Lesson 1: Grid Complexity is Complex
The Electric Reliability Council of Texas (ERCOT) is the independent system operator (ISO) for most of the state of Texas. It manages the electric grid serving more than 26 million customers, or about 90% of the state’s electric load. The grid connects more than 46,500 miles of transmission lines and about 680 generation units.
On Monday, February 15, at about 3:30 am, ERCOT declared a Level 3 emergency. The amount of power being used was quickly outstripping the amount of power being generated by all those 680 electricity suppliers. A few hours earlier on Sunday evening, Texas had set a new record for power demand of 69,150 megawatts –– more than 3,200 megawatts higher than the previous record set in 2018.
An enormous mass of super cold polar-vortex air pushed into Texas from the north at the same time another enormous weather front was bringing moisture in from the south. The collision of the two had temperatures plunging, ice forming and snow falling over the entire state.
When ERCOT activated its Level 3 protocols, it meant that the grid’s energy reserves dropped to 2,300 megawatts (Level 1)… and then again below 1,700 megawatts (Level 2)… and then again to 1,000 megawatts after the ISO has drawn on its 1,100 megawatts of emergency reserve.
Once Level 3 was declared, ERCOT directed its member utilities to initiate rolling outages to reduce electrical demand. Local utilities, in turn, shut power off across their service-territory neighborhoods. These typically last for 10 minutes to 40 minutes, the net effect of which is that demand is forcibly reduced so that ERCOT can continue to dispatch power to the entire grid while local utilities prioritize essential services like hospitals and water treatment plants to keep them powered. But something didn’t work.
In spite of the precisely defined protocols, people in the grip of freezing temperatures were without power for many hours, and in some cases, more than two days. The rolling blackouts didn’t roll because there wasn’t any power to move from one neighborhood to the next. Every watt of non-essential power that utilities were giving back to ERCOT was soaked up by other ERCOT members. One local utility manager responding to a reporter’s question about all of this simply said, “There’s no more energy we can shut off at this time…we’re stuck.”
In 2020, California experienced outages for weeks at a time due to its crazy weather and then catastrophic fires. The country’s two most populous states remind us that grid resilience is not to be taken lightly. And yet as 20 million Texans shivered through the extended cold snap, it’s not likely they were interested in discussing the finer points of grid management.
That’s a hard lesson to have to re-learn, and it gets complicated by another tendency in play these days. It’s not uncommon to hear from those who advocate for everything to be electrified that grid management is “the easiest problem to solve.” The good people working in ERCOT’s emergency operations center would be quick to disagree with that point of view because it’s absolutely not true.
Lesson 2: Grid Resilience Requires Multiple Path Thinking
Here’s an interesting question: Why didn’t ERCOT just call on operators to generate more power? One answer is that all of the 680-ish power generating units available and capable of operating in the weather conditions were, in fact, creating electricity.
Another is that unlike California, which simply imports electricity from other states when it runs low –– the most of any state as a matter of fact –– ERCOT “has relatively little connection with the rest of the country, making it an island when it comes to supplies.”
And finally, what may likely go unnoticed is that a big chunk of the state’s electrical generation capacity was suddenly offline. The supply was so strained that the average spot price for power across the Texas grid hit the state’s $9,000 per megawatt-hour price cap shortly after 9:30 a.m.
What happened? Frozen turbines and frozen lines.
On an annual basis, a full 20% of ERCOT’s generation capacity comes from west Texas wind, about 20 gigawatts of power. In the winter, that number falls to 10% but the impact was still felt as the mix of freezing temperatures and precipitation paralyzed wind farms across the state. One report claimed that output was down to 4.2 gigawatts. A guest on Path to Zero, Dr. Joshua Rhodes, told the Dallas Morning News, “When wind-turbine blades get covered with ice, they need to be shut down.”
Intermittent renewable energy like wind or snow-covered solar panels is just that –– intermittent. It reminds us that one-dimensional solutions to climate change like 100% renewables and electrifying everything can, and do, leave us in the cold.
At the same time, it’s only fair to acknowledge the new normal in which we find ourselves. The Texas cold was a whole new level of cold for that part of the country, so much so that even the natural gas infrastructure wasn’t up to the challenge.
Dan Woodfin, a senior director for ERCOT, said the same when, aside from wind turbines, he ticked off the main factors involved in the Texas power outage: “Frozen instruments at natural gas, coal and even nuclear facilities, as well as limited supplies of natural gas…[and]…natural gas pressure in particular is one reason power is coming back slower than expected.”
It’s awfully clear that we need multiple energies working together to move us toward net zero while ensuring people’s needs are met in every weather condition. A three-dimensional approach is in order: weather-resistant pipes in the ground, weather-resistant lines overhead and a flexible on-demand system to be where the other two can’t is the wide path necessary for anti-fragility.
In writing about this event, no one rounded it off any better than Robert Bryce, a Forbes columnist and as it turns out, and an Austin resident. He said, “This blizzard proves that attempting to electrify everything would be the opposite of anti-fragile.”
Let me follow Robert’s lead by rounding out with a story from the front lines.
The team at Ferrellgas in Austin should take a bow for keeping more than 6,500 customers near Robert warm throughout all of this by making deliveries, including a late-night run on treacherous roads. This news report highlighted a complaint, but whiffed on the opportunity to tell the whole story.
The location featured in the report –– Chaparral Crossing and Austin’s Colony –– isn’t a collection of rural ranches; it is a 700-home jurisdictional propane service fueled by a 30,000-gallon central tank. The tank was 55% full on Friday. Under challenging weather conditions, that level would not have posed an outage concern. The extraordinary conditions, however, spiked demand. A large transport truck typically serves the community, but icy roads made delivery impossible.
The Ferrellgas team, drawing on its experience in mobilizing for hurricane relief, pulled extra drivers in from San Antonio to make deliveries to the entire area, and in coordination with Austin Emergency Management got the use of a sand truck. Ferrellgas’ Austin District Manager, Luis Perez, and driver Jonathan Huerta were picked up at their homes by the sand truck and taken over to the Ferrellgas office. With the sand truck in the lead and those two in bobtail trucks, they set out into the weather. It took an hour and a half to travel the necessary 12 miles. At about 2:40 am, they arrived, filled the tank and began to restore warmth and comfort back to those neighbors. Luis and Jonathan didn’t get back to the office until after 6:00 am.
We have delivery stories like this playing out across the country. Drivers with cold feet and bloody knuckles worked around the clock in challenging conditions. For the Texas storm, it’s an understatement to say that it was an intense time, requiring extraordinary response.
While we take the big lessons away from this event and use them to think about the long-term problems of grid resilience, let’s also take time to appreciate the people, like Jonathan, Luis and all of the Ferrellgas folks, delivering every day.