A single power line failure outside Washington, D.C., this week caused more than 3 gigawatts of data center load to vanish from the PJM grid in under a minute, triggering voltage spikes that made lights flicker across the region. The event took over 11 minutes to stabilize. PJM Interconnection, which manages electricity for 67 million customers from New Jersey to Illinois, experienced the disruption when a power line went down. Data centers in Northern Virginia detected the voltage fluctuation and simultaneously switched to backup power; in about 30 seconds, roughly 3.1 gigawatts of demand disappeared, and the grid then saw an excess of 3.49 gigawatts before rebalancing, according to data from Ting Labs. Ricardo de Azevedo, CTO of ON.Energy, described the incident as “the canary in the coal mine.” The disconnection was twice as large as a similar event in 2024, when 60 data centers simultaneously pulled 1.5 gigawatts from the same grid. Data centers currently account for about 6% of PJM’s load, projected to reach 24% by 2040. Ali Zain Banatwala of the Independent Electricity System Operator stated that data centers need to “sequentially either disconnect or reconnect” rather than acting all at once. Grid operators including ERCOT in Texas are beginning to require large loads to “ride through” disruptions. Startups like ON.Energy are developing uninterruptible