Data centers caused a 10 minute grid disruption after a fallen power line

In short: A fallen power line near Washington, DC triggered many nearby data centers to change how they used electricity at the same time, and that made the regional power grid unstable for over 10 minutes.

What's going on

A power line went down outside Washington, DC this week, and the grid took more than 10 minutes to settle. Normally, grid systems can recover from this kind of issue in a few seconds.

The reason, according to PJM grid data cited by TechCrunch, is that data centers almost simultaneously stopped drawing power from the grid when they detected a problem. About 3.1 gigawatts of demand disappeared in around 30 seconds, and the total extra electricity on the grid peaked at about 3.49 gigawatts before things stabilized roughly 11 minutes later.

This sudden change made voltage spike across a wide area, from Northern Virginia to Chicago, based on data collected by Ting Labs, which uses sensors plugged into home outlets. There was no blackout, but lights flickered across the region.

Experts told TechCrunch this can happen because the grid needs supply and demand to stay closely matched at all times (like keeping a seesaw balanced). When many large buildings react at once, the grid can swing too far in the other direction.

What to watch

Northern Virginia has a very high concentration of data centers, and similar events have happened before. A 2024 incident saw about 1.5 gigawatts drop when dozens of data centers disconnected, and Reuters reported that this week’s disconnected load was about 3% of PJM demand at the time.

TechCrunch reports that one proposed fix is coordination, so nearby data centers disconnect and reconnect in sequence, not all at once. Another approach is adding large battery systems that can smooth out these changes, so the grid sees steadier demand, even during disruptions.

Source: TechCrunch AI