Huge winter storms plunged large parts of the central and southern United States into an energy crisis this week, while icy explosions from the Arctic again paralyzed electrical grids and left millions of Americans without power amid dangerously cold temperatures.
The network outages were the worst in Texas, where more than four million people woke up Tuesday morning due to power outages.
Analysts have begun to identify some key factors behind the failures in Texas. The record-breaking cold weather has prompted residents to push their electric heaters up and push the demand for electricity above the worst-case scenarios for network operators. At the same time, many of the state-owned gas-fired power plants have been pushed off track amid icy conditions, and some plants appear to have fuel shortages as demand for natural gas has risen nationwide. Many of the wind turbines in Texas also froze and stopped working, although this was a minor part of the problem.
The resulting power outages forced network operators in Texas to impose rotating interruptions on homes and businesses, which began Monday, to prevent a wider system crash. Separate regional networks in the South West and the Middle East are also coming under serious tension this week.
The crisis has highlighted a deeper warning for power systems across the country. Electrical grids can be designed to handle a wide range of serious conditions, as long as grid operators can reliably predict the dangers ahead. But as climate change accelerates, many electric grids will experience new and extreme weather conditions that go beyond the historical conditions for which the grids were designed, putting the systems at risk of catastrophic failure.
The experts said it would be a huge challenge to build electric grids that are resilient in light of increasingly wild and unpredictable weather. In many cases, it can be expensive, although the cost of network outages, as Texas points out, can also be very expensive.
“It’s essentially about 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 the past, especially with climate change, is no longer a good guide for the future. We need to get much better at preparing for the unexpected. ”
A grid to the extreme printed
Texas’ main electricity network, which operates largely independently of the rest of the state, is primarily designed to handle the state’s most predictable weather extremes: rising summer temperatures that prompt millions of Texans to turn on their air conditioners at the same time.
While icy weather is scarcer, network operators in Texas have long known that the demand for electricity could rise in winter as well, especially after severe cold in 2011 and 2018 led millions of Texans to turn on their electric heaters and power up 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 – pushing the grid to its breaking point.
Texas grid operators expected that in the worst case, the state would need 67 gigawatts of electricity to handle a winter peak. But by Sunday night, demand for power had risen above 69 gigawatts. As the temperature dropped, many homes relied on older, inefficient heaters for electrical resistance, consuming more power.
The problems worsened from there, as icy weather knocked out the power stations with a capacity of more than 30 gigawatts on Monday night. The vast majority of these failures have occurred at thermal plants, such as natural gas generators, because the fall in temperature-paralyzed operations and the rising demand for natural gas nationwide have apparently made some plants struggle to obtain fuel. A number of state power plants were also offline for scheduled maintenance in preparation for the summer peak.
Sometimes the state’s fleet of wind farms also lost up to 5 gigawatts of capacity as many turbines froze in the icy conditions and stopped working.
“No one foresaw the model of the power system that all 254 counties in Texas would come under a winter storm warning simultaneously,” said Joshua Rhodes, an expert on the state’s electrical network at the University of Texas, Austin. “It puts a lot of strain on both the electricity network and the gas network that supplies both electricity and heat.”
Build more resilience
In theory, experts said that there are technical solutions that can prevent such problems. But it can be expensive to install, and the problem is to expect exactly when and where such solutions are needed.
For example, wind turbines can be equipped with heaters and other appliances so that they can operate in icy conditions – as is usual in the upper Midwest, where cold weather occurs frequently. Gas plants can be built to store oil and burn fuel if necessary, as is usual in the Northeast, where natural gas shortages are more common. Grid regulators can design markets that pay extra to keep a fleet of backup power plants in reserves in case of emergency, as is usually done in the Mid-Atlantic.
But all of these solutions cost money, and network operators are often wary of forcing consumers to pay extra for warranties if they do not think they will be needed.
“Building resilience often comes at a cost, and there is a risk of underpayment, but also of overpayment,” said Daniel Cohan, an associate professor of civil and environmental engineering at Rice University. “It’s a difficult balance.”
As Texas network operators and policymakers study this week’s winter storm, they may begin to ask in the coming months how and whether the network can be strengthened to handle extremely cold temperatures. Is there outdated infrastructure that urgently needs to be repaired? Would it make sense to build more connections between Texas’ power grid and other parts of the state to balance electricity supply – a step the state has long resisted? Should homeowners be encouraged to install expensive backup batteries or more efficient heat pumps that use less electricity? Should the state’s electricity markets be adjusted to keep additional power stations in reserve?
One problem is that climate change makes it harder to prepare. In general, the state is getting warmer as world temperatures rise, and extreme cold weather is becoming less common on average.
But some climate scientists have also suggested that global warming could paradoxically lead to more winter storms than those seen this week. There is research that suggests that warming of the North Pole weakens the jet stream, the high-level air current that surrounds the northern latitudes and usually holds back the icy pulse vortex. This allows the cold air to escape to the South, especially when an explosion of extra heat hits the stratosphere and deforms the vortex. The result can be deliveries of downward temperatures, even in places that are rarely cut by frost.
But it remains an active area of debate among climate scientists, with some experts less certain that polar vortex disruptions are becoming more frequent. This makes it even more difficult for roster planners to anticipate the dangers that lie ahead.
Across the country, electric utilities and network operators face similar questions, as climate change could increase heat waves, droughts, floods, water shortages and other disasters, all of which could pose new and unforeseen risks to the country’s electricity systems. Dealing with the risks holds a solid price: One recent study found that the southeastern country may need 35 percent more electricity capacity by 2050, just to face the known dangers of climate change.
And the task of building resilience is becoming more urgent. Many policymakers are increasingly promoting electric cars and electric heating as a way to limit greenhouse gas emissions. But as more of the country’s economy depends on reliable flow of electricity, the cost of failures will become increasingly serious.
“It’s going to be a big challenge,” said Emily Grubert, an expert in electricity systems at Georgia Tech. ‘We need to make our power systems carbon-free so that climate change does not get worse, but at the same time we also need to adapt to changing conditions. And the latter alone is going to be very expensive. We can already see that the systems we have today do not handle this very well. ”
John Schwartz contribution made.