Huge winter storms plunged large parts of the central and southern United States into an energy crisis this week as frigid explosions in arctic weather crippled power grids and left millions of Americans without electricity in high temperatures dangerously cold.
The network outages were most severe in Texas, where more than four million people woke up to power outages Tuesday morning. Gov. Greg Abbott on Tuesday called for emergency reform of the Texas Electricity Reliability Council, saying the state’s power grid operator “has been anything but reliable for the past 48 hours.”
Analysts have started to identify some key factors behind the Texas network outages. Record-breaking cold weather prompted residents to ramp up their electric heaters and pushed demand for electricity beyond the worst-case scenarios predicted by network operators. At the same time, many of the state’s gas-fired power plants have been shut down in freezing conditions, and some factories appear to be suffering from fuel shortages as demand for natural gas has increased across the country. Many Texas wind turbines also froze and stopped working, although that was only a small part of the problem.
The resulting power shortages have forced grid operators in Texas to impose rotating power cuts on homes and businesses, starting Monday, to prevent a wider system collapse. Separate regional networks in the Southwest and Midwest are also under serious strain this week.
The crisis has highlighted a deeper warning for power systems across the country. Power grids can be designed to cope with a wide range of harsh conditions – provided that grid operators can reliably predict future dangers. But as climate change accelerates, many power grids will face new and extreme weather events that go beyond the historical conditions for which these grids were designed, putting systems at risk of catastrophic failure.
Building resilient power grids in the face of increasingly wild and unpredictable weather conditions will be a huge challenge, experts said. In many cases, this can prove to be costly, although, as Texas shows, the costs of a network outage can also be extremely expensive.
“It’s basically a matter of how much insurance you want to buy,” said Jesse Jenkins, an energy 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 for the future. We need to prepare much better for the unexpected. “
A grid taken to the extreme
Texas’ main power grid, which operates largely independently from the rest of the country, is primarily designed to deal with the state’s most predictable weather extremes: soaring summer temperatures that prompts millions of Texans to turn on their air conditioners at the same time.
Although freezing temperatures are rarer, grid operators in Texas have long known that demand for electricity can increase in the winter as well, especially after severe cold spells in 2011 and 2018 that drove millions of Texans to mount their electric heaters and put a strain on the system.
But this week’s winter storms, which buried the state in snow and ice, and led to record high temperatures, exceeded all expectations – and pushed the grid to its breaking point.
Texas grid operators had predicted that in a worst-case scenario, the state might need 67 gigawatts of electricity to handle a winter peak. But by Sunday evening, demand for electricity had exceeded 69 gigawatts. As temperatures dropped, many homes depended on older, inefficient electric resistance heaters, which used more energy.
The problems worsened from there, as freezing weather shut down power plants with a capacity of more than 30 gigawatts by Monday night. The vast majority of these outages occurred in thermal power plants, such as natural gas generators, as falling temperatures crippled plant operations and growing nationwide demand for natural gas seemed to leave some factories find it difficult to procure fuel. A number of state power plants were also offline for scheduled maintenance in preparation for the peak summer.
At times, the state’s wind farm fleet has also lost up to 5 gigawatts of capacity as many turbines froze in freezing conditions and stopped working.
“No power system model imagined that all 254 Texas counties would be subject to a winter storm warning at the same time,” said Joshua Rhodes, a state power grid expert at the University of Texas at Austin . “This puts a strain on the electricity grid and the gas grid, which supply both electricity and heat.”
In theory, experts say, there are technical solutions that can avoid such problems. But their installation can be expensive and the difficulty is to anticipate exactly when and where such solutions will be needed.
Wind turbines, for example, can be fitted with heaters and other devices so they can operate in freezing conditions – as is often done in the upper Midwest, where the cold is more common. Gas plants can be built to store the oil on site and burn the fuel if needed, as is often done in the Northeast, where natural gas shortages are more common. Grid regulators can design markets that pay extra to keep a fleet of standby power plants in reserve for emergencies, as is often the case in the Mid-Atlantic.
But all of these solutions cost money, and network operators are often reluctant to force consumers to pay extra for warranties if they don’t think it will be necessary.
“Building resilience often comes at a cost, and there is a risk of both underpaying but also overpaying,” said Daniel Cohan, associate professor of civil and environmental engineering at Rice University. “It‘s a difficult balancing act.”
In the coming months, as network operators and policymakers in Texas study this week’s winter storm, they may begin to wonder how and if the network could be hardened to withstand extremely cold temperatures. Are there aging infrastructures that are in urgent need of repair? Would it make sense to create more connections between the Texas power grid and other parts of the country to balance electricity supplies – a move the state has long resisted? Should homeowners be encouraged to install expensive backup batteries or more efficient heat pumps that consume less electricity? Should state electricity markets be altered to keep additional power plants in reserve?
One of the challenges is that climate change makes preparation more difficult. Overall, the state is warming as global temperatures rise, and cold weather extremes are becoming, on average, less frequent over time.
But some climatologists have also suggested that global warming could, paradoxically, lead to more winter storms like this week’s. Some research suggests that the warming of the Arctic is weakening the jet stream, the high-level air current that circles northern latitudes and generally holds back the icy polar vortex. This allows cold air to escape southward, especially when an additional warming explosion hits the stratosphere and warps the vortex. The result can be episodes of plunging temperatures, even in places rarely suffocated by frost.
But this remains an active topic of debate among climatologists, with some experts less convinced that polar vortex disturbances are more and more frequent, which makes it even more difficult for network planners to anticipate the dangers ahead.
Power utilities and grid operators across the country face similar issues as climate change threatens to intensify heat waves, droughts, floods, water shortages and other calamities, all of which could create new and unforeseen risks to the country’s power systems. Dealing with these risks will come at a cost: A recent study found that the South East alone may need 35% more electrical capacity by 2050 just to cope with the known dangers of climate change.
And the task of building resilience is becoming increasingly urgent. Many policymakers are increasingly promoting electric cars and electric heaters as a means of reducing greenhouse gas emissions. But as more of the national economy depends on reliable electricity flows, the cost of blackouts will become increasingly dire.
“It’s going to be a tall order,” said Emily Grubert, electrical systems expert at Georgia Tech. “We need to decarbonize our power systems so that climate change doesn’t get worse, but we also need to adapt to changing conditions at the same time. And the latter alone is going to be very expensive. We can already see that the systems we have today don’t handle this very well.
John Schwartz and Dave montgomery contribution to reports.