Huge winter storms plunged large parts of the central and southern United States into an energy crisis this week, when the blasts of the Arctic climate damaged electrical grids and left millions of Americans without power amid dangerously low temperatures.
The grid failures were most severe in Texas, where more than four million people woke up Tuesday morning to power failures.
Analysts have begun to identify some key factors behind the Texas network failures. Record cold weather spurred residents to increase their electric heaters and pushed demand for electricity beyond the worst scenario that network operators had planned. At the same time, many of the state’s gas-fired power plants were shut down amid icy conditions, and some plants appeared to suffer from fuel shortages due to increased demand for natural gas across the country. Many Texas wind turbines also froze and stopped working, although that was a minor part of the problem.
The resulting electricity deficits forced Texas grid operators to impose rotating blackouts on homes and businesses, starting on Monday, to prevent a wider system collapse. Separate regional networks in the southwest and midwest are also under heavy pressure this week.
The crisis highlighted a deeper alert for energy systems across the country. Electrical networks can be designed to handle a wide range of harsh conditions – as long as network operators can safely predict the dangers ahead. But as climate change accelerates, many electrical networks will face new and extreme weather events that go beyond the historical conditions for which these networks were designed, putting systems at risk of catastrophic failure.
Building electrical networks that are resilient in the face of an increasingly wild and unpredictable climate will be a huge challenge, experts say. In many cases, it can be expensive, although, as Texas shows, network failure costs can also be extremely expensive.
“It’s essentially a matter of how much insurance you want to buy,” said Jesse Jenkins, a power systems engineer at Princeton University. “What makes this problem even more difficult is that we are now in a world where, especially with climate change, the past is no longer a good guide to the future. We need to prepare ourselves much better for the unexpected. “
A grid pushed to the limit
Texas’s main power grid, which operates independently from the rest of the country, is designed primarily to deal with the state’s most predictable climatic extremes: the high summer temperatures that encourage millions of Texans to turn on their air conditioners at once.
Although cold weather is more rare, network operators in Texas have long known that the demand for electricity can also increase in the winter, especially after severe chills in 2011 and 2018 prompted millions of Texans to turn on their electric heaters and overload the system.
But this week’s winter storms, which buried the state in snow and ice and led to record cold temperatures, exceeded all expectations – and brought the network to its breaking point.
Texas network operators predicted that, in the worst case scenario, the state could need 67 gigawatts of electricity to handle the winter spike. But on Sunday night, the energy demand had surpassed 69 gigawatts. With the drop in temperatures, many homes have come to rely on older, inefficient electrical resistance heaters, which consume more energy.
The problems worsened thereafter, when cold weather disrupted power plants with more than 30 gigawatts of capacity on Monday night. The vast majority of these failures occurred in thermal plants, such as natural gas generators, as the sharp drop in temperatures paralyzed the plant’s operations and increased demand for natural gas across the country appeared to leave some plants struggling to obtain fuel. Several state power plants were also shut down for scheduled maintenance in preparation for peak summer.
Sometimes, the fleet of wind farms in the state also lost up to 5 gigawatts of capacity, as many turbines froze in icy conditions and stopped working.
“No model of power system predicted that all 254 counties in Texas would be under a winter storm alert at the same time,” said Joshua Rhodes, a state power grid specialist at the University of Texas, Austin. “It is putting a lot of pressure on the electricity network and the gas network that feeds electricity and heat.”
Building more resilience
In theory, experts say, there are technical solutions that can prevent these problems. But installation can be expensive, and the difficulty lies in predicting exactly when and where these solutions will be needed.
Wind turbines, for example, can be equipped with heaters and other devices so that they can operate in icy conditions – as is usually done in the upper midwest, where the cold is more frequent. Gas plants can be built to store oil on site and burn fuel if necessary, as is usually done in the Northeast, where natural gas shortages are more common. Network regulators can design markets that pay more to keep a fleet of backup plants in reserve in case of emergencies, as is usually done in the Mid-Atlantic.
But all of these solutions cost money, and network operators are often cautious about forcing consumers to pay more for safeguards if they think they won’t be necessary.
“Building resilience usually comes at a cost and there is a risk of paying less, but also more,” said Daniel Cohan, associate professor of civil and environmental engineering at Rice University. “It is a difficult balancing act.”
In the coming months, as Texas network operators and lawmakers study this week’s winter storm, they may begin to wonder how and if the network can be strengthened to deal with extremely cold temperatures. Is there an obsolete infrastructure that is in dire need of repair? Would it make sense to build more connections between the Texas grid and other parts of the country to balance the electricity supply – a measure that the state has long resisted? Should homeowners be encouraged to install expensive backup battery storage units or more efficient heat pumps that use less electricity? Should the state’s electricity markets be adjusted to keep additional power plants in reserve?
One difficulty is that climate change is making preparation difficult. Overall, the state is getting warmer as global temperatures rise, and cold extremes are, on average, becoming less common over time.
But some climate scientists have also suggested that global warming could, paradoxically, bring on more winter storms like the one seen this week. There is some research suggesting that warming in the Arctic is weakening the jet stream, the high-level airflow that surrounds northern latitudes and generally retains the icy polar vortex. This allows cold air to escape south, especially when an additional heating explosion hits the stratosphere and deforms the vortex. The result can be episodes of temperature drop, even in places that are rarely cut by frost.
But this remains an active area of debate among climate scientists, with some experts less certain that disruptions in the polar vortexes are becoming more frequent, making it even more complicated for network planners to predict the dangers to come.
Across the country, electricity utilities and network operators are facing similar issues, as climate change threatens to intensify heat waves, droughts, floods, water scarcity and other calamities, which can create new and unforeseen risks for consumers. country’s electrical systems. Dealing with these risks will come at a high price: a recent study found that only the Southeast may need 35% more electrical capacity by 2050 simply to deal with the known risks of climate change.
And the task of building resilience is becoming more and more urgent. Many policymakers are increasingly promoting electric cars and electric heating as a way to reduce greenhouse gas emissions. But as the country’s economy depends on reliable flows of electricity, the cost of failures will become increasingly dire.
“This is going to be a significant challenge,” said Emily Grubert, an expert in electrical systems at Georgia Tech. “We need to decarbonize our energy systems so that climate change does not continue to get worse, but we also need to adapt to changing conditions at the same time. And only the last one will be very expensive. We can already see that the systems we have today are not handling it very well. “
John Schwartz contributed reports.