Capital Grid Project

Increased system reliability and resiliency will help prepare the District for extreme weather events anticipated
with climate change.

2016.07.17 Power Outage in Shaw, Washington, DC USA 07068 by Ted Eytan is licensed under CC BY-SA 2.0

Pepco’s Capital Grid Project (Formal Case No. 1144) is a long-term electric utility initiative to address aging infrastructure, enhanced system resiliency, improved reliability, and load growth in the District of Columbia.
Phase I of the Capital Grid Project will address aging infrastructure, and Phase II will focus on the increasing energy needs of District residents in a specific section of the city that is expected to experience rapid growth and development: Mt. Vernon Triangle, NoMa, Capitol Crossing and Northwest One. 

Capital Grid Project

The Capital Grid project will increase the electric distribution system’s reliability and resiliency and help prepare the District of Columbia for extreme weather events anticipated with climate change by:

  1. Upgrading the Harvard and Champlain Substations, which are 60 and 110 years old, respectively.
  2. Creating a networked transmission system by constructing 10 miles of new 230 kV underground transmission line.
  3. Constructing a new Mount Vernon Substation at First and K Streets, NW, to address growth.
  4. Converting the existing Waterfront Substation from its current 138 kV radial supply configuration to a 230 kV network configuration and connecting it to the new 230kV underground transmission line.
After reviewing all the filings and multiple rounds of public comments, the DCPSC concluded that the project will help modernize the District’s electric system by creating a networked transmission system and provide about 70 MW of additional hosting capacity for future Distributed Energy Resource (DER) projects. The project will ultimately help D.C. achieve its clean energy and climate goals of 100% renewables, 50% carbon reduction, and 5.5%  solar by 2032. Construction efforts for this project will also boost the local economy and provide jobs for local residents.
Additionally, Pepco will be installing a 1 MW pilot battery energy storage unit, which will be capable of storing 3 MWh of energy. This pilot project will provide a window on emerging technologies and non-wires alternative (NWA) solutions for the traditional electric grid. This battery energy storage pilot project will be deployed within the Mt. Vernon Substation and may defer the future installation of the fourth transformer inside the substation when the transformer would otherwise be needed.
The Commission also expects Pepco to explore other pilot and demonstration projects, which would integrate more NWAs throughout the District.  To that end, Pepco is currently developing an energy storage project in the area of Alabama Avenue (in Ward 8) for the purpose of deferring investment in new distribution feeders for three years.

Construction updates
The entire Capital Grid Project construction timeframe is approximately six years. Pepco began construction on the Capital Grid Project in February 2020 and plans to complete it by 2028. Originally expected to take six years, material unavailability, permitting issues, and supply chain disruptions have delayed some construction goals. The DCPSC continues to monitor the construction activities.

  • The new 10-mile 230 kV underground transmission line construction will affect all the Wards in the District. The new 230 kV line construction line started on March 30, 2020 and is expected to be completed by December 2023.
  • The construction of Harvard Substation (Ward 1)  in the Columbia Heights neighborhood began in August 2020 and is expected to be completed between April and August 2023.
  • Both the Harvard and Mt. Vernon Substations will be 230 kV/13 kV substations with an initial capacity of 140 MVA. Both substations will operate using state-of-the-art switchgear equipment in an above-ground indoor facility.
  • The construction of Mt. Vernon Substation (Ward 6) in the NoMA neighborhood began in  April 2021 and is expected to be completed by November 2023.
  • Construction of the Champlain Substation (Ward 1) in the Adams Morgan neighborhood is scheduled to begin in October 2025 and is expected to be completed by November 2028.
  • Champlain Substation - Current Picture
  • Champlain Substation - Rendering
  • Harvard Substation - Current Picture
  • Harvard Substation - Rendering
  • Mount Vernon Substation - Current Picture
  • Mount Vernon Substation - Rendering

Additional information
The DCPSC directed Pepco to convene Community Advisory Group (CAG) meetings to disseminate information to the community about the substations, to provide periodic construction updates and to address any construction concerns from the community. Commission staff continues to attend the CAG meetings on the Harvard Substation and the Mt. Vernon Substation. Staff also continue to attend Pepco’s community meetings.
Commission staff also attend monthly District Department of Transportation utility construction coordination meetings, review Pepco’s Capital Grid Project website regularly, monitor all construction activities, and periodically inspect construction sites. Additionally, Commission staff monitor and review all compliance filings related to the Capital Grid Project.
The DCPSC Office of Consumer Services continue to monitor the execution of Pepco’s Customer Communications Plan, as required in the Commission Order.
See Pepco’s Capital Grid Project website for further information.