U.S. electric grid operators on Saturday stepped up precautions to avoid rotating blackouts as frigid weather hitting half of the country’s population stressed their operations.

The PJM Interconnection – the largest U.S. regional grid that serves 67 million people in the East and Mid-Atlantic – reported temporary spikes in spot wholesale electricity prices that soared above $3,000 per megawatt hour on Saturday morning from earlier levels of less than $200 per MWh.

Older power plants, typically idled much of the year, are coming online to take advantage of the elevated prices to serve higher than expected demand, said Georg Rute, CEO of grid software company Gridraven, and an expert on how weather affects power line capacity.

“A 40-year-old gas turbine switches on because it sees these super-high prices,” Rute told Reuters. He added it is a sign of stress in the PJM system and elsewhere.

Prices also soared in other regions as stormy weather and temperatures hovering around 0 degrees Fahrenheit (-18 Celsius) pushed up electricity demand and prompted some operators to shut in natural gas production in key basins, while grid companies also faced constraints on gas pipeline supply.

Dominion Energy, whose Virginia operations include the largest collection of data centers in the world, said if its ice forecast holds, it has the potential to be one of the largest winter events to affect the utility’s operations.

While regional grid operators juggle restricted fuel supplies, congested transmission lines and wild weather, electric utilities are staging crews to repair expected ice and snow damage on low-voltage distribution lines that bring power to homes and businesses.

Faced with constricted gas supplies, regional U.S. grid operators are asking coal and gas-fired power plants to boost output, according to grid operations reports.

The Midcontinent Independent System Operator called on power plants to maximize output and curtailed electricity exports in a territory that stretches across 15 states in the Midwest and South and Manitoba, Canada.

Over the past 24 hours, MISO imported up to several thousand megawatts of power from PJM’s territory to meet demand, according to MISO’s operations reports.

PJM faces greater reliability threats in winter because natural gas plants – the backbone of its generation – frequently face fuel supply constraints and mechanical freezing during extreme cold, according to analysts at consulting firm ICF International.

Neighboring grid MISO issued an all-hands-on-deck emergency action designed to avoid capacity shortfalls as some power plants are forced offline or reduce their output because of freezing temperatures, alerting utilities to be prepared to produce as much electricity as possible.

MISO spot wholesale electricity prices soared to nearly $500 per MWh in MISO’s Minnesota hub, as the upper Midwest experienced transmission bottlenecks across high-voltage power lines. By contrast, spot electricity prices in MISO’s southern territory were less than $50 per MWh.

In New England, fuel oil generation kicked into high gear to help the six-state region’s electric grid conserve natural gas, its top fuel source.

Early Saturday, oil-fired generation accounted for 35% of the New England grid’s output, compared with a typical level of about 1% or less, ISO New England’s operations display showed. Natural gas, usually the grid’s main fuel source, accounted for 22% of the grid’s generation output.

New England spot electricity prices were more than $300 per MWh, or about double the price on Friday.

For the Electric Reliability Council of Texas, the winter storm is the biggest test for the state’s main grid operator since 2021, when a storm nearly caused a catastrophic regional blackout.

More than 200 people died as ERCOT lost about half of its generation capacity amid frigid weather.

Since then, stricter state and federal rules have been implemented to require better winter readiness by utilities and grid operators throughout the country.

Rute said ERCOT appears to be in good shape as it has abundant fossil-fuel generation, big contributions from wind and solar power, and more battery storage than any other grid.

“I think there’s very little chance of a (2021) rerun,” he said. “But no blackout happens the same way twice.”

(Reporting by Tim McLaughlin; Editing by Jan Harvey, Liz Hampton, Rod Nickel)

A federal appeals court ruled on Friday that the Justice Department established probable cause to charge former CNN host Don Lemon and four others over the anti-ICE church storming in Minneapolis last weekend. The appeals court, however, declined to force a lower court judge to sign arrest warrants.

The ruling from the U.S. Court of Appeals for the Eighth District was unsealed on Saturday after the Justice Department asked the appeals court to force a lower district court in Minnesota to sign the five arrest warrants. The ruling did not make the names of the five defendants public, but CBS News reported that its sources confirmed one of the defendants is Lemon. The Justice Department vowed on Friday to pursue charges against Lemon “to the ends of the Earth.”

While Friday’s ruling supported the Trump administration’s pursuit of charging Lemon on paper, it did not solve the Justice Department’s request. Assistant Attorney General for Civil Rights Harmeet Dhillon responded to the ruling, writing on X, “Stay tuned 🤨.” The Justice Department could now seek a grand jury indictment or represent the charges to a magistrate judge.”

Lemon joined a large group of anti-ICE protesters who stormed Cities Church in Minneapolis last Sunday during the worship service because one of the church’s pastors is believed to be an Immigration and Customs Enforcement officer. Three of the anti-ICE agitators who organized the church storming have been arrested by the FBI, including Black Lives Matter activist Nekima Levy Armstrong.

Lemon’s attorney argued that he is protected under the First Amendment since he was with the anti-ICE agitators to cover the church storming as an independent journalist. The Justice Department, however, argues that Lemon was coordinating with leaders of the anti-ICE group before the church storming.

“Freedom of the press extends to a lot of different areas,” Deputy Attorney General Todd Blanche said earlier this week. “It does not extend to somebody just trespassing and being embedded with a group of rioters and being part of the group that storms inside of a church.”

Magistrate Judge Doug Micko refused to sign the arrest warrant for Lemon, saying that federal prosecutors failed to present enough evidence to justify his arrest.

The Trump administration is pursuing charges against Lemon and others who participated in the storming of Cities Church through the FACE Act, which penalizes people for interfering with Americans who are exercising their right to religious freedom. The FACE act was used by the Biden administration to go after pro-lifers who were accused of blocking access to abortion clinics.

News of the appeals court ruling broke as Minneapolis erupts into chaos again after an armed man was shot and killed by federal agents on Saturday morning. Video showed federal officers attempting to detain a man on the street during what the Department of Homeland Security said was a “targeted operation” for an illegal immigrant “wanted for violent assault.” The man was armed with a loaded “semi-automatic handgun” and was shot and killed by a federal agent who was fearing for his life and the lives of his fellow agents, according to Homeland Security.