Dunstan Substation

Reliability Upgrades

Dunstan Substation


Project Overview

Central Maine Power Company, in conjunction with its  parent company AVANGRID, is undertaking a multi-year effort to upgrade or replace 10 distribution substations throughout its service territory, including one in  Scarborough, that have aged and/or have condition or  capacity issues in need of attention.

As part of CMP’s Substation Modernization Plan,  a new 34kV distribution substation will be built at 35 Broadturn Road in Scarborough to replace an existing substation in a residential neighborhood at 645 U.S. Route 1. Like the existing substation, it will connect to the same transmission line (Section 193).

CMP and AVANGRID’s significant investment in  communities large and small is part of our  commitment to provide safe, reliable service to  our customers.

CMP is working with communities and reaching out to neighbors to ensure that all improvements are performed safely and with minimal disruptions to their daily lives, the community, and 
the environment.


Project Purpose and Need 

The existing electric distribution substation on U.S. Route 1 is nearing its capacity to support the  associated 34.5kV transmission line’s load with 
its breakers, and many of its components are  supported by wood foundations or poles that  require maintenance. Additionally, its yard is too small to accommodate the construction and instal-lation of new substation equipment that’s required for modern day operation plus meet AVANGRID and National Electrical Safety Code (NESC) standards.

The new, larger substation on a portion of a 3.75-acre vacant lot adjacent to the Scarborough Sanitary District will allow CMP to respond to the area’s energy needs and provide us with space to expand when warranted.

The modernized substation will be outfitted with new infrastructure that includes 34.5/22.24 MVA transformer on a concrete foundation, two station service transformers on concrete foundations, and oil containment system, and site lighting. Upgraded substation operations technology will be installed in a new, locked control house, as well as enhanced remote substation monitoring  capabilities and connections to CMP’s control center.


Fact Sheet

For more information, view the Dunstan Substation Fact Sheet here.

Estimated Timetable

  • Construction Start: June 2020
  • Completion/In-Service Date: April 2021

For more information or questions

Please contact the Electrical Infrastructure Projects Information Line at 1-888-267-0831 and include the name of the project - Dunstan Substation - with your detailed message.  A representative from the project team will return your call within three (3) business days. Or please email us at