The inability of grid operators to recover quickly from this week’s extreme winter weather drew increasing customer anger Tuesday, along with scrutiny from legislators and regulators.

ERCOT, MISO and SPP continued to shed load Tuesday, with some customers warned that a second round of storms is expected to roll through the Southwest, and they may not get their lights back until Thursday. The storm and its record-breaking low temperatures, which left millions without power, has been blamed for at least 17 deaths, and prompted FERC, NERC and Texas officials to launch investigations.

The situation is especially dire in Texas, where ERCOT has been struggling to bring back load without nearly 30,000 GW of thermal and nuclear generation that’s been literally frozen out of the market. Rotating blackouts have never rotated, leaving more than 3.1 million customers without power, according to PowerOutage.US. Some customers have been left in the dark and cold for more than 40 hours.

“It’s a very uncomfortable and frustrating event for many Texans,” said ERCOT CEO Bill Magness, who himself has been without power since Sunday. “Our No. 1 priority since this event began was getting customers’ service back on. The amount of time it’s taken is terrible. It’s unacceptable.”

“The wild card, the biggest variable … has been getting enough generation on the system,” he said.

At least four people have died in Houston area, where 1.3 million people were without power Tuesday morning. The deaths included a mother and her daughter who succumbed to carbon monoxide poisoning after the family ran a vehicle in its attached garage.

Texans have noticed their downtown metropolises have retained power while they shiver in the cold. That led Austin Energy to release a statement explaining that downtown networks are excluded from load sheds during ERCOT’s controlled outages because they include critical facilities. The municipality said it was working with the downtown facilities to reduce nonessential power use.

Houston Mayor Sylvester Turner made it clear to his social media followers that his city had no control over the outages. “The power outages are the responsibility of the state, and they must explain to Texans and Houstonians how this happened,” he tweeted.

On Monday, Texas Gov. Greg Abbott promised “results are on the way,” with the news that about 200,000 residential customers “are coming back online now.” Tuesday, apparently unsatisfied with the results, he issued an executive order adding a new emergency item for lawmakers “to review the preparations and decisions by ERCOT so we can determine what caused this problem and find long-term solutions.”

“The Electric Reliability Council of Texas has been anything but reliable over the past 48 hours,” Abbott said in a statement. “Far too many Texans are without power and heat for their homes as our state faces freezing temperatures and severe winter weather. This is unacceptable.”

Abbott’s announcement came shortly after Dade Phelan, speaker of the Texas House of Representatives, called for the House State Affairs and Energy Resources committees to hold a joint hearing “to review the factors that led to megawatts of electric generation being dropped off the ERCOT system and the subsequent statewide blackouts.”

Phelan said he is asking the two committees to hold the hearing on Feb. 25 “for the express purpose of helping Texans understand what went wrong and how we can prevent these conditions from happening again.”

“We must cut through the finger-pointing and hear directly from stakeholders about the factors that contributed to generation staying down at a time when families needed it most, what our state can do to correct these issues, and what steps regulators and grid operators are taking to safeguard our electric grid.”

Magness welcomed the political oversight.

“Electricity is an essential service. It’s the lifeblood of Texas,” he said. “It’s completely appropriate to look at an issue like this, to look at ERCOT’s actions and everyone else’s actions, to ensure everything is done in an appropriate way. That will require a close look by the policy makers, the governor and everyone else. We’re happy to participate in that process.”

FERC, NERC Announce Joint Inquiry

Also Tuesday, FERC and NERC announced a joint inquiry into the grid’s operational issues in the Midwest and South.

“For now, the emphasis must remain on restoring power to customers and securing the reliability of the bulk-power system,” the agencies said in a joint statement. “In the days ahead, FERC and NERC will formally begin the inquiry, which will work with other federal agencies, states, regional entities and utilities to identify problems with the performance of the bulk-power system and, where appropriate, solutions for addressing those issues.”

In a separate statement Monday, FERC Chairman Richard Glick said the commission is in contact with ERCOT, SPP and MISO, and that he has directed staff to coordinate closely with the RTOs/ISO, utilities, NERC and regional reliability entities “to do what we can to help.”

“In the days ahead, we will be examining the root causes of these reliability events,” Glick said. “But, for now, the focus must remain on restoring power as quickly as possible and keeping people safe during this incredibly challenging situation.”

MISO spokesperson Brandon Morris said the RTO “will constructively cooperate with FERC and NERC to provide them with the necessary information during the inquiry.”

Although ERCOT is not bound by FERC regulation over its markets, it is subject to NERC reliability standards.

“There will be a lot of review and determination afterward, and there should be. We don’t want to see this happen again,” Magness said.

ERCOT Struggles to Balance Supply, Demand

The Texas grid operator’s senior director of system operations, Dan Woodfin, explained to the media the delicate balance between supply and demand following Sunday’s massive loss of generation. (See ERCOT, MISO, SPP Slough Load in Wintry Blast.)

He said about 15 GW of load was still off, with roughly 45 GW of generation online. Load basically fluctuated between 44 GW and 46 GW Tuesday.

“We’ve been able to bring some areas back online today as the day has progressed,” Woodfin said. “We’ve gotten some supply from certain generators, but we’re also losing some. We haven’t been able to add as much as we thought we could add back.”

The loss of renewable energy to frozen wind turbines and overcast skies has drawn national criticism, but Woodfin said of the 16 GW of installed renewable capacity offline, ERCOT only includes about 30% of that in its resource adequacy measures.

During an emergency meeting Monday night of the Public Utility Commission, which oversees ERCOT, the commissioners directed the ISO to modify its pricing models so they more accurately reflected the market’s scarcity conditions. Magness said staff discovered that energy prices were clearing at less than the maximum system-wide offer cap of $9,000/MWh.

ERCOT also received authorization from the U.S. Department of Energy to run the market’s power plants at maximum output levels, even if that results in exceeding pollution limits.

Midwest Briefly Joins MISO South’s Woes

After shedding load in portions of southeast Texas early Monday, MISO announced a continuation of emergency procedures for MISO South through Tuesday. The grid operator also separately declared a maximum generation emergency for Midwestern portions of its footprint that lasted until Tuesday afternoon as the cold snap dragged on.

However, the RTO extended conservative operations that were to begin on Valentine’s Day for the entire footprint through Wednesday night.

By midday Tuesday, prices at MISO’s Texas Hub exceeded $1,000/MWh.

The grid operator instructed members to continue making public appeals for electricity conservation to avoid further outages.

“We’re moving into uncertain territory, which is why we are asking the public for assistance,” System Operations Executive Director Renuka Chatterjee said.

Portions of the South saw temperatures plunge to their lowest in 85 years. Northern Minnesota experienced -40 F temperatures late Monday.

MISO characterized the deep freeze as a “highly unusual situation with … power demand nearly exceeding what current generation and transmission can supply because of the extreme weather.”

“The situation has been taking a toll on parts of the bulk electric system, limiting MISO’s ability to import electricity from neighbors that are in a similar situation,” the grid operator said.

SPP Expects Fluctuating EEA Levels

Real-time wholesale prices in SPP momentarily hit a staggering $55,000/MWh Tuesday after the RTO declared an EEA Level 3 alert for its 14-state Eastern Interconnection balancing authority that morning, saying capacity had dropped below its then-current load of about 42 GW. That spike represented the cost to bring an oil-fired peaker online, a market participant said.

The RTO downgraded the EEA to Level 2 shortly before noon and then again to Level 1 an hour later.

“It is likely its system will fluctuate between EEA levels over the next 48 hours,” SPP said, pointing to high demand and persistent cold weather.

The grid operator said it is continuing to urge its member companies to instruct consumers to conserve electricity at home and work and to follow their local utility’s directions.