Exelon’s (NYSE:EXC) Baltimore Gas and Electric (BGE) is proposing to modify a certain segment of an existing double-circuit, 230-kV transmission line that runs between the Riverside substation in Baltimore County, Md., and the Brandon Shores substation in Anne Arundel County, Md., according to the Feb. 19 direct testimony of James Casey, principal project manager in the Project and Contract Management Department of the Technical Services Division, filed with the Maryland Public Service Commission on behalf of the company.
As noted in the Feb. 19 direct testimony of Robert Munley, principal engineer in the Substation Engineering Design & Standards unit, filed with the commission on behalf of BGE, the project is needed because the existing transmission line segment crossing under the Patapsco River adjacent to the Francis Scott Key Bridge – the Key Bridge – from Hawkins Point in Baltimore City to Sollers Point in Baltimore County, which was installed in 1976, has reached the end of its useful life and is at risk of failing.
As noted in BGE’s application for a certificate of public convenience and necessity for the Key Crossing Reliability Initiative Transmission Line Project filed with the commission in December 2018, the company would replace the existing underground pipe-type cable along an approximate 2.25-mile stretch of the existing transmission line between Hawkins Point and Sollers Point beneath the Patapsco River with overhead wire and eight support structures.
The new overhead segment would be supported by eight new monopole-style towers, Casey said, adding that the existing underground segment and the terminal stations where the existing underground segment transitions to BGE’s overhead transmission system would then be decommissioned.
The new overhead segment would tie into existing BGE-owned overhead lines on each side of the Patapsco River that are part of the existing double-circuit, 230-kV transmission line. Casey also said that the new overhead segment would be supported by three land-based steel monopole towers with foundation structures and five water-based steel monopole towers with foundation structures.
BGE would need to acquire a small amount of additional property or property rights – such as an easement – to install Tower #1 on the Hawkins Point side of the project, Casey said, adding that the area required is about 0.51 acres and is currently owned by the Maryland Port Administration. BGE is in discussions with the Maryland Port Administration to obtain the property in fee or to have the right to access and build Tower #1 on the property, Casey said.
As noted in Munley’s testimony, the towers would range in height from 126 feet to 397 feet tall.
Casey said that BGE estimates the capital cost of the project to be about $243m, which assumes that Patapsco River closure restrictions would be applied by the applicable environmental agencies through the permitting process and that those restrictions would prohibit any construction activity on the project that impacts the Patapsco River bottom between Feb. 15 and June 15 annually.
Such restrictions would prevent pipe pile installation during the closure periods resulting in an increase in the overall duration required to complete pile installation, and thus increasing the overall cost of the project, Casey said. If no river closure restrictions are applied through permitting, the estimated capital cost of the project is reduced by about $20m, for a total estimated capital cost of $223m, Casey said.
The project has a target in-service date of Dec. 31, 2022, for the new double-circuit, 230-kV, overhead transmission line segment. The decommissioning of the existing Hawkins Point Terminal Station, Sollers Point Terminal Station, and the existing 230-kV underground transmission line segment would then begin, with a target date of Dec. 31, 2024, to complete those activities, Casey added. To ensure that the new double-circuit, 230-kV, overhead transmission line segment is placed into service by Dec. 31, 2022, BGE must begin construction activity by Jan. 1, 2021, Casey said.
Among other things, Casey said that BGE plans to have several open houses in the spring/summer, with the first open house scheduled at the Sollers Point Recreation Center in the Turner Station/Dundalk community of Baltimore County on March 21.