CARMEL, Ind. — MISO will take a breather from its long-range transmission planning over 2025 to retool the 20-year future scenarios that are the foundation of the transmission portfolios.
Speaking at a Nov. 13 Planning Advisory Committee meeting, MISO’s Jeremiah Doner said after consultation with stakeholders, MISO will concentrate on a futures makeover throughout 2025. MISO maintains three possible futures scenarios in Goldilocks style: a conservative view of the system with limited load growth and decarbonization, a middle-of-the-road view, and a progressive outlook where clean energy, innovation and demand thrive.
Some MISO stakeholders have said repeatedly the rate of change the three planning futures predict is obsolete considering that clean energy goals are revised frequently to be more aggressive and load additions are rising. MISO last overhauled its futures in 2019 and refreshed them in 2022.
MISO said it won’t embark on another long-range transmission plan (LRTP) analysis until 2026, when the RTO will work on a follow-up portfolio to the second Midwestern LRTP portfolio. That would leave MISO South’s comprehensive planning needs unaddressed until at least 2027.
Doner said MISO’s futures update will kick off unofficially with the RTO’s Dec. 18 stakeholder workshop on medium- and long-term load forecasting, where it plans to discuss probable load increases over the next 20 years.
“Let’s get through the futures update, and this time next year, we’ll have better answers” on when the Midwest follow-up portfolio and a third LRTP portfolio will take place, Doner said.
“One thing we want to do with the futures update is to make sure it serves multiple masters,” Executive Director of Transmission Planning Laura Rauch said, adding that discussion on the futures revision would start in workshops, and likely in Planning Advisory Committee and Resource Adequacy Subcommittee meetings.
The Organization of MISO States lent support to the futures revision, though it emphasized the “importance of improving connections between Midwest and South and needs within South region.”
Some of the regulators in the Organization of MISO States have asked what MISO plans to do about MISO South planning in the meantime. Illinois Commerce Commissioner Michael Carrigan pointed out at a Nov. 11 OMS board meeting that MISO’s LRTP timeline seems to leave MISO South without an economic planning study for about six years.
The working group of the Entergy Regional State Committee also recently asked MISO to perform a market congestion planning study for the MISO South region as part of MISO’s 2025 Transmission Expansion Plan (MTEP 25). So far, the RTO hasn’t added an economic study to its MTEP 25 tasks.
Doner said in addition to the futures renovation and usual MTEP 25 studies next year, MISO would like to examine how it can address large load additions in planning, focus on its current interregional planning studies with PJM and SPP and make sure it’s ready for compliance under FERC Order 1920.
Doner said MISO also has to devote staff hours to making sure approved LRTP projects are best positioned to advance through state permitting processes.
“Even though [LRTP] Tranche 1 was approved two years ago, there’s work to support [these projects] in regulatory processes. Until those projects are certain, there’s still some risk there,” Doner said.
Finally, Doner said MISO will work on planning coordination with neighbor Associated Electric Cooperative Inc. (AECI) over next year. He said AECI has planned projects that will tie into Ameren and SPP’s territories and the cooperative has approached MISO for some advice on how best to proceed.
