By Ginika Igboke
Power plant outages rose sharply across the eastern United States on Sunday as frigid temperatures and constrained natural gas supplies reduced electricity generation at a critical time for regional power grids.
PJM Interconnection, the nation’s largest regional transmission organization, reported nearly 21 gigawatts of generation outages across its system, which serves about 67 million people in the Mid-Atlantic and eastern states. Most of the lost capacity was forced offline, accounting for roughly 16 percent of PJM’s Sunday afternoon electricity demand of 127.4 gigawatts.
In response to tightening conditions, PJM issued a pre-emergency order Sunday afternoon requiring some customers enrolled in its curtailment program to reduce electricity use. Participants in the program are compensated for cutting consumption during periods of grid stress. The order was intended to manage rising demand while encouraging certain power plant operators to conserve fuel and operating capacity for colder weather and even higher demand expected later in the week.
Natural Gas Constraints Add Pressure
Energy experts say the outages highlight long-standing vulnerabilities in the eastern U.S. energy system. Unlike regions with local natural gas production, the Eastern Seaboard depends heavily on pipeline networks that can become constrained during prolonged cold spells.
“Without native supplies of natural gas, the Eastern Seaboard relies on a pipeline network that is historically constricted during extended bouts of frigid weather,” said Pieter Mul, a grid expert and associate partner at PA Consulting’s energy and utilities practice.
Domestic natural gas demand, excluding exports, was estimated at 146.7 billion cubic feet per day, down slightly from Saturday but still ranking among the top 10 highest demand days on record.
“From a natural gas production and price perspective, the current U.S. winter storm so far is less severe than prior storms such as Uri and Elliott,” said Matthew Palmer, head of Americas Gas Research at S&P Global Energy. “However, the risk isn’t over, with sustained cold lingering behind the storm.”
Mul added that PJM’s outages exceeded what grid planners had anticipated, in part because the system has less flexibility than in past years. Power plant retirements, combined with rapidly growing electricity demand—particularly from data centers—have reduced the margin for error during extreme weather.
Transmission Bottlenecks and Weather Impacts
Transmission constraints also limited PJM’s ability to move electricity to where it was needed most. Bottlenecks in high-voltage transmission lines prevented low-cost power in the Midwest, including Illinois, from reaching eastern parts of the grid. On Sunday, electricity prices in Illinois at times dipped into negative territory due to abundant wind generation, but that surplus could not be transferred eastward to relieve shortages.
Weather conditions further strained the system. As snow and sleet moved through major cities including Boston, New York, Philadelphia, and Washington, D.C., increased cloud cover reduced solar power output during the afternoon hours, removing another source of generation just as demand surged.
Wholesale electricity prices reflected the tightening conditions. Prices across PJM, as well as in New York and New England, surged to between $400 and $700 per megawatt-hour Sunday afternoon—well above normal levels—as demand exceeded grid operators’ forecasts.
New England and Data Center Demand
In New England, ISO New England reported electricity demand of about 20.2 gigawatts at 1:45 p.m. Eastern Time, surpassing its projected peak load of 19.5 gigawatts expected later in the day. With limited access to natural gas, nearly 40 percent of the region’s power generation came from oil-fired plants, while natural gas—typically the dominant fuel source—accounted for just 30 percent.
Experts warned that reliance on oil-fired generation presents its own risks. Diesel fuel supplies can be depleted quickly and are difficult to replenish during hazardous winter conditions. ISO New England’s surplus capacity fell to roughly 1.1 gigawatts, down from earlier estimates of several gigawatts. Earlier in the day, the grid operator issued an “abnormal conditions” alert urging power plant operators to avoid any maintenance that could further threaten reliability.
In Virginia, home to the world’s largest concentration of data centers, electricity demand and prices spiked sharply. Real-time wholesale prices in Dominion Energy’s service territory outside Washington, D.C., briefly topped $1,800 per megawatt-hour early Sunday, up from around $200 per megawatt-hour on Saturday morning. Data centers, which support cloud computing and artificial intelligence workloads, have become a major driver of rising electricity demand in the region.
Record Demand Forecasts and Widespread Outages
The surge in demand began late Saturday night as Winter Storm Fern moved across parts of the country. PJM now forecasts an all-time winter electricity demand record of 147.2 gigawatts on Tuesday, surpassing the previous record of 143.7 gigawatts set in January 2025. Dominion Energy has warned that prolonged cold and heavy snow this week could rank among the most significant winter events affecting its operations.
High demand and elevated wholesale prices have rippled down to local distribution systems. Nearly 1 million customers were without power on Sunday, according to PowerOutage.us, including more than 300,000 in Tennessee and over 100,000 each in Mississippi, Texas, and Louisiana. Additional outages were reported in Kentucky, Georgia, Virginia, and Alabama.
In Texas, the Electric Reliability Council of Texas (ERCOT) forecast peak demand of 85.1 gigawatts for Monday morning, compared with seasonal capacity of nearly 100 gigawatts. Day-ahead market prices indicated electricity could exceed $1,000 per megawatt-hour, underscoring the strain extreme winter weather continues to place on U.S. power grids nationwide.