Greenwich Substation and Line Project

Eversource filed a Petition for Reconsideration of the proposed Greenwich Substation and Line Project.

Eversource and Greenwich officials have been working together over the past year to re-examine the proposed project’s need and scope to address the adequacy of the electric system serving the town of Greenwich.

In May 2016, the Connecticut Siting Council (CSC) denied, without prejudice, Eversource’s application to build a new transmission line and substation in Greenwich.

The CSC had found that although the current system was in need of improvements, the project proposal, as presented, did not justify the cost and magnitude of the project. 

New Design Options

After a thorough examination of a number of solution options and variations, Eversource filed a petition for reconsideration with the CSC in the second quarter of 2017.

The petition is to re-open the project’s CSC docket for consideration of a revised project scope for the Greenwich Substation and Line Project.

Eversource has submitted two design options for consideration by the CSC:

  • A proposed, hybrid, overhead and underground transmission line that would run mostly overhead along the south side of the Metro-North rail corridor, before transitioning to underground within town streets. The proposed solution also includes a new Greenwich Substation at 290 Railroad Avenue.
  • An alternative, all-underground design option, proposed by the town of Greenwich, that would run mostly underground within town streets and Bruce Park. The alternative solution also includes a new Greenwich Substation at 281 Railroad Avenue. 

Both design options call for modifications to equipment at the existing Cos Cob substation.

 Greenwich Map May 10 2017

Click to enlarge

Project Facts:

  • Proposed route length: 2.1 miles
  • Alternate route length: 2.3 miles
  • Location: Greenwich, Connecticut
  • Line voltage: 115,000-volt (115-kV) transmission line
  • Substation: One new transmission-level substation and modifications to the existing Cos Cob substation
  • Siting review by: ​The Connecticut Siting Council (CSC)

Estimated Timetable:

  • ​​Municipal Consultation Filing (MCF): February 6, 2015
  • Connecticut Siting Council (CSC) Application filing: June 26, 2015
  • CSC Denial without Prejudice: ​May 13, 2016
  • Petition to reopen CSC Docket: May 5, 2017
  • Start of Construction (pending approval): Fourth Quarter 2017


On June 26, 2015, Eversource applied to the CSC for a Certificate of Environmental Compatibility and Public Need (Application) for the construction of the Greenwich Substation and Line Project. On May 13, 2016, the CSC voted to deny the project without prejudice.

On May 5, 2017, Eversource submitted a petition to the CSC to reopen Docket 461.

Contact Information

For more information about the Greenwich Substation and Line Project, send an email to or call 800-793-2202.​