One fallen power line exposes growing AI data center problem; solutions in development
After a power line failure near Washington, D.C., over 3 GW of data center load simultaneously disconnected, causing voltage spikes and light flickering across several states. Experts warn such events will become more frequent and offer solutions, including specialized uninterruptible power systems.
A fallen power line near Washington, D.C., this week highlighted a growing challenge for the U.S. electrical grid. Normally, the grid recovers from such an outage in seconds, but this time it took more than 10 minutes because over 3 gigawatts (GW) of data center load stopped drawing power nearly simultaneously, according to data from grid operator PJM Interconnection. The event caused voltage to spike across PJM's network from Northern Virginia to Chicago, resulting in lights flickering across the region, though no blackout occurred.
The incident echoes a similar one in 2024, when 60 data centers simultaneously disconnected, pulling 1.5 GW of load. This time, approximately 3.1 GW of load vanished within 30 seconds, and after a brief recovery, additional loads dropped off, peaking at an extra 3.49 GW. The disconnected data centers represented about 3% of total PJM demand at the time, according to Reuters. While a few percent may seem small, the grid requires near-perfect balance between supply and demand.
"It's the canary in the coal mine," said Ricardo de Azevedo, CTO of ON.Energy. "These sorts of events involving large loads like data centers are happening more and more." Northern Virginia, within PJM's territory, hosts the world's highest concentration of data centers. Most data centers make decisions in split seconds, and all disconnected within seconds of sensing the voltage dip, explained Ali Zain Banatwala of the Independent Electricity System Operator. He advocates for sequential disconnection and reconnection procedures to help grid operators prepare.
Startup ON.Energy has developed a product to help data centers ride through such events: an uninterruptible power supply for entire campuses, hiding the data center behind a bank of batteries and power conversion equipment. This makes the grid "see" a consistent, well-behaved load. The system can absorb fluctuations by charging batteries or dispatching power to servers, responding within milliseconds. ON.Energy is currently installing 3 GW of these systems at four data center campuses.
Grid operators are waking up to the issue. For instance, ERCOT will require large loads like data centers to "ride through" disruptions. Time is critical: in 2024, data centers accounted for about 6% of PJM's load, but by 2040 that share is expected to reach 24%. If the problem is not addressed soon, the consequences could become far worse.
