Extreme temperatures pose one of the biggest challenges to the U.S. electric grid, with summer heat waves and winter cold snaps driving especially high demand for electricity to stay cool or warm.1 As climate change continues to increase the frequency and intensity of extreme temperatures, the reliability of an already stressed and aging electric grid will decrease, increasing the likelihood of blackouts.2 In recent years, extreme temperatures have coincided with power outages in most regions across the country, threatening the health and safety of Americans who lose access to electricity needed to regulate indoor temperatures and use lifesaving medical equipment.3
The U.S. electric grid needs to be modernized to handle the hotter summers and more intense winter storms that come with climate change, as well as the resulting increase in electricity demand from air conditioning and heating equipment.4 While the fossil fuel industry may suggest that conventional fossil fuels are the solution to meet the growing needs of the electric grid, fossil fuels are increasingly unreliable during extreme temperatures.5 Instead, relying on a diverse range of clean energy sources, along with investments in the transmission of electricity, can increase the resilience of the electric grid during periods of extreme temperatures while simultaneously reducing public health risks and greenhouse gas emissions.
Recent events have highlighted the devastating impacts of extreme temperatures and power outages
The past five years have seen the devastating effects of extreme temperatures on the electric grid:
- Winter Storm Uri hit Texas in February 2021, leaving millions of Texans without electricity to keep warm from the freezing cold. Uri resulted in the deaths of 246 people and economic damages of up to $130 billion.6 The storm froze natural gas wellheads and gathering facilities, resulting in a lack of natural gas supply to both home furnaces and power plants.7
- In 2022, nearly 13 percent of the East Coast’s generating capacity—again, primarily natural gas—failed when Winter Storm Elliott hit, resulting in more than 60 deaths.8
- In June 2025, an extreme heat wave affected nearly half the U.S. population, from Utah to Maine, and approximately 80,000 people experienced power outages amid life-threatening temperatures.9
These examples highlight a larger trend threatening grid reliability and public health: Temperature-related power outages have seen a significant increase in recent years, with 60 percent and 97 percent more heat-related and cold weather-related power outages, respectively, from 2014 to 2023 than from 2000 to 2009.10 As climate change increases the frequency and intensity of extreme heat and cold events, this increase in temperature-related power outages is likely to continue.
The North American Electric Reliability Corporation (NERC) is responsible for ensuring a reliable and secure electric grid, regularly assessing grid reliability. In its 2024–2025 Winter Reliability Assessment, NERC found that “more extreme winter conditions extending over a wide area could result in electricity supply and energy shortfalls.”11 And in its 2025 Summer Reliability Assessment, NERC found “an elevated risk of supply shortfalls during wide-area heat waves and abnormal weather conditions like those that have occurred in recent summers.”12 NERC assessed similar risks in its 10-year assessment, with several regions projected to face elevated risks of electricity supply shortfalls during extreme conditions.13
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Natural gas and coal are unreliable and unaffordable for ensuring grid reliability during periods of extreme heat and cold
The current approach of overreliance on fossil fuels for electricity generation to maintain grid reliability is inadequate and threatens more widespread power outages. Conventional fossil fuels—namely, natural gas and coal—generated roughly 60 percent of utility-scale electricity in the country in 2024.14 However, these energy sources are particularly vulnerable to both extreme heat and cold.
In extreme heat conditions, the efficiency and maximum generating capacity of fossil fuels—that is, the amount of electricity they can produce—is reduced. Higher ambient air temperatures lower the density of air and leave less room in the turbine for natural gas to be burned, meaning that natural gas plants can burn less fuel and, as a result, produce less electricity.15 Both natural gas and coal plants also need water or air to act as a coolant to get rid of “waste heat” from combustion. Hotter coolant temperatures mean that the fossil fuel plants cannot get rid of as much waste heat after burning fuel and, again, produce less electricity as a result.16 While grid operators typically account for the reduced capacity and efficiency, more intense and frequent extreme heat conditions can result in fossil fuel plants being forced to reduce their output beyond expectations and sometimes even be shut down entirely.17
Extreme cold conditions can affect the production of natural gas, primarily through the freezing of water and hydrates in natural gas streams, resulting in a domino effect across the supply chain.18 For example, during Winter Storm Uri, freezing temperatures resulted in frozen natural gas production wellheads and a 45 percent decline in production volumes.19 Consequently, natural gas processing facilities, pipeline operations, and natural gas power plants were all affected. During Winter Storm Uri, natural gas fuel supply issues, which include natural gas production declines and related natural gas pipeline pressure issues, accounted for 27 percent of power plant generation outages.20
During Winter Storm Uri, natural gas fuel supply issues, which include natural gas production decline and related natural gas pipeline pressure issues, accounted for 27 percent of power plant generation outages.
The overreliance on fossil fuels is not only unreliable but also expensive. Grid operators in the Northeast and the Midwest typically pay plant owners “capacity payments” funded by ratepayers to ensure that the plants are capable of producing electricity when needed, especially in times of extreme temperatures when the grid is stressed.21 This mechanism is meant to compensate plant owners for only operating a few hours per year when the additional electricity generation is really needed. For example, in New York City, the grid operator paid an estimated $4.5 billion to power plant owners between 2010 and 2019 at the ultimate expense of ratepayers.22 However, in recent years, capacity payments have failed to economically meet grid reliability; for example, capacity auctions in the Eastern region increased electricity bills by 30 percent for 65 million people in 2025, and are projected to increase them another 5 percent in 2026 and 2027.23 Furthermore, the price of natural gas is extremely volatile, and overreliance can result in increased utility bills for households.24
Coal’s role in generating electricity in this country has been declining primarily due to poor economics. Coal plants are also aging, with more than half of the current coal fleet scheduled to retire in the coming years.25 These aging units have seen an increased number of unplanned outages in recent years—more than any other power source.26 Despite the Trump administration’s attempts to revive the dying coal industry, and multiple national efforts to delay the retirement of coal plants, coal is simply too expensive and unreliable.27 In fact, 99 percent of coal power plants in the United States are more expensive to operate than to replace with new wind or solar, and coal plants are only getting more expensive as they continue to age.28
Administrative intervention to extend the lives of these uneconomic and unreliable coal plants may cost customers more than $3 billion per year through 2028.29 This does not even take into account the fact that coal and gas emit large amounts of greenhouse gas emissions, which would trigger a feedback loop of more extreme heat and cold events from climate change as well as more potential power outages from a stressed grid.30 The reality is that as several fossil fuel plants approach retirement, the electric grid needs more energy—and quickly, especially with energy demand expected to increase by up to 29 percent over 2023 levels in 2035.31
Extreme temperature-induced power outages are a major threat to public health, especially for vulnerable communities
Extreme temperatures not only strain the grid but also expose people to dangerous and potentially deadly conditions when the grid fails, depriving people of refrigeration, heating, and cooling at the times when they may need them most.32 Prolonged exposure to extreme heat in particular can result in a variety of heat-related illnesses, including heat cramps, exhaustion, and stroke.33 Meanwhile, exposure to extreme cold puts people at risk of hypothermia and carbon monoxide poisoning from burning fossil fuels as use of backup generators increases.34 Older adults, disabled people, and others reliant on electricity-dependent medical equipment; those unable to evacuate; and those with underlying health conditions face increased vulnerability when they lose power.35 For example, models show that a heat wave coinciding with a multiday power blackout in Phoenix could put 1 million residents at high risk of heat-related illness, with more than 50 percent of the city’s population requiring urgent medical care simultaneously.36 With more people increasingly dependent on electricity for their medical equipment and other underlying health conditions, an increase in power outages would spell disaster.
Models show that a heat wave coinciding with a multiday power blackout in Phoenix could put 1 million residents at high risk of heat-related illness, with more than 50 percent of the city’s population requiring urgent medical care simultaneously.
Power outages disproportionately affect the public health of communities that experience higher social and economic inequalities. In particular, counties in Louisiana, Arkansas, and Michigan with higher racial and ethnic minority populations, higher poverty rates, and higher usage of electricity-dependent medical equipment also experienced frequent power outages that lasted longer than eight hours from 2018 to 2020.37 Predominantly Black communities are more likely to be affected by an increase in the frequency of power outages and experience an increase in the number of heat-related deaths over the next several decades.38 It is also important to note that economic and racial inequality, unequal access to health care, and other factors have caused higher rates of chronic diseases among Black people, including cardiovascular disease, respiratory disease, cerebrovascular disease, kidney disease, hypertension, and diabetes—all of which are exacerbated by extreme heat.39 This means that Black communities could face increased public health risks when power outages coincide with extreme heat conditions.
Rural communities, too, face disproportionate impacts from power outages. Rural populations are twice as likely as those in urban areas to have preexisting health conditions that make them more vulnerable to heat-related illness and death.40 Rural areas also have larger numbers of underinsured and uninsured people than urban areas, along with inadequate public health infrastructure.41 This combination of factors makes them severely underprepared for any health emergencies during extreme temperatures. Furthermore, rural communities have a higher proportion of older and substandard homes as well as mobile homes, which are particularly vulnerable to extreme temperatures.42
In addition to outages, low-income households sometimes cannot afford to use electricity for cooling, even if they have access to it, and are less likely than higher-income households to increase their electricity usage in response to both extreme heat and cold.43 As a result, these households are subject to more unsafe temperatures and are exposed to the associated public health risks.
A diverse array of clean energy resources can improve reliability and help consumers save money during extreme temperatures
No single energy source can maintain a reliable grid, especially during extreme conditions. The electric grid needs a diverse range of clean energy resources, including intermittent solar and wind that operate at different times, clean firm sources such as nuclear and geothermal power plants that operate continuously, and variable sources that can be called upon when needed such as batteries and hydropower, as well as flexible energy efficiency and demand response measures that are capable of preventing power outages during extreme temperatures. Additionally, the grid requires investments to upgrade and increase transmission and distribution capacity to ensure electricity can be delivered to where it is needed the most. And while no resource is completely immune to failures (even a wind turbine is subject to freezing under the wrong conditions), policy decisions in states across the country to invest in more clean energy resources have proved both flexible and capable in preventing outages.44
Solar and wind energy are particularly capable of generating electricity during extreme temperatures. A study found that in all regions of the United States, the potential for solar energy is significantly higher during extreme heat conditions than normal conditions. The same study also found that the potential for wind energy is significantly higher during both extreme heat and cold in at least three regions in the United States.45
Solar and wind energy in Texas
The state of Texas is an example of how deploying more solar and wind energy at a rapid pace has improved the reliability of the grid, while simultaneously reducing prices.46 From January 2021 to January 2025, the Texas grid invested in expanding electricity generation by adding 23,114 megawatts (MW) of solar capacity and 8,343 MW of wind capacity.47 The Texas grid operator predicted a less than 1 percent chance of a grid emergency during summer 2025, down from a 16 percent chance during the previous summer.48 Wind and solar also played a significant role in meeting peak electricity demand during a period of cold in January 2025, with wind and solar exceeding generation of 20 gigawatts (GW) and 10 GW, respectively.49
Wind and solar are intermittent resources, and a reliable grid needs to leverage their potential with battery storage. Battery storage can charge when electricity demand is lower or when there is excess electricity and discharge when demand increases.50 California offers an example of how batteries can improve grid reliability. After the state experienced rolling blackouts in August 2020 during an extreme heat wave, California responded with new energy policies to deploy grid-connected batteries.51 Installed battery storage capacity grew from 503 MW in 2020 to 4,217 MW in 2022 and more than 13,300 MW in 2024.52 As a result, the state was able to avoid blackouts during similar periods of extreme heat in 2022 and 2024.53
Another tool to increase grid reliability is the use of distributed energy resources such as rooftop solar panels and battery storage, typically located in or near residential and commercial customers, or “behind the meter.”54 Tapping into these resources during times of need can help balance supply and demand while saving costs, as it is often faster and cheaper to aggregate existing customer-side resources as a virtual power plant (VPP) than it is to build new generation.55 Take, for example, the use of behind-the-meter solar in New England during the June 2025 heat wave, which met more than 15 percent of the gross peak demand in the region and saved customers at least $8.2 million in total.56 VPPs have rescued the grid and helped avoid blackouts in previous winters, including during Winter Storm Elliott, when they helped provide energy equivalent to the daily use of 1.7 million homes.57
Alongside these strategies to help meet peak and variable demand, it is important to diversify the grid for baseload power, or the generation of electricity to meet the minimum amount of demand through a day. Nuclear and geothermal energy are reliable low-carbon sources of baseload power.58 Nuclear power plants do not need the same level of maintenance as fossil fuel generation, nor do they experience the same level of vulnerability to extreme temperatures.59 From 2011 to 2020, the nuclear fleet in the United States demonstrated the capability to operate with limited reductions in generation, experiencing only 12 extreme heat and 11 extreme cold events that resulted in loss of generating capacity.60 Similarly, geothermal energy is also resilient to extreme heat and cold, as much of the system is underground and protected from extreme temperatures, allowing it to maintain baseload power.61
There are other areas that require significant investment or policy interventions to increase resilience to extreme heat and cold—and extreme weather in general. Alongside development of more diverse clean energy resources, policymakers should invest in building more regional and interregional transmission lines to effectively move electricity to regions where demand is high.62 Additional measures such as energy efficiency and demand response also contribute to grid reliability during extreme temperatures by reducing the overall demand for electricity and reducing the stress on the grid.63
Conclusion
Extreme temperatures will continue to threaten the reliability of the grid and the health and safety of families and communities. Americans can no longer rely on fossil fuel-fired power plants that are vulnerable to temperature-induced power outages, are increasingly more expensive, and further contribute to the damaging effects of climate change. Addressing this growing issue requires policymakers to recognize and advocate for clean energy sources that have demonstrated their ability to protect public health and reduce emissions.