LCRA Transmission Services Corporation (TSC), in its application filed on March 1 with the Public Utility Commission (PUC) of Texas, said that the Zorn to Marion 345-kV Transmission Line Project would provide reliability benefits to all of the ERCOT region as it is part of the bulk electric 345-kV electric system.
The proposed project within Guadalupe County, Texas, would extend from the existing LCRA TSC Zorn substation to the existing LCRA TSC Marion substation, according to the application.
The proposed project area includes portions of the cities of New Braunfels, Santa Clara, Marion and Seguin, and is primarily rural with occasional concentrations of residential and commercial development along the Guadalupe River, LCRA TSC said. The predominant land use within the area is undeveloped or agricultural land represented by pastureland, rangeland and cropland, LCRA TSC added.
The first portion of the proposed project is the installation of a single circuit on the previously certificated open position of LCRA TSC 345-kV structures from the Zorn substation to the vicinity of the existing LCRA TSC-owned Clear Springs substation. LCRA TSC also said that the second portion of the proposed project involves the construction of new 345-kV double-circuit capable structures from the vicinity of the Clear Springs substation to the Marion substation, with one circuit to be installed initially and a second circuit to be installed on the double-circuit structures at a future date.
The portion of the proposed project to be built on new structures within new right of way (ROW) would be about 10 miles to 14 miles in length, depending on the final route selected. LCRA TSC also said that it would install new equipment at the existing Marion and Zorn substations.
The typical heights of pole structures generally proposed for the project range from 120 feet to 175 feet above ground.
Further describing the project, LCRA TSC added that it entails:
- About 9.9 miles to 13.6 miles of new ROW and about 7.4 miles to 10.4 miles of existing ROW would be used for the proposed project
- About 18.4 miles to 23.6 miles of circuit would be installed for the first circuit of the proposed project, and about 9.9 to 13.6 of additional miles of circuit would be installed on the double-circuit structures at a future date
- ROW width for the proposed project would vary from an estimated minimum width of 120 feet to an estimated maximum width of 200 feet where low-profile structures may be required
According to the estimated schedule, ROW and land acquisition is set to begin in October and be completed in December 2017, while engineering and design is set to begin in March 2017, and be completed in February 2018. Material and equipment procurement is set to begin in December 2017, and be completed in June 2018, while construction of the facilities is set to begin in June 2018, and be completed in May 2019. The facilities are to be energized in May 2019.
In work related to the proposed project, the following transmission improvements would also be made, LCRA TSC said:
- The Guadalupe Valley Electric Cooperative (GVEC)-owned Cibolo to Schertz 138-kV transmission line would be upgraded with an emergency rating of at least 477 MVA
- CPS Energy would reconfigure the existing Hill Country–Elm Creek/Marion and Skyline–Marion/Elm Creek 345-kV double-circuit lines
- LCRA TSC would add a second 345/138-kV autotransformer at the Marion substation with an emergency rating of at least 525 MVA
LCRA TSC said that it would finance the facilities associated with its application in a manner similar to that which has been used for projects that it has previously built. That is, the proposed project would be financed initially with a combination of tax-exempt commercial paper, tax-exempt private revolving note, and subsequently with fixed-rate debt.
LCRA TSC also said that the project is needed to add electric transmission infrastructure to serve northern Bexar County and the Interstate 35 corridor between San Antonio and Austin in Texas. Noting that that area has been growing, LCRA TSC said that growth in electricity demand connected to its system along that path has been and continues to among the fastest in the LCRA TSC system.
Additionally, ERCOT issued a market notice in the fall of 2013, providing a notice of suspension of operations at the CPS Energy J.T. Deely generating station – 845 MW – by December 2018. LCRA TSC added that CPS Energy’s plan to decommission that power plant, located in the southern portion of Bexar County, increases reliance on the 345-kV transmission system north of the Marion substation. The proposed project meets the system need by providing a second 345-kV transmission line from the north into the Marion substation.
On alternatives to the project, LCRA TSC said that it considered rebuilding the existing 345-kV transmission line between the Marion and Clear Springs substations, but that option was not recommended as it required an extended outage on the line that formed the contingency creating the need for the project, and would require an upgrade of the Henne to Zorn 345-kV transmission line after the upgrade was complete.
On routing, LCRA TSC said that it retained POWER Engineers Inc., to prepare the environmental assessment (EA), and that through application of certain routing criteria, 72 preliminary alternative route segments were identified and developed into potentially viable preliminary alternative routes for comparative purposes. Ultimately, 15 primary alternative routes were identified for comparison, LCRA TSC said, adding that it identified “Route 10” as the primary alternative route that it believes best addresses certain requirements for the proposed project. Route 10 requires the shortest length of new ROW – 9.9 miles; has the least number of habitable structures within 500 feet of the route centerline – 42; and has the lowest estimated cost – about $47.7m.
In its opinion, LCRA TSC said that all alternative routes included in its application, as well as forward progressing alternative routes that may be created using the noticed segments included in the application, are acceptable routes for the proposed project.
Among other things, LCRA TSC said that no significant impacts to the use or enjoyment of the parks and recreation facilities located within the study area are anticipated from any of the primary alternative routes.