Virginia State Corporation Commission (SCC) staff, in a Sept. 28 report, said that it does not oppose Virginia Electric and Power’s (Dominion Energy Virginia) request for a certificate of public convenience and necessity (CPCN) to rebuild Possum Point-Smoketown 115-kV Line #18 and Line #145.
The existing, approximately 8.5-mile lines were completed between 1948 and 1954, staff said, noting that according to the company, the lines are reaching their end-of-life, consistent with the company’s planning criteria. In addition, faster than expected load growth in the zone serviced by the lines, and the possible addition of a 70-MW block load at the Northern Virginia Electric Cooperative (NOVEC) Independent Hill delivery point (DP), would require Dominion Energy Virginia to reconfigure its transmission facilities in the area, including the lines, to operate at 230 kV rather than 115 kV, staff said.
The company is seeking approval to rebuild the lines, wholly within existing right of way (ROW), with new galvanized steel monopoles that are taller than the existing structures, staff said. The estimated cost of the rebuild is $18.8m, which would be allocated entirely to Virginia customers, staff noted.
Staff said, “The visual impact of newly introduced undulled galvanized steel structures and non-deglared conductors alongside existing structures that have become dulled over several years of exposure to the elements could initially be significant.”
If the SCC determines that the company should mitigate the visual impacts of the “undulled” galvanized steel structures, staff believes that the use of factory-dulled galvanized steel structures and de-glared conductors may be a reasonable means of achieving such mitigation at an additional cost of $248,230 and $56,938, respectively, staff said.
Staff noted, however, that the proceeding has no respondents, nor have any public comments been received expressing visual impact concerns.
As noted by staff, the company filed its application in June, seeking approval to rebuild the lines from structures #18/1A and #145/1A inside the company’s existing 115-kV switch yard at the Possum Point power station site to structures #18/102 and #145/302 at the NOVEC Smoketown DP, entirely in Prince William County, Va.
The lines feed three NOVEC DPs: Country Club DP, Garber DP, and Smoketown DP.
Staff added that the lines would be rebuilt, including the removal of the conductors and 125 of the 130 existing structures, and replacement with 88 new structures and conductors capable of operating at 230 kV on all but a 0.7-mile segment (rebuilt to 115 kV). According to the company, that would allow it to maintain long-term reliability, while providing flexibility to support future load growth in the area, staff said.
The company would continue to operate the lines at 115 kV until such time as operation at 230 kV is needed to serve the Northern Virginia Load Area, staff said.
Staff said that it has analyzed the company’s application and supporting documentation and concludes that the company has reasonably demonstrated that Lines #18 and #145 meet the company’s end-of-life criteria.
Staff also noted that the company submitted the proposed project to the PJM Interconnection Transmission Expansion Advisory Committee (TEAC) in March 2015, and received approval as part of the 2015 Regional Transmission Expansion Plan (RTEP); it is classified as a baseline reliability project identified as b2624.
Staff said that it believes that the company has reasonably demonstrated the need for the project based on its end-of-life criteria, and agrees with the company’s assessment that the cost of continuing to repair the lines is about $6.1m greater than the estimated cost of the proposed project, and thus justifies the need to replace the aging infrastructure.
Staff further noted that it does not oppose the rebuild of the lines, designed for 230 kV but operated at 115 kV.
“Due to the diverse and dynamic nature of load growth in the area, particularly the potential for block load additions, the staff believes the proposed 230 kV design provides flexibility for the company to create a more robust 230 kV network within the area, should the need arise,” staff said.
The company has reasonably demonstrated that it will likely need to operate the facilities at 230 kV at some point in the future, and, as such, construction to 230-kV specifications now appears to be prudent, staff noted.
The estimated construction time for the proposed project is about 15 months, with engineering, material procurement, and permitting expected to be completed by June 2018. Staff added that construction is expected to be completed by the desired in-service date of December 2019.