While the Electric Reliability Council of Texas (ERCOT) grid was running along smoothly on Sunday, a federal order in the afternoon required the grid operator to begin asking all very large electricity users such as data centers to begin using backup emergency generators.
The order from the US Department of Energy (DoE) appears to stem from cautious concern as Texas joins the rest of the nation in record-breaking cold temperatures that's now started to strain the electric grid in the Midwest and Northeast.
There are no reports of problems at ERCOT and the grid has held up well through the first portion of a statewide cold weather event.
But the electricity system in other parts of the US have been strained -- in some cases severely -- during this event, and the DoE says it's concerned about the availability of power during extreme cold during the coming week.