Don't snow on Texas: Diving into the 2021 blackouts

Much has already been written about this week's power outages in Texas and their devastating impact on the millions of people who are left in the dark and the cold. Unfortunately, much of the original reporting about the cause of the blackouts contained misinformation. So we want to join the growing chorus of articles setting the record straight on what happened in Texas and take a look at how to prepare to keep the lights on during severe weather events in the future.

As a quick recap, beginning Sunday, February 14th, the entire American South–including Texas–was plunged into a deep freeze as arctic conditions managed to escape the polar vortex (remember that?) and head to southern latitudes. In an ironic twist of fate, scientists believe that the Arctic blast is at least partially attributable to climate change: abnormally warm conditions above the Arctic weakened the climatic system that typically keeps cold temperatures isolated above the North Pole, allowing them to seep to lower, more populated locations.

As we reached record low temperatures across the region, and within Texas specifically, demand for electricity and natural gas for heating increased rapidly. However, for several reasons that we'll expand on below, power plants in Texas couldn't meet that need, ultimately leaving more than 4 million customers without electricity in the Lone Star State.

While many initial reports looked for one silver bullet responsible for leaving millions of Texans in the dark, the real answer is more of a perfect storm of scenarios. There are a few key factors that contributed significantly to the outages:

The Lone Star State has a lonely grid

The first thing to know about electricity in Texas is that the state runs its own electrical grid. This may not sound particularly remarkable–New York has its own grid operator too, but the devil's in the details. Not only does Texas operate its grid, the state's electrical grid is separate from the rest of the country's electrical system.

As seen in the image below from the DOE, the entire Eastern part of the country is one interconnected electrical grid, as is the Western part of the country. Texas, meanwhile, has its own "interconnection," the Electricity Reliability Council of Texas Interconnection (ERCOT). The transmission topology of Texas is important because it means that they're entirely self-reliant–if something goes wrong, they're mainly out of luck and can't call on other states for help. In New York, on the other hand, if multiple of the state's power plants can't operate, New York can get extra energy from Pennsylvania/New Jersey, New England, or Canada.

Texas plans for a summer, not a winter, peak

Every region plans for its "peak" period, i.e., when electricity demand is the highest across the state. States as hot as Texas plan for summer peaks, generating a sophisticated demand forecast under different weather conditions. For instance, in a hot year, if everyone in the state has their air conditioning units on at the same time on the same day of the year, the peak demand will be higher than if it's a cooler weather year when people don't run their air conditioners as frequently.

The trouble is that Texas didn't plan for the entire state to be in a winter warning simultaneously. (And really, why would they - this was the first time it's ever happened.) But that meant the Texas electrical grid wasn't designed with a winter storm event in mind.

Power plants expected natural gas; it went to homes (or froze) instead

A significant portion of Texas's electricity generation comes from natural gas power plants: according to a 2020 report from ERCOT, nearly half of the state's electricity is produced by natural gas.

During cold snaps, though, natural gas is needed by power plants and for home-heating needs. The US Energy Information Administration (EIA) says that natural gas is the primary heating fuel for more than a third of households in Texas. So when the temperature drops, like this week, natural gas power plants compete for natural gas supply with home heating needs.

But natural gas contracts (and pipeline regulations) are typically structured to meet home heating needs first before sending additional natural gas to power plants. By all reports, that happened this week: natural gas was diverted to home heating and away from power plants, leading to outages at natural gas plants.

Also, some interesting reports indicate that mechanisms that keep natural gas pipelines functional (like compressors) froze, and the temperature was so cold that liquids literally froze inside pipelines and in wells, contributing to its lack of availability.

Yes, some wind turbines froze, but don't blame wind

The deep freeze in Texas adversely impacted all energy sources. However, several of the first headlines about the outages–including from major outlets like the Wall Street Journal–blamed the outages solely on wind turbines. This is a red herring and a misdirection.

Yes, some wind turbines froze. But wind produced more electricity than expected at this time of year, according to ERCOT as per Bloomberg.

Some observers have pointed out that despite having nearly 30 megawatts of wind resources in Texas (more than any other state!), the operator only expects about a quarter to operate in the winter. There is definitely a discussion to be had about how to design an electric grid that takes advantage of the seasonal perks of different types of electricity as we continue to move towards a cleaner grid, but that's not ultimately the cause (or even a major contributing factor) to what happened here: ERCOT planned for a certain amount of wind production, and got most of it, but was primarily let down by coal and natural gas units.

It already has! But the regions where this type of event has happened in the past learned from the outage event and adapted the grid so that it wouldn't happen again (or would at least be less likely to occur in the future).

The best example is New England: in 1965, a November snowstorm plunged much of the region into darkness. (Don't take my word for it, I wasn't there.) In response, the region created a power pool to share resources with a central power dispatcher. Ultimately, that meant that in 2003, when blackouts hit much of the eastern part of the country, the Northeast was largely spared from the outage (ISO-NE's words, not mine). So it is possible to learn from what happened and build a more resilient grid to better withstand extreme weather events like the arctic cold snap in Texas this week.

For those energy wonks out there, there's a certain level of risk that grid operators have deemed acceptable. In most places in the country, the grid is designed to a "one-day-in-ten" standard. This means they plan on having system-wide outages no more frequently than one day every ten years. If you planned more conservatively than this, the cost to the system would be unacceptably high. All of which is to say that blackouts aren't common, but it's expected under standard grid planning practices that they will occur about once a decade.

Installing a solar-plus-storage system is one clear way to ensure your home has electricity even when the rest of the grid doesn't. When you pair a solar-plus-storage system, whatever electricity from your solar panels you don't use during daylight hours charges your battery, which powers your home through the night until the sun rises and the process repeats the following day. Most batteries provide more than enough power to keep your essentials running–think lights, refrigerators, wifi, and chargers–for multiple days. In contrast, some larger systems can power more of your home for longer (at a higher cost).

Now you may think, "Hold on...if the solar panels are covered in snow, they won't work, right?" This is true, but only to a certain extent: solar panels won't operate when they're still covered in snow, but they shed that snow faster than your roof typically would, meaning the snow will slide off your glass panels pretty soon after the storm, especially if the sun is up. As a solar owner in a snowy climate, I can attest to this–it's sometimes a bit frightening to hear the mini-avalanche slide off the panels on my roof, but knowing how quickly they are back to powering my home is reassuring.

If you're looking for the peace of mind of knowing that you'll have power even when the grid goes dark, you can take the first steps towards improved resiliency for your home today by registering for an account on EnergySage. We do the hard work of screening installers in your area and gathering quotes, so you can compare your options from the comfort of your couch without ever picking up the phone. Sign up for a free account today to see what solar and storage can do for you.