What happened

The US Department of Energy issued a Federal Power Act section 202(c) emergency order permitting PJM and Talen Energy to operate Wagner Unit 4 beyond its existing operating limit when needed to meet anticipated demand. PJM told DOE that the unit remained necessary during high-demand periods to maintain reliable grid operations and avoid possible firm load shedding under specified system or transmission conditions. This is evidence of a documented capacity and reliability constraint, but not of an actual regional blackout: the reviewed order describes preventive operation intended to avoid outages. No physical or cyberattack is alleged in the order. The marker identifies Wagner Unit 4, while the reliability concern covers the wider PJM region.

When cited sources give different casualty, damage or spill figures for this event, they’re reported side by side above rather than merged into one number. See how confidence levels work.