FirstEnergy’s (NYSE:FE) Potomac Edison, in a July 21 application, requested from the Virginia State Corporation Commission (SCC) a certificate of public convenience and necessity (CPCN) in order to rebuild a substantial portion of its Double Toll Gate–Riverton 138-kV Transmission Line in Clarke and Warren counties in Virginia.
The line is a 7.07-mile, single circuit, three phase transmission line with shield wires that originates at the Double Toll Gate substation in Clarke County and extends to the Riverton substation in Warren County. The line is a critical component of the electric transmission grid that serves Virginia, the company added.
The rebuild project is necessary so that the company can continue to comply with the standards of NERC for transmission facilities, as well as its internal reliability standards, the company said. PJM Interconnection’s 2012 Regional Transmission Expansion Plan (RTEP) analysis for model year 2017 showed that by the summer – beginning June 1 – of 2017, an outage of various 138-kV and 115-kV lines in combination with other 138-kV and 115-kV lines would result in an overload of the Double Toll Gate–Riverton Line, resulting in a thermal violation on that line, the company said.
The failure to address those projected NERC contingency violations could potentially damage the company’s electrical facilities, which would be detrimental to grid reliability, the company said, adding that PJM identified the Double Toll Gate–Riverton Line as being in need of upgrades so as to ensure that Potomac Edison will be able to continue to provide adequate transmission service in the state.
The rebuild project will involve:
- Replacing 6.3 miles of existing 336.5 kcmil 26/7 aluminum conductor steel reinforced (ACSR) conductor with 556.5 kcmil 26/7 ACSR conductor in order to increase the thermal capacity of the line
- Replacing 52 of the 60 existing support structures with structures that are on average five feet higher than the existing structures in order to accommodate increased sag associated with the new conductors
- Associated substation modifications in connection with the new conductors
The existing right of way (ROW) for the line varies between 65 feet and 100 feet in width, the company added, noting that no new ROW is required for the rebuild project.
Among other things, Potomac Edison said that it estimates that the total cost of the rebuild project will be $6.1m. Noting that the in-service date for the completed rebuild project set by PJM is June 1, 2017, the company said that construction must begin at the latest by March 2017, but it would ideally begin work in mid-January.