Entergy Mississippi seeks approval of estimated $18.5m substation, line project in Mississippi

Subject to the receipt of necessary permits and required approvals, the proposed electrical facilities are expected to be placed in service by June 2021, the company said

Entergy’s Entergy Mississippi, LLC (EML) on Oct. 8 filed with the Mississippi Public Service Commission a petition for a certificate of public convenience and necessity (CCN), seeking authorization to acquire, build, expand, own, operate, and maintain a new 230-kV substation near Lewisburg, Miss., (the Byhalia substation), a new line bay, and associated upgrades at its existing Getwell substation in Hernando, Miss., as well as a new transmission line built to 230-kV specifications.

The line would run between the existing Getwell substation and the new Byhalia substation, and would be about 5.7 miles long along the soon-to-be-completed Interstate 69 (I-69) corridor.

The company added that the 230-kV Byhalia substation portion of the project involves:

  • Installing one 40 MVA, 230/13.86-kV load tap changing (LTC) transformer
  • Installing one 3,000 ampere main breaker
  • Building 12.47-kV low-side operating and transfer buses
  • Installing one 2,000 ampere operating bus-tie breaker and bay, which would include eight feeder bays, with overhead exits
  • Installing four 1,200 ampere feeder breakers, which would serve feeders. All low side bus, switches, and breaker bays would be built at this time with plans of adding a second 40 MVA power transformer and three additional feeders in 2025

The company noted that the project involves building distribution from the new Byhalia substation, which includes configuring two of the new 1,200 ampere feeder breakers to tie into the existing feeder 1E07 and split the load between the two new circuits.

EML also said that it would expand the existing 230-kV Getwell substation by adding a new Byhalia line bay and breaker.

EML added that project is within its certificated public utility service area in DeSoto County, Miss. The company noted that the proposed electrical facilities are needed to continue providing reliable electrical service to meet the growing demand for power in DeSoto County, and in particular, the Lewisburg area of DeSoto County. The company said that its engineering analyses indicate that, as a result of the forecast load growth in the Lewisburg area, it would be difficult for EML to continue to maintain steady state voltage levels to customers in that fast-growing area without the construction of the proposed electrical facilities.

The company noted that the proposed electrical facilities would provide voltage support and improve distribution reliability in the Lewisburg area and surrounding DeSoto County area by reducing the load on the existing 12.47-kV lines out of the Getwell substation, as well as by providing another transmission source into the area, thereby mitigating risk for nearly 700 customers in the event of a power outage.

Among other things, the company said that the total cost of the proposed electrical facilities is estimated to be $18.5m. Subject to the receipt of necessary permits and required approvals, the proposed electrical facilities are expected to be placed in service by June 2021, the company said.