Public Service Company of New Hampshire (PSNH) d/b/a Eversource Energy on April 12 filed an application for a certificate of site and facility with the New Hampshire Site Evaluation Committee (SEC) for the construction of a new 12.9-mile, 115-kV transmission line extending from the existing Madbury substation in Madbury, N.H., to the existing Portsmouth substation in Portsmouth, N.H.
Eversource said in an April 12 statement that the SEC has up to 14 months to review the application and determine whether to issue the certificate.
A company spokesperson told TransmissionHub on April 20 that once the SEC "rules that our application is ‘complete,’ a clock starts on the review process. We estimate that construction on the project could begin in mid-2017 and that the project could be operational in the third quarter [of] 2018."
The spokesperson also noted that besides the comprehensive state review process, some aspects of the project require review and approval by the U.S. Army Corps of Engineers.
The new line would be comprised of a combination of overhead, underground and underwater segments, the company said in the application, adding that the “Seacoast Reliability Project” would travel within or along existing electric utility corridors, which traverse portions of the towns of Madbury, Durham and Newington, as well as the City of Portsmouth, including a submarine cable crossing from Durham to Newington under Little Bay.
The project would not change existing land uses within or along the corridor, the company said, adding that most of the project route is within or along the edge of forested areas, and does not require clearing outside the existing utility corridor.
The company noted that the purpose of the project is to provide an additional path to enhance the existing 115-kV transmission system between the Deerfield and Scobie Pond substations, along with 115-kV transmission ties to Maine in order to address reliability concerns in the New Hampshire Seacoast Region, which have been previously identified by ISO New England (ISO-NE).
The project would strengthen system reliability by addressing specific thermal and voltage issues identified by ISO-NE in the Seacoast Region.
The company also said that working with ISO-NE, it conducted an assessment of the New Hampshire and Vermont portion of the New England transmission system to determine whether the electrical infrastructure is sufficient to reliably deliver electricity under a wide range of system conditions. The study concluded that, for the New Hampshire Seacoast Region, additional transmission capacity is needed to support the reliable delivery of electric power to meet the region’s current demand and future increased demand, the company said.
ISO-NE considered a range of alternatives to increase transmission system thermal capacity, to increase transformer thermal capacity, and to improve system voltage performance. After performing a detailed analysis of such alternatives, the project “was selected as the preferred solution, as it is much less costly than the other alternative and addresses the needs in the area” that were previously identified by ISO-NE in a needs assessment, the company added.
The project’s cost is estimated to be about $77m, the company said, noting that PSNH initially finances construction projects with internally generated cash and short-term borrowings from Eversource.
Discussing the project site, the company said that beginning at the Madbury substation, the project would travel south along the existing PanAm-owned railroad corridor, along with an existing electric distribution line, until it reaches Route 4 in Durham. From Route 4, the project would continue south along the railway, to the University of New Hampshire (UNH) “A Lot” parking lot, where the line would transition to an underground cable crossing Main Street and transition to an overhead line south of Main Street through the UNH campus toward the Packers Fall substation.
From the Packers Falls substation, the company added, the line would diverge from the railroad corridor and turn east towards Route 108, occupying an existing PSNH right of way (ROW). Once crossing Route 108, the line would continue east until transitioning to an underground/submarine cable inland from the westerly shore of Little Bay. After crossing under Little Bay, and traveling within a municipally owned road, the underground/submarine cable would transition to an overhead design on the eastern side of Little Bay Road.
Continuing east through the existing ROW, the company added, the line would cross Fox Point Road and thereafter head south-easterly, paralleling the Spaulding Turnpike. The line would cross the Spaulding Turnpike and continue in an easterly direction on the southern side of the Crossings at Fox Run Mall until it reaches the Portsmouth substation.
The company added that the project would require that work be completed at each of the terminal substations, including structural bracing modifications to the existing terminal structure and installation of new electrical equipment at the Madbury substation. A new terminal structure, control enclosure expansion, bus extension and electrical equipment additions are required at the Portsmouth substation. The company also said that the work conducted at both substations would be built within the existing fence line of the facilities.
The company said that it would relocate and upgrade portions of the current distribution lines in the project corridor in Newington and Durham onto public streets that are maintained by the towns, where there are existing distribution lines.
After reviewing all of the alternatives and considering input from the local communities, the company said that it concluded that, on balance, the proposed project route was the best solution because it is consistent with “good utility practice” and will result in the fewest impacts to communities and resources in the region, while ensuring increased reliability and improvements to the system in the most cost-effective manner.
Discussing potential effects and proposed mitigation measures, the company said that the co-location of the project within an existing electric corridor significantly reduces the visual effects associated with project development as those areas are more densely settled and developed portions of New Hampshire.
The company also said that the project was designed to avoid and minimize effects on historic resources where feasible.
One state-listed rare plant, crested sedge, and four exemplary natural communities were found within the project site, the company said, adding that the corridor also contains habitat likely to be occasionally used by eight species of birds, reptiles and mammals, although none were found during project surveys. Impacts to those species would be alleviated by a combination of avoidance and minimization, including time-of-year restrictions and habitat protection with timber mats, the company said.
Among other things, the company said that its application contains confidential archaeological information, critical energy infrastructure information, other confidential infrastructure information, as well as confidential information relating to the location of rare, threatened and endangered plants and natural communities. The company said that it is concurrently submitting a motion for protective order and confidential treatment regarding those materials.
In addition, the company said that it is concurrently filing two petitions – each addressed to the New Hampshire Public Utilities Commission – for licenses to cross state public waters and lands owned by the state. Furthermore, the company said that it is submitting two waiver requests form the SEC’s rules.