Power outages disrupt everything from your home electronics to your ability to cook and heat. If the lights in your house go out abruptly, check your circuit breaker panel (or fuse box) to see if any switches have tipped. Whether due to ice or lightning, storms can bring down power lines. The grid, however, is not immune to other issues.
Power Plants
As the name suggests, power plants generate electricity through a complex network of transmission lines and distribution centers. This vast system called the grid, balances the supply and demand for energy that powers everything from industry to household appliances. Power plants convert mechanical energy from coal, natural gas, nuclear fuel, hydroelectricity, or wind into electrical energy to meet consumer demands. Then that energy is sent over long distances through high-voltage transmission lines to local facilities known as substations, which lower the voltage and distribute the electricity to homes and businesses. There are various power interruption causes on the generation side of the system. These can include damage from storms, fires, or other events. They can also result from equipment failures or planned maintenance.
After generating power, it moves through a grid of thousands of miles of high-voltage transmission lines and millions of low-voltage distribution lines with transformers that bring it to your home. For reliability and commercial reasons, most of these grids are interconnected, with utilities in different states or regions sharing transmission systems for the benefit of their customers. While these grids are highly reliable, they can fail for various reasons. If your house loses power, call your TDSP (Transmission & Distribution Service Provider), EDU (Electricity Delivery Utilities) or TDU (Transmission and Distribution Utility) to report the problem.
Transmission Lines
If the power goes out in just one room, it may indicate something is wrong with your electrical system. A faulty appliance or cord might have shorted out and caused your circuit breaker to trip. Unplugging electronics or moving them to other outlets could solve this problem. You may also need to replace a blown fuse or switch. If you’re experiencing a full-house outage, you likely have a different problem. Power lines carry electricity across long distances from power plants, and the transmission grid can fail in several ways. Lightning can cause outages and high winds that blow down poles and other equipment. Ice storms are another big threat. Heavy ice can make power lines sag and break under the weight. It can take days to fix power lines after a storm.
Overhead power lines can also become disconnected or cut by animals, trees, and debris. It’s common for squirrels and rodents to chew through wires to create nests or build homes. Luckily, they rarely succeed in cutting through the entire line. But you’ll lose power if they manage to gnaw through a wire enough that it short-circuits. You can usually tell when this happens because your lights flash on and off a few times before they go out entirely.
Generators
A generator is the heart of an electricity generation system. It generates the electric current that goes into the grid and transmits it over long distances to end users. The generator is also the power source in facilities that must always have a backup, such as hospitals and sewage treatment plants. In addition, telecommunications centers usually have arrays of lead-acid batteries to keep the telephone lines up in case of an electrical outage. At its most basic, a generator uses Michael Faraday’s principle of electromagnetic induction to produce an electric current. When a copper wire moves near a magnet, it induces electromagnetic fields that can be used to create and direct the flow of electricity. In modern generators, these magnetic fields are generated by units called exciter windings. The windings are then connected to rotating rectifiers. These convert the AC voltage produced by the exciter windings into DC voltage, which is then fed to a rotor or armature unit. The rotor or armature converts the DC into an AC voltage, which is then fed to the main assembly/frame of the generator. It is the unit we see in a home or business generator, and it contains an engine that supplies the mechanical power to run the generator. This power can cause a blackout if interrupted by something as simple as a downed tree or thunderstorm.
Other Equipment
A wide variety of other equipment can go down in the event of a grid failure, from individual pieces of electrical machinery to entire communities. Computer systems, alarm systems and data networking hardware are particularly vulnerable to the loss of power because they use logic circuitry that can be lost or damaged when electricity is cut off for a short period. An uninterruptible power supply (UPS) that absorbs surges can help to keep computers and other electronic equipment running. When the power goes out in a single room of your house, it might be caused by an overload of the electrical circuit breaker for that room. Usually, this is simply a matter of unplugging some electronics and resetting the breaker. It could also be due to faulty wiring or a defective cord, which is much harder to fix and should be investigated by an electrician. The good news is that once a single part of the grid fails, other factors can pick up the slack. But, if enough pieces of equipment fail, a massive blackout can ensue. In addition to human error and mechanical breakdowns, other things that can lead to a widespread power outage include: