NSTAR Electric has proposed to build and operate a new transmission switching station and distribution substation on Electric Avenue in the North Brighton neighborhood of Boston (the station), and the construction of new 115-kV underground transmission line sections to connect existing NSTAR Electric facilities with the station.
In its Aug. 9 petition filed with the Massachusetts Department of Public Utilities (DPU), NSTAR Electric requested that the DPU grant individual and comprehensive zoning exemptions from the operation of the Boston zoning code and approve the construction of proposed transmission lines.
NSTAR Electric said it is seeking the individual zoning exemptions to allow for the timely construction of the station, adding that project construction is needed in the immediate time frame in order to provide reliable distribution service to customers.
“The [DPU] has recognized that comprehensive zoning relief is appropriate in circumstances where, as here, individual exemptions are required and the issuance of a blanket exemption could avoid substantial public harm by serving to prevent delay in the construction and operation of needed utility infrastructure,” NSTAR said.
The company also noted that if it were to pursue the zoning relief from the city separately from the petition, that could result in substantial delay and uncertainty in building the project.
NSTAR is looking to build new sections of underground 115-kV pipe-type cable (PTC) transmission lines that will connect the existing Brighton-Waltham 115-kV Lines #282-520 and #282-521 with the new Electric Avenue station. Lines #282-520 and #282-521 are installed in public ways and will be used to facilitate the connection with the Electric Avenue station #315.
There will be two new looped underground 115-kV PTC transmission lines coming into the station and two new looped underground 115-kV PTC transmission lines coming out of the station.
NSTAR also said that it will also install about 30,000 feet of underground duct banks within about 16,500 linear feet of road to house new distribution lines. The station and related equipment will be built on NSTAR-owned property.
The project consists of building a new 115-kV transmission switching station and a 115/14-kV distribution substation at the intersection of North Beacon Street, Goodenough Street and Electric Avenue in Brighton. The proposed station’s site is about 49,788 square feet of vacant property situated between the Massachusetts Turnpike and Electric Avenue.
The new station’s initial firm capacity will be 150 MVA and it will be designed to accommodate up to four transformers, associated 14-kV switchgear and an additional six GIS breakers, thereby allowing the station to be later expanded to 212 MVA of firm capacity.
The station’s development will provide additional capacity to relieve four heavily loaded bulk supply stations in the area: Newton Station #292, Brighton station #329, Colburn Street station #350 and Watertown station #467, and will improve the reliability to the area.
“The project is an integrated solution to improve the reliability of service to an area currently served by four heavily loaded substations,” NSTAR said.
The new station will establish a foundation to reliably supply the anticipated increased load requirements for portions” of the town of Watertown, the city of Newton and the Boston neighborhoods of Brighton, Allston and Longwood Avenue Medical. NSTAR also said that the station and the installation of the new transmission and distribution lines will support the rapidly growing load requirements in the area as well as ensure the regional reliability needs and performance of the local 115-kV transmission system.
The four bulk supply stations currently supply the load in the area that would be serviced by the Electric Avenue station, including portions of Brighton, Dorchester, Jamaica Plain, Mission Hill, Longwood Medical Area, Roxbury, Kenmore-Fenway, Newton, Waltham and Watertown. The projected new load in the area is anticipated to be 132 MVA by 2015 and up to 171 MVA by 2020, NSTAR added, noting that the new load will strain the capability of the existing substation and distribution system infrastructure.
NSTAR began pre-construction activities for the project, whose current total cost estimate, based on a design level estimate, is $120m, in January with consultations and preliminary permitting meetings with the applicable state and local permitting agencies, including the state Department of Transportation and the Boston Redevelopment Authority.
The construction of the station and conductor installation for the project is set to begin in the spring of 2014, with the station’s required in-service date begin June 1, 2015.
NSTAR added that the station must be in service by then in order to support the distribution cutovers that will relieve the heavily loaded Colburn Street station #350, Watertown station #467 and Newton station #292.
Among other things, the company said that while higher loads may present greater opportunity for energy efficiency (EE), EE will not be able to provide the magnitude, timing and location of load reductions that would be required to obviate the need for the project.
Also, given that the new load in the area is projected to be 132 MVA by 2015 and up to 171 MVA by 2020, the reliance on distributed generation resources would not be effective in reliably serving load requirements for the affected areas.
NSTAR Electric is a Northeast Utilities (NYSE:NU) company.