You know the feeling… You’re going about your business – putting freshly washed clothes into the dryer, heating water for your dinner pasta, running the dishwasher, and checking email on your laptop. Then, Bam! The power goes out.
And in that dark (no pun intended) moment, you realize just how dependent you are on the power grid. Ugh. “Why is this happening to me?” you ask.
Well, let me tell you.
Power outages fall into three basic categories:
- Permanent Fault – An outage typically caused by a fault on a power line. These can frequently be quickly cleared by the system (fractions of a second in many cases), resulting in just a brief flicker of the lights.
- Brownout – A drop in voltage (electrical ‘pressure’) that literally causes incandescent lights to dim.
- Blackout – The most severe kind of power outage, marked by a complete loss of power. Blackouts can be initiated by the grid operator (called load shedding) or happen unexpectedly when unforeseen events exceed the ability to control the system. Depending on the reason for the blackout and the severity of any equipment damage, power can remain off for just a short period or last for days or longer.
But why do these breakdowns occur?
Similar in nature to our roadway system, the electrical power grid is a complex network of:
- Substations, including breakers, switches and other controls;
- High-voltage transmission lines that carry power between substations;
- Lower-voltage lines that move power between distribution substations; and
- Individual lines that transmit power into homes and businesses.
Sound complicated? It is. But this complexity actually strengthens the system. An intricately connected system creates a more robust power grid. And a stronger grid is a more dependable grid, especially during extreme weather conditions.
But, as with any multifaceted system, many things can go wrong. A whole slew of circumstances can trigger the power overloads that lead to outages.
Generators must produce power as consumers need it, meaning the grid must constantly respond to shifting demands. An imbalance between electrical generation and load (the consumption of electrical energy) can lead to an outage. When the system is unable to stably serve the entire load in a constrained area, the grid operator may need to shut off certain areas and pass that load onto other parts of its network. Areas served by the disconnected parts of the grid then experience a blackout.
What causes imbalances within the grid?
- Weather Conditions. Extreme ice, wind, lightning, wildfires and flooding all can cause damage to the grid that, in turn, leads to power outages. Lightning, for example, can strike electrical equipment directly or strike a tree that may fall onto power lines. The buildup of ice on power lines or trees that may fall on power lines can also trigger outages.
- Vehicle and Construction Accidents. If a car runs into a power pole alongside the road, it can break the pole, causing the power lines to break or touch. This might lead to an outage.
- Trees. Even without severe weather conditions, trees branches can affect power lines. Electric utilities institute regular tree-trimming programs to help prevent this interference.
- Equipment Overload. This happens most frequently on hot or cold days when more people use air conditioners or electrical heaters, placing the highest stresses on the system.
So that about sums it up. But let me leave you with a little food for thought…
What can strengthen the power grid?
The grid operator employs powerful computer modeling of the transmission system, both for the near-term future and for as far as eight years out. These studies are aimed at identifying potential violations of Federal reliability standards and initiating system upgrades proactively, well before the conditions would occur that could cause the most severe and widespread outages. The Silver Run Project is one such system upgrade – bringing stability to the system and adding a new connection to the Delmarva power grid to help keep it up and running. And this is important because as we become more dependent on energy from the power grid, we must work to keep it resilient to interruptions in order to maintain the daily flow of life itself.