Rayburn Country Electric Cooperative (RCEC) on March 28 submitted to the Public Utility Commission (PUC) of Texas an application to amend its certificate of convenience and necessity for the Dent Road Expansion to Wieland Switch 138-kV Transmission Line in Hunt County, Texas.
RCEC said that it is proposing to build a new single-circuit 138-kV electric transmission line that would connect expanded portions of the existing Dent Road substation owned by Greenville Electric Utility System (GEUS), located about 0.65 miles east of the intersection of State Highway (SH) 34 and County Road (CR) 1570 near Greenville, Texas, to the proposed tap point switch/meter station – planned to be named the Wieland switching station – located along RCEC’s existing Blackland to Wieland 138-kV transmission line, located about 0.5 miles southwest of the existing Wieland substation, which is located about 1.2 miles south of Wieland, Texas.
The project is one component of the Greenville Area Project evaluated and accepted by the ERCOT Regional Planning Group by letter dated Feb. 15, 2016, to address system reliability issues in the Greenville area, RCEC said.
A study by Garland Power & Light (GPL) shows that under n-1 conditions, the Greenville area has significant voltage dips with the loss of one of the two 138-kV transmission ties into the GEUS system and, with local generation offline, voltage in the area drops below acceptable ranges and violates certain NERC reliability standards, as well as ERCOT planning criteria.
RCEC added that ERCOT reviewed the study and determined that the Greenville area is vulnerable to islanding and voltage issues on the GEUS 69-kV system under certain contingency conditions.
The ERCOT independent review of the Greenville Area Project concluded that these components were the best option for addressing the reliability concerns in the Greenville area: expand the Dent Road 69-kV substation to 69/138-kV service; install a 69/138-kV transformer at the Dent Road substation; build a Dent Road to Shelby 138-kV transmission line; build a Dent Road to Wieland 138-kV transmission line; and build a new breaker station at the Quinlan 138-kV Tap.
RCEC also said that since it owns the Blackland to Wieland line that feeds the Wieland substation and the Quinlan 138-kV Tap, RCEC was designated as a transmission co-provider for the project, along with GEUS, which owns the Dent Road substation, and Texas Municipal Power Agency (TMPA), which owns the Shelby substation.
For its role in the Greenville Area Project, RCEC said that it would build the new Dent Road Expansion to Wieland Switch line and associated Wieland switching station, and the new breaker station at the Quinlan 138-kV Tap. Building the new breaker station at the Quinlan 138-kV Tap is not part of this project, RCEC said, adding that the proposed Dent Road Expansion to Wieland Switch line would terminate into the expanded portion of the Dent Road substation, which would be owned by GPL.
While GEUS owns the existing Dent Road substation, GEUS and GPL have agreed that GPL would perform the expansion of the Dent Road substation and build the Dent Road to Shelby 138-kV transmission line, as contemplated by the Greenville Area Project.
RCEC added that GPL would expand the existing Dent Road substation to 69/138-kV service at an adjacent location to the south, which includes installing a 138/69-kV autotransformer and a new 69-kV tie-line connecting the 138/69-kV autotransformer to GEUS’ existing Dent Road substation 69-kV facilities (referred to as the Dent Road Expansion). GPL would build, own, and operate the expanded 138-kV portions of the Dent Road substation, RCEC said, noting that the expansion work is not part of this project.
RCEC said that it would install new transmission switching equipment at the Wieland switching station; that station’s site would be about eight acres in size.
RCEC said that it selected a location for that station based primarily on the need to connect to the existing Blackland to Wieland line; connect to that line in a location near the Wieland substation; have sufficient space and all-weather road access for the switching station; and accommodate a planned future interconnection with Oncor’s existing Sulphur Springs to Royse Switch 345-kV transmission line that crosses the Blackland to Wieland line at the proposed location.
The entire project would be about 6.85 miles to 10.90 miles long, depending on the final route selected, RCEC said.
RCEC said that it would own, operate, and maintain all transmission line facilities associated with the project, and that it has acquired the Wieland switching station property. RCEC further noted that it would own, operate, and maintain all of the facilities associated with that station where the new 138-kV line would connect to the existing Blackland to Wieland line.
GPL would own the Dent Road Expansion, to be located south of the existing Dent Road substation at about 0.65 miles east of the intersection of SH 34 and CR 1570. RCEC added that it would design and build the new 138-kV transmission facilities up to buss work and a dead-end structure owned by GPL at the Dent Road Expansion; RCEC would not install or own any equipment within the Dent Road Expansion.
RCEC said that the standard single pole transmission structures proposed for the project are concrete poles with steel davit arms supporting the conductors. Land uses within the project area include commercial and residential areas, as well as agricultural areas represented by pastureland, rangeland, and cropland. RCEC also said that residential development is densest in the center of the project area, and exists at various densities throughout the project area. The project area is situated within the Blackland Prairies Physiographic Province of Texas, which represent the innermost subdivision of the Gulf Coastal Plains, RCEC said.
According to the estimated schedule, right of way and land acquisition would begin in March 2018, and be completed in August 2018; engineering and design would begin in March 2018, and be completed in May 2018; material and equipment procurement would begin in May 2018, and be completed in August 2018; construction of the facilities would begin in August 2018, and be completed in May 2019; and the facilities would be energized in May 2019.
RCEC said that it evaluated the 20 alternative routes included in the application and selected “Route S” as the route that best complies with Public Utility Regulatory Act (PURA) and the PUC’s substantive rules. RCEC said that Route S:
- Is the fourth shortest route at about 8.21 miles
- Impacts the third fewest habitable structures – 22 – within 300 feet of its centerline
- Is the fifth least expensive route at about $6.6m. RCEC said that it intends to finance the project through long-term debt with National Rural Utilities Cooperative Finance Corporation (CFC) or CoBank; interest on the debt may be capitalized until the project is in service, at which point it is intended that the principal and interest would be serviced with transmission cost of service revenues
- Parallels the third greatest length of existing transmission lines – about 1.16 miles
- Crosses the second shortest distance of combined woodland/brushland – about 1.56 miles
- Does not cross any mapped 100-year floodplains or parallel any mapped streams within 100 feet
- Crosses the second least number of mapped streams – eight
- Crosses the fifth least amount of HPA for cultural resources – 5.81 miles
Among other things, RCEC said that Route S is very similar to “Route T,” which is the route identified by its routing consultant Burns & McDonnell as the best-suited route from an environmental perspective. Route S differs from Route T in that Route S uses segments 46 and 48 instead of segment 47.
RCEC added that it identified Route S because it parallels approximate property lines for a greater distance, which reduces bisecting property, and it should avoid tree clearing on property that is currently owned by Lynch Funeral Service and two individuals that would otherwise occur on segment 47, making Route S easier to build.