How frigid weather stresses the US electric grid — and could lead to potential blackouts

BOSTON, Jan 24 — 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 (D.N), 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.”