Chances are that you’ve already heard about the ongoing power outages in Texas and other nearby states. If you haven’t gotten the message already, the situation is dire and totally unprecedented. In the midst of a historic cold snap, electricity demand has outstripped supply by a massive amount. Faced with no other choice, the electrical grid operator in Texas shut off power to millions of Texans early Monday morning, and many are still without power even now.
This particular type of power outage, where demand for electricity exceeds supply, is rare. The last time this type of power outage made headlines was in August 2020, when California’s grid operator was forced to implement rotating outages two days in a row during a historic heat wave.
Over the past few days, I have been glued to my screen reading anything and everything about the Texas power outages to try to make sense of what went wrong. At the same time, I’ve also been reflecting on the similarities and differences between the ongoing power outages in Texas and the California power outages last summer.
On the surface, the power outages in Texas and California are similar. But when you dig deeper, they have less in common than you’d think. Let’s start with the similarities.
Similarity #1: Extreme weather drove the electrical grid over the brink
The power outages in Texas and California were both instigated by extreme weather that drove the electrical grid over the brink. In Texas, it has been an icy arctic weather system that brought snow and freezing temperatures to much of the southern US. In California, it was a record heatwave that baked most of the western US for days.
Climate change is likely to exacerbate the types of extreme weather that led to both of these outages. Not only will extreme heatwaves become more common, but scientists are also studying the connection between climate change and extreme cold events. We need to make sure the power grid is ready for both.
Similarity #2: Clean energy is not to blame
A blast of déjà vu came over me as I read the first reports out of Texas, blaming frozen wind turbines for the power outages. Of course, despite the misinformation propagated by fossil-fuel industry interests, news eventually emerged that frozen wind turbines are not the primary cause. Though a significant amount of renewable capacity has been forced offline, the biggest factor contributing to the power outages in Texas has been the jaw-dropping number of power plants that have unexpectedly gone offline, and the biggest culprit has been thermal power plants that run on fossil fuels like natural gas.
California had to fight back against similarly disingenuous claims blaming renewables for the August 2020 rotating outages. In the end, the official analysis of the California blackouts highlighted three main reasons for the outages: extremely hot weather, antiquated grid reliability planning, and malfunctioning energy markets. Renewables are not to blame for either outage.
Difference #1: The power outages in Texas are much worse
The rotating power outages in Texas started at 1:25 AM on Monday morning, and after days of power outages, the end is only finally coming into sight. The grid operator in Texas has been instructing utilities to reduce load by 10,000 MW (and up to 16,500 MW of load at times), cutting off power to millions of homes for extended periods of time in the middle of dangerously cold weather. To put those numbers in perspective, Texas’s grid operator set a new record on Sunday for winter peak electricity demand at 69,000 MW, so utilities have been cutting off power to a huge portion of the grid. To me, the enormous scale of these rotating power outages and the multi-day duration is what’s most shocking.
In California, the August 2020 outages were much smaller and far shorter. On August 14, the California grid operator asked utilities to shed 500 MW of load for approximately two hours. On August 15, it was 500 MW of load for 20 minutes.
To make the comparison more explicit,
the Texas power grid has been cutting off 20-30 times as much electricity demand as California did, and this has been happening for days on end.
To be clear, I’m definitely not saying that California’s power outages were no big deal. (Even short power outages can be deadly for certain folks.) Instead, I’m drawing this comparison because, if what happened in California was shocking last summer, then there are no words to capture the disastrous scale of the 72 hours and counting of power outages in Texas.
Difference #2: Texas natural gas power plants have failed in a big way
When I first saw the news reports with the number of power plants that have been forced offline in Texas, I was certain it was a typo. But I was wrong.
While the situation has improved since then, as of 9am Wednesday morning an eye-popping 46,000 MW of generation had been forced offline due to the cold weather. According to the Texas grid operator, roughly 28,000 MW was thermal generation, while the other 18,000 MW was wind and solar. To put some perspective on these numbers, California’s peak electricity demand on August 14 was nearly 47,000 MW, so if all the resources that have been forced offline in Texas were running at their maximum output, they could just about power California.
Much of the thermal generation capacity that has gone offline in Texas is natural gas power plants that can’t run because there just isn’t enough gas. The cold weather has put a major dent in natural gas production, and Texans are also using more gas than usual to heat their homes. This has left many Texas gas plants without fuel to burn, and the power outages have continued for so long because the weather has stayed cold and there hasn’t been enough gas for the power plants.
The August 2020 power outages in California are an entirely different story. California had a couple thousand megawatts of natural gas power plants that were offline, and those levels were more or less what grid operators were expecting.
The big take-away here is that Texas’s natural gas system along with its power plants have failed on an unprecedented scale due to the cold weather. This correlated failure of the gas system and gas power plants, in conjunction with record electricity demand due to the cold spell, have all combined to create these historic outages in Texas.
Due to the freezing temperatures, huge numbers of natural gas power plants in Texas have been forced offline due to insufficient natural gas supplies or equipment failure.
Difference #3: Texas’s power grid is isolated
Because Texas has its own power grid, its grid is mostly isolated from the rest of the country. As a result, Texas is much less able to import power from other states during emergencies like this one. Even if Texas’s electrical grid were more connected to nearby states, it’s unclear exactly how much extra electricity Texas would have been able to import since many of its neighbors have also resorted to rotating outages. But increasing grid connectivity is one of the best strategies for ensuring grid reliability.
On the other hand, California’s electrical grid is very connected to its neighbors, which allows California to import electricity from nearby states. As a result, California has the ability to import over 10,000 MW of electricity. However, during the west-wide heatwave that caused the August 2020 outages, California’s neighbors didn’t have much electricity to spare, and California was only able to import a few thousand megawatts when the state was most in need. Even though those imports were lower than usual, they helped prevent even more severe rotating outages in California.
After the August 2020 outages in California, state regulators set to work to revamp energy market rules and grid reliability planning to
ensure extreme heatwaves don’t hobble California’s electrical grid again in the future. In particular, regulators have been working on changes to California’s resource adequacy program to ensure grid reliability as California transitions to 100% clean electricity grid.
Texas does things differently. The grid operator there has no such program to ensure grid reliability – they just count on the profit motive to keep the grid reliable. The idea is that, when electricity is in short supply and electricity prices skyrocket, investors will be incentivized to add generation to the system and power plant owners will make sure their plants are able to operate so that they can make a ton of money. But that’s obviously not how this has played out. Texas power plants were not ready, and they weren’t ready the last time a winter cold-front descended on Texas in 2011. Now the question is whether Texas regulators will do more to ensure grid reliability, especially in extreme cold conditions, or whether they will continue to leave it up to energy markets and power plant owners.
Ultimately, the electrical grids in both California and Texas have been facing the impacts of climate change, and those impacts will only get worse over time. From heatwaves to cold snaps, hurricanes to wildfires, our current methods for ensuring grid reliability are clearly not meeting these challenges. Our electrical grids must evolve not only to reduce emissions and mitigate climate change, but also to adapt to climate change impacts.
Featured image: Ash and call for help on car in 2017. Image by Joseph Wachunas.