Electricity outages in Texas could occur again this summer 鈥� just a few months after the devastating winter storm that left millions of Texans without power for days 鈥� if the state experiences a severe heat wave or drought combined with high demand for power, according to recent assessments by the state鈥檚 grid operator.
Experts and company executives are warning that the power grid that covers most of the state is at risk of another crisis this summer, when demand for electricity typically peaks as homes and businesses crank up air conditioning to ride out the Texas heat. Texas is likely to see a hotter and drier summer than normal this year, according to , and 2021 is very likely to rank among the 10 warmest years on record globally.
鈥淭his summer, I am as worried right now [about the grid] as I was coming into this winter,鈥� said Curt Morgan, CEO of Vistra Corp., an Irving-based power company. 鈥淪ounds like I鈥檓 the boy that cries wolf, but I鈥檓 not. I鈥檝e seen this stuff repeat itself. We can have the same event happen if we don鈥檛 fix this.鈥�
As state lawmakers continue debating how to improve the grid after February鈥檚 storm nearly caused its collapse, on Tuesday Texans were asked to conserve electricity because the supply of power could . A significant chunk of the grid鈥檚 power plants were offline due to maintenance this week, some a result of damage from the winter storm.
The warning triggered a torrent of outrage from residents and political leaders across the state who questioned why the Electric Reliability Council of Texas, which manages the grid, allowed it to come so close to emergency conditions on a relatively mild spring day. 鈥淚 appreciate the increased effort toward transparency, but wow this is nervewracking to see in April,鈥� state Rep. , D-Driftwood, Tuesday.
Heading into the summer, ERCOT included three extreme scenarios in a preliminary assessment of the state鈥檚 power resources for the summer 鈥� the most extreme calculations ERCOT has ever considered for the seasonal assessment. Each scenario would leave the grid short a significant amount of power, which would trigger outages to residents:
- In the first scenario, a drought similar to what the state saw in 2011, combined with low winds, several natural gas plants offline and an increase in economic activity as the pandemic eases, would leave the power grid short 3,600 megawatts, or enough to power 720,000 homes.
- Add low solar power generation to the first projection (say it鈥檚 a cloudy day), and the grid would be short 7,500 megawatts, or enough to power 1.5 million homes.
- In the most extreme scenario ERCOT considered, a severe heat wave across the entire state combined with outages for every major power source would leave the grid short 14,000 megawatts, or enough to power 2.8 million homes.
Power grids must keep supply and demand in balance at all times. When Texas鈥� grid falls below its safety margin of in excess supply, the grid operator , like what happened on Tuesday, to avoid blackouts.
Pete Warnken, ERCOT鈥檚 manager of resource adequacy, told reporters near the end of March that the grid operator included the extreme scenarios to 鈥渂roaden the debate on how to make the grid more resilient.鈥� Still, he said ERCOT expects sufficient power reserves, 鈥渁ssuming normal conditions鈥� this summer.
While the extreme scenarios have a very low chance of actually occurring, an unlikely and severe event happened in February, when extreme cold knocked out several different sources of power at once just as the cold triggered surging demand for power and natural gas fuel shortages. More than 4.8 million customers lost power and at.
A final summer assessment will be published May 6.
鈥淎 catastrophic event like the winter storm could not be predicted several months in advance,鈥� Warnken said, adding that the preliminary report isn鈥檛 intended to forecast unprecedented events.
Rather, Warnken said the scenarios should help inform state leaders and the public of what鈥檚 possible 鈥� 鈥渢he idea is the planners and stakeholders are aware that there鈥檚 a possibility something like that could happen,鈥� he said. 鈥淭hese have a much lower probability of occurring than the traditional grid scenarios.鈥�
Hot, dry summer
, the Texas State Climatologist and director of the Texas Center for Climate Studies, said that this summer in Texas is shaping up to be hot and dry. While it鈥檚 still early, he said temperatures this summer will depend on how much rain the state gets between now and June. Parts of the state 鈥� South Texas to far West Texas 鈥� have been in drought conditions for more than a year, he said.
鈥淭emperatures during the summer depend a lot on how much rain there has been over the preceding several months,鈥� he said. 鈥淚t鈥檚 been fairly dry this past fall and winter and spring so far.鈥�
When heat waves hit large swaths of the state, that puts stress on the grid.
鈥淚n 2011, for example, most of the summer was a heat wave,鈥� Nielsen-Gammon said. That was the driest year on record in Texas, and what ERCOT based its extreme scenarios on this year. That summer, , but widespread outages did not occur.
鈥淲e were in an extreme drought with little moisture available [in 2011],鈥� Nielsen-Gammon said. 鈥淯sually, if you have a heat wave, it鈥檚 going to affect at least half the state if not most of it.鈥�
ERCOT is 鈥渃arefully looking at鈥� the potential for big heat waves and drought this year, Warnken said.
Climate change has than they used to be in the southwest, according to a authored by National Oceanic and Atmospheric Administration scientists. The study found that droughts occurring in today鈥檚 warmer climate cause hotter temperatures than the same drought decades ago 鈥� the low soil moisture combined with higher temperatures produce stronger heat waves.
A large area of Texas will likely have above average temperatures this summer, according to an .
, an associate professor of civil and environmental engineering at Rice University, is concerned about the power grid鈥檚 performance this summer.
鈥淚f ERCOT is struggling to keep the lights on this week, that doesn鈥檛 bode well for summer,鈥� Cohan said. 鈥淐ertainly with climate change, it鈥檚 possible we鈥檒l hit new records for heat waves.鈥�
And despite state lawmakers鈥� advances on legislation aimed to address February鈥檚 outages, Cohan said there is little the Legislature can do to better prepare the state鈥檚 energy infrastructure for this summer. 鈥淚t鈥檚 too late to do a whole lot for this summer,鈥� he said.
Texas鈥� susceptibility to blackouts has long been a concern for the North American Electric Reliability Corp., which has some authority to regulate power plants and oversee grid operators in the U.S.
鈥淔rom my perspective, [Texas] doesn鈥檛 have as much cushion as even ERCOT鈥檚 math says that they should,鈥� said , its CEO and president.
Still, , a fellow in energy at Rice University鈥檚 Baker Institute, said Texas鈥� grid is better prepared for summer heat than extreme cold, and it鈥檚 not unusual for the grid to creep close to its capacity in the hottest months.
鈥淲e deal with [heat] more often,鈥� she said. During the summer, she said, 鈥渢he energy systems are better prepared.鈥�
