2021 Texas Power Outage
Hi and welcome to Failurology; a podcast about engineering failures. I’m your host, Nicole
And I’m Brian. And we’re both from Calgary, AB.
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This week in engineering news, or interesting things we recently read about, Smart Watches for Dolphins.
Similar to how a smart watch can tell the wearer how many calories they burn or steps they take, wearables for dolphins can now estimate how much energy they use when swimming.
This study comes from the University of Michigan and Dolphin Quest Oahu where they’ve developed wearables, known as biologging tags, to monitor dolphin behavior and movement.
Animal habitats are impacted by a number of factors, including climate change, shipping, overfishing, oil exploration, construction, etc. since they live underwater, it’s much harder for humans to track how these factors impact their ability to find food and socialize.
Scientists are trying to determine how much energy dolphins consume to forage for food and then extrapolate to determine the energetic costs when the dolphins' habitats are disturbed.
They can also use the wearables to determine how much energy dolphins use to swim and therefore the energetic costs of relocation.
Unlike other tags that are similar to a piercing or embedded under the skin, the dolphin wearables sit between the dolphin's blowhole and fin and are attached with suction cups. They measure speed, temperature, pressure and movement.
While the study is focused on bottlenose dolphins for now, the technology can be extrapolated to many other animals in and out of the water. This will help better inform humans on how we are impacting their habitats.
If you want to read more about the study, check out the link on the web page for this episode at failurology.ca
Now on to this week’s engineering failure; the 2021 Texas Power Outage.
Winter Storm Uri formed on February 13, 2021 in the Pacific Northwestern United States, quickly moved into the Southern US and then over to the Midwest and Northeastern US a couple days later. The storm had 130 kph wind speeds for 1 minute sustained, there were 6 confirmed tornadoes, up to 66c m of snow in some areas, hundreds of deaths, and over 9 million people were without power (just over half in the US and the rest in Mexico). Winter Storm Uri is the costliest winter storm on record.
Even though the storm impacted most of the US, Texas got it worse due to some flaws in their energy infrastructure.
A lot of the information we are getting about the storm comes from a University of Texas at Austin Energy Institute report issued 5 months after the storm. Link to this report is on the webpage for this episode at failurology.ca and they outline their objective, participants, and information sources.
The Electric Reliability Council of Texas, known as ERCOT, an independent system operator (re private sector) provides the majority of the state's consumers with power via an intra-state grid with limited interconnection to two other main electrical grids serving the US and Canada. The line between the east and west grids isn’t quite along state lines, but for the purpose of this discussion, everything west of and including Alberta, Montana, Wyoming, Colorado, and New Mexico are on the west grid and everything east of there is on the east grid.
US power generation began in the late 1800s with small power plants and local transmission. As the individual systems grew, they started to connect together to create a stronger, more robust grid. Except Texas. To avoid federal regulation in 1935, Texas avoided connecting their network to the national grid.
While there is some interconnection between the Texas grid and the west and east national grid as well as the Mexican grid, it’s not enough to power all of Texas and the Texas grid remains mostly isolated from the rest of the national network.
Deregulation of the Texas electricity market started in the 1990s, which offered retail competition and potentially lower fees for consumers, but also meant cutting costs for contingency preparation.
Natural gas has been the main fuel source for power generation in Texas, although they have been working on renewable energy sources in recent years. Even though the natural gas and electricity sectors intersect in power generation, they are managed by two separate regulators in Texas. The Public Utility Commission of Texas (PUCT) oversees electricity services and the Texas Railroad Commission (RRC) oversees natural gas.
ERCOT’s meteorologists use models to predict weather events, like the winter storm, but even a day or two before the storm, the models disagreed on forecasted temperatures by as much as 5°C and the actual temperatures were lower than the predictions by up to 12°C. Electricity load projections are based on weather forecasts, and the disagreement on the forecast impacted ERCOT’s ability to understand the load requirements.
But they discovered quickly that blackouts would be likely and at least 10% of the grid would be shut off. But the actual demand was higher than expected in extreme winter weather and they were not prepared. The demand was more than 12,000 MW higher than the grid's capacity, and 3,200 MW higher than the previous record set.
Although, and I am not an electrical engineer or have any experience with power generation, wouldn't you plan for the worst case scenario and then adjust for actual conditions?
The storm brought freezing temperatures, which for those of us in Canada who spend half the year in this condition, we know how to manage this, but for Texas, who spends very little time at this temperature, they are not as well prepared. Most homes in Texas have poor insulation and are heated with inefficient electric heaters.
There were a number of outages across all Texas power generation methods, they are as follows:
Wind turbines were the first to go as freezing rain and fog formed ice on the blades and the cold temperatures impacted the gearboxes and nacelles. Wind energy accounts for about 23% of Texas power generation.
Fuel delivery curtailments were impacting natural gas generators even before the storm. This was made worse by the storm as processing plant outputs dropped 85% as some compressors that push gas through pipelines were disabled when power was cut. Natural gas storage was also limited.
Frozen water intakes, frozen sensing lines, and freezing of other general equipment.
There were existing scheduled and planned outages or mothballed units that were unable to get back online in time, as well as other equipment issues not related to the storm.
Power generation plants experienced frequency issues as well as some of the transmission and substations experienced outages.
Of the winterized generators, some were inadequately prepared for the winter conditions experienced.
For the equipment that was still running, the output was derated for the temperature. Equipment has an optimal operating temperature range and when you go above or below that the equipment starts to become less efficient and its capacity reduces in relation to the temperature. Unrelated to this storm, but interesting fact, fuel burning appliances also derate for elevation so in Alberta, Colorado and other high elevation areas, you need to use high elevation equipment.
Outages accounted for up to 40% of ERCOT’s infrastructure by February 15th and didn’t come back online fully until February 19th. Had one of the many issues we listed been avoided, there might have still been blackouts, but their duration and severity would have likely been lower. It was the perfect storm really.
With the demand continuing to rise and supply dropping, ERCOT started to reduce the demand on the system to prevent catastrophic failure and they started shedding load, resulting in rolling blackouts and for some just a blackout. According to ERCOT, the grid was “seconds or minutes away from” complete failure when they started shedding load. Had they not started rolling outages, the grid would have been overwhelmed and equipment would have caught fire and power lines would have gone down, which would probably have caused a worse blackout than what they saw.
Impact on Residents
This led to 4.5 million homes and businesses without power for several days, shortages of water, food and heat, and officially 246 deaths (directly and indirectly) with estimates as high as 700.
Some pipes froze and burst, resulting in water disruption to over 12 million people. By the end of the storm, the city of Austin alone lost more than a billion liters of water due to broken pipes.
The food shortages were due to lost power at several stores, and the ones who remained open were completely cleared out of staple items.
A fire near San Antonio required firefighters to use a water tender, which is a truck that can draw water into its holding tank from a stream or river, to fight a fire because the hydrant was unusable.
Due to licensing requirements, a shortage of plumbers led to months long delays to repair burst pipes.
Of the deaths, several hundred were from carbon monoxide poisoning from people running their cars or generators indoors for heat.
About 1000 doses of the COVID-19 vaccine were lost as a result of not being able to store or transfer them properly.
Another consequence of the outages were the additional release of pollutants from stopping and starting fossil fuel infrastructure. Most of this infrastructure has a purge cycle to clear the burner as a safety function. The purge cycle flushes the burner of inert gas before and after every fire. There is also additional fuel used when cold starting an engine. This pollution is estimated to account for 1 ton of the carcinogen benzene, 2 tons of sulfur dioxide, 12 tons of natural gas, and 34 tons of carbon monoxide.
While state officials tried to deflect blame, the failure to winterize power sources was the cause of the grid failure. If I remember correctly, their senator fled to Mexico in the midst of the disaster. A federal report a decade before the 2021 failure warned Texas that the power plants would fail in such a winter storm, but it went ignored. We will get to the storm that instigated this report in a minute.
Costs for the winter storm damage are at least $195 billion USD. We have talked about this before, in almost all cases, the cost of the failure and subsequent fines or penalties almost always outweigh the cost of doing it right the first time. Which makes this so much more annoying.
That said, some energy firms made billions in profits by charging extremely high wholesale prices ($9,000 / MWh instead of $50 / MWh). It’s been alleged that ERCOT held the price at the cap of $9,000 / MWh for two days longer than necessary, resulting in $16 billion in unnecessary charges. Then-CEO of ERCOT testified in court that he was following directives from the Texas governor when he allowed prices to remain at the inflated level. Other energy firms who couldn’t charge the higher prices went bankrupt. The cost of electricity on February 16th alone is said to be higher than the cost in all of 2020.
Residents received about $200 per person to offset the higher electricity costs, but that doesn’t make a very big dent for those with a $5,000 bill.
1989 and 2011 Events
In December of 1989 and February of 2011 there were also similarly cold winter weather events. These storms saw temperatures the same or slightly colder than the 2021 storm.
In 1989, there was less market competition and more oversight; although they still experienced outages and issues due to the weather. While there were still rolling blackouts in 1989, they lasted less than 10 hours, rather than 4 days.
On groundhog day (February 2nd) 2011, a blizzard hit Taxas and caused rolling blackouts for 75% of the state. Many roads were impassable and there were boil water advisories for several areas.
In 2011, while there was more competition, the weather was not quite as bad as 1989 or 2021, and the outages were limited to 8 hours at most.
After the 2011 storm, the North American Reliability Corporation, who we talked alot about in episode 37 about the 2003 NE Blackout, recommended several upgrades to protect Texas’ infrastructure and prevent a similar winter blackout. But these recommendations were ignored due to the cost of winterizing the systems.
Best we can tell, everyone is pointing fingers at everyone else and little has been done to actually protect Texas from another winter blackout. If you’re listening to this in Texas, you might want to move, or take some steps to run your house off the grid in case another storm comes through.
So there you have it, the 2021 Texas Power Outage. A lack of interconnection to the East and West grids, money not spent on upgrading electrical infrastructure to deal with winter storms, and conflicting weather models led to a catastrophic electrical shutdown for over 9 million people.
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Bye everyone, talk soon!