[EDITOR’S NOTE: A previous version of this article incorrectly quoted MISO’s Trevor Armstrong as Trevor “Anderson.”]

MISO’s preliminary 2023 Transmission Expansion Plan (MTEP 23) will double recent spending, driven by a record number of proposed baseline reliability projects in MISO South.

MTEP23 has a proposed investment of $7.8 billion, nearly twice that of standalone packages over the last five years.

Almost half of the 2023 transmission planning cycle’s tab goes to essential reliability projects in the South, as deemed by transmission owners. That prompted many stakeholder questions and assurances from MISO that it will examine proposals for larger, combined project opportunities.

The project cost estimate includes $4.1 billion of baseline reliability projects (BRPs), $757 million in generator-interconnection projects, $2 million in market participant-funded projects, and $2.9 billion in “other” category projects. The RTO defines the latter as transmission owners’ projects needed for load growth and to address existing facilities’ age and condition.

MISO South accounts for $3.6 billion of the baseline reliability projects, equal to previous MTEP packages’ total cost. Entergy Louisiana submitted more than half of the South’s BRPs, with 13 projects costing $2.4 billion.

BRPs are proposed by transmission owners, not cost shared, and billed only to the local transmission zone in which they’re located. TOs typically deem the projects necessary to meet reliability criteria. MTEP 22’s BRPs accounted for $545 million of the package’s total $4.3 billion. (See Stakeholders Endorse MISO’s Final MTEP 22.)

This year’s drastic increase in MISO South reliability transmission investment raised eyebrows among stakeholders, who said staff should determine whether some of the larger projects should be classified as regional.

During a Feb. 3 South Subregional Planning meeting, MISO’s Trevor Armstrong said planners are aware of the record number of BRPs put forth by MISO South TOs.

During a series of subregional planning meetings this week and last, staff emphasized that the projects are merely proposals at this point. MISO has yet to perform independent assessments to determine whether the projects can effectively solve system issues.

“We’ll be talking to our transmission owners about alternatives to some of these projects,” Armstrong said. “I’d like to note that these projects have only been proposed; they still have to go through all the usual MTEP analyses.”

Southern Renewable Energy Association Executive Director Simon Mahan asked whether any of the BRPs will be evaluated to potentially become market efficiency projects (MEPs) or long-range transmission plan projects, which are allocated on a subregional basis. Staff promised test results by the third round of subregional planning meetings in September.

“I know that there are a lot of questions around this process,” Furnish said, adding that MISO will hold discussions on the projects’ eligibility at future subregional planning meetings. She also said staff can schedule technical study task force meetings if it appears that South BRPs qualify as regional projects.

“We’ve never had a market efficiency project built in MISO South,” Mahan said.

Armstrong said MISO could even extend its December deadline for approving certain MTEP 23 projects. He said some of the BRPs proposed in the South are complex and it will take several engineering hours to ascertain whether a more comprehensive project is needed.

“When you say that you might delay certain projects out of this MTEP cycle … when might be hearing about this?” Mahan asked.

Furnish said MISO will have a better handle later this spring.

Stakeholders asked whether MISO’s tariff stipulates that it must first conduct a market congestion planning study to recommend MEPs. Those normally identify MEPs. Furnish said she didn’t think the RTO’s rules were that “prescriptive.”

The skepticism over the MISO South BRPs continues a debate over whether the grid operator is adequately exploring project alternatives. Last year, a spate of expedited project recommendations in the region led some stakeholders to question whether the RTO is engaging in thorough and cost-effective transmission planning. (See Stakeholders Doubt MISO Study of Alternative Tx Projects.)

During a West subregional planning meeting Tuesday, planners reassured stakeholders that MTEP 23 project classifications won’t be confirmed until late summer.

Expansion Planning Manager Zheng Zhou said if MISO finds that a project meets the criteria for both a BRP and an MEP, the MEP classification will take precedence and the project will be allocated as such.

“Alternatives are a hot topic,” Zhou said.

He urged stakeholders to remember that MTEP23 amounts are preliminary and subject to change. He also said that it’s sometimes impossible to find a “cheaper, more economic” solution for certain localized issues.

During Wednesday’s East subregional meeting, Thompson Adu, senior manager of expansion planning, said MISO may look into more expensive projects than originally proposed that resolve a host of problem areas. On the other hand, he said, staff may discover that some local upgrades have no viable alternative.

Stakeholders have until May to propose alternatives to the TOs’ project proposals.