Extreme winter weather has placed much of the country’s heartland in a deep freeze, from Minnesota to Texas, and left grid operators scrambling to meet anticipated record winter demand.

MISO, SPP and ERCOT all declared conservative operations and issued other advisories in advance of the storms, which hit Sunday night and are expected to last through much of the week. SPP was the first to declare an energy emergency alert (EEA), issuing a Level 1 alert on Sunday to be effective at 5 a.m. CT Monday.

All three grid operators are expecting record winter peaks in at least a portion of their footprints, with consumers shut in by snow, ice and sub-freezing temperatures.

Wind turbines have been shut down, and gas prices on the region’s spot market have surged to as high as $600/MMBtu, driven by curtailed production and increased heating demand.

ERCOT, expecting to set a new all-time winter peak this week in the face of the state’s lowest temperatures since the 1980s, asked consumers on Sunday to reduce their usage or face the possibility of emergency measures. Among the options in its toolbox are rotating outages, last used during scarcity conditions in early February 2011. (See ERCOT Bracing for Winter Storm, Record Demand.)

Demand was 64.7 GW for the interval ending at 3 p.m., close to the all-time peak of 65.9 GW set in January 2018.

“We are experiencing record-breaking electric demand due to the extreme cold temperatures that have gripped Texas,” ERCOT CEO Bill Magness said in a statement. “At the same time, we are dealing with higher-than-normal generation outages due to frozen wind turbines and limited natural gas supplies available to generating units. We are asking Texans to take some simple, safe steps to lower their energy use during this time.”

The Texas grid operator stressed that rotating outages, the third level of an EEA, are only a “last resort” in maintaining reliability. Declaring an EEA, permitted when operating reserves drop below 2.3 GW or system frequency cannot be maintained above certain levels and durations, allows it to take advantage of additional resources that are only available during scarcity conditions.

Generators have benefited from the tight conditions, with wholesale prices spending much of Saturday and Sunday above four figures. Prices peaked at $9,368.86/MWh Saturday in San Antonio’s CPS Energy load zone during the interval ending at 9:15 a.m.

The National Weather Service has sent out winter storm warnings or watches for much of Texas, and Gov. Greg Abbott issued a disaster declaration for every county in the state. Abbott said during a Saturday press conference that snow could probably cover a “larger swath of land to a higher degree than ever before in Texas history.”

“This period will go down in Texas weather history as one of the most extreme events to ever impact the state,” predicted Chris Coleman, ERCOT’s senior meteorologist. “That’s even more amazing when considering the 1980s’ coldest periods occurred in December with a low sun angle, compared to the extreme cold now with spring soon approaching.”

Coleman said there is “still room for even colder changes,” and he expected near-blizzard temperatures Sunday in windswept West Texas. A second storm “appears increasingly stronger,” he said, and should arrive mid-week.

Forecasts for Amarillo, Abilene and Midland call for temperatures as low as -11 degrees Fahrenheit on Monday. Dallas and Austin are expected to see single-digit temperatures Monday and Tuesday.

State officials are encouraging residents to stay off the roadways to avoid accidents like the 133-car pileup that killed six people on an icy overpass last week in Fort Worth.

SPP Issues EEA1 for Monday

SPP said it issued the EEA1 because it “foresees or is experiencing conditions where all available resources are scheduled to meet firm load obligations and that we may be unable to sustain its required contingency reserves.”

The RTO said its analysis of current forecast data indicates that conditions may continue to tighten over the next several days because of persistent, widespread and extreme cold.

“We have recommended that load-serving utilities throughout our region take conservation measures to mitigate the risk of more widespread and longer-lasting outages,” the company said in a statement.

Expecting the abnormal weather conditions — including temperatures near zero Monday in its Little Rock, Ark., hometown — SPP issued a cold-weather alert early last week. The grid operator later added a resource alert and then a call for conservative operations on Feb. 9.

COO Lanny Nickell warned the RTO’s Regional State Committee on Friday that more extreme measures may be needed.

“It’s not a transmission system issue; it’s a resource adequacy issue,” he said. “Some resources we rely on aren’t showing up.”

Nickell said SPP lost about 5 GW of forecasted wind generation on Feb. 7, with fog causing wind turbines to ice up. With load expected to pick up over the weekend into the week and gas supplies tightening, staff have been coordinating with gas companies and neighboring RTOs to ensure demand can be met.

“We’re ensuring we have all resources available,” Nickell said. “It’s all about keeping the lights on.”

‘Particularly Harsh’ in MISO South

MISO on Saturday declared conservative operations for Sunday through Tuesday for its entire footprint, saying it was expecting “extremely cold temperatures and generator fuel supply risks.” The declaration asks that market participants halt transmission and generation maintenance.

Within hours, the RTO singled out its South region — which spans Arkansas, Louisiana, portions of Mississippi and part of East Texas — for a maximum generation capacity advisory effective Monday at 9 a.m. ET and until “further notice.” MISO’s capacity advisories ask members to prepare for possible use of load-modifying resources and report any natural gas restrictions.

“The impact of winter weather is widespread across MISO’s footprint but is particularly harsh in the South region,” the RTO said Sunday. “MISO is working closely with its members to maintain system reliability amid the extreme conditions.”

MISO said the arctic blast could have the South approaching its all-time demand peak of 32.1 GW set in mid-January 2018. That year, bitter cold set in motion a two-day emergency declaration, a breach of the RTO’s subregional transfer limit, near-load shedding, and subsequent FERC and NERC inquiries. (See FERC Orders Cold Weather Reliability Standard.)

“The current load forecasts in the South Region are … making this a very difficult situation,” said Renuka Chatterjee, system operations executive director. “We are in constant contact with our members and our partner ISO/RTOs to ensure the reliability of the bulk electric system.”

On Sunday, MISO said its market functions were performing “as designed” despite the frigid weather and heavy demand. Spokesperson Brandon Morris said the RTO stood “prepared to take additional actions if generation or transmission sufficiency changes.”

“Keeping the lights on requires a high level of coordination and collaboration with our members and the communities they serve,” MISO South Executive Director Daryl Brown said. “Although we are experiencing unusual weather in the South, we are working together to meet that challenge.”