Virginia Electric and Power (Dominion Energy Virginia) recently filed with the Virginia State Corporation Commission an application seeking approval to reconductor about 6.7 miles of a 230-kV transmission line.
As noted in the filing, in order to resolve potential criteria violations of mandatory NERC Reliability Standards by increasing transmission capacity, as well as to maintain reliable service to overall growth in the area, Dominion proposes to — entirely within existing right of way (ROW) or company owned property in Loudoun County:
- Reconductor about 6.7 miles of the company’s networked overhead 230-kV transmission Line #227 between its existing Beaumeade and Belmont substations, using 2-768.2 ACSS/TW/HS conductor, designed for a maximum operating temperature (MOT) of 250 degrees Celsius and a minimum summer transfer capacity of 1573 MVA
- Uprate the line terminal equipment at the Beaumeade and Belmont substations to 4000 Amp standards by replacing line switches, line leads, wave traps, breakers, breaker switches, and bus segments, as needed
- Uprate line switches at the company’s Ashburn substation and Northern Virginia Electric Cooperative’s (NOVEC) Cochran Mill Delivery Point (DP), which are intermediate stations tapped from Line #227, to 4000 Amps
- Remove an idle 230-kV conductor between Structures #227/182-188
Dominion added that within the 6.7-mile reconductor project, it proposes to remove five double-circuit, 230-kV, weathering steel lattice towers (Structures #227/182-186) supporting 0.76 mile of the existing Line #227 and an idle 230-kV conductor, which would be replaced with four double-circuit and two single-circuit 230-kV galvanized steel poles.
The company noted that the project is necessary to assure that Dominion can maintain and improve reliable electric service to customers in Loudoun County’s Data Center Alley (DCA) Load Area and the regional transmission system as a whole.
Specifically, the company said, the reconductor project would increase the transmission capacity of the 230-kV Line #227 between the company’s Beaumeade and Belmont substations to a minimum summer transfer capacity of 1573 MVA and resolve potential NERC criteria violations that have been identified by PJM Interconnection.
Dominion noted that the desired in-service date for the project is Dec. 31, 2023. Should the commission issue a final order by April 1, 2022, the company estimates that construction of the project should begin on June 1, 2022, and be completed by Dec. 31, 2023.
The company added that the estimated conceptual cost of the proposed project is about $15.1m, including about $11.3m for transmission-related work and about $3.8m for substation-related work (2021 dollars).