Downed Power Line Exposes Growing Data Center Problem: How to Solve It

This week, a power line fell outside Washington, D.C. Normally, the grid recovers in seconds, but this time it took over 10 minutes because more than 3 GW of data centers simultaneously stopped consuming power. The event caused a voltage surge in the PJM grid from Northern Virginia to Chicago, according to Ting Labs. Although no blackout occurred, lights flickered in the region. Northern Virginia, part of the PJM zone, hosts the highest concentration of data centers in the world. Ricardo de Azevedo, CTO of ON.Energy, called it a "canary in the coal mine": such incidents are becoming more frequent. The event echoes a two-year-old accident on the same PJM grid (the largest US operator, serving 67 million consumers from New Jersey to Illinois). When the power line fell, data centers switched to backup power, and about 3.1 GW of load disappeared within 30 seconds. Additional loads later disconnected; the peak surplus reached 3.49 GW, and stabilization took another 11 minutes. The disconnected data centers accounted for about 3% of PJM demand. If fluctuations become too large, circuit breakers trip on the grid or at facilities. Most data centers make decisions in fractions of a second; those that disconnected did so simultaneously. Ali Zain Banatwala from IESO suggested developing a method for sequentially disconnecting/reconnecting such loads. An alternative is creating data centers capable of absorbing disturbances. ON.Energy developed an uninterruptible power supply (UPS) for an entire data center campus, hiding it behind batteries and converters, allowing the grid to "see" a stable load and absorb fluctuations—excess goes to charging, and during drops, batteries discharge. The company is installing systems totaling 3 GW across four campuses. ERCOT plans to require large loads, such as data centers, to "ride through" disturbances. This week's mass disconnection was twice as large as a similar event in 2024 (60 data centers, 1.5 GW). By 2040, data centers' share of PJM load could grow from 6% to 24%.