The lights have stayed on in Texas among the recent freezes the state has been experiencing, but experts aren't sure whether the energy grids are winterized enough to withstand the next deep freeze.
Texas typically experiences deep freezes that really test its power grids once every decade, Ramanan Krishnamoorti, vice president of energy and innovation at the University of Houston, told ABC News. December 1983 holds the record for the coldest December for both Dallas-Fort Worth and Waco.
In 1991, a Halloween blizzard and ice storm overtook southeast Houston. Other freezes occurred in the early 2000s, specifically in 2011, which is known colloquially as the "Super Bowl freeze" because it took place over the Super Bowl weekend hosted at AT&T Stadium in Arlington, Texas. In 2021, more than 100 people died as a result of rolling blackouts during back-to-back ice storms that brought temperatures as low as 6 degrees.
How the grids have held up amid the recent tests, including freezes this week and in December around the Christmas holiday, has been "remarkable," Krishnamoorti said.
In terms of demand and capacity, both renewable energy production and natural gas supply have been available "as predicted," he added.
"We're not seeing any significant challenges with the power grid at this point," other than occasional local outages associated with icing on transmission cables, Krishnamoorti said.
Energy-wise, the winter season has been so successful that price spikes for electricity have stayed well below what was anticipated, Krishnamoorti said. While predictions were measuring electricity prices to increase to about $100 megawatts per hour, it was stayed closed to $25 to $30, Krishnamoorti said.
Several coal and gas production plants underperformed during the December freeze, and ERCOT underestimated the demand by about 10%, Daniel Cohan, associate professor of environmental engineering at Rice University in Houston, told ABC News. Despite there being "record amounts" of demand on the grid, no widespread outages have occurred. In addition, because it has been so windy in the region, the wind production made up for the coal and gas production facilities that did go down, Cohan said.
"That was a great sign that the grid performed better than it had in 2021," Cohan said.
However, the tests to the grid these past two winter seasons have not acted as "true stress tests," Krishnamoorti said. The current freeze is "much less intense" in terms of temperature and temperament, compared to the back-to-back winter storms of 2021 that caused a statewide energy catastrophe, he said. In addition, there has been no ice and snow, Cohan said.
During this cold spell, temperatures have not dipped into the negatives or even to single digits. In addition, the ice that did cause some local outages only fell in select regions, such as Dallas and Austin, Krishnamoorti said.
Changes have been made to the grid, Krishnamoorti said. In June 2021, Texas Gov. Greg Abbott signed a bill to reform the state's power grid and how it is operated.
Power plants in Texas have installed hundreds of millions of dollars worth of updates to better winterize their facilities, Cohan said.
But it is unclear whether those changes have led to a true winterization of the system, Krishnamoorti said.
"Nature is the best stress test," he said. "The only way we will know whether the system can stand through the stress test is actually put it through that stress test."
ERCOT expects sufficient generation to meet demand this season and is continuing to monitor forecasts throughout this week, a spokesperson told ABC News in an email statement on Monday.
"Ice on trees, powerlines can lead to localized outages," the ERCOT spokesperson said. "If customers are experiencing a local power outage they are to reach out to their local power provider or visit the PUCT outage map for more information."
One of the challenges to winterizing Texas' energy grid is that the freezes don't happen often, Cohan said. After about a third of homes blacked out during the "Super Bowl" freeze in 2011, it would be near-impossible to determine what the demand would have been had the lights stayed on, Cohan said.
The energy sector is also in the middle of a "dynamic shift," as electrification becomes more commonplace than less sustainable sources, such as coal, nuclear energy and natural gas, Krishnamoorti said.
"That's great for reducing natural gas use and reducing emissions most of the year, but it makes us more vulnerable to having big surges in demand," Cohan said.
While Krishnamoorti expects the "next big one" to occur some time in the 2030s, climate scientists believe that climate change increase the frequency in which deep freezes reach the southern-most states in the U.S.
While those types of deep freezes have historically occurred once every decade, climate change could threaten the Lone Star State with more frequent occurrences in the future, scientists say.
As the Arctic warms and Arctic ice melts, the jet stream, a band of strong winds moving west to east created by cold air meeting warmer air, becomes weaker. As the jet stream becomes more "wavy," it allows very warm temperatures to extend far into the Arctic and very cold temperatures further south than usual, Jessica Moerman, vice president of science and policy at the Evangelical Environmental Network, a faith-based environmental group, told ABC News in 2021.
The loss of human life as a result of extreme weather events is "highly avoidable" in the U.S., Krishnamoorti said. In addition, the economic fallout that occurs as a result of blackout situations in Texas can also be catastrophic, especially in the medical and natural gas industries, he added.
"If Texas sneezes, the world will probably catch a cold," Krishnamoorti said.