Virginia Electric and Power d/b/a Dominion Energy Virginia on April 1 filed with the Virginia State Corporation Commission an application seeking approval to rebuild, entirely within its existing right of way (ROW), about 64.5 miles of its existing Mt. Storm-Valley 500-kV Line #550, of which 30.9 miles are located in Virginia, with the remaining portion of the line located in West Virginia.
The company added that the line runs from the company’s existing Valley substation in Augusta County, Va., to the company’s existing Mt. Storm substation in Grant County, W.Va.
The company said that there is an immediate and current need for the proposed project to assure that Dominion Energy Virginia can continue to provide reliable electric transmission service consistent with the company’s obligation under Virginia law to serve retail electric customers in its exclusive service territory.
The company noted that the proposed rebuild project would replace aging infrastructure that is at the end of its service life in order to comply with the company’s mandatory planning criteria, thereby enabling the company to maintain the overall long-term reliability of its transmission system and to maintain the overall generating capabilities of the system.
The company said that it submitted the rebuild project proposal to the PJM Interconnection RTEP process in December 2016 to address the end-of-life criteria. The proposed rebuild project was approved by PJM at its February 2017 board meeting and assigned baseline number b2759.
Dominion Energy Virginia said that with authorization from the commission by April 30, 2020, and the ability to obtain outages from PJM, the company anticipates that construction should be completed by Dec. 31, 2021.
The estimated conceptual cost of the proposed project is about $288.2m (in 2019 dollars), which includes about $255.9m for transmission-related work and about $32.3m for substation-related work ($0.2m for the Valley substation and $32.1m for the Mt. Storm substation). The company added that that is the total for all Virginia and West Virginia portions of the rebuild project.
Among other things, the company noted that as part of the project, it proposes the removal of 258 single-circuit, 500-kV, weathering steel lattice towers, one 500-kV single-circuit weathering steel H-frame (Structure #550/2), and two 500-kV, single-circuit, galvanized steel lattice towers (Structures #550/17 and #550/33) supporting existing Line #550 (135 structures in West Virginia, 125 structures in Virginia, and one structure – #550/137 – on the state line), which would be replaced with 261 galvanized steel lattice towers.
The company added that it also proposes the replacement of the existing 3-phase twin-bundled 2049.5 AAAC conductors with 3-phase triple-bundled 1351.5 ACSS/TW (HS-285) conductors and two 7#7 alumoweld shield wires with two fiber optic shield wires.