NSTAR Electric d/b/a Eversource Energy (NYSE:ES) on Sept. 29 filed a petition with the Massachusetts Department of Public Utilities (DPU) requesting that the DPU grant individual and comprehensive zoning exemptions from the operation of the Boston Zoning Code in connection with the company’s proposed modifications to an existing substation.
The modifications to be made at the “Station #385,” or the K Street substation, which is located at 500 East First Street in Boston, support two distinct projects: the installation of a 345-kV, 160 MVar voltage regulator and related equipment, along with the conversion of the existing 345-kV straight bus to a ring bus; and the construction of a new perimeter fence and barriers around certain equipment at the substation.
The voltage regulator would be installed and operated on a portion of a parcel of land that the company bought in 2007 (referred to as the new parcel). The new parcel abuts and is to the rear of the substation site, the company added. The voltage regulator project would include the installation of a perimeter fence around the voltage regulator. With the installation and operation of the voltage regulator and surrounding perimeter fence, the portion of the new parcel utilized for the voltage regulator project would become part of the substation site and, as a result, the fence line currently surrounding the substation site would be expanded to include that portion of the new parcel, the company added.
The new voltage regulator is required in order to meet transmission system needs, as identified in the Greater Boston Area Updated Transmission Needs Assessment issued by ISO New England (ISO-NE) in January 2015, the company said.
As part of the security fence project, in addition to the installation of a new fence around a portion of the new parcel, the existing fence around the entire perimeter of the substation site would be replaced and barriers would be erected around certain existing equipment. The company also said that the new perimeter fence, including around a portion of the new parcel, and equipment barriers are needed for the company to comply with new federal reliability and physical security standards.
Overall, the company said, the projects would contribute to a more secure and reliable supply of electricity to customers in the Greater Boston area.
Eversource said that it proposes to expand the K Street substation footprint in the northwest corner of the substation site in order to add the proposed voltage regulator, which would be about 27 feet long by 27 feet high by 26 feet wide, and would be placed on a concrete foundation with an oil-spill containment system, surrounded by crushed stone.
The company said that it would expand the existing perimeter fence around the substation to include that portion of the new parcel where the new voltage regulator and circuit breaker would be located; that additional fenced area would be about 86 feet wide by 121 feet long.
An existing 345-kV bus would be converted to a new ring bus, portions of which would be installed within the expanded fence line on the new parcel to connect the new voltage regulator to additional related and necessary equipment such as disconnect switches and circuit breakers.
The company added that new breaker control equipment and wiring to accommodate the voltage regulator would be installed in an existing single-story control house in the existing substation footprint. Three new circuit breakers would also be installed in a portion of the existing substation footprint.
Among other things, the company said that the current total planning level cost estimate for the voltage regulator project is $12m.
Of the security fence project, the company said that it proposes to replace the perimeter fence and gates at the substation and to install barriers around certain equipment within the substation fence line, in order to increase the security and safety of the substation. Specifically, the new construction would include about 2,045 linear feet of fencing at 15 feet in height; 1,775 linear feet of fencing at 20 feet in height; and 895 linear feet of fencing at 26 feet in height, for a total of 4,630 linear feet of enhanced fence and associated gates.
The company added that the new fence would be located immediately adjacent to the existing fence on company property and, as a result, would not expand the overall footprint of the substation to a material degree.
Among other things, the company said that the current total planning level cost estimate for the security fence project is $21.4m.
The primary purpose of the voltage regulator is to provide the capability to reduce high voltages under light load in the K Street/Kingston Street area to acceptable levels and to meet the needs identified by ISO-NE, the company said. The new voltage regulator would mitigate high 345-kV and 115-kV voltages in subarea C (Downtown Boston 115-kV cables) and subarea E (West Medway, West Walpole, and Holbrook) that are not resolved by any of the other Greater Boston Solution Projects. The company added that the voltage regulator project also addresses reliability issues associated with 345-kV breaker failure contingencies at the K Street substation that are not addressed by other Greater Boston Solution Projects. To address the identified need, the company said that it seeks to have the voltage regulator project in service by 1Q19.
The company also said that the new perimeter fence and equipment barriers are needed to enable the company to comply with new federal reliability and physical security standards for electric infrastructure on the company’s system. To achieve compliance with federal reliability and physical security standards, the company seeks to have the security fence project in service by 4Q19.