A variety of things can cause power outages. From severe storms to a wayward Mylar balloon becoming entangled in a line to cars hitting utility poles, they can range from minor to major. Often, they can last for hours or even days. To prepare for such an event, you should have a support network and communication devices that work without home power.
In the United States, most power outages are caused by weather conditions. A single severe storm can knock out electricity for hundreds of thousands of homes, and it only takes one high-speed wind to cause damage to transmission lines. Long distances are covered by electricity as it moves from power plants to distribution centers, where the voltage is reduced before being delivered via utility poles to our houses. This transmission system is vulnerable to outages due to weather conditions, equipment failure and grid overload. These outages can occur when the temperature rises and electricity demand soars. As temperatures climb, more and more people turn on air conditioning, causing the electricity demand to exceed the transmission system’s capacity. This results in a power outage, and a sweltering summer is one of the most common times for this event.
Winds can also bring down trees near transmission lines, causing them to break and short-circuit. Occasionally, these lines are also damaged by animals. Squirrels, raccoons and rodents often climb onto and into utility equipment to access food or build nests. The hum of the power line attracts them, and they can also short-circuit the lines while playing or foraging for food. In addition, cars sometimes crash into utility poles, resulting in power outages that affect nearby buildings.
When an entire community loses electricity, it impacts many vital services. Businesses close, and customers lose access to goods and services. Food can spoil, and people relying on power-dependent medical equipment may be left in the dark. Even if you work in a business that relies on something other than electrical power, extended outages can lead to lost productivity, damaged equipment, lost data and unplanned expenses. Weather is among the most common causes of power outages, including lightning strikes, heavy rains and extreme heat or cold. In addition, mudslides and floods can damage power lines, while earthquakes can destroy them altogether. Wind and high winds can also knock down trees or limbs that come into contact with towers or transmission lines.
Electrical power travels from a power plant to a transformer at a substation before being distributed to utility poles and your home. A power failure in the transmission system can cause energy loss across multiple neighborhoods. A blackout occurs when the entire grid shuts down due to the loss of power in all transmission stations and substations. A less severe but still disruptive alternative is a brownout. A brownout occurs when the amount of available energy is reduced due to demand or for safety reasons. These planned events include pruning tree limbs that pose a risk to overhead wires or reducing the energy delivered to customers during peak usage.
Motor Vehicle Accidents
Whether it’s from a driver suffering from impairment or a momentary lapse in attention, motor vehicle accidents can cause power outages on a local level. A car or truck skidding out of control can crash into a utility pole, knocking it down along with the lines and equipment attached. Typically, these types of power outages only affect a small area. However, the disruption can spread throughout the distribution network when a motor vehicle crashes into a transmission line or substation.
Animals can also be a major factor in power outages. The Edison Electric Institute found that animals caused 11% of all outages. From mischievous squirrels gnawing their way into insulation to raccoons and birds nesting in or on power lines, these tiny creatures can create short circuits when they contact fuses or relays. Natural disasters like storms, tornadoes, earthquakes and floods can cause massive power outages. Sometimes, these events may trigger preemptive power shutoffs by a utility company to minimize the impact on customers. Also, excavation digging or landscaping projects that go awry can damage underground lines.
Animals, including squirrels, birds and raccoons, are responsible for thousands of power outages yearly. These animals can chew through electrical lines and knockdown equipment while building nests or short-circuit connections. Curiosity and the hum of electricity attract these small creatures, who can easily get their teeth stuck in electrical equipment or accidentally come into contact with it. This category of outage typically impacts a relatively smaller percentage of distribution customers at any one time than other outages. Squirrels cause most animal-related outages due to their attraction to overhead electrical infrastructure for roosting, nesting and travel. Different types of animals, such as raccoons, birds, snakes and ungulates, also cause outages. While the redundancies built into the modern grid help reduce these outages, utilities still experience many animal-related outages. Utility companies work to mitigate these outages by using critter guards on pole-mounted transformers, wrapping vulnerable parts of the substation in polymer covering, and deploying special fencing to keep animals away from the equipment. Whether the cause is a storm, tree debris, a car crash or a human error, power outages disrupt daily life. If a power outage occurs, it’s important to have an action plan for your family. Gather your family members into the safest part of the house — often the basement in winter or an interior room during a thunderstorm. Unplug any devices and appliances to shield them from the initial surge when the power returns.