The South Is Smashing Electricity Records in the Dead of Winter

America’s largest public power company just set a new record. The Tennessee Valley Authority said consumers used around 34,500 megawatts of electricity on Wednesday morning, about 1,000 megawatts more than its previous all-time record of around 33,500 megawatts in August 2007.

While the cold weather across much of the country has strained many power grids, especially those in the South where electric heating is more common, it’s noteworthy that TVA not only broke its winter record, but it’s all-time record as well. By contrast, the market that covers 90% of Texas, ERCOT, set a winter demand record earlier this week, but its overall record is still from this past summer.

Much of the area around the Tennessee Valley served by the Authority have seen persistent low temperatures over the past few days. Nashville has a forecast high of 30 degrees Wednesday and has gotten as cold as -1 degree Fahrenheit, only the second time the city has experienced below-zero temperatures since 1996, according to the National Weather Service.

And cold temperatures mean more electricity usage. Like much of the region, Tennesseans largely heat their homes using electricity as opposed to fuel oil or natural gas.

“Heavy snow and bitter cold temperatures are creating record high demand for electricity across the Southeast region,” the TVA said in a warning released Tuesday, asking its customers to reduce their electricity consumption from 6 am to 10 am. Similar warnings were issued by ERCOT, which also serves millions of households who heat their homes via electricity. The cold snap is expected to last through the weekend.

And like in Texas, the amount of power TVA is called upon to provide has grown as the region it serves has seen its population and economy grow.

While TVA has a relatively modest solar portfolio compared to the large and growing amounts of wind and solar in Texas, the TVA can still struggle with cold mornings. Some of this is due to what solar power it does have not being available, but it’s largely because of the nature of electricity demand in the winter. On cold days, it is especially chilly in the morning, when people are trying to heat their homes between waking up and going to work or school. By contrast, summer afternoons and early evenings are tough for grids to manage because temperatures stay high even as the sun goes down and people return to their homes and cool them and start operating appliances.

TVA’s generation mix is almost unique within the United States in that much of it is non-carbon-emitting but with relatively little wind or solar. About 60% of its power comes from carbon-free sources, which are nearly entirely its three nuclear plants and its iconic dams.