More than a year after the events of February 2021, in which an unprecedented winter storm nearly led to the entire collapse of the Texas Interconnection, FERC and NERC continue to gather information from utilities, generators and grid operators on maintaining electric reliability during severe cold weather.
That continued this week with a two-day joint FERC-NERC technical conference on winterizing generation. Staff heard from more than 25 stakeholders on the best practices, lessons learned and continuing challenges of generator owners’ and operators’ preparations for the winter season.
“It’s a very important discussion,” Chairman Richard Glick said, starting off the conference Wednesday. “I think people recognize what happened in Texas. … One of [the] factors was that the generating facilities, in many cases, didn’t operate very well under the cold weather that was experienced, and we need to make sure that doesn’t happen again.”
He referred to a similar event 10 years before, when an arctic cold front in Texas and New Mexico caused 1.3 million customers to lose power in early February 2011. More than 200 generating units in ERCOT experienced an outage, derate or failure to start, and a joint FERC-NERC report found that many generators had failed to adequately prepare for winter, even though extreme cold fronts hit the region every few years.
“We know for a fact that a decade before Winter Storm Uri, there was a similar issue in Texas and some of the other Southwest states,” Glick said. “A report was done. The report said, ‘We have a problem. We need to winterize these generating facilities.’ The report was put on the shelf, and nothing happened.”
During last year’s storm, dubbed by The Weather Channel as “Uri,” ERCOT ordered a total of 20,000 MW of rolling blackouts as it tried to prevent grid collapse — the largest manually controlled load shedding event in U.S. history.
More than 4.5 million people lost power for as long as four days, with numerous deaths resulting from the outages, another report by FERC, NERC and six regional entities said. Among its recommendations was to hold a tech conference “to discuss how to improve the winter readiness of generating units” before NERC reliability standards approved by FERC in August — in response to another prior cold snap in the Midwest in 2018 — become effective on April 1, 2023. (See FERC, NERC Release Final Texas Storm Report.)
“We’re not going to let that happen again, and today’s technical conference is one of the steps that we are taking to ensure that to be the case,” Glick said. “We will work with our partners at NERC and the regional entities as well. I think at the end of the day, we’re going to have a much stronger and much more reliable grid because of it.”
“I can’t stress enough how important communication is,” NERC CEO Jim Robb said in opening Day 2 of the conference Thursday. “I think one of the worst things to happen to a grid operator is to be surprised when they’re expecting resources to be there and they aren’t. … We’re hoping for a lot of insights to come out of this conference. …
“And of course, while this is focused on winter prep, we have to remember that changing climate conditions aren’t just limited to cold-weather events. We also have to be cognizant of hot-weather events and in general rethink how we plan and operate the system to deal with extreme events, which are not rare, as we’ve seen over the last several years.”
Cold Weather Preparedness Plans
The conference’s first panel consisted of utility executives discussing the measures they were taking to head off another winter catastrophe.
Most natural gas plants in Texas are outdoor facilities that require additional protection during cold fronts, they said.
Garry Waggoner, senior director of engineering services for Luminant, the main generation subsidiary of Vistra, said that following the 2011 cold front, the company began hardening its generation units against freezing by instituting measures to be completed by November of each year.
Luminant’s fleetwide measures include temporary wind breaks for critical equipment, freeze-protection circuitry monitoring and enclosing sensitive equipment in heat- and humidity-controlled boxes, he said.
Other generators said they use similar measures.
Roger Morgan, vice president of operations at NRG Energy, said that the company’s outdoor generating units in ERCOT installed wind breaks, additional insulation and roofing over essential systems susceptible to the cold and precipitation.
Precipitation, especially in the form of freezing rain, had a big impact during the storm and “probably caused a lot more grief at the plant levels than people may recognize or understand,” Morgan said.
NRG also pre-starts gas units before cold snaps to avoid icing, he said. Each generation site has a winter-readiness coordinator who reports to a regional coordinator. And after every winter, the company conducts a root-cause analysis of problems to avoid repeating them in future years, he said.
“We revise and develop mitigation plans and put those back into our procedure to make sure that we never have a repeat issue at any of our sites,” Morgan said.
Experiences and Lessons Learned
A panel on planning, engineering and technologies for weatherization offered some practical insights and suggestions for addressing cold weather events in what are typically warm climates.
“In the South, we used to use an event time of about 24 hours as a common design [standard],” said Mark Dittus, a project manager for infrastructure consulting firm Black and Veatch. “You would expect to see the freeze event during the night, but then you’d expect to go above freezing again the next day. So you only had a short period that you were worried about.”
But growing instances of “unprecedented” long-duration cold snaps are driving the firm’s clients to upgrade their systems, Dittus said.
El Paso Electric (EPE) is one of those clients. The utility, which serves about 450,000 customers in far West Texas and southeast New Mexico, dealt with the winter events of 2011 and 2021 but faced “severely different” outcomes in each, according to Kyle Olson, director of power generation and asset management at the utility.
EPE “did not do so well” during and after the 2011 storm. “We had major issues with our generation fleet, and we had days of rolling blackouts as a result,” Olson said, noting that in 2011 the majority of the EPE’s generation fleet had been built between 1957 and 1988.
In the wake of the storm, EPE worked with Black and Veatch to devise new facility design criteria rated to -10 degrees F, 2 degrees below El Paso’s all-time low temperature. The consulting firm helped the utility prioritize equipment for freeze protection based on risk to a unit’s operational ability. Top priorities included steam drum level transmitters and major control valves; further down the list were water lines used for a facility’s drinking water.
EPE has also brought on about 500 MW of new generation since 2011 and is currently adding another 228 MW, most of which is gas-fired. Olson said the utility’s newer gas-fired Montana plant is designed for minimal water use and freezing risk and can run on diesel as a backup.
The utility fared much better during the 2021 storm, in part because of its access to power from the Palo Verde nuclear plant in Arizona, which helped the utility avoid price spikes in the market. But the utility did identify one new vulnerability after the storm: inexperienced staff.
“They hadn’t gone through the training and then gone through the implementation of the freeze protection in 2011, so what they thought was good freeze protection, being a summer-peaking utility,” was inadequate, Olson said. “We found gaps where they would go by and walk past something and go, ‘That looks fine; that looks good.’”
Amanda Frazier, senior vice president of regulatory policy at Vistra, said her company “had a disappointing performance” during the 2011 storm but experienced different problems in February 2021, despite having worked with NERC, ERCOT and Texas regulators to implement recommended best practices around weatherization.
Between 2011 and 2021, Vistra retired about 4,000 MW of coal-fired generation and discontinued use of fuel oil backup at several plants because both were considered uneconomic, Frazier said. Like other Texas utilities, Vistra faced frozen coal piles and limitations on the gas system during the 2021 storm. The company has since invested $50 million to winterize its plants and is working to restore dual-fuel capability at those facilities with permitted fuel tanks.
But Frazier said weatherization of generating plants won’t be enough to head off another grid event like that stemming from Uri.
“It’s necessary, but it’s not sufficient to prevent the next winter storm event,” Frazier said. “Unique to Winter Storm Uri were gas shortages, exceptionally high gas prices and lack of incentives to invest properly in the weatherization of the gas infrastructure facilities. … So, there must be an equivalent focus on improving the reliability of that key supply chain.”
In a similar vein, Steve Metcalf, vice president of power production and delivery at Arkansas Electric Cooperative Corporation, pointed to yet another exigency that’s not within a utility’s control during cold weather events: the standards of other utilities.
Metcalf noted that while his co-op’s consumer-owners might be willing to pay more than other electricity customers to ensure winter reliability, the broader market might have higher tolerance for risk that could force his company to institute outages anyway.
“It’s not up to us whether or not we’re experiencing or required to do rolling blackouts or brownouts; it’s up to the market,” he said.
A Rare Success Story
During the third panel, FERC heard from representatives of ISO-NE, NYISO, PJM and SPP about their generators’ winter readiness procedures.
But also on the panel was Andrew Valencia, senior vice president of generation for Lower Colorado River Authority, whom FERC and NERC were “very eager to hear from,” according to Heather Polzin, of the commission’s Office of Enforcement.
While many gas plants did not operate during the 2021 storm, the Austin, Texas-based nonprofit utility’s Thomas C. Ferguson plant — a 556-MW gas-fired combined cycle facility located in the nearby city of Horseshoe Bay — “actually performed quite well” despite the many challenges staff faced, Valencia said.
The plant broke ground in 2012 and, according to Valencia, was “designed with the 2011 event in mind,” able to withstand down to 0 F and up to 40-mph winds.
But the plant was not designed to withstand below-freezing temps for extended periods of time. Valencia said that is true of most plants in Texas, even those with very low temperature ratings, so “it’s definitely a concern going forward.” Even with the plant’s performance, LCRA installed permanent wind walls and shielding around certain pieces of equipment that froze during the event, Valencia said. Though they required responses, increased staffing meant the freezing did not impact plant operations. LCRA called for Level 3 staffing — what Valencia said is called “battle stations” — in place about two days before the most severe weather hit because in 2011, the extreme cold came earlier than forecast.
One of the challenges to cold weather preparation that Valencia wanted to stress during his presentation is that a plant “can’t functionally test [its] weather-protection systems. You know we can test relays; we can test water-induction systems; we can test all of the different subsystems … [but] the only way [to test] is to actually endure some type of an event.”
Another challenge, especially in Texas, is “that the things that you do to protect your plant from extreme cold hurt your plant in extreme heat. We can go and add enclosures and things of that nature to protect us from the cold, but an enclosure around a pump or a motor during the hot summer season is going to be problematic.”
Gas-Electric Coordination Key to Resilience
In the last panel, participants discussed how last year’s winter revealed just how intertwined the gas and electric industries have become, and the pitfalls that can result when they don’t communicate their needs.
“We’ve found that training and drill exercises are critical to preparedness,” said Jessica Lucas, senior director of reliability coordination at MISO. “Experience has proven to be the best teacher, and we’ve had quite a bit of that in recent years.”
Among the lessons that MISO learned from Uri was to bring more urgency to both its weekly fuel data requests and its annual generation winterization survey. Both information requests are still voluntary, but for the latest winter, Lucas said the RTO attempted to impress on its entities the importance of supplying accurate information.
Measures to encourage cooperation with the annual survey this year included preseason conferences with major utilities. For the weekly fuel surveys, Lucas said MISO has elevated them to formal data requests. While this format is still voluntary, she said the goal is to emphasize to respondents how seriously the RTO views the situation.
Last year’s storms also brought home the fact that generators’ theoretical performance doesn’t always match their real-world functioning, said Todd Staples, president of the Texas Oil and Gas Association. He reminded participants not to take for granted the ability to respond to changing grid conditions in real time.
“Even with the best hardening of field assets, we have to keep in mind that most of these assets are unmanned. … There are more assets than there are people,” Staples said. “And so there’s going to be a production decline, depending on the severity of the weather, and it’s very important for reliability that we plan on this production decline and take the steps that are going to mitigate that.”
Representatives of the pipeline industry focused on the efforts their companies have made to work with electric utilities and regulators on predicting how loads are likely to shift in response to changing weather conditions.
“We really believe in the continued improvement of the balancing authority websites — that’s a huge asset for us as a pipeline operator,” said Frank Rozmus, vice president of gas control and facility planning at Northern Natural Gas. Rozmus said he and his team “spend possibly hours a day on the websites of the [BAs] in our footprint, making sure that we get up-to-date information, and it really assists us with our load supply forecast.”
Speakers also highlighted the role that government can play in facilitating the sharing of information across industries. Staples pointed to the Railroad Commission of Texas’ recent designation of critical load facilities as a sign that the needed collaboration, not only between industry segments but also with the public sector, is finally taking root.
“In my eight years here … I’ve never seen this level of engagement … between industries. The Railroad Commission of Texas, ERCOT, the Public Utility Commission [and] Division of Emergency Management have all been fully engaged, and private industry has been having multiple conversations,” Staples said. “And so I think we’re moving in the right direction.”
