The Virginia State Corporation Commission (SCC) staff, in a Jan. 5 report filed with the SCC, said it concludes that Delmarva Power & Light has reasonably demonstrated the need for a proposed 138-kV transmission project, which would use existing right of way (ROW) to increase system reliability and address potential overloading due to common mode contingencies identified in the PJM Interconnection transmission planning process.
Staff said it does not oppose the proposed project.
As TransmissionHub reported, the company in August 2015 filed with the SCC an application for a certificate of public convenience and necessity (CPCN) in order to build the Virginia portion of the new transmission line from Delmarva Power’s Piney Grove substation in Wicomico County, Md., to its Wattsville substation in Accomack County, Va.
The company has also filed with Maryland state regulators for a CPCN to build the Maryland portion of the line.
In its application filed with the SCC, the company said that as part of the project, it will rebuild the 69-kV transmission lines spanning from the Piney Grove substation to the company’s Kenney substation in Worcester County, Md., and from the Kenney substation to the Wattsville substation.
The total length of the project is 30.9 miles long, 6.15 miles of which will be built in Virginia in an existing ROW. The estimated cost of the entire proposed project is $44.7m, and the estimated cost of the Virginia project is $8.9m, the company added.
The new 138-kV line from the Piney Grove substation to the Wattsville substation must be in place by June 1, 2018, and has been properly included in PJM’s regional transmission expansion plan (RTEP), the company said.
Discussing the need for the project, Delmarva Power said that PJM identified a post-contingency violation during the application of the baseline generation deliverability testing criteria while studying its planning cases for 2018: an unacceptable thermal overload on the 138-kV transmission line spanning from the company’s Piney Grove substation to its New Church substation in Accomack County that could, if left unaddressed, disrupt the power flow from generation in the Virginia section of the Delmarva Peninsula and adversely impact reliability as early as June 2018.
The Virginia Department of Environmental Quality (DEQ) in October 2015 told the SCC that it agrees with Delmarva Power’s proposal of “Alternative A” as the preferred alternative route for the company’s Virginia portion of the Piney Grove–Wattsville 138-kV/69-kV transmission line project.
In its Jan. 5 report, staff noted that the company states that the desired in-service date is June 1, 2018, with cleanup and site restoration scheduled to be completed by August 2018. The estimated construction time is 17 months. Staff added that the existing 69-kV line cannot be de-energized between the months of June and August 2017, meaning that the construction of the project must begin by next October to meet the desired in-service date.
Discussing the proposed route, staff noted that the southern terminus of the route is the existing Wattsville substation located on Chincoteague Road in Accomack County. The route heads northeasterly about 0.10 mile, including the crossing of Vernon Road. The route then heads northwesterly for about 0.76 miles. Staff added that the line then heads east about 0.40 mile where it crosses Route 679 (Fleming Rd.) and continues about 0.17 miles. The route then heads northeasterly about 4.6 miles, where it crosses Route 679 a second time, Route 709 (Horntown Rd.), Route 712 (Sign Post Rd.) and Route 714 (Silverthorne Rd). About 0.12 miles northeasterly of where it crosses Route 714, the route leaves Virginia and enters Maryland, staff added.
Since the new transmission line contains 138-kV transmission conductors in addition to the 69-kV conductors, supplementation of the existing easement along the north side of the Wattsville substation will be necessary in order to terminate the conductors at that substation, staff said.
Among other things, staff said that the company considered three alternatives to the project: rebuilding the existing 138-kV transmission line from the Piney Grove substation to the New Church substation; building a new 138-kV transmission line from the Piney Grove substation to the New Church substation; and building a new 138-kV transmission line that would follow the existing transmission lines from the Loretto substation to the Pocomoke substation and from the Pocomoke substation to the Oak Hall substation.
Those alternatives each had higher cost estimates compared to the proposed project, staff said.
Staff also noted that according to the application, the project is necessary to ensure adequate and reliable electric service to customers in Worcester County, and wholesale electric customers of Old Dominion Electric Cooperative, a transmission owner and operator in Accomack and Northampton counties in Virginia. According to the company, the benefits will further many energy objectives, such as ensuring an adequate energy supply, using energy resources more efficiently and optimizing intrastate and interstate use of energy supply and delivery to maximize energy availability and reliability, staff said.
Delmarva Power is a subsidiary of Pepco Holdings (NYSE:POM).