Lights Out

One winter evening my younger brother and I were making jokes and snacking in the kitchen until everything went dark. We froze. There were no lights, and it was quieter than normal – the refrigerator no longer hummed and the digital clock on the microwave disappeared. It was one of my first experiences with a power outage, an event when the electricity goes out. When our parents came home, they went through a list of questions. Was the food still safe to eat? Will bundling up with extra layers of clothes and blankets keep us warm at night? How long will this power outage last? How many folks in our neighborhood lacked power?

  Power outages can cause many challenges for communities, including fear, stress, and even health problems. For example, if an individual needs electricity to refrigerate medicines, a power outage could ruin those medicines. Additionally, for others who rely on electricity to power machines for their health such as a continuous positive airway pressure (CPAP), a machine that helps with breathing throughout the night, a power outage can be dangerous for those people. A need for a working refrigerator or a special machine are examples of what we call vulnerability factors for health. Vulnerability factors for health are differences that make people or communities more likely to get sick after an event like a power outage. Knowing where vulnerable people live can allow us to help them stay safe. This information can help community organizers and political leaders direct resources such as back-up electrical generators to support those in greatest need.

  Past studies have found a link between power outages and poor health outcomes. For example, one study found that a large power outage event in New York City increased the risk of people dying, and another study in New York State found that power outages were associated with more respiratory hospitalizations. While these studies show that power outages can threaten health, they are mainly focused on a single power outage event or a small area and therefore more research needs to be done to fully understand the effects of power outages. 

Although we know power outages pose health risks, are there times when power outages are more common? Bad weather such as storms can damage the electrical grid and cause power outages. Hurricanes and extreme heat could impact the electrical grid differently, so we need to consider the type of weather event when looking at the likelihood of power outages. Additionally, climate change increases the chances of bad weather, and monitoring this can tell us when to especially prepare for power outages.

To protect people and their health from power outages, we must know who is exposed to power outages, where populations are most at risk, and if bad storms are associated with these power outages. Our study looked at power outages across the entire United States (U.S.). 


We asked three questions:


We used data about the number of people in a power outage in U.S. counties between 2018-2020 to create several variables of power outage. Importantly, we focused on outages lasting at least 8 hours because these longer power outages can threaten health in various ways. An 8+ hour outage during extremely hot days can put people at risk of getting too hot and becoming sick. The batteries on medical machines that need access to electricity may not last long enough if an 8+ hour outage happens. Knowing the location and times of these longer outages can let governments, policy makers, and communities plan and help prevent as many bad outcomes as possible.

Our study found that many counties in the U.S. have outages and that these power outages happened more often in certain places, like the South, the Northeast, and Appalachia. Additionally, we found more 8+ hour outages during June, July, and August, and during the evenings around 6PM.

  For our second question, we needed to define vulnerability. We wanted to learn about both social and medical vulnerability. For social vulnerability, we used a Social Vulnerability Index from the Centers for Disease Control, a national U.S. organization dedicated to public health. This index identifies places that are more likely to require higher levels of support during disasters because these areas have more poverty or worse housing. For medical vulnerability, we used emPOWER data from the U.S. Department of Health and Human Services, which is part of the federal government with a mission to improve the health of Americans. The emPOWER data tell us where most people aged 65+ live in the U.S. that use medical machines that require electricity to work. Once we defined vulnerability, we wanted to see which places had a lot of power outages and were socially or medically vulnerable. We used a statistical technique to compare the amount of power outages in different areas and determine vulnerability. We learned that counties in Arkansas, Louisiana, and Michigan had both a lot of 8+ hour power outages as well as high social and medical vulnerability.

  Last, we investigated how often bad weather happened at the same time as long 8+ hour power outages. We wanted to study weather events that could damage parts of the electrical system such as electrical lines. We also studied extreme heat, extreme cold, rain, snow, cyclones, lightning, and wildfires. We compared the number of power outages that happened with a weather event and the number of power outages that happened without a specific weather event. We found power outages were more common during most weather events we looked at. For example, when there was a cyclone, power outages were 10x more likely to happen.

  We studied power outages across the entire U.S., but challenges remain. Though our study looked at power outages occurring in counties, people actually experience power outages in the buildings where they learn, work, and sleep. Future studies could find data on power outages in specific buildings. This information could help governments improve electrical grids, provide cooling stations, and warn people when power outages might happen.

Our study was able to evaluate where and when outages occurred, identify places with more outages and high vulnerability, and understand if weather events and power outages happen at the same time. We found that many people living in the U.S. experience power outages, certain counties face a double burden of power outages and vulnerability, and power outages are much more common when there are weather events. Given how common and impactful power outages are, we push for more research to look at how power outages most affect health and ways we can better support communities.

Written by: Vivian Do

Academic Editor: Neuroscientist

Non-Academic Editor: Small Business Owner

Original Paper

• Title: Spatiotemporal distribution of power outages with climate events and social vulnerability in the USA

• Journal: Nature Communications

• Date Published: 29 April 2023

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