Common Causes of Power Outages

A power outage can be disruptive. You lose lights, appliances, and the ability to cook or cool your home. Be prepared by knowing what to do. Ensure you have communication devices that work without electricity (like a crank radio, a non-cordless phone, and alternate chargers for your cell phones). Also, sign up for local alert systems.

The United States has one of the most robust power grids in the world, which is why wide-scale or random outages are uncommon. A power outage can still disrupt your life and cause problems at home or work. You may be unable to charge your phone or use your electronic devices, and you could lose important documents or data. So what is the reason for power outage? In most cases, power outages are caused by severe weather conditions, like lightning, high winds, or ice buildup on lines. However, earthquakes and volcanic eruptions can also wreak havoc on the electricity system.

In the case of California’s recent rolling blackouts, it was a combination of factors that prompted them to occur, including an extreme heat wave that boosted electricity demand and a series of equipment failures in the distribution system. Often, these power outages only affect a small portion of the city and are fixed relatively quickly. Other times, they can cause major disruptions that last for hours or even days. The most severe type of power outage is a blackout when the system fails and no one can access any power.

Power outages can be frustrating, but they are also potentially dangerous. Fire alarms will not function during a power outage, making it difficult to escape if there is a fire in your home. Additionally, if your medical device requires electricity to work (CPAP machine, for example), you will need an alternate method of breathing during an outage. While the United States has one of the most robust electrical systems in the world, power outages can occur. The reasons for power outages range from severe weather conditions to equipment failure or even scheduled maintenance.

Unfortunately, human error can be a major cause of power outages. From vehicle accidents that knock over poles to contractors forgetting to call 811 before digging, these errors can lead to power interruptions. Too many air conditioners running at once can overload the system during hot months, causing outages. An outage can mean lost revenue for business owners as employees cannot work while the lights are off. And for residents in a remote area, an outage can make them vulnerable to extreme temperatures and hypothermia.

While heavy winter snow or a powerful storm may be the first thing that comes to mind when you think of power outages, there’s one unlikely cause of them: animals. From squirrels to raccoons, birds to snakes, critters are attracted to power equipment for shelter and warmth. Their gnashing teeth sometimes make their way through insulators and cause outages. Animal-related outages can be expensive for utilities, whether due to direct contact with sensitive equipment or “streamers” (conductive trails of bird droppings).

A squirrel that short-circuited a substation in Richmond, Virginia, 2015 halted electricity throughout the city, closing businesses and schools. A raccoon that invaded a substation in Seattle last year also shut down the Nasdaq stock exchange for 82 minutes. These are just a few examples of the thousands of outages caused by animals each year. To cut down on these costly outages, some companies use specialized fencing or deterrents to keep animals away from the equipment they depend on to provide energy. For example, disks that fit around insulators can prevent animals from reaching energized areas of the grid.

A car crash can bring down a power line, leaving thousands without electricity. It’s a common cause of outages in regions with harsh winters, where snow and ice can build up on poles or trees, causing them to collapse. Other human-caused issues can also cause power outages. Construction equipment such as cranes and excavators can damage lines when they aren’t correctly operated, while landscaping and tree trimming can cut underground lines.

In addition, humans tend to draw too much power at one time, which can overload the system and lead to outages. On a hot day when everyone’s air conditioner is working overtime, it can be especially hard for the system to keep up. Regardless of the causes, any weather event can quickly turn a simple outage into a major catastrophe. And because a lot of medical equipment requires electrical power, this can be a life-threatening situation for some people. That’s why it’s important to take precautions and prepare for the possibility of a power outage before it happens.

Despite best efforts, nature can sometimes wreak havoc on power systems. From hurricanes and tornadoes to lightning and snowstorms, the whims of Mother Nature cause millions of outages each year. Old and aging trees can fall over and snap utility poles and wires. It happens more often during storms and when trees are weakened by climate stresses such as drought or heat waves.

Another reason for power outages is that some animals are attracted to electrical infrastructure — they chew through components while foraging or build nests near the warm, flowing current. It can result in short-circuiting and an outage. In some cases, a power outage is caused by an intentional act by thieves who want to steal copper and other materials. These acts are often a cascading chain reaction that can disrupt power for an entire area or region. Although these outages are rare, they occur, particularly in densely populated areas with the highest energy demand. In such cases, utilities must initiate rolling blackouts to protect the overall system.