ERCOT Energy Failure

On Sunday night, as the Arctic air swept south across the Great Plains, Texas power plants began to flicker offline.

Wind generation fell by 32 percent between 9 p.m. It's Sunday and 3 a.m. Local time on Monday, according to the U.S. Data on the Energy Information Administration. Coal dropped by 13 percent. And the generation of natural gas, the cornerstone of the Texas grid, has plummeted 25 percent over the six hours.

By the time the sun rose over Texas around 7 a.m., the energy demand for the state's primary electrical grid had been increased to about 71 gigawatts. Texas power plants have accumulated only about 51 GW of electricity, leaving millions without power and shivering in the cold.

It was a different story in the far north. Temperatures were even colder in parts of the Southwest Power Pool, a 14-state electricity system that stretched from North Texas to the Canadian border. But the generation of coal and gas plants there remained steady and even increased. Wind output, meanwhile, followed a typical pattern of decline throughout the day before it picked up again later on Monday. The situation was similar in the Midcontinent Independent System Operator (MISO), a 15-state system from Louisiana to Manitoba's Canadian province.

Neither MISO nor SPP was able to avoid cold grips altogether. They were both forced to cut the electricity off from customers in a bid to stabilize their grids. Yet, these outages were limited in duration and scope compared to what was unfolding in Texas.

The differences point to some of the critical failures that have forced the Texas Electric Reliability Council, the state's primary grid operator, to enforce sustained blackouts since Monday. It also highlights the Biden administration and climate activists' challenge to decarbonize America's electricity grid collection.

The challenges of ERCOT are several. For one thing, it is more dependent on gas for electricity generation than its neighbors, who still boast large coal fleets.

This is important for two reasons. Gas also meets the heating needs, i.e., the demand for fuel surges during a cold snap. Coal doesn't face such competition. It also leaves the state vulnerable to disruptions in the supply of gas. Many gas wells also produce water and distillates, which can freeze during cold periods.

One of the big lessons here is that gas is treated as a firm resource, but not because it relies on just-in-time delivery, explained Alex Gilbert, a fellow who studies energy systems at the Payne Institute for Public Policy, Colorado School of Mines. Looking at SPP and MISO South, there are other planning reasons involved, but they have a more diversified mix, and that helps them.

This isn't the endorsement of coal. Most coal-fired plants in the United States are older, and utilities are investing less in them now. Two factors increase the likelihood of forced outages during extreme weather events. Instead, Gilbert argued that the United States needs to adopt a holistic approach to energy planning that includes other factors, such as energy efficiency and clean technologies, to complement wind and solar energy.

Another item on the list is the planning of extreme weather events, an area where ERCOT has fallen short. In its most recent winter reliability assessment, North American Electric Reliability Corp. predicted that winter demand in ERCOT would peak at around 67 GW in extreme weather conditions. U.S.— Energy Information Administration data shows that the market for ERCOT reached a forecast peak of 75 GW on Tuesday morning.

Simultaneously, the number of plant outages for the ERCOT grid is much higher than expected. The grid operator predicted almost 14 GW of plant outages during the extreme winter weather event. Last night, ERCOT officials said some 43 GW was forced offline. That sum includes plants that have already been offline for scheduled maintenance.

The sheer number of plant outages indicates the most significant difference between ERCOT and its counterparts. The Texas system was not prepared for the cold, despite having experienced freezing temperatures in 2011, which saw gas wellheads lock up and coal plants seize.
Many power plants in the south of the United States are not enclosed inside the building, with boilers and turbines exposed to the elements. It's by design. Leaving critical power plant infrastructure outside prevents overheating during warmer periods. But it can leave power plants vulnerable to cold weather, as the NERC report on the 2018 cold snap in the southeastern U.S. makes clear in 2019.

Power planners in the Great Plains and Upper Midwest, on the other hand, generally enclose their plants because they expect to have to perform under cold weather conditions, explains a former Energy Department official who now works as a consultant. She says, "That's not the case in Texas, so the unprecedented cold weather over so much of the state made it hard for the equipment to perform."

The power plant's design is essential in the context of the political debate as to why the ERCOT grid failed. Republicans have seized cooling wind turbines as a warning that renewables are endangering the grid.
Democrats have responded by noting that the majority of Texas plant outages today account for gas and coal. But both wind turbines and fossil fuels regularly operate at cold temperatures in the northern climates, where they are designed to withstand winter rage.

Wind and solar were not significant contributors to what happened in Texas. They are planning these particular events; they know that events like this will be low in the wind and solar production. That said, looking forward, wind and solar will face challenges with winter demand. And that's something we've got to deal with as we try to decarbonize the electricity system.

Texas' woes highlight some of the challenges facing American climate hawks. Renewable generation is declining in much of the U.S. during the winter months as demand for energy surges. On the other hand, summer is a relatively more comfortable challenge because solar generation generally matches the heat-induced demand spikes.

Solving this problem is exacerbated because the country is trying to make two energy transitions simultaneously, said Emily Grubert, a professor. She studies energy systems at the Georgia Institute of Technology. One is the shift from dirty power plants to cleaner ones. The other is a move to electrify buildings and cars that had previously relied on oil and gas.

Expanding energy planning to include building efficiency standards will be crucial in reducing demand and easing the strain on the girdle, Grubert said. Even so, she explained that it's going to be very, very difficult.