO states, at more than $3.4 billion in reliability projects and projects needed to meet load growth. (See MISO 2025 Tx Expansion Estimate Drops Slightly to $12.4B.) Louisiana contains four of the 10 most expensive projects in MTEP 25. That portfolio is destined for a vote from the MISO Board of Directors in early December.
MISO South states still are weighing whether to propose their own cost allocation under FERC’s Order 1920, which could override the RTO’s current 100% postage stamp-to-load rate used in its long-range planning. (See State Regulators Weigh Drafting Alternative to MISO Tx Cost Allocation.) Southern regulators expect the Organization of MISO States would allow them to form their own agreement to establish a subregional cost allocation for long-range projects.
