Modernizing the Future with Gas-Insulated Substations

January 11, 2023


As our infrastructure ages and our population increases, the need for a more reliable and resilient power grid has never been greater. To that end, Clark is helping utility companies modernize their facilities to support growing demand and ensure they can continue to provide safe and reliable electric service to the communities they serve. A key component to modernizing the grid system is upgrading substations, which change the voltage from long-distance high voltage transmission lines to the voltages used to supply our homes.

When upgrading these facilities, utility companies today often choose to invest in gas-insulated substation (GIS) technology, which uses inert gas sulfur hexafluoride for insulation and quenching of electric arcs, as opposed to the traditional air-insulated technology.

In addition to providing greater reliability, GIS technology allows for high-voltage gear to be housed in a much smaller footprint – a benefit of particular importance to utility companies supporting large cities. In the Washington, DC metropolitan area, Clark is helping utility provider Pepco enhance reliability and redundancy to its power grid while operating within its existing footprint – better serving its customers while minimizing impact to its neighbors.

Pepco’s Capital Grid Project is a major renewal of the District’s energy infrastructure that will ensure aging substations that distribute power to Washington, DC’s businesses and residences will meet the long-term energy needs of the areas they serve. As part of the project, Clark Civil is currently upgrading the Takoma and Harvard substations to leverage more reliable and efficient GIS technology.


Takoma Substation
At the Takoma substation, gas-insulated substation technology allows for high-voltage gear to be housed in a much smaller footprint.

In Washington, DC’s Columbia Heights neighborhood, Clark Civil demolished the existing Harvard substation while preserving components of the facility’s brick façade, which was part of the original structure built in 1907. Maintaining the substation’s cohesiveness within the neighborhood through accurate façade restoration was paramount to the design team and client.


At the Harvard substation, the project team demolished the entire structure except for the historic brick façade

In Virginia, Clark is working alongside HICO America Sales and Technology to deliver another piece of critical infrastructure – Dominion Energy’s Crystal Substation Improvement and Expansion project. The project is designed to increase the reliability of electrical service in the National Landing area of Arlington, Virginia. Upon completion, the project will be trimmed with decorative metal panels and inset mosaic tiles designed to evoke an electric circuit and enhance the neighborhood's aesthetic. Completion is slated for early 2023.

Both the Harvard and Takoma substations are expected to be completed in 2023. The Clark team is excited about its new venture in the substation market and looks forward to future work as the demand for more reliable energy grows around the country.