The PJM Interconnection is considering bolstering its interconnection reliability requirements for “computational loads,” such as data centers and crypto-mining facilities, the grid operator said Tuesday.
The move to consider “ride-through” standards and other requirements comes after about 3,800 MW of data center load tripped offline in northern Virginia on July 22, the latest and largest such event in PJM’s history, the grid operator said.
The event — triggered by a fault on a 230-kV line in Dominion Energy’s zone — caused a high imbalance between generation and load, and large swings in voltage and frequency, PJM said.
During the event, which occurred in two waves, PJM’s overall load fell about 3.8% to 96,205 MW from 99,984 MW, according to the grid operator, which runs the electric system and wholesale power markets in 13 Mid-Atlantic and Midwest states and the District of Columbia.
PJM said it recovered the Balancing Authority Area Control Error Limit — a measure of the imbalance between sources and uses of power — within nine minutes, compared with North American Electric Reliability Corp. standard of 30 minutes, and dispatched reactive power resources to lower system voltage.
Two similar events in Dominion’s zone in northern Virginia — home to the largest data center cluster in the world — caused sudden load transfers of about 1,500 MW each in 2025 and 2024, PJM said.
The issue was discussed at an Aug. 6 PJM Operating Committee meeting where PJM staff said data centers may be too sensitive to grid conditions.
“This was a normally cleared fault,” Operating Committee Chair Emanuel Bernabeu said at the meeting, per PJM. “They should not disconnect from the grid. These data centers are too sensitive to the kind of voltage that they like, and we feel they are disconnecting too early.”
As a result, PJM is evaluating a possible expansion of its reliability requirements, “with consideration of existing and future industry ride-through standards and practices,” Matthew Wharton, PJM manager of reliability engineering, said.
PJM’s effort comes as the NERC is moving to set reliability requirements for computational loads.
Under a Federal Energy Regulatory Commission directive, NERC is set to finalize by Dec. 31 registry criteria and initial reliability standards for adding computational loads to the bulk power system. NERC will also develop a plan by March for setting additional reliability standards for computational loads.
However, NERC will not address minimum voltage or frequency ride-through requirements until some time next year, according to PJM.
“You really need these requirements in place before the load comes on the system,” David Souder, PJM executive director of system operations, said at the meeting.
