Eversource seeks Connecticut regulatory approval for switching station project

Connecticut Light and Power d/b/a Eversource Energy (NYSE:ES), in an Aug. 30 petition filed with the Connecticut Public Utilities Regulatory Authority (PURA) requested that the PURA approve the method and manner of construction and provide permission to energize the Towantic switching station and 1575, 1585 and 1990 Lines Modification Project.

The project includes:

  • Building a new 115-kV switching station adjacent to the Towantic generating station
  • Modifying 115-kV electric transmission facilities from the Bunker Hill substation, located at Clough Road in Waterbury, south to the Towantic switching station
  • Modifying 115-kV electric transmission facilities from the new switching station south to Structure 1446 near the Oxford substation located at Commerce Drive in Oxford

The purpose of the project is to satisfy Eversource’s obligation to facilitate the installation of the necessary transmission systems and transmission system upgrades and equipment for power generator entities that request to interconnect to the Eversource transmission system in accordance with the large generator interconnection procedure that is included in ISO New England’s (ISO-NE) tariff.

The company also said that the construction would involve this line work:

  • Rebuilding the existing double circuit 1575 and 1585 Lines
  • Reconductoring a section of the 1575 Line
  • Looping the 1575, 1585, 1990 Lines into the new switching station

The proposed construction would take place between the Bunker Hill substation and Oxford substation in the municipalities of Waterbury, Middlebury and Oxford, within Eversource’s existing right of way (ROW). The total length of the project is about 7.1 miles, Eversource added, noting that the project line work is divided into sections of about 6.1 miles – between the Bunker Hill substation and Towantic switching station – and one mile – between the Towantic switching station and the Oxford Tap near the Oxford substation – of overhead line, and about 0.07 mile of underground line at the Towantic switching station.

The project involves:

  • Reconductoring segments of existing 115-kV, 60-hertz, three-phase, circuits
  • Replacing double-circuit lattice towers with double-circuit galvanized steel monopoles
  • Installing double-circuit galvanized steel monopoles
  • Installing a short section of underground cable in twin duct banks between transition structures and switching station riser structures

Eversource also said that project construction is scheduled to begin this month, with completion anticipated in October 2017; the project would be re-energized during and after construction.

Certain project construction would involve the daily outage and re-energizing of the circuits as the proposed work is being performed, and because of that, Eversource said it seeks permission to energize during and after the construction period.

The company also noted that the Connecticut Siting Council in May ruled that the project would not require a certificate of environmental compatibility and public need.

About Corina Rivera-Linares 3286 Articles
Corina Rivera-Linares was TransmissionHub’s chief editor until August 2021, as well as part of the team that established TransmissionHub in 2011. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial from 2005 to 2011. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines.