Grid operators, utilities, and regulators across the country continue to grapple with extreme winter conditions which, as The Washington Post reported on Feb. 16, has led to at least 14 deaths in four states since Feb. 14.
As noted by the U.S. Department of Energy, an arctic mass is impacting the central United States, bringing snow, ice, and extreme cold temperatures from the Canadian border to Texas, causing record winter power demand and impacting power generation.
The National Weather Service reported at 3:06 p.m. EST on Feb. 16 that Winter Storm Warnings and Advisories remain in effect for northeastern Maine; an area of low pressure will develop over southern Texas on the evening of Feb. 16, producing heavy snow and ice from the Southern Plains, through the Mississippi Valley on Feb. 17, and into the Northeast by Feb. 18; and a new system is forecast to arrive over the Pacific Northwest region on Feb. 18, bringing with it the chance for another round of coastal rain and mountain snow.
In its Feb. 16 statement, the Midcontinent ISO (MISO) noted that it and its members have managed multiple interdependent issues, including transmission constraints and generation outages. MISO said that it is also supporting its members’ restoration efforts in the South Region, which remains under emergency declarations due to high demand and frigid temperatures.
Noting that it has issued several emergency declarations since the week of Feb. 8, some of which resulted in temporary power interruptions in parts of Southeast Texas, Southwest/South-Central Louisiana and South-Central Illinois, MISO said that most of those outages have been restored, and that load demand is being driven by the freezing temperatures expected through the rest of this week.
The Southwest Power Pool (SPP) on Feb. 16 said that it was declaring an Energy Emergency Alert (EEA) Level 3, effective immediately for its entire 14-state balancing authority area. SPP said that system-wide generating capacity has dropped below its current load of about 42 GW due to extremely low temperatures and inadequate supplies of natural gas. SPP noted that it will work with its member utilities to implement controlled interruptions of electric service throughout its region, which is done as a last resort to preserve the reliability of the electric system as a whole.
Individuals in the SPP service territory should take steps to conserve energy use and follow their local utilities’ instructions regarding conservation, local conditions and the potential for outages to their homes and businesses, SPP said, adding that it forecasts a morning peak of above 44.6 GW around 9:00 a.m. Central time.
Regulatory response
The Public Utility Commission of Texas on Feb. 15 said that in response to the weather-induced electricity crisis affecting the state, it issued an order directing ERCOT to ensure that firm load being shed in ERCOT’s Energy Emergency Alert Level 3 operating condition is accounted for in ERCOT’s scarcity pricing.
The decision was spurred by ERCOT’s discovery that energy prices across the system were clearing at less than the current systemwide offer cap of $9,000 established by commission rule, the commission said, adding that when notified, it agreed that energy prices across the system clearing as low as about $1,200 during the first day of the weather crisis was inconsistent with the fundamental design of the ERCOT market.
Since energy prices should reflect scarcity of the supply, the market price for the energy needed to serve load being shed in the face of scarcity should also be at its highest, the commission said.
In its most recent statement, ERCOT on Feb. 15 noted that it was beginning to restore some of the power lost due to the winter weather event in Texas, with about 2,500 MW of load — or enough power to serve 500,000 households — in the process of being restored as of 4 p.m.
ERCOT said that it was instructing transmission owners to shed about 14,000 MW of load, down from 16,500 MW earlier on Feb. 15.
At about 1:25 a.m., on Feb. 15, ERCOT entered its third and highest level of emergency operations because electric demand was exceeding the available supply, the grid operator said, adding that controlled outages are occurring to protect the electric grid from uncontrolled, cascading outages.
ERCOT noted that while it was already contending with frozen wind turbines and limited gas supplies to generating units on Feb. 14, a significant number of additional generating units tripped offline when the weather worsened overnight. About 34,000 MW of generation has been forced off the system during this event, ERCOT said, adding that controlled outages will likely last throughout the evening and into tomorrow as ERCOT works to restore the electric system to normal operations.
Power load dropped
Noting that ERCOT has continued to direct utilities to drop power load through maintained controlled outages, Oncor Electric Delivery Company on Feb. 16 said that it was able to rotate some outages overnight, but poor grid conditions have continued to prevent the utility and others from rotating, or rolling, the entirety of those outages, leading to extended periods without power for many customers.
Oncor said that it is unable to predict when grid conditions will stabilize, and urged all customers to be prepared for extended outages to continue.
“We are closely watching the coming winter storm that is forecast for Tuesday night and Wednesday to ensure that we have the needed resources to address any damage from the storm,” Oncor said.
Similarly, American Electric Power’s (AEP) Southwestern Electric Power Co. (SWEPCO) on Feb. 16 said that it is monitoring a second, potentially dangerous winter storm that may bring a mix of snow and more than half an inch of ice to the Ark-La-Tex on Feb. 16 and 17, potentially causing extended power outages.
SWEPCO said that it is assembling a power restoration workforce of more than 2,600 utility linemen, tree trimmers and support personnel from 15 states and Canada to assist company resources, with workers to be positioned in Shreveport, Natchitoches, Longview and Texarkana.
Another AEP company, AEP Texas, on Feb. 16 said that damage to its electric system from the winter storm does not appear significant, and that once it receives the go-ahead from ERCOT, it will begin restoring power.
AEP Texas noted that rotating outages have been focused on such critical services as hospitals, city water plants, and other city services. Other outages expanded to new areas as ERCOT continues to direct utilities to interrupt service to additional customers, the company said, adding that electricity capacity produced by power plants did not increase even as electricity demand continued to increase.
AEP Texas noted, “This is the most extreme and widespread weather event in recent history and has affected all utilities in Texas, leaving 4 million customers throughout the state without power.”
CenterPoint Energy on Feb. 16 said that due to the continued issues with power generators’ ability to produce electricity, customers need to be prepared to be without power, potentially for the duration of the generation shortage event, which could last several more days. The company said that it continues to navigate this historic weather event to provide for the stabilization of its electric delivery system and the reliability of its natural gas infrastructure. CenterPoint noted that its transmission and distribution systems handled the severe weather well, with the company prepared to serve its customers when generating capacity from third-party generators is available.
As of 2:45 p.m., on Feb. 16, there were about 1.27 million Houston-area customers without power, CenterPoint said.
AEP’s Public Service Company of Oklahoma (PSO) on Feb. 16 said that it implemented an emergency load reduction plan at SPP’s request, and that as a result, PSO began a required series of service interruptions, lasting about two hours, for some customers. These planned outages will reduce the risk of lengthy, widespread outages and will continue until SPP authorizes a return to normal operations, PSO said.
Louisiana-based Cleco on Feb. 16 said that as of 4 p.m., it had restored power to more than 10,000 of the 11,110 customers impacted by Winter Storm Uri, which impacted much of the company’s service territory beginning the night of Feb. 14 and into the morning of Feb. 15.
The company said that in preparation for the possibility of more freezing rain, sleet and snow across its service territory, Cleco has secured nearly 400 contractors in addition to Cleco resources.
The Nebraska Public Power District (NPPD) on Feb. 16 said that it has moved from a Level 3 Emergency back to a Level 1 emergency, and that it is asking customers to conserve energy. The NPPD said that the current weather situation “is rather fluid and we expect that peak hours tonight after 5 p.m. could change our status and once again early in the morning hours, much as it did Tuesday morning.”
Moving east, Dominion Energy Virginia on Feb. 15 said that its crews continue to restore power after the most destructive ice storm in two decades brought significant damage to parts of Central and Southern Virginia over the weekend. More than 290,000 customers have lost power since 4 a.m., Feb. 13, the company said, adding that as of 4 p.m., Feb. 15, Dominion Energy crews have restored service to more than 85% of those customers, with fewer than 43,000 customers remaining without power at that time.
In the West, Pacific Power said on Feb. 15 that nearly 360 employees and contractors continued to assess and repair damage caused by a series of storms that brought heavy ice and snow to the region. Joining Pacific Power crews on the morning of Feb. 16 were 75 additional personnel from Rocky Mountain Power, MidAmerican Energy and Nevada Energy and other regional utilities, the company said.
At times during the past few days, upwards of 80,000 customers from across the Willamette Valley up to Portland and along the North Coast experienced service disruption due to the destructive ice storms, Pacific Power said, adding that as of 7 p.m., on Feb. 15, that total has dropped to 28,000 customers.
