The DCPSC has approved construction for Phase II of Pepco’s Capital Grid Project, Formal Case No. 1144. To address anticipated load growth and to ensure safety, reliability and resilience of the District’s electric system, the DCPSC authorized the construction of a new Mt. Vernon Substation.

The DCPSC concluded that the Mt. Vernon Substation will provide substantial reliability benefits to the District and help prepare for anticipated climate change challenges. Given the District’s objective to maintain a reliable distribution system during extreme weather events, the Mt. Vernon Substation is necessary to:

1) maintain and enhance reliability standards and performance;
2) provide for additional Distributed Energy Resources (DER) hosting capacity; and
3) reduce the risk of prolonged and widespread outages.

Pepco filed in 2018 the Capital Grid Application which involved two phases. Phase I addressed aging infrastructure. For Phase II, the DCPSC focused on the growing energy needs of District residents in areas experiencing rapid growth and development.

The Commission analyzed the construction plans of the Mt. Vernon Substation, as well as the feasibility of non-wires alternatives to address the impact on global climate change and the District’s climate commitments.

“After review of all filings and multiple rounds of public comments, the Commission determined that a new Mt. Vernon Substation, and the overall Capital Grid Project, will help modernize the District’s electric system and increase network capacity and accommodate more DERs, which will help the District achieve its goals of 100% renewables, 50% carbon reduction, and 5% solar by 2032,” stated Willie L. Phillips, Chairman of the Public Service Commission. “The project will also bring reliability, resilience, and sustainability benefits to the grid, and help boost the local economy by constructing the new substation.”

Click here to learn more about the proposed Capital Grid Project

Background

The Capital Grid Project, for which Pepco is seeking the DCPSC's approval, is a long-term plan that proposes to address multiple system needs: updating the aging infrastructure, enhancing resilience against transmission disruptions, increasing the reliability of downtown power supply, adding capacity in rapidly growing areas, and accommodating more customer-generated power.
 
The proposed project involves:
 
(1) rebuilding two existing substations that are 60 to 110 years old (Champlain and Harvard Substations, respectively);
 
(2) replacement of aging underground cabling;
 
(3) constructing 10 miles of new 230 kV underground transmission lines; and
 
(4) constructing a new Mount Vernon substation, located at First and K Streets NW.
 
Pepco  expects to start construction in 2020, and plans to complete it by 2026.