3.49 GW of data centers slammed offline in 30 seconds, lights flickered from DC to Chicago

A routine power line failure near Washington, DC, this week exposed a growing structural weakness in America’s electric grid — one driven by the world’s densest cluster of data centers. When the line went down, more than 3 gigawatts of data center load vanished in about half a minute as facilities instantly switched to backup power. The result wasn’t a blackout, but a massive supply-demand imbalance that sent voltage spiking across PJM Interconnection’s territory from Northern Virginia to Chicago, causing lights to flicker throughout the region.

“It’s the canary in the coal mine,” Ricardo de Azevedo, CTO at ON.Energy, told TechCrunch. Data collected by Ting Labs confirmed the voltage spike rippled across a vast footprint. PJM, which serves 67 million customers, watched as load dropped to 3.49 gigawatts below supply — roughly 3% of total demand at the time. That may sound marginal, but grids require near-perfect balance. The disturbance took 11 minutes to stabilize, far longer than the seconds a normal recovery would require.

The core problem is synchronization. When the voltage dip hit Northern Virginia, data centers made independent, split-second decisions to disconnect. Ali Zain Banatwala from the Independent Electricity System Operator told TechCrunch that these facilities all reacted within seconds of each other. “We need to figure a way for these loads that are located next to each other to sequentially either disconnect or reconnect,” he said. Without sequencing, the collective response amplifies the initial disruption.

Some solutions are emerging. ON.Energy is installing 3 gigawatts of campus-level battery systems that hide a data center’s erratic load behind sophisticated power electronics, letting the facility ride through grid disturbances rather than abandoning ship. ERCOT is already moving to require large loads to stay connected during disruptions. The urgency is real: this event was twice the size of a 2024 incident where 60 data centers pulled 1.5 gigawatts offline in the same fashion.