The grid failures were most severe in Texas, where more than 4 million people woke up Tuesday to rolling blackouts. Separate regional grids in the Southwest and Midwest also faced serious strain. As of Tuesday afternoon, at least 23 people nationwide had died in the storm or its aftermath.
Analysts have begun to identify key factors behind the grid failures in Texas. Record-breaking cold weather spurred residents to crank up their electric heaters and pushed power demand beyond the worst-case scenarios that grid operators had planned for. At the same time, a large fraction of the state’s gas-fired power plants were knocked offline amid icy conditions, with some plants suffering fuel shortages as natural gas demand spiked. Many of Texas’ wind turbines also froze and stopped working.
The crisis sounded an alarm for power systems throughout the country. Electric grids can be engineered to handle a wide range of severe conditions — as long as grid operators can reliably predict the dangers ahead. But as climate change accelerates, many electric grids will face extreme weather events that go beyond the historical conditions those grids were designed for, putting them at risk of catastrophic failure.
While scientists are still analysing what role human-caused climate change may have played in this week’s winter storms, it is clear that global warming poses a barrage of additional threats to power systems nationwide, including fiercer heat waves and water shortages.
Measures that could help make electric grids more robust — such as fortifying power plants against extreme weather or installing more backup power sources — could prove expensive. But as Texas shows, blackouts can be extremely costly, too. And, experts said, unless grid planners start planning for increasingly wild and unpredictable climate conditions, grid failures will happen again and again.
“It’s essentially a question of how much insurance you want to buy,” said Jesse Jenkins, an energy systems engineer at Princeton University. “What makes this problem even harder is that we’re now in a world where, especially with climate change, the past is no longer a good guide to the future. We have to get much better at preparing for the unexpected.”
A System Pushed to the Limit
Texas’ main electric grid, which largely operates independently from the rest of the country, has been built with the state’s most common weather extremes in mind: soaring summer temperatures that cause millions of Texans to turn up their air conditioners all at once.
While freezing weather is rarer, grid operators in Texas have also long known that electricity demand can spike in the winter, particularly after damaging cold snaps in 2011 and 2018. But this week’s winter storms, which buried the state in snow and ice, and led to record-cold temperatures, surpassed all expectations — and pushed the grid to its breaking point.
Texas’ grid operators had anticipated that, in the worst case, the state would use 67 gigawatts of electricity during the winter peak. But by Sunday evening, power demand had surged past that level. As temperatures dropped, many homes were relying on older, inefficient electric heaters that consume more power.
The problems compounded from there, with frigid weather Monday disabling power plants with capacity totalling more than 30 gigawatts. The vast majority of those failures occurred at thermal power plants, like natural gas generators, as plummeting temperatures paralysed plant equipment and soaring demand for natural gas left some plants struggling to obtain sufficient fuel. A number of the state’s power plants were also offline for scheduled maintenance in preparation for the summer peak.
The state’s fleet of wind farms also lost up to 4.5 gigawatts of capacity at times, as many turbines stopped working in the cold and icy conditions, although this was a smaller part of the problem.
In essence, experts said, an electric grid optimised to deliver huge quantities of power on the hottest days of the year was caught unprepared when temperatures plummeted.
“No one’s model of the power system envisioned that all 254 Texas counties would come under a winter storm warning at the same time,” said Joshua Rhodes, an expert on the state’s electric grid at the University of Texas, Austin. “It’s putting major strain on both the electricity grid and the gas grid that feeds both electricity and heat.”
While analysts are still working to untangle all of the reasons behind Texas’ grid failures, some have also wondered whether the unique way the state manages its largely deregulated electricity system may have played a role. In the mid-1990s, for instance, Texas decided against paying energy producers to hold a fixed number of backup power plants in reserve, instead letting market forces dictate what happens on the grid.
On Tuesday, Gov. Greg Abbott called for an emergency reform of the Electric Reliability Council of Texas, the nonprofit corporation that oversees the flow of power in the state, saying its performance had been “anything but reliable” over the previous 48 hours.
‘A Difficult Balancing Act’
In theory, experts said, there are technical solutions that can avert such problems.
Wind turbines can be equipped with heaters and other devices so that they can operate in icy conditions — as is often done in the upper Midwest, where cold weather is more common. Gas plants can be built to store oil on-site and switch over to burning the fuel if needed, as is often done in the Northeast, where natural gas shortages are common. Grid regulators can design markets that pay extra to keep a fleet of backup power plants in reserve in case of emergencies, as is done in the Mid-Atlantic.
But these solutions all cost money, and grid operators are often wary of forcing consumers to pay extra for safeguards.
“Building in resilience often comes at a cost, and there’s a risk of both underpaying but also of overpaying,” said Daniel Cohan, an associate professor of civil and environmental engineering at Rice University. “It’s a difficult balancing act.”
In the months ahead, as Texas grid operators and policymakers investigate this week’s blackouts, they will likely explore how the grid might be bolstered to handle extremely cold weather. Some possible ideas include: Building more connections between Texas and other states to balance electricity supplies, a move the state has long resisted; encouraging homeowners to install battery backup systems; or keeping additional power plants in reserve.
The search for answers will be complicated by climate change. Overall, the state is getting warmer as global temperatures rise, and cold-weather extremes are, on average, becoming less common over time.
But some climate scientists have also suggested that global warming could, paradoxically, bring more unusually fierce winter storms. Some research indicates that Arctic warming is weakening the jet stream, the high-level air current that circles the northern latitudes and usually holds back the frigid polar vortex. This can allow cold air to periodically escape to the South, resulting in episodes of bitter cold in places that rarely get nipped by frost.
But this remains an active area of debate among climate scientists, with some experts less certain that polar vortex disruptions are becoming more frequent, making it even trickier for electricity planners to anticipate the dangers ahead.
All over the country, utilities and grid operators are confronting similar questions, as climate change threatens to intensify heat waves, floods, water shortages and other calamities, all of which could create novel risks for the nation’s electricity systems. Adapting to those risks could carry a hefty price tag: One recent study found that the Southeast alone may need 35% more electric capacity by 2050 simply to deal with the known hazards of climate change.
The task of building resilience is becoming increasingly urgent. Many policymakers are promoting electric cars and electric heating as a way of curbing greenhouse gas emissions. But as more of the nation’s economy depends on reliable flows of electricity, the cost of blackouts will become ever more dire.
“This is going to be a significant challenge,” said Emily Grubert, an infrastructure expert at Georgia Tech. “We need to decarbonise our power systems so that climate change doesn’t keep getting worse, but we also need to adapt to changing conditions at the same time. And the latter alone is going to be very costly. We can already see that the systems we have today aren’t handling this very well.”
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