Entergy’s (NYSE:ETR) Entergy Arkansas has proposed to build, operate and maintain a 69-kV transmission line connection from its 69/34.5-kV Imboden substation to the Arkansas Electric Cooperative Corporation (AECC) 161/69-kV Black Rock substation located near U.S. Route 63, about 4.3 miles south of the community of Imboden, Ark.
The proposed line would be built on lands bought and owned by Entergy Arkansas, AECC and/or on existing transmission line right of way (ROW), the company added in its March 11 application for a certificate of public convenience and necessity (CCN) filed with the Arkansas Public Service Commission (APSC). No additional ROW would be required.
The proposed line is needed to restore the loop capability between the Imboden substation and Entergy Arkansas’ 161-kV Walnut Ridge substation, the company added. The proposed line would eliminate the need for Entergy Arkansas’ existing 10.9-mile, 69-kV Water Valley to Imboden Substation Transmission Line, which would be taken out of service after the proposed line goes into service, and would provide a new reliable source to serve area customers, the company said.
According to the March 18 supplemental direct testimony on behalf of Entergy Arkansas of Lloyd Cambre, who is employed by IK Power System Solutions and contracted to Entergy Arkansas as a project manager in the Transmission and Substation Project Management Organization, Entergy Arkansas considered rebuilding the Imboden to Water Valley 69-kV line, but the cost to rebuild it is estimated to be much greater than the estimated cost of the proposed line. That is primarily due to the length of the proposed line being 0.3 miles, as compared to the 10.9 miles that would be required to rebuild the Imboden to Water Valley line, Cambre said. Additionally, to rebuild the line would require taking it out of service for an extended period of time, which would increase the probability that service to customers could be interrupted, Cambre said.
AECC has revised its in-service date from Sept. 1 to Oct. 18. Therefore, Entergy Arkansas requests that the APSC issue an order approving the CCN by June 28, Cambre added.
Entergy Arkansas said in its application that the project was approved by the Midcontinent ISO (MISO) Board of Directors last December, and is included as Project ID 7925 in Appendix A of MISO’s Transmission Expansion Plan 15.
The company said that the total estimated investment in the proposed line is about $1.8m. Entergy Arkansas said that it would finance the construction with funds available from various sources, including retained earnings, debt and capital securities.
Entergy Arkansas’ project team selected the line’s route – which is in the S1/2 SE1/4, Section 2, and the N1/2 NE1/4, Section 11, all in Township 17 North, Range 2 West, Lawrence County – based on the existing locations of the Imboden substation and the Black Rock substation.
The 0.3-mile transmission line would be routed from the Black Rock substation on AECC property, and then under the existing Thayer South to Walnut Ridge 161-kV transmission line, at which point the proposed line would enter Entergy Arkansas’ existing ROW, cross over U.S. Highway 63, and terminate at the Imboden substation, the company added.
The 69-kV overhead, three-phase, shielded, single circuit proposed line would be supported by steel or concrete pole structures directly buried in the ground. Those pole structures would consist of single-pole tangent and single-pole type structures. The company also said that the proposed line would consist of vertical design tangent prop-structures and two 3-pole design dead-end structures.
Among other things, the company said that construction, operation and maintenance of the proposed line along the proposed route would result in minimal adverse environmental impact to the natural, cultural, residential, commercial, recreational and industrial environment.