ERCOT, MISO and SPP cut loads Monday as an unprecedented winter storm shut down wind turbines and fuel shortages idled gas-fired generation, reducing supply in the face of record winter demand.
SPP initiated its first rolling blackouts in its history, while ERCOT did so for the first time in a decade. For MISO, it was the second load-shedding event in less than six months. ERCOT prices have been touching the $9,000/MWh cap since Saturday, while MISO saw prices close to $1,000/MWh.
In a press conference Monday, Dan Woodfin, senior director of system operations, said multiple generators began tripping offline Sunday night in “somewhat rapid progression due to the weather” after the grid operator had set a new winter peak record of 69,150 MW earlier that evening.
At 1:25 a.m. CT, ERCOT declared a level 3 energy emergency alert and asked transmission owners to take 16,500 MW — or about 3.3 million homes — of load offline based on load-ratio-share basis.
About 34 GW was unavailable as of noon, including a significant number of gas units because of restrictions on the gas system and wind facilities because of icing on turbine blades.
“As more generators tripped offline, we had to implement more of these controlled outages to protect the system as a whole,” Woodfin said. “It became such a big number that the transmission providers are having difficulty with their normal rotations. They just don’t have enough options that don’t have critical facilities like hospitals and first-responders. They’ve kind of used all the circuits that they can to balance supply and demand.”
He added that ERCOT has seen a slow down in the number of generators tripping offline. “We don’t think these outages will be multiday outages. We think they should be able to come back in a number of hours.”
The last time ERCOT had to institute rolling blackouts was in 2011, just days before Super Bowl XLV was played in Dallas. In its annual seasonal assessment of resource adequacy for the winter, released in November, ERCOT had said it expected to have enough installed capacity to meet a forecasted 57.7 GW of demand, in part because of a record amount of new wind resources. (See ERCOT: Record 5 GW of Installed Wind Capacity.)
“We are doing everything in our power, not just ERCOT, but the generation owners and the transmission owners, trying to keep the situation reliable,” Woodfin said. “We’re trying to reduce the length of these outages as much as we can to make sure the system as a whole can operate.”
“Every grid operator and every electric company is fighting to restore power right now,” ERCOT CEO Bill Magness said in a statement.
ERCOT gave notice over the weekend that service interruptions were a real possibility. (See Grid Operators Face Historic Arctic Blast.)
MISO South Jettisons Load Again
The sustained deep freeze also brought MISO South its second load-shedding event in less than six months.
MISO said the frigid temperatures contributed to generation and transmission outages, leaving it no choice but to direct rotating power outages. The blackouts began Monday morning for some customers in Southeast Texas, MISO said.
“We fully committed every available operating asset before the event to lessen the impact on our system, but conditions eventually deteriorated to a point where demand exceeded supply,” Executive Director of System Operations Renuka Chatterjee said. “The accelerated change in conditions led us to our last resort in order to maintain grid reliability, and we are in direct communication with our members to support their restoration efforts in the affected areas.”
MISO said it consulted with members before the load-shed to identify “the worst-case scenarios to limit the effects of temporary power supply interruptions to those areas that will provide the most relief.” The grid operator said their plan was informed by weather forecasts, predicted demand and worst-case reliability risks. Load-shedding is the last-ditch effort in a MISO maximum emergency event.
MISO issued its first-ever load-shedding orders in MISO South in late August, after Hurricane Laura tore through the heel of Louisiana. (See MISO Keeps Advisories in Effect a Week After Laura.)
“This was truly a coordinated effort with all of our members to avoid a potentially larger grid outage,” MISO South Executive Director Daryl Brown said.
Entergy agreed in a press release that the outages were carried out to “prevent a more extensive, prolonged power outage that could severely affect the reliability of the power grid.” It said its demand had hit an all-time high and that outages could continue throughout the day.
“We apologize for the inconvenience these outages may cause, but we have an unusual situation right now driven by extreme weather conditions. We are working to respond and restore power as soon as it is safely possible,” Entergy Vice President of Customer Service Stuart Barrett said. “While our crews worked to prepare for this storm, a loss of generation combined with the peak load has caused a strain on the system. As a result, we are short of the power needed to meet our customers’ demands across southeast Texas.”
Pricing at MISO’s Texas hub flirted with $1,000/MWh at 10 a.m. ET.
Southern Renewable Energy Association Executive Director Simon Mahan took to Twitter on Sunday to criticize the $37 to $39/MWh real-time pricing across MISO South the morning before the emergency, when temperatures near MISO’s Little Rock, Ark., offices were around 18 degrees Fahrenheit. By 9 p.m., pricing in MISO’s Texas territory hit about $284/MWh, though other parts of MISO South hovered around $45/MWh.
It’s unclear how MISO will price load lost to the winter storm, as it is currently investigating how to better price force majeure events. Stakeholders have told the RTO that it made inappropriate after-the-fact price corrections to the $3,500/MWh value of lost load during and after Hurricane Laura. (See MISO to Outline New Pricing Plan for Hurricanes.)
SPP’s 1st Rolling Blackouts in History
SPP was spared from a load-shedding event until just after noon, when it said regionwide demand had exceeded available generation across its 14-state Eastern Interconnection footprint and its available reserve energy had been “exhausted.”
It is the first time SPP has ever resorted to rolling blackouts.
“In our history as a grid operator, this is an unprecedented event and marks the first time SPP has ever had to call for controlled interruptions of service,” COO Lanny Nickell said. “It’s a last resort that we understand puts a burden on our member utilities and the customers they serve, but it’s a step we’re consciously taking to prevent circumstances from getting worse, which could result in uncontrolled outages of even greater magnitude.”
SPP said it had to interrupt service given the decline in imports from its neighbors. It said it has directed its members’ transmission system operators to reduce electricity demand by an amount needed to prevent further uncontrolled outages.
Speaking in a Monday afternoon press conference, senior Vice President of Governmental Affairs Mike Ross said SPP planned for the weather and projected a new winter peak a week in advance. Ross said he was “pleased” to announce that the RTO only had to direct rolling blackouts for a little under an hour until about 2 p.m. CT.
“It doesn’t mean we’ll stay there,” he warned of SPP’s ability to serve load, citing record-high demand and record-low temperatures. “We’ve been coordinating power since 1941; this is the first time in the history of SPP that we’ve found ourselves in this position.”
SPP said that overall, it was just 641 MW shy of its load obligations.
“I don’t want to trivialize any load shedding,” Nickell said. “It’s unprecedented for us. It’s unprecedented for a lot of the country. … Thankfully it didn’t turn out as bad as we expected, and we’re not out of the woods yet.”
Nickell said SPP members already have plans in place to strategically withdraw load when necessary. “We could very well be in and out of this situation until Thursday,” he added. That proved to be the case, as just this morning, SPP was forced to declare another EEA.
The executives said talk about more stringent reserve requirements will be imminent.
“There’s no doubt there will be a lot of policy discussions forthcoming,” Nickell said.
SPP has canceled several stakeholder meetings over the next few days.
“FERC is closely monitoring the extreme weather conditions occurring in much of the country and the impact they are having on electric reliability,” Chairman Richard Glick said in a press release issued Monday afternoon. “The commission is in contact with ERCOT, SPP and MISO, as the regions served by these grid operators have been particularly hard hit by record cold and wintry precipitation. Safeguarding the reliability of the bulk power system is paramount, and I have directed FERC staff to coordinate closely with the RTOs/ISOs, 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, but, for now, the focus must remain on restoring power as quickly as possible and keeping people safe during this incredibly challenging situation.”
