MISO is putting the final touches on its most expensive annual transmission investment package yet after a final round of subregional planning meetings last week.

The RTO’s 2020 Transmission Expansion Plan (MTEP 20) now contains 519 new projects costing slightly more than $4 billion. Last year’s 480-project portfolio was just shy of $4 billion.

The Planning Advisory Committee will vote on the package during its Sept. 23 meeting. If approved, the Board of Directors’ System Planning Committee will then vote on it during an Oct. 26 meeting, with the full board deciding on final approval during its December meeting.

MISO Executive Director of System Planning Aubrey Johnson last month said MTEP 20 investment closely resembles that of MTEP 19.

The grid operator said the majority of MTEP 20 projects are line and substation work and will go into service within four years. Assuming the portfolio’s approval, MISO members will spend $684 million in baseline reliability projects (BRPs) and another $538 million on generator interconnection projects. Ameren alone proposed 156 new projects costing $1.6 billion for reliability and interconnection reasons in Illinois and Missouri and to replace aging equipment and accommodate load growth. Ameren has embarked on a $7.6 billion, five-year grid modernization plan in Missouri.

MTEP 20 doesn’t yet contain any market efficiency projects.

Speaking during a West subregional planning teleconference Thursday, Senior Expansion Planning Engineer James Slegers said MISO tested four BRPs that were rated 230 kV and higher and cost at least $5 million. The projects — in central Illinois, southeast Michigan, eastern Missouri and eastern Louisiana — didn’t show enough economic benefits, Slegers said.

Project investment in MISO South will be less this year than in 2019. The region will pick up $530 million worth of 46 new projects. Most of the investment — $309 million — is to accommodate load growth. Last year, MISO South was on the receiving end of 71 new projects costing about $811 million.

Entergy Cancels MTEP 16 Project

Entergy Louisiana, meanwhile, will withdraw a major project near New Orleans originally approved in MTEP 16. The utility announced that the nearly $74 million, 27-mile, 230-kV Waterford-to-Churchill transmission line no longer demonstrates the benefits it once did. Over four years, the benefit-cost ratio dropped from 2.3 to about 0.2, according to the company.

The line has not entered the construction phase. It was originally estimated to be in service by early 2022.

Entergy has since built new projects in the area that have eased congestion and eroded the original project’s benefits, MISO Senior Manager of Expansion Planning Edin Habibovic said during an Aug. 25 South subregional planning meeting. He also said Entergy found cost increases after more detailed project scoping.

“We are OK with removing this project from the economic point of view, the reliability point of view [and] the impact of any other processes,” Habibovic said. “If the load didn’t materialize, then obviously there’s no need for this project.”