Some data centers suddenly unplugged in northern Virginia earlier this week, destabilizing the power grid for several minutes.

Around 3 gigawatts of data-center power demand in an area known as "Data Center Alley" disconnected Wednesday morning, according to Ting Labs, which has a network of around 1.4 million home sensors.

For the grid, it was roughly like being oversupplied with three nuclear reactors of electricity. "You might think several minutes is not long. Several minutes in electricity time is like an eternity," said Bob Marshall, chief executive of Ting Labs.

Ting sensors picked up voltage spikes as far away as Chicago, Boston and Baton Rouge, La. Homes from Richmond, Va., to Washington, D.C., reported flickering lights.

Dominion Energy said that a fault caused a transmission line to go out of service, and that some data centers switched to using backup power. "Within minutes of the incident occurring, our system operations team was able to stabilize the situation and return to normal operating conditions," the company said.

Federal regulators, utilities and grid operators have been working to establish "ride-through" requirements so that large customers don't unexpectedly disconnect and destabilize the system.