A transmission line fault in Northern Virginia caused 3 gigawatts of data center load to disconnect from the PJM grid.

A transmission line fault in Ashburn, Virginia, caused more than 3 gigawatts of data center load to abruptly disconnect from the PJM grid on Wednesday. The event, which occurred in the world's highest concentration of data centers, caused a voltage disturbance felt from Washington, D.C., to Chicago. While the grid did not experience a total blackout, the sudden drop in demand caused lights to flicker across the Eastern United States for approximately 10 minutes. Dominion Energy reported that the data centers' own control systems automatically transferred to backup power rather than being disconnected by the utility. This event represents one of the largest sudden load changes publicly reported on the U.S. grid. Experts noted that as data centers account for a larger share of total demand, grid operators must develop more robust procedures to handle these simultaneous shifts. The administration recently directed the PJM Interconnection to accelerate reforms to support the growth of AI infrastructure. The North American Electric Reliability Corporation is currently reviewing the event to determine if it will produce new reliability recommendations.

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