Power Scare Shows Texas Grid Still at Risk After Blackouts

Texas faced a brief power-grid scare Tuesday night, less than 60 days after widespread blackouts left millions without light and heat for days during a deep winter freeze.

The grid operator, the Electric Reliability Council of Texas, asked for conservation for nearly four hours with a quarter of generators down for repairs and a mild cold front failing to reduce electricity demand as much as had been anticipated, leaving supply tight. Wholesale electricity prices jumped as high as 10,000% in some parts of the state.

Ercot ended the conservation appeal shortly after 8:30 p.m. Houston time without needing to call ...