Entergy Mississippi seeks approval for project, including 230-kV transmission interconnect line

Entergy’s (NYSE:ETR) Entergy Mississippi Inc., (EMI) on Oct. 18 filed with Mississippi state regulators a petition for a certificate of public convenience and necessity to build, acquire, expand, operate, own and maintain a replacement generating resource needed for critical reliability purpose in EMI’s service territory before June 2019, along with certain transmission facilities that are needed to interconnect Hinds Unit 2 to EMI’s power grid.

Specifically, the company said that it is requesting Mississippi Public Service Commission approval to:

  • Build a GE LM2500+G4 combustion turbine (CT), which is an aero derivative CT nominally rated at 32 MW, at the existing Hinds Energy Facility in Jackson, Miss., including installation of a generator step-up transformer and other balance of plant equipment designed to provide a highly reliable quick-start unit (Hinds Unit 2)
  • Build a 230-kV transmission interconnect line from the proposed new Hinds Unit 2 to the existing Lakeover switchyard on EMI property. The line would use 954 ACSR “Cardinal” with the line rated at 251 amps or 100 MVA at 230-kV. Additionally, the existing lines from the Hinds combined cycle gas turbine (Hinds Unit 1), just west of the Lakeover switchyard, would be raised to allow the new lines to cross underneath
  • Expand the 230-kV Lakeover substation to the south to accommodate the connection of the new Hinds Unit 2; install all new relay and metering panels in the existing 230-kV control house to accommodate the substation connection and transmission line; and upgrade relay settings at the Lakeover switching station

The proposed electrical facilities’ total estimated cost is about $63.3m, and subject to the receipt of the necessary permits and required approvals, construction is scheduled to begin in the second half of 2017, with the proposed electrical facilities expected to be placed in service in June 2019.

The purpose of the proposed electrical facilities is to develop before June 2019 a replacement for a generating resource that is critical to the overall reliability of EMI’s system in that it will meet EMI’s requirements to support system restoration, maintain compliance with mandatory NERC standards, and ensure that EMI can continue to reliably serve its customers.

Upon completion, the company added, the proposed electrical facilities would be expected to fulfill a critical resource role in the company’s system restoration and black-start plan and provide about 32 MW – 29 MW in summer conditions – of peaking capacity.

In addition to serving in a reliability role that is critical to overall power grid reliability for EMI, Hinds Unit 2 could potentially provide capacity and energy benefits within the Midcontinent ISO (MISO) market, EMI said.

“EMI will have the option of operating the unit as a peaking resource and offering the resource into the MISO market if doing so is economical or would be expected to provide additional benefits to EMI customers, and if such operation does not interfere with the critical reliability role being served by Hinds Unit 2,” the company said.

Among other things, the company said that it requests a waiver of, and permission for deviation from, part of certain requirements, allowing it not to file with the petition a complete set of plans and specifications for the proposed facilities, but rather to make such a complete set of plans available, upon request, to regulatory staff when such plans and specifications are completed and thereby available.

About Corina Rivera-Linares 3229 Articles
Corina Rivera-Linares, chief editor for TransmissionHub, has covered the U.S. power industry for the past 15 years. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines. She can be reached at clinares@endeavorb2b.com.