Xcel Energy (NYSE:XEL) subsidiary Southwestern Public Service (SPS) on Oct. 23 filed with the Public Utility Commission of Texas an application to amend a certificate of convenience and necessity for a proposed 115-kV Transmission Line (Mustang to Seminole) within Yoakum and Gaines counties in Texas.
SPS said that it is proposing to build and operate the primarily single-circuit electric transmission line between SPS’ existing Mustang substation, located in Yoakum County, and SPS’ existing Seminole substation, located in Gaines County.
The typical heights for the structures would be between 80 feet and 140 feet, SPS said, adding that it proposes the use of single-pole steel structures as the standard structure type for the proposed project instead of H-frame structures because of, for instance, the amount of oil and gas development and associated infrastructure in the area.
The miles of right of way (ROW), as well as the miles of circuit, would be about 17 miles to 22 miles. SPS also said that the width of the ROW would be 70 feet, and it would be wider in some circumstances. About 7% of the ROW has been acquired due to the use of approved and/or existing circuits.
The Mustang substation would have a new 115-kV terminal added to the south of the 115-kV bus for the new line, and the existing Seminole substation would have a new 115-kV terminal added to the south of the 115-kV bus for the new line, SPS added.
The Southwest Power Pool (SPP) identified the proposed project as needed for reliability to address the overload issues of the Denver City Substation to San Andres Tap to Seminole Substation 115-kV line, as well as the low voltages at the Flannagan 69-kV substation; and the Amerada Hess, Doss, Oxy West-Seminole Tap, Roz, and Seminole 115-kV substations.
SPS added that the SPP issued a notification to construct (NTC) for the project in August 2016, which included specific endpoints of the existing Mustang substation and the existing Seminole substation. Xcel accepted the NTC in November 2016.
The study area is located within the Southern High Plains Physiographic Province, which is located west of the North-Central Plains Province and is bounded to the south by the Edwards Plateau, as well as the Basin and Range provinces. That region is described as flat with playa lakes and local dune fields, SPS added. The land use is predominantly rural, with numerous oil and gas fields, agricultural cropland with prominent pivot irrigation, extensive oil and gas developments, as well as some residential and commercial/industrial developments.
The EA/routing study for the proposed project was prepared by Burns & McDonnell, which recommended “Route J” for the project from an environmental and land use perspective, SPS added.
Route J, the company said:
- One of three routes with the fewest habitable structures – 2 – within 300 feet of its centerline
- Ranks as the fifth-shortest route – about 975 feet longer than the shortest alternative
- Utilizes and parallels existing transmission lines, other compatible ROW, and property lines for about 15.76 miles – about 90.2% of its total length
- Is one of three routes with just one stream crossing
- Does not cross potential wetlands or playa lakes
- Crosses the least amount of high probability area for cultural resources – 0.58 miles (tied with H)
SPS said that it selected that route as the route best meeting certain rules. Route J is the third least expensive route, SPS said, adding that the added cost is largely due to double circuiting part of the routing, which, while more expensive, tends to be preferred by landowners, is necessary on that route due to the constraints in the area – oil wells – and reduces the environmental impact of the route.
Among other things, the filing noted that the total cost, including the transmission line and substation costs, is about $15.9m to $18.1m, depending on which route is selected.