South Carolina Electric & Gas (SCE&G) last month filed with the Public Service Commission of South Carolina an application for a certificate of environmental compatibility and public convenience and necessity to build and operate two 230-kV transmission lines in Aiken County, S.C.
The Graniteville-South Augusta 230-kV Tie Line, for instance, would extend from Southern Company’s (NYSE:SO) South Augusta substation on Dan Bowles Road in Augusta, Ga., to the Graniteville No. 1 substation in Aiken County. The portion of line to be owned and operated from SCE&G and measured from the first transmission line structure on the South Carolina side of the Savannah River would be an estimated 18.1 miles long, the company added.
The estimated 17.6-mile Urquhart-Graniteville #2 230-kV Line would extend from the Urquhart substation in Aiken County to the Graniteville No. 2 substation in Aiken County, the company said.
Discussing need, the company said that its transmission planning studies indicate that the occurrence of certain contingencies will result in heavy electrical loading on the existing Vogtle-Savannah River Site 230-kV Tie Line, a critical Southern Company-SCE&G interconnecting 230-kV line, as early as 2019.
SCE&G said that to prevent future excessive loading conditions on that line and to distribute the flow of power more reliably and evenly into the SCE&G system, additional electrical transmission paths are necessary between Southern Company and SCE&G.
After studying multiple options with Southern Company and others to decrease the power flow on the Vogtle-Savannah River tie line, SCE&G and Southern Company have agreed to establish two new Southern Company/SCE&G interconnecting tie lines – the Graniteville-South Augusta tie line and the Graniteville-South Augusta 115-kV Tie Line – that would cross the Savannah River and enter South Carolina onto SCE&G’s Urquhart generating station site.
SCE&G also said that in addition to decreasing the power flow on the existing Vogtle-Savannah River Site tie line and more reliably and evenly distributing the flow of power into the SCE&G system, the new tie lines would increase the transfer capacity for all utilities interconnected to SCE&G’s electrical transmission system.
The existing Urquhart-Graniteville #2 line is one of two transmission lines that service the Urquhart generating station’s two 230-kV generators totaling 330 MW, the company said, adding that relocating the Urquhart-Graniteville #2 line onto double-circuit 230-kV structures alongside the Graniteville-South Augusta tie line would maintain the current operating flexibility and level of reliability required for the Urquhart generators.
The company also said that based on the April “Transmission Line Siting and Environmental Report for the Graniteville-South Augusta” tie line and Urquhart-Graniteville #2 line and associated facilities – which was prepared by the Facilities Planning & Siting Division of UC Synergetic, LLC – the proposed lines and associated facilities would have no significant environmental impacts to vegetation, wildlife, threatened or endangered species, jurisdictional wetlands, streams, designated floodplains, or floodways.
The company also said that the construction of the proposed lines and associated facilities would have no adverse effects on archaeological resources, and that construction of the lines would have no adverse visual impact on historic resources.
The company further stated that the lines would have low visual effects due to the placement of the lines within existing and cleared transmission line right of way (ROW); the replacement of existing transmission lines; and the existing visual modifications resulting from existing transmission lines that would remain in the ROW alongside the lines.
The South Carolina Department of Parks, Recreation and Tourism, in an Aug. 22 letter to the South Carolina Office of Regulatory Staff, said that it has no comments or concerns pertinent to the project at this time.
SCE&G is a SCANA (NYSE:SCG) company.