The TVA says it supplied a total of 703 gigawatt-hours of electricity over 24 hours on Tuesday amid a wave of arctic weather. The previous record was 701 gigawatt-hours set on Jan. 8, 2010.
Temperatures in the region never got above 21 degrees on Tuesday, and the average was just 4 degrees in the morning, when the TVA power system hit its second-highest winter peak power demand.
TVA is the nation's largest public utility, supplying power to about 9 million people in Tennessee, Alabama, Mississippi, Kentucky, Georgia, North Carolina and Virginia.
Temperatures in the region are expected to hit highs in the 50s by Friday.