Potomac Edison is seeking approval from Maryland state regulators to rebuild part of the existing Mt. Storm to Doubs transmission line in Frederick County, Md.
In its Nov. 15 application for a certificate of public convenience and necessity (CPCN) filed with the state Public Service Commission, Potomac Edison, a FirstEnergy (NYSE:FE) subsidiary, said it owns a 2.8 mile segment of the nearly 100-mile line. Its portion runs from the Virginia-Maryland state line to the Doubs substation in Frederick County.
Dominion Virginia Power, a Dominion (NYSE:D) company, owns the remaining 96.4 miles of the line. Its portion begins at the Mt. Storm power station in Grant County, W.Va., travels through West Virginia into portions of Virginia, and ends at the Virginia-Maryland state line.
Dominion has started rebuilding its portion of the line and Potomac Edison is seeking approval to make a corresponding upgrade to the 2.8-mile segment of the line to address several concerns, including potential overloads, the age of existing facilities and future growth in electrical demand.
“The Mt. Storm-Doubs line is a critical component of the electric transmission network that serves Maryland, Virginia, West Virginia and beyond,” Potomac Edison added, noting that it is a heavily loaded line for most of the year and has been the driver of major transmission reinforcement projects since 2006.
The opportunity to rebuild the line exists now that the Trans-Allegheny Interstate Line (TrAIL) is in service, Potomac Edison said.
According to TransmissionHub data, TrAIL is a 165-mile, 500-kV transmission line that begins at 502 Junction, Pa., and ends at Loudon, Va. The project, which is sponsored by FirstEnergy subsidiary Allegheny Energy, improves system reliability, east-west transfer capability and growing electric demand. The project, which runs through Pennsylvania, Virginia and West Virginia, was energized and put into service in June 2011.
Potomac Edison said the Mt. Storm-Doubs Rebuild will replace facilities that have been in service for more than 40 years and are approaching their expected end of life.
PJM Interconnection concluded that Potomac Edison and Dominion should seek to complete the rebuild by June 1, 2015.
Potomac Edison also said that the proposed route for the project uses existing transmission right-of-way (ROW) and therefore will not deviate from the existing route.
While the project is a modification of existing transmission facilities and an analysis of alternative routes is not required, Potomac Edison did consider alternative solutions to the project, including re-routing portions of the existing line or building a new 500-kV line or multiple lower voltage lines to replace the line.
The company asked that the PSC issue a procedural schedule that would allow it to enter a final order granting the CPCN by August 2013 when construction work should begin in order to meet PJM’s requested in-service date.
The proposed rebuild will use 100% of the existing approximately 57-acre electric utility corridor, with no additional ROW required. Potomac Edison also said the Mt. Storm-Doubs Rebuild will be an alternating current, single-circuit, 500-kV line, consisting of three electrical phases elevated above the ground by self-supporting lattice steel towers in a horizontal configuration.
The Mt. Storm-Doubs line is heavily loaded and has been in service for more than 44 years.
“Aging equipment, without replacement, will increase the probability of a failure that will severely impact the reliability of the transmission network serving Potomac Edison’s customers,” the company added. “More fundamentally, a rebuild of the line will increase capacity, thereby further enhancing reliability.”
Should the project not proceed as planned, the transmission system for Maryland will be at risk, the company said, adding that “delaying the rebuilding of this line increases the risk of infrastructure failures that would compromise the availability and reliability of transmission service for Maryland customers.”
The current authorized budget for the project is about $14.5m for rebuilding the existing transmission line, Potomac Edison said.
Among other things, Potomac Edison said its additional investment will increase the tax base in Frederick County and that during construction, opportunities will exist for local companies to supply labor and some materials, such as concrete.