Lyntegar Electric Coopertive Inc., (LEC), on Dec. 22 filed with the Public Utility Commission of Texas an application to amend its certificate of convenience and necessity for the Welch 115-kV Transmission Line in Gaines and Dawson counties in Texas.
The line would be designed and operated at 115 kV and would be a radial tap extending from a dedicated bay in the Southwestern Public Service (SPS) Diamondback substation, LEC said.
The proposed line consists of two parts, LEC said, adding that one segment of the proposed line – the Welch Segment – would extend from the Diamondback substation to the east/north east about 11.5 miles to 12.5 miles, depending on the route selected, to the proposed new Welch substation near the town of Welch in Dawson County.
LEC said that it also proposes to build a tap in the Welch Segment and run a radial transmission line south for about 5.83 miles to 7.83 miles, depending on the route selected, to the proposed new Thunderhead substation that is being built by LEC to serve U.S. Silica – the U.S. Silica Segment.
In total, LEC said, the two segments are expected to extend for about 18.19 miles to 20.27 miles, depending on the route selected.
The project is to be built and operated entirely within the Southwest Power Pool (SPP), LEC said.
LEC noted that the proposed line is needed to serve load growth and for reliability. By 2023, the total load in the area served by the Welch and Thunderhead substations is expected to be in the range of 16.34 MW. Existing capacity in the area is limited to 5 MW by Oncor, and thus, the existing available capacity is not sufficient to serve the load, LEC said. Without the proposed line, load additions are expected to cause significant deterioration in voltage, LEC said.
LEC noted that it plans to build the line with steel or concrete single pole tangent structures and self-supporting concrete caisson mounted steel poles on all angle and dead-end structures. The height of the typical structures would be 80 feet, while the estimated maximum height of the structures would be 90 feet, LEC said.
The entire proposed project would be financed initially through long-term debt with National Rural Utilities Cooperative Finance Corporation (CFC). LEC added that it would be reimbursed by U.S. Silica for the portion of the project dedicated solely to U.S. Silica; the cost of the U.S. Silica portion of the line is estimated to be between $2.6m and $2.9m, depending on the route selected.
LEC said that it evaluated the four alternative routes and identified the 19.56-mile “Route 4” as the route that best complies with certain rules.
The estimated project costs for Route 4 are about $7.2m for the transmission facilities, and about $3.7m for the substation facilities, for an estimated grand total cost of about $10.9m, LEC said.
Among other things, LEC said that there are no habitable structures within 300 feet of the right of way (ROW) centerline of Route 4, and there are no parks or recreational areas within 1,000 feet of the centerline of any alternative route.
According to the estimated schedule, ROW and land acquisition would begin in June 2018 and be completed in September 2018; engineering and design would begin in January 2018 and be completed in June 2018; material and equipment procurement would begin in June 2018 and be completed in October 2018; construction of the facilities would begin in October 2018 and be completed in February 2019; and energizing of the facilities would begin in February 2019 and be completed in March 2019.