What Are Blackouts? Here's What Causes Them and Why They're So Dangerous

Learn more about these outages and how to prepare in advance.

Michelle Honeyager Contributor
Michelle is a contributor for CNET.
Michelle Honeyager
5 min read
electricity transmission tower against a dramatic sunset

Blackouts can create a lot of problems and even pose safety risks.

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Blackouts are a severe inconvenience, to say the least. They can disrupt any work you're doing from home, halt gaming time or movie night and leave you feeling like you're roughing it in your own house as you look for something to do by lantern light. Blackouts are also getting more common: The average American saw around eight hours of interrupted power in 2020, up from around three and a half hours in 2013, according to the US Energy Information Administration.   

However, blackouts can be more than annoying. They can also be dangerous. Blackouts can prevent access to electric medical supplies, cut the air conditioning unit during heat waves or shut down the heater during freezing cold months. Below we'll look into what blackouts are, what causes them, explore in more detail why they're so dangerous and look at ways to prepare for them.  

What are blackouts?  

Blackouts, sometimes called power outages, are simply when the power goes totally out unexpectedly, according to ready.gov. The main feature of a blackout is that it affects whole areas and regions -- it's not limited to just one home, which can point to a problem with a home's electric system, such as its circuit breakers.      

Power outages can have many causes. Natural causes like storms with heavy wind can knock down power lines, or generation facilities could be struck by lightning. It could be something a person did, such as accidentally driving a car into a power line pole and knocking the pole down. Sometimes, the local power grid can also be overloaded and cause a blackout, such as during very hot periods in warm climates when too many air conditioning units are running at full capacity.

a city skyline in the dark with no lights on

Blackouts are events that impact a large area, not just one building.

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Why are blackouts so dangerous? 

One of the main issues with blackouts is that they can be difficult to fix quickly, according to Texas energy provider Tara Energy. In worst-case scenarios, outages can affect areas for several weeks if the damage to facilities or equipment was severe enough.

Not having power for days or weeks can affect our modern lives in ways we might not even think about. Most people might think about not being able to charge their phones. But without power, running water is halted since most of the plumbing system runs on electricity, restricting access to clean and hot water. Also, people with medical care dependent on refrigerating meds or electrical health devices are at risk. Electric stoves cannot prepare food. 

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Perhaps the most dangerous aspect of blackouts is that heating and cooling systems cannot run, since most of them rely on electricity. On very hot days, that means a home can dangerously overheat its residents, which can be especially dangerous for at-risk populations like people who have compromised health, according to the Centers for Disease Control and Prevention (PDF). Other at-risk populations include young children, people who are over 65 and the socially isolated. The Environmental Protection Agency estimates that there are over 1,300 deaths per year in the US due to extreme heat. Conversely, the extreme cold puts people at risk of freezing. According to the EPA, over 19,000 people died of cold-related causes between 1979 and 2016 in the US.

Read more: Will Your Solar Panels Keep the Lights On During a Blackout? What to Know

Are there ways to prevent blackouts? 

Blackouts happen because of many reasons beyond our control. We can't control what the weather is doing or if the local power grid is overpowered by air conditioning units. We're often also at the whims of how well-maintained the local unity keeps the power grid -- and we often can't choose our utility.  

However, it might be worth it to invest in a home generator, as long as you take care to operate it safely to mitigate the risks of carbon monoxide poisoning due to improper use. Home generators vary widely in price based on how large the home is and how much power it needs. Whole-home generators can cost in the thousands for installation and purchasing the materials for the generator, so it's often a cost people must budget for (though you can sometimes find generator deals). However, if someone in the family has high-risk conditions during an outage situation, it might be worth the peace of mind to install a generator. (Check out our generator buying guide here, and our picks for the best portable generators.)   

To make sure local power outages in just the home do not happen, maintain all electrical equipment and systems.  

How to keep safe during a blackout  

To keep safe when a blackout does occur, make sure to be prepared. The first step is to plan for anything that will need charging or other backup power options. Keep stocked on batteries. Consider investing in a portable charger or power bank. Have flashlights and other portable light sources like lanterns.  

If someone in the home has medical care dependent on electricity, have a contingency plan in place. Check to see how long meds can be stored in different temperatures and make plans to keep meds cool, if they require it, such as using a battery-powered cooler. Portable chargers, power stations or backup batteries may be necessary for electric medical devices. 

Also, have an emergency kit in place. Stock it with weeks to months of nonperishable food, water and first-aid supplies. Also, prepare for weather conditions, like having portable heaters and coolers or added blankets. You can also check out how to keep your pets safe and calm during a storm

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Supplies that can help during a power outage 

At CNET, we've reviewed and outlined several different items that could come in handy during a power outage. For instance, this solar power bank can keep your devices running in a blackout. Portable solar charging panels can also be a good solution to keep devices running. And if you don't want to spend the big bucks on a whole home generator, a small portable generator can supply just enough power for some main needs. You can check out our guide on portable generators. We've also got a guide on how to save your refrigerated food during a power outage

For people who want to be the most prepared, powering the whole home with solar can actually mean independence from the whole energy grid. If there's a wide-scale power outage, homes that are solar powered can still stay bright using the stored power from the solar panel system. Take a look at our picks for the best solar companies to explore. 

Another option is to look into more contained heating and cooling solutions. Portable air conditioners could mean the difference between staying cool in a power outage and a dangerous heat situation. When paired with a generator or charger options, these portable air conditioners could work for your home, along with this AC designed for blackout use. In colder months, consider space heaters for a portable heating appliance you can move from room to room as needed.