One Fallen Power Line Exposed How AI Data Centers Destabilize the Grid
When a power line failed near Washington, 3.1 gigawatts of AI data centers dropped off PJM's grid in seconds, spiking voltage from Virginia to Chicago and revealing a growing risk.
In Brief
- A downed power line near Washington, DC triggered about 3.1 gigawatts of data centers to switch to backup power in roughly 30 seconds, and the grid took more than 10 minutes to stabilize instead of the usual few seconds
- The mass disconnection was twice as large as a similar 2024 PJM event, when 60 data centers pulled 1.5 gigawatts off the grid; data centers are projected to reach 24 percent of PJM load by 2040
- Startups like ON.Energy are installing whole-campus battery buffers so data centers appear as one steady load, while grid operator ERCOT plans to require large loads to “ride through” disruptions
A power line went down outside Washington, DC, this week, and the grid — which normally shrugs off such an event in seconds — took more than 10 minutes to recover. The reason: more than 3 gigawatts of data centers stopped drawing power nearly simultaneously, TechCrunch reported. The event caused voltage across the PJM grid to spike from Northern Virginia to Chicago.
The incident did not cause a blackout, but it did make lights across the region flicker, demonstrating the effect data centers can have on the grid — an outcome experts believe will become more frequent. Northern Virginia, in PJM’s territory, is home to the highest concentration of data centers in the world.
“It’s the canary in the coal mine,” Ricardo de Azevedo, CTO at ON.Energy, told TechCrunch, adding that events involving large loads like data centers are “happening more and more.” PJM manages grids from New Jersey to Illinois and serves 67 million customers, making it the largest grid operator in the United States.
How the AI data center grid problem cascades
When the power line went down, it triggered data centers to switch to backup power, and about 3.1 gigawatts of load vanished in roughly 30 seconds, according to PJM data. The grid appeared to recover, but additional loads then dropped off; at its peak, PJM’s grid had an extra 3.49 gigawatts on it, and it took another 11 minutes to stabilize. The disconnected data centers represented about 3 percent of total demand at the time, according to Reuters.
A few percent may not sound like much, but the grid must operate in near-perfect balance between supply and demand. When the voltage dip reached the Northern Virginia facilities, they switched to backup power almost in unison, removing their load and turning a small drop in supply into a larger drop in demand — sending supply surging and bulbs flickering.
“Most data centers make decisions in a split second,” and those that disconnected appear no different, said Ali Zain Banatwala of the Independent Electricity System Operator. “We need to figure a way for these loads that are located next to each other to sequentially either disconnect or reconnect,” he said, arguing a more orderly process would let grid operators build more robust procedures in advance.
Fixes are arriving, but the clock is ticking
One alternative is to build data centers that absorb disruptions rather than fleeing them. ON.Energy has developed an uninterruptible power supply for an entire data-center campus — servers, chillers, and all — hiding the facility behind a bank of batteries and power-conversion equipment so the grid “sees” one consistent, well-behaved load. The system can also charge on excess grid power and dispatch it to servers within milliseconds, preventing the kind of sags and surges seen this week.
ON.Energy is currently installing a total of 3 gigawatts of its systems at four data-center campuses, de Azevedo said. Grid managers are also acting: ERCOT, for example, is going to require large loads like data centers to “ride through” disruptions.
The urgency is clear from the trend line. The mass disconnection this week was twice as large as a similar 2024 event, when 60 data centers simultaneously disconnected and pulled 1.5 gigawatts from the grid — when data centers were about 6 percent of PJM’s load. By 2040, they are expected to make up 24 percent, according to Synapse Energy Economics. If the problem is not addressed soon, things could get a lot worse.
FAQ
What happened to the grid near Washington this week?
A single power line failed, and roughly 3.1 gigawatts of AI data centers switched to backup power within about 30 seconds. Instead of recovering in seconds, PJM’s grid took more than 10 minutes to stabilize, and voltage spiked from Northern Virginia to Chicago, making lights flicker.
Why do data center disconnections destabilize the grid?
The grid must keep supply and demand in near-perfect balance. When many co-located data centers sense a voltage dip and switch to backup power almost simultaneously, they remove huge amounts of load at once, turning a small supply drop into a larger demand drop that sends voltage surging.
How are companies and regulators responding?
Startups like ON.Energy are installing whole-campus battery buffers so a data center appears as one steady load and can ride through disruptions, and grid operator ERCOT plans to require large loads to ride through disturbances rather than instantly disconnecting.
