PJM Interconnection took emergency steps Sept. 17 after unusually warm September weather increased electricity demand while some power plants and major power lines were offline for scheduled maintenance.
PJM called on participating businesses and other large electricity users in parts of its system to temporarily reduce power use, helping ease demand on the regional grid.
The action matters locally because Manassas, Manassas Park and Prince William County all receive electricity through utilities connected to the regional system coordinated by PJM.
2-Minute Brief
What happened: Higher electricity use combined with scheduled maintenance left less power available than usual across parts of the regional grid.
What PJM did: It called on customers enrolled in special programs to temporarily reduce electricity use. The U.S. Department of Energy also authorized PJM to call on additional power generation, including backup power, if needed.
Why it matters locally: Residents in Manassas, Manassas Park and Prince William County are served by different local utilities, but all rely on the regional power system coordinated by PJM.
What Is PJM?
PJM originally stood for Pennsylvania-New Jersey-Maryland.
It began in 1927 when utilities in those states connected their systems to share electricity more efficiently.
Today, PJM Interconnection coordinates the regional electric grid across Virginia, the District of Columbia and all or parts of 12 other states.
Its job is to keep electricity supply and demand balanced across that system.
Why Did PJM Take Action?
PJM said unusually warm September weather increased electricity use while some power plants and major power lines were already offline for scheduled maintenance.
That left less extra power available than usual.
PJM is also preparing for continued growth in electricity demand across the region, including significant growth from data centers in Virginia. Adding new power supplies and major power lines can take years.
Those longer-term pressures provide context for the challenge PJM faces, but the Sept. 17 action was prompted by the conditions that day.
What Does This Mean Locally?
Manassas operates its own municipal electric utility. The City owns the local distribution system and purchases electricity for its customers.
Manassas Park is served by Northern Virginia Electric Cooperative, or NOVEC.
Prince William County includes customers served by both NOVEC and Dominion Energy Virginia.
Those utilities are connected to the larger regional power system coordinated by PJM.
How regional power costs affect customers depends on their local utility and rate structure.
In Manassas, changes in purchased-power costs can be reflected through the City’s Power Cost Adjustment, or PCA.
The Manassas Journal previously explained the PCA and the City’s electric rate structure in Utility Bills Spike: Higher Rates Hit Manassas Households Across the Board.
Sources / Reference Links
PJM Interconnection: Sept. 17, 2026 emergency notices and operating updates
PJM Interconnection: PJM History
U.S. Department of Energy: Sept. 17, 2026 PJM emergency order
PJM Interconnection: Long-term electricity demand forecast
City of Manassas: Electric rates and Power Cost Adjustment
NOVEC: Service territory and Power Cost Adjustment
Prince William County: Electric utility providers
Manassas Journal: Utility Bills Spike: Higher Rates Hit Manassas Households Across the Board
