by For decades, power grid managers feared that increasing demand for power on hot summer days would lead to blackouts. Increasingly, they have similar concerns about the coldest days of winter.
Largely due to increasing demand from homes and businesses, and supply constraints due to aging utility equipment, many networks are under greater strain in winter. By 2033, winter electricity demand growth, compared to the current level, is expected to exceed summer demand growth, according to North American Electric Reliability Corporationa nonprofit organization that develops and enforces standards for the utility industry.
Just 10 years ago, winter electricity consumption was about 11 percent less than summer, according to the group. By 2033, that gap is expected to narrow to about 8 percent. And by 2050, winter demand could exceed summer electricity use.
“We are seeing the summer and winter peaks grow, but we are seeing the winter peaks grow faster,” said Jim Robb, CEO of Reliability Corporation. “The demand curve just shoots up very, very quickly.”
In the years following the 2008 financial crisis, annual electricity demand remained virtually stable. The Obama administration promoted energy efficiency as a way to address climate change, and consumers used less electricity to save money.
But that trend has reversed in recent years as companies have built hundreds of large data centers, each of which can use as much energy as a small city, and individuals have purchased more cars and electric appliances. A major contributing factor in the winter is the increasing use of electricity to power heaters in homes and businesses that previously used oil or gas boilers.
While they are very efficient overall, electric heat pumps become less efficient when the outside temperature is below 30 degrees Fahrenheit, Robb said. As a result, power companies have to work harder in very cold weather and during winter storms.
On January 17, as bitter cold swept through many of the seven states it serves, the Tennessee Valley Authority reached its maximum electricity demand ever. The public electricity system, which has nine million customers, was able to withstand it thanks to the improvements it had made to cope with the increased winter demand. The previous record was set on August 16, 2007.
“In our region we are already seeing higher winter peaks and more challenges than summer peaks,” said Aaron Melda, senior vice president of power transmission and supply for the authority.
PJM, which is the nation’s largest network serving 65 million people in 13 states, also exceeded its projected demand on Jan. 17 as snow, sleet and freezing rain blanketed the Mid-Atlantic. The system met that demand and supplied power to neighboring grids. A year earlier, PJM needed help from his neighbors during a major winter storm.
U.S. grids are also struggling because they import less power during the winter from Canada. Demand for electricity in that country is growing strongly, and decreased rain and snow has reduced supply to its hydroelectric plants, said Robert McCullough of McCullough Research, an energy consulting firm based in Portland, Oregon.
America’s aging and poorly maintained power lines and utility equipment are another major problem, he said. The power grid serving much of Texas collapsed during a 2021 winter storm, in part because natural gas pipelines and power plant equipment froze or malfunctioned. Almost 250 people died due to the storm and power outage, state officials said.
“It’s pretty clear that we’re entering a period where we don’t know what’s going to happen next,” McCullough said. “Electrification is clearly going to change it and make it worse.”
Like many Americans, Michael Pittman had become accustomed to strains on the power grid due to summer heat waves or storms. He lives outside Houston, where he works as general manager of Star Pizza, a restaurant that has two locations in the city.
The 50-year-old restaurant’s original store, where dough and sauce are made for both stores, lost power during the 2021 storm.
“There was a feeling of great helplessness,” said Pittman, who has worked at the restaurant since 1994 and previously experienced power outages during hot summer days and hurricanes. “Now everyone gets that feeling of shock when they hear that a freeze is coming. The news immediately goes online.”
The restaurant considered purchasing generators for backup power, but Pittman said doing so would cost too much. Instead, it is preparing for the worst when freezing temperatures hit and hopes to continue operating from its second location, in an area that tends to lose power less frequently during bad weather.
“There are certain things that are taken for granted,” Pittman said. “The electrical grid is one of them.”
The network faces many challenges as the country moves to reduce greenhouse gas emissions. And the increasing demand for electricity in winter makes many of them more difficult.
In much of the country, power grids were designed to handle high demand in the summer, when people turn on their air conditioners. As a result, utilities typically shut down some power plants and other parts of the grid for maintenance and upgrades for the rest of the year.
Energy experts said high demand at several stations could make it difficult to repair and upgrade worn-out and aging systems.
The North American Electric Reliability Corporation believes winter electricity use could exceed summer demand in New York and other northeastern states within six years. That would also mean higher electricity bills, which have been rising steadily in recent years. In November, the average U.S. homeowner paid $162 for typical use of 1,000 kilowatt-hours, up from $156 a year earlier, according to the Energy Information Administration.
“As more and more jurisdictions transition to all-electric, you’re going to see that maximum shift,” said Calvin Butler, CEO of Exelon, which owns regulated utilities in New Jersey, Maryland, Delaware, Pennsylvania and Illinois. “We’re going to start seeing more peak winter seasons.”
Butler said he believed growing demand for electricity would require improvements and additions to the grid to keep the lights on, including the continued use of some fossil fuels.
Renewable energy sources, such as solar panels and wind turbines, produce less electricity during the winter, partly because there are fewer hours of sunshine and because wind and weather conditions are more variable. That’s why Butler maintains that the United States will need to continue using natural gas power plants, which supply about 40 percent of its electricity.
“It just reinforces the need to have natural gas within the system,” Butler said. “You’re going to need gas for the foreseeable future.”
Of course, continuing to burn a large amount of natural gas to produce electricity will undermine efforts to reduce emissions of carbon dioxide and methane, two of the main greenhouse gases. But replacing gas is difficult because batteries and other energy storage technologies cannot provide enough power for several days at a reasonable cost right now, although some experts believe that will change in the future.
Utilities could also build more transmission lines to transport renewable energy from places where it is abundant to where it is needed, for example, from large solar farms in the Southwest to the Midwest in winter. But approval of projects of this type can take many years.
“We’re talking about a lot of energy that we’re trying to eliminate,” said Robb, of the grid reliability corporation. “We need a technology that is available at scale and can provide the same type of balancing services that we get from gas.”
McCullough, the consultant, said focusing on more natural gas was shortsighted in part because gas plants had also been unreliable in winter. He argues that grid managers and utilities need to consider more distributed resources, such as rooftop solar, and better plan for rising winter demand in ways that allow the country to address climate change.
“The bottom line is,” he said, “we’re having spikes in both summer and winter, and we’re not predicting them.”
