Brazos Electric Power Cooperative on Jan. 26 filed with the Public Utility Commission of Texas an application for a certificate of convenience and necessity for the Clairemont to Salt Creek Switch Transmission Line and Switch Station Project.
The company said that it proposes to build about 2.18 miles of 138-kV double-circuit capable transmission line with one circuit initially in place in Kent County, Texas, between the existing Brazos Electric Clairemont substation, located about seven miles northwest of Clairemont, Texas, to the proposed new Salt Creek switch, located about 1.6 miles northwest of the existing Clairemont substation and about 2.3 miles east of Ranch Road 1081.
The proposed Salt Creek switch would encompass about 7.5 acres, the company said, adding that it would own 100% of the proposed line and switch station.
The study area considered for the proposed project is located in western Kent County, west of the City of Jayton and south of the City of Spur. The landscape of the study area and surrounding area encompasses multiple gas and oil refining units along with multiple well pads, the company added. The study area, which primarily consists of gas and oil exploration/refining units, also contains undeveloped land used for grazing of livestock, the company said.
Discussing the project’s need, the company noted that the proposed project and associated station work were reviewed by ERCOT stakeholders through the ERCOT Regional Planning Group project review process as part of the Salt Creek Area Project. Currently, the Brazos Electric Salt Creek substation, located in Kent County south of the City of Spur, serves about 60 MW of load. Salt Creek is served by the 22-mile, 138-kV line from Brazos Electric’s Scurry switching station in Scurry County, and the 17-mile, 138-kV line from American Electric Power’s (NYSE:AEP) Spur switching station in Dickens County. The transmission sources to that area are from Oncor’s Sun switching station connected to the Scurry switching station and from AEP’s Aspermont and Paint Creek switching stations connected to the Spur switching station, the company added.
The lack of operational flexibility when multiple transmission facilities are taken out of service is an increasing problem in West Texas, the company said, adding that due to increasing load levels, the ability to take facilities out of service for scheduled clearances, maintenance, or testing is limited by unacceptable voltage and thermal loading conditions caused by the next contingency.
Steady-state power flow analysis indicates that adequate voltage cannot be maintained in the area after “P6” contingencies – two overlapping single contingencies – under NERC Standard TPL-001-4 reliability criteria without significantly reducing the load at Salt Creek.
The company added that studies have shown that loss of either the Sun-Scurry Switch or Scurry Switch-Salt Creek 138-kV line sections, followed by loss of any line section along the Paint Creek-Aspermont-Spur 138-kV Line, results in an unsolved contingency during power flow analysis.
That is an indication of possible voltage collapse in the area, the company said, adding that such a scenario would result in loss of service to customers served on those transmission lines.
Construction of the proposed project would strengthen the transmission system by creating a new 138-kV source to the Salt Creek area, the company said, noting that the resulting 138-kV system would become more networked to support voltage conditions and alleviate thermal overloads during single forced or planned outages on different sections of the area transmission lines.
Additionally, the company said, that would improve operational flexibility during emergency conditions, obtaining clearances for maintenance of equipment and connecting new loads to the system.
Among other things, the company noted that there are no habitable structures located within 300 feet of the proposed route centerline, the company said.
Also, no parks or recreational areas owned by a government body or an organized group, club, or church were identified within 1,000 feet of the route centerline of the proposed project.
The company added that the Texas Historic Commission (THC) recorded two archeological sites that are within 1,000 feet of the proposed route centerline. No further investigations were recommended for the portions of those two sites within the ROW of the Salt Creek to Sun Transmission Line, the company said. During the cultural resources survey for the proposed project, any portion of those previously recorded sites that are found to extend into the proposed route’s ROW would be assessed for eligibility and those findings would be coordinated with the THC, the company said.
The filing noted that during construction, temporary impacts to land uses within the ROW could occur due to the movement of workers and materials through the area. Coordination between Brazos Electric, its contractors, and landowners regarding access to the ROW and construction scheduling would minimize those disruptions, the filing said, adding that most existing land uses would continue during construction.
The estimated total cost of the transmission facilities portion of the project would be about $5m, while the substation facilities portion would be about $6.9m, the company said.
According to the estimated schedule, right of way (ROW) and land acquisition would begin in May and be completed in June; engineering and design would begin in June and be completed in September; material and equipment procurement would begin in October and be completed in December; and construction of facilities would begin in November and be completed in January 2019, which is also when the facilities would be energized.