The recent deep, biting chill that froze the United States forced millions of furnaces to switch on at the same time, raising energy demand to new seasonal highs during one of the diciest times of year for power reliability.

In fact, the Tennessee Valley Authority — the federal power utility that covers states including Tennessee, Alabama, Mississippi, and Kentucky — set a new power demand record last week, not just for winter, but for all time.

The good news is that for the most part, the lights stayed on and toes stayed warm as most of the US avoided sweeping blackouts. But some homes in states like Oregon, Louisiana, and Kentucky did go dark amid the icy weather, while other regions came precariously close to shortages.

The cold weather makes these vulnerabilities clear — but it also reveals that wintertime energy demand is rapidly changing. As more homes switch to electric heating, winter electricity usage is rising faster than it is in the summer across much of the US, and that’s a mounting challenge for utilities.

Our current energy infrastructure is getting by — but just barely. And parts of the country have already seen what happens when it doesn’t hold up: Power outages across Texas during Winter Storm Uri in February 2021 contributed to at least 700 deaths across the state.

In power markets like PJM, which serves 13 Eastern states and the District of Columbia, winter energy needs are increasing faster than any other time of year — even more rapidly than the ever-hotter summers.

“In PJM, the highest electricity demand peaks are in the summer, but you will see that the long-term expected increase in the winter peak actually outpaces the growth in the summer peak,” said Jeff Shields, a spokesperson for PJM, in an email. “That is primarily attributable to the growth in electrification of heating systems.”

Why winter is becoming a trickier time for the power grid

In 2020, electricity met 44 percent of residential energy needs while natural gas, for appliances like stoves and furnaces, provided 43 percent. About half of total household energy demand goes to just heating and cooling. As temperatures dipped last week, natural gas demand for heating and power generation reached a new record high across the US — just as gas wells also froze........

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