Two Ways the Lights Go Out This Winter: The Cold, and the Sun

The short version

Most of us only think about the power grid when it fails. This winter there are two different ways it could fail, and neither one asks permission. The first is old and familiar: a hard freeze that pushes demand past what the grid can deliver. The second sounds like science fiction but is not: a storm on the sun that sends a surge of energy into power lines here on Earth. The good news is that getting ready for one gets you most of the way ready for the other.

Threat one: the cold snap

Last January showed how fast it can happen. Winter Storm Fern spread ice and snow across dozens of states, and at its worst more than a million homes and businesses had no electricity, according to outage trackers cited by the insurance analytics firm Verisk. The South took the hardest hit. Mississippi, Louisiana, Georgia and Texas were among the worst states, and some families in Tennessee and Mississippi waited days for the lights to come back. More than 100 deaths were blamed on the storm.

The bigger worry is that the cushion keeps getting thinner. Last winter's assessment from the North American Electric Reliability Corporation, the industry body that watches over the grid, warned that demand is growing faster than new power plants are being built, POWER magazine reported. Much of that new demand comes from data centers, the giant warehouses of computers behind the internet and artificial intelligence. Insurance Journal reported that a polar-vortex freeze could trigger power shortfalls in a wide arc that runs through the Pacific Northwest, Texas and the Carolinas. The watchdog also noted that in a severe freeze, actual demand can run as much as a quarter higher than the forecast, as Texas learned in 2021. Its long-term report in January painted an even tougher picture for the years ahead.

Its assessment for this coming winter is expected later this month. We will report on it when it lands. But nothing about the basic picture has changed: more demand, tight supply, and plants that struggle when it gets very cold.

Threat two: the sun

The sun goes through an 11-year cycle of activity. Space.com reports that the current cycle most likely peaked in October 2024 and is now winding down. That sounds reassuring. It is not the whole story. Scientists quoted by Gulf News point out that some of the most violent storms on record arrived after a cycle's peak, not at it. In November 2025, Earth was hit by a "severe" G4 geomagnetic storm, one of the strongest of this cycle. In May 2024 a storm painted the northern lights as far south as Florida and knocked out the satellite navigation that farmers use to plant, a loss Space.com put at about $500 million for US agriculture.

Here is how a solar storm reaches your house. The sun hurls a cloud of charged particles toward Earth. When it slams into the planet's magnetic field, it drives extra electric currents into long high-voltage power lines. Those currents can overheat the huge transformers that step power down for towns and cities. In January, British space-weather scientists updated their worst-case planning report for the kind of solar storm that comes along once every 100 to 200 years. Space.com summarized the warning: overloaded transformers can trip offline, wear out early, and leave the grid weaker for months or even years. A second report covered by Space.com warned that a storm like that could set off panic buying and public unrest.

It has happened before. In March 1989, a solar storm knocked out the main power supply for the Canadian province of Quebec, leaving some 6 million people in the dark for about nine hours, Fox Weather recounted. The same storm melted transformers as far away as New Jersey. The biggest storm on record, the Carrington Event of 1859, set telegraph lines sparking and started fires in some telegraph offices. There was almost no electric grid to break in 1859. Today there is nothing but grid. A study for the insurance market Lloyd's estimated that a Carrington-size storm could put 20 million to 40 million people in North America at risk of a long blackout, lasting anywhere from about two weeks to a year or two in the worst-hit places.

There is one piece of good news. A big storm usually takes a day or more to travel from the sun to Earth, and forecasters watch the sun around the clock. That is time you can use, but only if your plan is already made.

Why the two threats are really one

A frozen grid and a fried transformer end the same way: no heat, no water pressure in some homes, no gas pumps, no card machines, no phone charging and, after a day or two, a lot of very cold people. A solar storm can also scramble GPS and satellite signals at the same time. That is why the same short checklist covers both.

What to do this month

Plan for a week, not a night. Keep 7 days of water (about a gallon per person per day), food that needs no cooking, and at least two weeks of every prescription.

Have one safe way to stay warm without the grid. An indoor-rated heater with its fuel, or a wood stove, plus blankets and sleeping bags. Pick one room to heat and close off the rest.

Carbon monoxide is one of the biggest killers after winter storms. Never run a generator, grill or camp stove indoors or in a garage, and put a battery carbon monoxide alarm near where you sleep.

Keep light, news and a charge. Flashlights, spare batteries, a hand-crank or battery radio, and a charged power bank for each phone.

Keep some cash at home. When the power is out, card readers and ATMs go down with it.

Write down what your phone remembers for you. Key phone numbers, your doctor and pharmacy, and a paper road map of your area, in case GPS and cell service go down too.

Keep the car's tank at least half full, since gas pumps need electricity.

If you depend on powered medical equipment, talk to your power company now about a priority list, and line up a battery backup.

When a big solar storm is forecast, unplug expensive electronics and run your surge protectors. It costs nothing and could save a TV, a computer or a furnace control board.

The bottom line

No one can stop a cold front or a burst from the sun. What you can control is whether a blackout is a crisis or just an inconvenience in your house. The families who came through Fern in good shape were the ones who already had water, heat, light and medicine on hand. That is the whole plan, and it works no matter which way the lights go out.

What would you miss most in a week without power?