MISO announced it will honor a request from Texas regulators and include southeastern Texas in its first long-range transmission study for MISO South.
The grid operator earlier said it would start the process of drawing up planning studies for areas of Louisiana with heavy load pockets, marking the first long-range transmission plan for MISO South. (See MISO Kicks off South’s Long-range Tx Plan with More Restrained Approach.) Now a portion of Texas will be part of the equation.
MISO Executive Director of Transmission Planning Laura Rauch confirmed that Texas regulators approached MISO to request that part of the state be included in the study and that MISO agreed.
Speaking at a Nov. 11 Entergy Regional State Committee meeting, Rauch told South state regulators that MISO’s approach to South long-term system planning would differ from the planning conducted in MISO Midwest.
Rauch said MISO Midwest had several years of membership before MISO proposed the first, $10 billion long-range transmission portfolio in 2022 followed by the second, $22 billion portfolio in 2024.
“That journey took many, many years in the Midwest. … While I can’t guarantee the outcome, I know the outcome will look very, very different in the South than in the Midwest,” said Rauch, who emphasized different planning needs in MISO South.
Rauch said that over the course of 2026, MISO will assemble a study scope for Louisiana and Texas, build system models and hold discussions around potential needs in the South.
“It’s very likely that we’ll need to do additional analysis,” Rauch said. “Really, the goal is to practice the conversation around long-term needs.”
Rauch said MISO “may have to divide and conquer on” which issues to tackle first and could focus first on Louisiana before turning its attention to possible projects in southeastern Texas.
“My goal is for information at this point, not necessarily a certain amount of transmission approved,” Rauch said.
Arkansas Public Service Commission consultant Keith Berry asked if MISO has considered how to divide the costs of the projects.
Rauch said cost allocation negotiations “realistically” arise only when transmission needs are named. However, she said the first MISO South long-range planning — being limited to Louisiana and Texas — likely won’t require the region-wide postage stamp to load cost allocation used in MISO’s other long-range transmission portfolios.
“I will say with a focus on two states, I don’t see a need for a multivalue project cost allocation,” Rauch said.
Rauch said she doubted that “engineering studies won’t show sufficient value spread” across the entire South region.
Texas utilities Commissioner Courtney Hjaltman previously said she intended to ask the MISO board to include Entergy’s Texas footprint when it begins work on a long-range MISO South plan.
“My request will be to include Texas, as we obviously have load growth that we need to have included in that study,” Hjaltman said at the Oct. 23 Texas Public Utility Commission meeting.
Asked by an audience member why MISO’s focus is on Louisiana, she said, “They are trying to really home in on certain areas and include Louisiana, and specifically New Orleans, which obviously had a load shed event this past summer, and that might be why, but there’s just no reason that Texas shouldn’t be included.”
At the Entergy meeting, Berry asked where MISO stands on launching a planning study aimed at increasing transfer capability between MISO South and MISO Midwest.
Rauch said at this point, MISO believes operational fixes and increased coordination on the transmission contract path are the best way forward. MISO no longer talks about a fourth long-term transmission plan portfolio, which it once said might result in an expansion of Midwest-South transmission.
